1651
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Shan R, Stadler M, Sterner O, Anke H. New metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. VIII. Isolation, structure determination and biological activities of minor metabolites structurally related to mycorrhizin A. J Antibiot (Tokyo) 1996; 49:447-52. [PMID: 8682721 DOI: 10.7164/antibiotics.49.447] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Five new minor metabolites, papyracon D (6), 6-O-methylpapyracon B (9), 6-O-methylpapyracon C (10), lachnumfuran A (11) and lachnumlactone A (12a), together with the known chloromycorrhizinol A (4), have been isolated from extracts of the culture fluids of the ascomycete Lachnum papyraceum. The compounds, which structures were determined by spectroscopic methods, are structurally related to the nematicidal and antibiotic mycorrhizin A (1), which also is produced by the fungus. The nematicidal, antibiotic and cytotoxic activities of the new compounds are weaker compared to those of mycorrhizin A (1). Papyracon D (6) possesses the highest antibiotic activities while lachnumlactone A (12a) is the most nematicidal and cytotoxic.
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Affiliation(s)
- R Shan
- Lund University, Department of Organic Chemistry 2, Sweden
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1652
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Roggo BE, Hug P, Moss S, Stämpfli A, Kriemler HP, Peter HH. Novel spirodihydrobenzofuranlactams as antagonists of endothelin and as inhibitors of HIV-1 protease produced by Stachybotrys sp. II. Structure determination. J Antibiot (Tokyo) 1996; 49:374-9. [PMID: 8642001 DOI: 10.7164/antibiotics.49.374] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- B E Roggo
- Core Drug Discovery Technologies, Pharmaceutical Division, Ciba-Geigy Limited, Basel, Switzerland
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1653
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Brill GM, Premachandran U, Karwowski JP, Henry R, Cwik DK, Traphagen LM, Humphrey PE, Jackson M, Clement JJ, Burres NS, Kadam S, Chen RH, McAlpine JB. Dibefurin, a novel fungal metabolite inhibiting calcineurin phosphatase activity. J Antibiot (Tokyo) 1996; 49:124-8. [PMID: 8621350 DOI: 10.7164/antibiotics.49.124] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The novel calcineurin inhibitor, dibefurin, has been isolated from the fungal culture AB 1650I-759. The isolation was bioactivity-directed fractionation using an assay which measures the phosphatase activity of calcineurin. The compound was purified by countercurrent, reverse phase and gel filtration chromatographies. Several studies, including crystallographic, NMR and MS, revealed that dibefurin is a novel dimeric compound of a unique structural type.
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Affiliation(s)
- G M Brill
- Abbott Laboratories, Abbott Park, Illinois 60064, USA
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1654
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Dickerson R, Keller LH, Safe S. Alkyl polychlorinated dibenzofurans and related compounds as antiestrogens in the female rat uterus: structure-activity studies. Toxicol Appl Pharmacol 1995; 135:287-98. [PMID: 8545839 DOI: 10.1006/taap.1995.1235] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The antiestrogenic activity of a series of alkyl-substituted polychlorinated dibenzofurans (PCDFs) were determined in the immature female Sprague-Dawley rat uterus. The compounds utilized in this study contain two, three, or four lateral substitutents and include: 6-methyl-1,3,8-triCDF, 6-ethyl-1,3,8-triCDF, 6-n-propyl-1,3,8-triCDF, 6-i-propyl-1,3,8-triCDF, 6-t-butyl-1,3,8-triCDF, 8-methyl-1,3,6-triCDF (two lateral substituents); 6-methyl-2,3,8-triCDF, 6-methyl-2,3,4,8-tetraCDF, 8-methyl-1,3,7-triCDF, and 8-methyl-1,2,4,7-tetraCDF (three lateral substituents); 8-methyl-2,3,7-triCDF, 8-methyl-2,3,4,7-tetraCDF (four lateral substituents). Two additional compounds, 8-methyl-2,3,7-trichlorodibenzo-p-dioxin and 8-methyl-2,3,7-tribromodibenzo-p- dioxin (four lateral substituents), were also utilized. All of the alkyl-substituted compounds inhibited estrogen-induced uterine wet weight increase and cytosolic and nuclear progesterone and estrogen receptor binding. The effects of structure on the antiestrogenic potencies were determined using 6-i-propyl-1,3,8-triCDF, 6-methyl-2,3,4,8-tetraCDF, and 8-methyl-2,3,4,7-tetraCDF as representative congeners containing two, three, and four lateral substituents, respectively. The ED50 values for antiestrogenicity were similar for the three compounds; however, the ED50 values for induction of hepatic CYP1A1-dependent activity were 73,600 (estimated), 8.52, and 5.31 mumol/kg for 6-i-propyl-1,3,8-triCDF, 6-methyl-2,3,4,8-tetraCDF, and 8-methyl-2,3,4,7-tetraCDF, respectively. Since CYP1A1 can be used as a surrogate for toxic potency in the rat then high ED50 (induction)/ED50 (antiestrogenicity) ratios would be indicative of low toxicity and high antiestrogenic potency. The ratio was 13,990 to 17,100 for 6-i-propyl-1,3,8-triCDF, whereas the corresponding value for the compounds with three or four lateral substituents varied from 0.64 to 3.34. The results suggests that the 1,3,6,8-substituted alkyl PCDFs are useful structural models for developing new aryl hydrocarbon receptor-mediated antiestrogens for future clinical use as antiestrogens.
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Affiliation(s)
- R Dickerson
- Veterinary Physiology and Pharmacology, Texas A&M University, College Station 77843-4466, USA
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1655
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Wang W, Hu JZ, Alderman DW, Pugmire RJ, Grant DM. Use of relaxation agent doping to shorten very long spin-lattice relaxation times in a magic-angle turning experiment. Solid State Nucl Magn Reson 1995; 5:257-262. [PMID: 9053116 DOI: 10.1016/0926-2040(95)00041-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A practical method is described for measuring the principal values of the chemical shift tensors in compounds with very long proton spin-lattice relaxation times (T1). This technique involves shortening the effective proton T1. by mixing a compound of interest with another compound having a much shorter T1 value. The doped mixture, partly consisting of a monophasic glass, allows efficient intermolecular spin diffusion between the two compounds. Using a slow magic-angle turning (MAT) experiment, we have successfully used such mixtures to measure the principal values of the chemical shift tensors of all the carbons in dibenzofuran in just four days. Without using this technique the experimental time required for the pure compound would have been several months.
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Affiliation(s)
- W Wang
- Department of Chemistry, University of Utah, Salt Lake City 84112, USA
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1656
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Nakamura M, Ito Y, Ogawa K, Michisuji Y, Sato S, Takada M, Hayashi M, Yaginuma S, Yamamoto S. Stachybocins, novel endothelin receptor antagonists, produced by Stachybotrys sp. M6222. I. Taxonomy, fermentation, isolation and characterization. J Antibiot (Tokyo) 1995; 48:1389-95. [PMID: 8557592 DOI: 10.7164/antibiotics.48.1389] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Stachybocins A, B and C, novel endothelin (ET) receptor antagonists, were isolated from the culture filtrate of Stachybotrys sp. M6222. They were extracted with ethyl acetate and then purified by alumina and silica gel column chromatographies. The molecular formulae of stachybocins were determined to be C52H70N2O10 (stachybocin A) and C52H70N2O11 (stachybocins B and C). It was supposed that they consisted of spirobenzofuran and terpene units from NMR spectra. They showed the inhibitory activity of 125I-ET-1 binding to rate ETA, human ETA and human ETB receptors.
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MESH Headings
- Animals
- Aorta/drug effects
- Aorta/physiology
- Benzofurans/chemistry
- Benzofurans/isolation & purification
- Benzofurans/pharmacology
- Cardiovascular Agents/chemistry
- Cardiovascular Agents/isolation & purification
- Cardiovascular Agents/pharmacology
- Cells, Cultured
- Endothelin Receptor Antagonists
- Endothelins/metabolism
- Fermentation
- Humans
- In Vitro Techniques
- Magnetic Resonance Spectroscopy
- Male
- Mice
- Mice, Inbred ICR
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Rabbits
- Radioligand Assay
- Rats
- Receptors, Endothelin/metabolism
- Spectrometry, Mass, Fast Atom Bombardment
- Spiro Compounds/chemistry
- Spiro Compounds/isolation & purification
- Spiro Compounds/pharmacology
- Stachybotrys/metabolism
- Vasodilation/drug effects
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Affiliation(s)
- M Nakamura
- Institute for Life Science Research, Asahi Chemical Industry Co., Ltd., Shizuoka, Japan
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1657
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Ogawa K, Nakamura M, Hayashi M, Yaginuma S, Yamamoto S, Furihata K, Shin-Ya K, Seta H. Stachybocins, novel endothelin receptor antagonists, produced by Stachybotrys sp. M6222. II. Structure determination of stachybocins A, B and C. J Antibiot (Tokyo) 1995; 48:1396-400. [PMID: 8557593 DOI: 10.7164/antibiotics.48.1396] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The structures of stachybocins A, B and C, new endothelin receptor antagonist, were determined by NMR spectral analysis using pulse-field-gradient technique. Stachybocin A consists of two spirobenzofuran units each fused to a substituted decalin, which were connected by a lysine residue. Stachybocins B and C are derivatives of stachybocin A with an additional hydroxy group at the same position in the different decalin unit.
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Affiliation(s)
- K Ogawa
- Institute for Life Science Research, Asahi Chemical Industry Co. Ltd, Shizuoka, Japan
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1658
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Abstract
Bioassay-directed fractionation of a methylene chloride extract of the root bark of Erythrina eriotricha resulted in the isolation of a novel isoflavanone, named eriotrichin B, and the five known pterocarpans, isonorautenol, erybraedin A, erybraedin C, erybraedin D and erybraedin E. The structure of the new compound has been investigated by extensive spectroscopic studies, including 2D NMR and chemical evidence. The in vitro antimicrobial spectrum and potencies of the isolated compounds are also reported.
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Affiliation(s)
- A E Nkengfack
- Department of Organic Chemistry, University of Yaounde, Cameroon
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1659
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Jonkman-De Vries JD, Rosing H, Henrar RE, Bult A, Beijnen JH. The influence of formulation excipients on the stability of the novel antitumor agent carzelesin (U-80,244). PDA J Pharm Sci Technol 1995; 49:283-8. [PMID: 8581459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The stability of carzelesin in a polyethylene glycol 400 (PEG 400)/absolute ethanol/polysorbate 80 (Tween 80) (6:3:1, v/v/v) formulation (PET formulation) was investigated as a function of the inter-batch variability of the three excipients. Twenty different PET formulations were tested and the stability of carzelesin in the PET formulation was found to be influenced by the type of PEG 400 used. Subsequent investigations showed that the pH of PEG 400, and consequently the pH of the PET formulation, was responsible for the variable stability characteristics of carzelesin in the PET formulation. The higher the pH of the PET formulation, the higher the rate of degradation of carzelesin in PET. The major degradation products were found to be U-76,073 and U-76,074.
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Affiliation(s)
- J D Jonkman-De Vries
- Department of Pharmacy, Slotervaart Hospital/Netherlands Cancer Institute, Amsterdam, The Netherlands
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1660
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Abstract
To better understand the role of shape complementarity in ligand binding and protein core interactions, the structures have been determined of a set of ligands bound within a cavity-containing mutant of T4 lysozyme. The interior cavity is seen to consist of two parts that respond very differently to the binding of ligands. First, there is a relatively rigid region that does not relax significantly upon binding any ligand. Second, there is a more flexible region that moves to various extents in response to binding the different ligands. The part of the binding site that remains rigid is characterized by low temperature factors and strong protection from hydrogen exchange. This part of the site appears to be primarily responsible for discriminating between ligands of different shape (i.e., for determining specificity). The more flexible region, characterized by relatively high temperature factors and weak protection from hydrogen exchange, allows some promiscuity in binding by undergoing variable amounts of deformation at essentially the same energetic cost. This linkage between the dynamic information represented by crystallographic temperature factors and hydrogen-exchange behavior on the one hand, and structural plasticity in response to ligand binding on the other hand, suggests a way to improve our understanding of steric interactions in protein cores and protein-ligand binding sites. Ligand design and packing algorithms might take advantage of this information, requiring complementary interactions where the protein is rigid and allowing some overlap in regions where the protein is flexible.
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Affiliation(s)
- A Morton
- Institute of Molecular Biology, Howard Hughes Medical Institute, Eugene, Oregon, USA
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1661
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Lu JR, Miyata H, Huang CW, Tsai HT, Sheng VZ, Mase Y, Aozasa O, Ohta S. Pollution by PCDDS and PCDFS in sediment from freshwater fish culture ponds near incineration sites for metal reclamation in Wan-Li, Taiwan, Republic of China. Chemosphere 1995; 31:2779-2789. [PMID: 7663954 DOI: 10.1016/0045-6535(95)00094-o] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Sediment samples from nine culture ponds for freshwater fish at and near waste incineration sites for metal reclamation in Wan-Li, southern Taiwan, Republic of China were analyzed for PCDDs and PCDFs by HRGC-HRMS. Four of nine samples were heavily polluted by PCDDs and PCDFs, indicating the latter to be dominant. The total TEQ concentrations of PCDDs and PCDFs in the four samples were in the range of 257 to 12200 pg/g dry weight. In addition, the levels corresponded to those of surface soil samples from the same waste combustion areas.
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Affiliation(s)
- J R Lu
- Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taiwan, Republic of China
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1662
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Sakai K, Watanabe K, Masuda K, Tsuji M, Hasumi K, Endo A. Isolation, characterization and biological activities of novel triprenyl phenols as pancreatic cholesterol esterase inhibitors produced by Stachybotrys sp. F-1839. J Antibiot (Tokyo) 1995; 48:447-56. [PMID: 7622428 DOI: 10.7164/antibiotics.48.447] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Ten triprenyl phenol metabolites were isolated as inhibitors of pancreatic cholesterol esterase from cultures of Stachybotrys sp. F-1839 by solvent extraction and column chromatographies. Combination of spectroscopic analyses revealed that two of these compounds are K-76 (1) and stachybotrydial (2), and that the remaining eight are new congeners (designated F1839-A (3), -B (4), -C (5), -D (6), -E (7), -F (8), -I (9) and -J (10). These compounds inhibited pancreatic cholesterol esterase by 50% at 6 x 10(-5) to 1.1 x 10(-1) M. Inhibition of the enzyme by compound 2, the most potent one among these compounds, was time-dependent and irreversible. When administered to normal rats, 2, at a single oral dose of 100 mg/kg, reduced [14C]cholesterol absorption by 50-60%. In cholesterol-fed mice, dietary supplementation of 2 (0.1%) for 14 days resulted in a 20% reduction in serum total cholesterol level without causing significant change in the high density lipoprotein cholesterol level.
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Affiliation(s)
- K Sakai
- Research Laboratories, Tokyo Tanabe Co. Ltd., Japan
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1663
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Abstract
The fluorescent indicator PBFI is widely used for the determination of intracellular concentrations of K+. To investigate the binding reaction of K+ to PBFI in the ground and excited states, steady-state and time-resolved measurements were performed. The fluorescence decay surface was analyzed with global compartmental analysis yielding the following values for the rate constants at room temperature in aqueous solution at pH 7.2: k01 = 1.1 x 10(9) s-1, k21 = 2.7 x 10(8) M-1s-1, k02 = 1.8 x 10(9) s-1, and k12 = 1.4 x 10(9) s-1. k01 and k02 denote the respective deactivation rate constants of the K+ free and bound forms of PBFI in the excited state. k21 represents the second-order rate constant of binding of K+ to the indicator in the excited state whereas k12 is the first-order rate constant of dissociation of the excited K(+)-PBFI complex. From the estimated values of k12 and k21, the dissociation constant Kd* in the excited state was calculated. It was found that pKd* (-0.7) is smaller than pKd (2.2). The effect of the excited-state reaction can be neglected in the determination of Kd and/or the K+ concentration. Therefore, intracellular K+ concentrations can be accurately determined from fluorimetric measurements by using PBFI as K+ indicator.
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Affiliation(s)
- K Meuwis
- Department of Chemistry, Katholieke Universiteit Leuven, Heverlee, Belgium
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1664
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Abstract
The title compound, C10H10O3, is nearly planar with a maximum deviation from planarity of 0.140 (2) A for methoxy atom C11. The geometry of the benzo[c]furan moiety is indicative of a non-aromatic ring system. The bond lengths more closely resemble those of two non-interacting diene systems than those of an aromatic one. There are alternating long and short bond lengths around the ring skeleton with the long and short C-C bonds averaging 1.437 (2) and 1.354 (2) A, respectively. There are close C-H ... O intermolecular contacts which may help stabilize the molecule in the solid state.
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Affiliation(s)
- V M Lynch
- Department of Chemistry & Biochemistry, University of Texas at Austin 78712, USA
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1665
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Haj-Yehia AI, Benet LZ. 2-(4-N-maleimidophenyl)-6-methoxybenzofuran: a superior derivatizing agent for fluorimetric determination of aliphatic thiols by high-performance liquid chromatography. J Chromatogr B Biomed Appl 1995; 666:45-53. [PMID: 7655620 DOI: 10.1016/0378-4347(94)00548-j] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The use of 2-(4-N-maleimidophenyl)-6-methoxybenzofuran as a fluorogenic pre-column derivatizing agent for sensitive high-performance liquid chromatographic (HPLC) determination of aliphatic thiols is described. The maleamic acid, its methyl ester and the N-maleimide derivatives of the common amine precursor were easily synthesized and characterized according to conventional methods. These derivatives lack fluorescent properties in their native form but display strong fluorescence upon reaction with aliphatic thiols. The reaction is rapid and highly selective for thiols over a wide pH range (7.1-8.8). Following derivatization, the thiol adducts were separated on a reversed-phase column (Ultrasphere-ODS) using 0.1% hexanesulfonic acid in 10 mM potassium hydrogen phosphate-acetonitrile (65:35, pH 4.5) and were detected fluorimetrically (excitation at 310 nm; emission at 390 nm). The method is highly sensitive (femtomole range) and is easily applied to the determination of SH-containing drugs and endogenous thiols in biological samples.
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Affiliation(s)
- A I Haj-Yehia
- Department of Pharmacy, University of California, San Francisco 94143-0446, USA
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1666
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Okuyama E, Umeyama K, Yamazaki M, Kinoshita Y, Yamamoto Y. Usnic acid and diffractaic acid as analgesic and antipyretic components of Usnea diffracta. Planta Med 1995; 61:113-5. [PMID: 7753915 DOI: 10.1055/s-2006-958027] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Diffractaic acid and usnic acid were identified as the analgesic and antipyretic components of a lichen, Usnea diffracta. Both compounds showed an analgesic effect by the acetic acid-induced writhing and tail-pressure methods in mice. Regarding the effect on normal body temperature and LPS-induced hyperthermia in mice, diffractaic acid showed a significant effect only on the former and usnic acid only on the latter.
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Affiliation(s)
- E Okuyama
- Faculty of Pharmaceutical Sciences, Chiba University, Japan
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1667
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Eitzer BD. Polychlorinated dibenzo-p-dioxins and dibenzofurans in raw milk samples from farms located near a new resource recovery incinerator. Chemosphere 1995; 30:1237-1248. [PMID: 7749722 DOI: 10.1016/0045-6535(95)00020-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Bovine milk samples were taken from farms near a new resource recovery incinerator both before and one year after the incinerator went into operation. These samples were analyzed for 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans using liquid-liquid extraction, a semi-automated clean-up procedure and high resolution gas chromatography/high resolution mass spectrometry. No significant differences were observed between the PCDD/F concentrations in the pre-operational and post-operational samples.
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Affiliation(s)
- B D Eitzer
- Department of Analytical Chemistry, Connecticut Agricultural Experiment Station, New Haven 06504, USA
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1668
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Nakashima K, Ishimaru T, Kuroda N, Akiyama S. High-performance liquid chromatographic separation of penicillamine enantiomers labelled with N-[4-(6-dimethylamino-2-benzofuranyl)phenyl] maleimide on a chiral stationary phase. Biomed Chromatogr 1995; 9:90-3. [PMID: 7795392 DOI: 10.1002/bmc.1130090207] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Penicillamine enantiomers derivatized with N-[4-(6-dimethylamino-2-benzofuranyl)phenyl]maleimide (DBPM) were separated and determined by high-performance liquid chromatography. A fluorogenic reagent, DBPM easily reacted with D- or L-penicillamine to give each two kinds of strong fluorescent derivatives (D1-, D2-, L1- and L2-DBPM), which could be separated on a Pirkle-type chiral stationary phase using an eluent of 75% aqueous methanol solution containing 0.15 M CH3COONH4 and 0.05 M tetra-n-butylammonium bromide. Two of the peaks (D1- or L1-DBPM), having a shorter retention time than the others, had almost the same retention times (25 min for D1-DBPM and 25.7 min for L1-DBPM). The retention times of the peaks eluted later were 28 min and 31.6 min for D2- and L2-DBPM respectively. Linear calibration curves over the range of 2-50 pmol per injection were obtained for D- and L-penicillamines with a detection limit of 290 and 350 fmol at respectively at a signal-to-noise ratio of 3. Using the proposed method, the absence of contamination of L-penicillamine in a commercially available D-penicillamine preparation (capsule) was confirmed.
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Affiliation(s)
- K Nakashima
- School of Pharmaceutical Sciences, Nagasaki University, Japan
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1669
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Grisar JM, Bolkenius FN, Petty MA, Verne J. 2,3-Dihydro-1-benzofuran-5-ols as analogues of alpha-tocopherol that inhibit in vitro and ex vivo lipid autoxidation and protect mice against central nervous system trauma. J Med Chem 1995; 38:453-8. [PMID: 7853338 DOI: 10.1021/jm00003a008] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A series of alpha-tocopherol analogues was synthesized with potential therapeutic value for such pathological conditions as stroke and trauma. A set of criteria such as the inhibition of in vitro lipid peroxidation, superoxyl radical scavenging, and brain penetration, as measured by ex vivo inhibition of lipid peroxidation, was applied to select the most effective compound. 2,3-Dihydro-2,2,4,6,7-pentamethyl-3-[(4-methylpiperazino)methyl]-1 - benzofuran-5-ol dihydrochloride (22) was selected because of its superior antioxidant properties and better brain penetration. This compound also protected mice against the effects of head injury. The criteria thus turned out to be useful for the characterization of a neuroprotective analogue of alpha-tocopherol.
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Affiliation(s)
- J M Grisar
- Marion Merrell Dow Research Institute, Strasbourg, France
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1670
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Weber R, Schrenk D, Schmitz HJ, Hagenmaier A, Hagenmaier H. Polyfluorinated dibenzodioxins and dibenzofurans--synthesis, analysis, formation and toxicology. Chemosphere 1995; 30:629-639. [PMID: 7889348 DOI: 10.1016/0045-6535(94)00429-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The 75 congeners of the polyfluorinated dibenzodioxins (PFDDs) and about half of the 135 polyfluorinated dibenzofurans (PFDFs) have been synthesized by pyrolysis of fluorophenols and fluorobenzenes. The individual congeners were characterized by GC/MS. 2,3,7,8-TFDD was also characterized by 1H-, 13C- and 19F-NMR spectroscopy. The retention behaviour of PFDDs and PFDFs during gaschromatographic separation is entirely different from that of PCDDs/PCDFs or PBDDs/PBDFs. The PFDDs/PFDFs elute earlier than the PCDDs/PCDFs and the order of the elution is not governed by the degree of substitution, O8FDD eluting e.g. much earlier than the M1FDDs. A preliminary toxicological evaluation of 2,3,7,8-TFDD was carried out. The elimination of 2,3,7,8-TFDD from mice after a single i.p. injection is biphasic with a very rapid elimination half-life of 5 minutes and a slower phase of 165 minutes. This means a dramatically reduced half-life compared to 2,3,7,8-TCDD with 8.5 d. In liver the TFDD level reaches a maximum 30 minutes after injection and also declined in a biphasic manner. In rat hepatocytes a primary culture induction of CYP4501A1-catalyzed EROD activity could be demonstrated, indicating that 2,3,7,8-TFDD activates the dioxin receptor. In rat hepatocyte cultures similar EC50 values were found for 2,3,7,8-TCDD and 2,3,7,8-TFDD. So far no de novo synthesis of PFDD/PFDF could be detected under conditions were PCDDs/PCDFs are formed. Also, formation of PFDDs/PFDFs could not be detected during thermal treatment of fluorotrichloromethane or Teflon.
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Affiliation(s)
- R Weber
- Institute of Organic Chemistry, University of Tübingen, FRG
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1671
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Erkel G, Lorenzen K, Anke T, Velten R, Gimenez A, Steglich W. Kuehneromycins A and B, two new biological active compounds from a Tasmanian Kuehneromyces sp. (Strophariaceae, Basidiomycetes). Z NATURFORSCH C 1995; 50:1-9. [PMID: 7535532 DOI: 10.1515/znc-1995-1-202] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In a search for new inhibitors of RNA-directed DNA-polymerases kuehneromycin A (1) was isolated from fermentations of a Tasmanian Kuehneromyces species. Its structure was elucidated by spectroscopic methods. Kuehneromycin A (1) is a non-competitive inhibitor of avian myeloblastosis virus (Ki 200 microM) and moloney murine leukemia virus (Ki 40 microM) reverse transcriptases. The second compound, kuehneromycin B (2) is a strong inhibitor of platelet aggregation stimulated with different inducers. In addition, both compounds exhibit cytotoxic and antimicrobial activities.
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Affiliation(s)
- G Erkel
- Lehrbereich Biotechnologie der Universität, Bundesrepublik, Deutschland
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1672
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Fukushima T, Kato M, Santa T, Imai K. Enantiomeric separation and sensitive determination of D,L-amino acids derivatized with fluorogenic benzofurazan reagents on Pirkle type stationary phases. Biomed Chromatogr 1995; 9:10-7. [PMID: 7734928 DOI: 10.1002/bmc.1130090103] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The enantiomeric separations of D,L-amino acids derivatized with fluorogenic reagents, 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), 4-(N,N-dimethylaminosulphonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F) and 4-aminosulphonyl-7-fluoro-2,1,3-benzoxadiazole (ABD-F) by high-performance liquid chromatography (HPLC) on various Pirkle type chiral stationary phases (CSPs, Sumichiral OA series) with citric acid in methanol as a mobile phase were studied. Since the least retention and no separation was observed for the derivatives of racemic phenylalanine methyl-ester, -amide and a drug without an alpha-carboxyl group, the carboxylic acid group of the amino acid derivatives seemed to contribute to the enantioselective fixation of the derivatives through hydrogen bonding on the N-acyl-amino acid amide moiety of the CSP. The enantioselective retention of the derivatives was attained through the (S) or (R) configuration of valine, phenylglycine, naphthylglycine, naphthylethylamine or the tert-leucine moiety in the CSP. The 2,1,3-benzoxadiazole (benzofurazan) moiety in the derivatives helps the effective fixation of the derivatives through a pi-pi interaction with an aromatic moiety such as a 3,5-dinitrophenyl or naphthyl group in the Pirkle type chiral stationary phases. D-Amino acids in biological samples were easily determined utilizing the present derivatization with NBD-F, enantiomeric separation and fluorometric detection (530 nm em/470 nm ex) following deproteinization of biological samples (serum or brain homogenate) with methanol and centrifugation. The applications of the method were clearly demonstrated by the following results; D-Ala was detected in sera of healthy volunteers at a level of 0.48-3.10 microM. D-Lys was found in the serum of a patient with myeloma and requiring renal dialysis, and D-Ser was found in rat and bovine cerebrum. Peak identification was performed by use of different types of stationary phases especially those bearing the opposite configuration to that of the chiral centre.
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Affiliation(s)
- T Fukushima
- Faculty of Pharmaceutical Sciences, University of Tokyo, Japan
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1673
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Sparapano L, Evidente A. Biological activity of cyclopaldic acid, a major toxin of Seiridium cupressi, its six derivatives, and iso-cyclopaldic acid. Nat Toxins 1995; 3:156-65. [PMID: 7648024 DOI: 10.1002/nt.2620030307] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cyclopaldic acid (CA), its six derivatives, and iso-cyclopaldic acid (IsoCA) were assayed for toxicity to cuttings of three species of cypress, as well as to mung bean, oat, and tomato explants. Toxicity to host and non-host plants of CA derivatives having one or both of the aldehyde groups transformed was less than that of CA. Shoot tissues of Cupressus macrocarpa artificially infected by Seiridium cupressi leached electrolytes more than those of C. sempervirens and C. arizonica. CA, IsoCA, and to a lesser extent the monoacetylated, phenylhydrazone and hydrogenated derivatives of CA caused loss of electrolytes from cypress tissues. CA, IsoCA, and monoacetyl CA caused limited callus development of cypress tissues. Diacetylhydrazone CA enhanced the yield of cypress callus tissue. CA derivatives having both aldehyde groups modified induced root formation on cypress cuttings. The antifungal activity showed by CA toward species of Botrytis, Fusarium, and Geotrichum markedly decreased in its derivatives. The inhibitory effect of CA on esterases was exhibited also by IsoCA and the monoacetylated derivative.
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Affiliation(s)
- L Sparapano
- Dipartimento di Patologia Vegetale, Università degli Studi di Bari, Italy
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1674
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Kodavanti PR, Ward TR, McKinney JD, Tilson HA. Increased [3H]phorbol ester binding in rat cerebellar granule cells by polychlorinated biphenyl mixtures and congeners: structure-activity relationships. Toxicol Appl Pharmacol 1995; 130:140-8. [PMID: 7839361 DOI: 10.1006/taap.1995.1018] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Our previous reports indicate that polychlorinated biphenyl (PCB) congeners in vitro perturbed cellular Ca2+ homeostasis and protein kinase C (PKC) translocation. We have now studied the structure-activity relationship (SAR) of 3 PCB mixtures, 24 PCB congeners, and 1 dibenzofuran for their effects on PKC translocation by measuring [3H]phorbol ester ([3H]PDBu) binding in cerebellar granule cells (7 days in culture). All the PCB mixtures studied increased [3H]PDBu binding significantly and in a concentration-dependent manner. However, Aroclor 1016 and Aroclor 1254 were more potent than Aroclor 1260. Of the 24 congeners studied, di-ortho congeners such as 2,2',5,5'-tetrachlorobiphenyl (-TeCB), 2,2',4,6,6'-pentachlorobiphenyl (-PeCB), 2,2',4,6-TeCB, and 2,2'-dichlorobiphenyl (-DCB) were the most potent (E50 = 28-43 microM) while non-ortho congeners such as 3,3',4,4'-TeCB and 3,3',4,4'5-PeCB were not effective. The potential contaminant of PCB mixtures, 1,2,3,7,8-pentachlorodibenzofuran had no significant effect on [3H]PDBu binding. The SAR among these congeners revealed: (i) congeners with ortho-chlorine substitution such as 2,2'-DCB (EC50 = 43 +/- 3 microM) or ortho-lateral (meta, para) chlorine substitution such as 2,2',5,5'-TeCB (EC50 = 28 +/- 3 microM) and 2,2'4,6-TeCB (E50 = 41 +/- 6 microM) were most potent; (ii) congeners with only para-substitution such as 4,4'-DCB or high lateral content in the absence of ortho-substitution such as 3,3',4,4',5,5'-HCB were not effective; and (iii) increased chlorination was not clearly related to the effectiveness of these congeners, although hexa- and heptachlorination was less effective than di- and tetrachlorination. Low lateral substitution, especially without para-substitution, or lateral content in the presence of ortho-substitution, may be the most important structural requirement for the in vitro activity of these PCB congeners in neuronal preparations.
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Affiliation(s)
- P R Kodavanti
- Cellular and Molecular Toxicology Branch, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
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1675
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Jonkman-de Vries JD, de Graaff-Teulen MJ, Henrar RE, Kettenes-van den Bosch JJ, Bult A, Beijnen JH. Pharmaceutical development of a parenteral formulation of the novel anti-tumor agent carzelesin (U-80,244). Invest New Drugs 1994; 12:303-14. [PMID: 7775131 DOI: 10.1007/bf00873045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The aim of this study was to design a parenteral dosage form for the investigational cytotoxic drug carzelesin. A stable formulation in PET (Polyethylene glycol 400/absolute ethanol/Tween 80, 6:3:1, v/v/v) was developed. The prototype, containing 0.50 mg carzelesin in 2.0 ml PET formulation, was found to be the optimal formulation in terms of solubility, stability and dosage requirements in phase I clinical trials. Quality control of the formulation showed that the pharmaceutical preparation of carzelesin in PET is not negatively influenced by the manufacturing process. Shelf life studies demonstrated that the formulation is stable for at least 1 year, when stored at -30 degrees C in the dark. In addition, the stability of carzelesin in the PET formulation is discussed as a function of temperature, additives and after dilution in infusion fluids.
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Affiliation(s)
- J D Jonkman-de Vries
- Department of Pharmacy, Slotervaart Hospital/Netherlands Cancer Institute, Amsterdam, The Netherlands
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1676
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Schecter A, Jiang K, Päpke O, Fürst P, Fürst C. Comparison of dibenzodioxin levels in blood and milk in agricultural workers and others following pentachlorophenol exposure in China. Chemosphere 1994; 29:2371-2380. [PMID: 7850386 DOI: 10.1016/0045-6535(94)90406-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Substantial amounts of sodium pentachlorophenol (Na-PCP) salts have been sprayed in certain areas in central China since the 1960s for control of snail-borne schistosomiasis. A sample of Na-PCP used in the area of concern was analyzed and showed 2,3,7,8-substituted dibenzodioxin (PCDD) and dibenzofuran (PCDF) congeners as well as some non-2,3,7,8-substituted congeners. Dibenzodioxin analysis of two pooled blood samples from 100 persons living in sprayed areas and a pooled sample from 26 individuals who had direct contact with the Na-PCP showed elevations of PCDD/F congeners found in the Na-PCP. Total PCDD/Fs ranged from 631 to 1252 parts per trillion (ppt) lipid in the blood of those exposed to Na-PCP, while two general population age-matched pooled blood samples from 50 persons each had total PCDD/Fs of 147 and 178 ppt. Toxic equivalents calculated with International Toxic Equivalency Factors (I-TEqs) ranged from 9 to 16.3 ppt in the blood samples from exposed persons while the general population blood I-TEqs were 4.8 and 6.4 ppt. A pooled breast milk sample from 50 women living in the sprayed areas was compared with a pooled sample from 50 women living in unsprayed areas. Total PCDD/Fs was low in both exposed and general population samples (134 and 42 ppt lipid, respectively), however, the women living in sprayed areas had considerably higher PCDDs, 129 ppt versus 34 ppt. The mothers exposed to Na-PCP had a I-TEq of 5.4, which was about double that of the mothers from the general population, 2.6 ppt, lipid. Although human PCDD and PCDF tissue levels in China are low compared with those in more industrialized countries, the higher levels in exposed persons are cause for concern.
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Affiliation(s)
- A Schecter
- Department of Preventive Medicine, State University of New York, Health Science Center-Syracuse, Binghamton 13903
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1677
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Abstract
70 blood samples--collected in 1993 in Germany--have been analysed for PCDD/PCDF. For all persons involved, no certain expose, except for food consumption, has been reported. The levels measured show a decrease of PCDD/PCDF compared to previous data on blood collected mainly in 1989 and in 1992. This trend for the dioxin values in blood corresponds well to the observations reported for human milk.
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Affiliation(s)
- O Päpke
- ERGO Forschungsgesellschaft mbH, Hamburg, FRG
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1678
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Schecter A, Ryan JJ, Päpke O. Elevated dioxin blood levels in Russian chemical workers and their children following maternal exposure. Chemosphere 1994; 29:2361-2370. [PMID: 7850385 DOI: 10.1016/0045-6535(94)90405-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Elevated dioxin levels in children of female workers with elevated dioxin body burden following workplace exposure has not been previously reported. We previously reported elevation of polychlorinated dibenzo-p-dioxins, particularly 2,3,7,8-TCDD, in Russia male and female chemical production workers' blood. Exposure is thought to have occurred in the early 1960s and blood was drawn in 1991. Among those with elevated dioxin levels were women with grown children. Since dioxins can be transferred transplacentally and by nursing, it was decided to see if a relationship existed between blood dioxin levels in mothers and their children. Individual samples were obtained from factory office workers, production workers and their now adult offspring. A pooled blood sample (n = 100) from adult Ufa residents was obtained for comparison. Samples were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (CoPCBs). Office workers, production workers and workers' children 2,3,7,8-TCDD (TCDD) blood levels ranged from 11 to 273 parts per trillion (ppt) on a lipid basis, while the pooled blood sample (n = 100) from adult Ufa residents had a TCDD level of 12 ppt. Elevated TCDD was detected in all adult children of female production workers tested while two adult children of a male production worker had dioxin levels similar to the general population of Ufa. All children of workers had been nursed by their mothers for the first year of life and none have worked at a chemical plant. The data suggest that relatively large amounts of TCDD were transferred from mother to child approximately 18 to 28 years prior to blood collection. A sample of 2,4,-D amine salt produced at this factory was also analyzed to determine if its dioxin congeners might be contributing to dioxin contamination. 2,3,7,8-TCDD was not detected in the 2,4-D (detection limit of 0.02 ppb), although other dioxins were present, including some with 2,3,7,8- chlorine substitution.
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Affiliation(s)
- A Schecter
- Department of Preventive Medicine, State University of New York, Health Science Center-Syracuse, Binghampton 13903
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1679
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Abstract
The effect of metabolic activation on the mutagenicity of nitrodibenzofurans (NDF) by rat liver S9 was evaluated with S. typhimurium tester strains. Except for 1-nitrodibenzofuran (NDF), five tested NDFs were mutagenic in strains TA98 and TA98/1,8-DNP6 without S9 mix but were not mutagenic in strain TA98NR. NDFs mutagenized strain TA98NR with S9 mix, and the NAD(P)H system plus 3-methylcholanthrene-induced S9 (3-MC-S9) was the most effective. The specificity of S9 enzyme(s) participating in the activation of NDFs was different from that of endogenous enzyme(s) in strain TA98, i.e., the order of mutagenic potency of NDFs in strain TA98 without S9 mix was 2,8- = 2,7-->3-->2-->4-->1-nitrated dibenzofuran and 2-NDF and 2,8-dinitrodibenzofuran (DNDF) were more mutagenic than 3-NDF and 2,7-DNDF, respectively, in strain TA98NR with S9 mix. The mutagenic potency of 2-NDF, 4-NDF, 2,7-DNDF and 2,8-DNDF in strain TA98NR with S9 mix was stronger than those in strain TA98 without S9 mix and the cytosolic fraction of the 3-MC-S9 accounted for more of the activation than the microsomal fraction. Studies with electron donors and inhibitors indicated that xanthine oxidase and/or NAD(P)H-quinone oxido-reductase (NQOR) participated in the activation of NDFs. The mutagenic potency of NDFs in strain TA98NR with S9 mix (3-MC-S9) was reflected in the induction of NQOR by pretreatment of rats with 3-MC.
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1680
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Abstract
Two new pigments, named grapheone and graphisquinone, were identified in the cultures of the spore-derived mycobionts of the lichens Graphis scripta and Graphis desquamescens, respectively.
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Affiliation(s)
- H Miyagawa
- Pesticide Research Institute, Faculty of Agriculture, Kyoto University, Japan
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1681
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Hashimoto T, Tanaka H, Asakawa Y. Stereostructure of plagiochiline A and conversion of plagiochiline A and stearoylvelutinal into hot-tasting compounds by human saliva. Chem Pharm Bull (Tokyo) 1994; 42:1542-4. [PMID: 7923476 DOI: 10.1248/cpb.42.1542] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The stereostructure of plagiochiline A (1) isolated from the liverwort Plagiochila fruticosa has been established by X-ray crystallographic analysis. Plagiochiline A was converted into plagiochilal B (2) and furanoplagiochilal (3) by human saliva, and stearoylvelutinal (4) isolated from the fungus Lactarius vellerus was converted into velleral (5), also by human saliva.
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Affiliation(s)
- T Hashimoto
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Japan
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1682
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Gollapudi SR, Telikepalli H, Jampani HB, Mirhom YW, Drake SD, Bhattiprolu KR, Vander Velde D, Mitscher LA. Alectosarmentin, a new antimicrobial dibenzofuranoid lactol from the lichen, Alectoria sarmentosa. J Nat Prod 1994; 57:934-938. [PMID: 7964789 DOI: 10.1021/np50109a009] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
From the alcoholic extract of the lichen Alectoria sarmentosa, four compounds showing antimicrobial activity were isolated. Of these, (-)-usnic acid and physodic acid are well known lichen products, 8'-O-ethyl-beta-alectoronic acid [2] is believed to be an artifact formed during isolation and fractionation, and alectosarmentin [1] is a new natural product whose structure was shown, by spectroscopy and chemical transformations, to be that of a dibenzofuranoid lactol. The antimicrobial activity of these substances accounts for the activity of the lichen.
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Affiliation(s)
- S R Gollapudi
- Department of Medicinal Chemistry, University of Kansas, Lawrence 66045
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1683
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Eisner DA, O'Neill SC, Donoso P. Properties of the fluorescent sodium indicator SBFI in rat and rabbit cardiac myocytes. J Cardiovasc Electrophysiol 1994; 5:637-9. [PMID: 7527284 DOI: 10.1111/j.1540-8167.1994.tb01305.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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1684
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Kaneto R, Dobashi K, Kojima I, Sakai K, Shibamoto N, Yoshioka T, Nishida H, Okamoto R, Akagawa H, Mizuno S. Mer-NF5003B, E and F, novel sesquiterpenoids as avian myeloblastosis virus protease inhibitors produced by Stachybotrys sp. J Antibiot (Tokyo) 1994; 47:727-30. [PMID: 8040079 DOI: 10.7164/antibiotics.47.727] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- R Kaneto
- Central Research Laboratories, Mercian Corporation, Kanagawa, Japan
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1685
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Tanfani F, Fiorini R, Tartaglini E, Kantar A, Wozniak M, Antosiewicz J, Bertoli E. A sensitive detection of neutrophil activation by fluorescence quenching of membrane inserted singlet oxygen probe. Biochem Mol Biol Int 1994; 32:1093-9. [PMID: 8061626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Fluorescence emission intensity of 1,3-diphenylisobenzofuran incorporated in polymorphonuclear granulocytes plasma membranes was investigated in basal conditions and during stimulation with different activators. Phorbol myristate acetate, known as the most effective "oxygen burst" inducer, produced a larger decrease in 1,3-diphenylisobenzofuran fluorescence intensity than 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platelet activating factor) and N-formyl-methionyl-leucyl-phenylalanine, known as weak stimulants of oxygen uptake. Diphenyl iodonium an inhibitor of leukocyte NADPH oxidase, and the singlet oxygen selective trap alpha-terpinene inhibited the quenching effect of phorbol myristate acetate on 1,3-diphenylisobenzofuran fluorescence. These data suggest formation of singlet oxygen in activated leukocytes and demonstrate that measurement of 1,3-diphenylisobenzofuran fluorescence intensity provides a new sensitive method of detection of neutrophils activation.
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Affiliation(s)
- F Tanfani
- Institute of Biochemistry, Medical School, University of Ancona, Italy
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1686
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Ducharme Y, Brideau C, Dubé D, Chan CC, Falgueyret JP, Gillard JW, Guay J, Hutchinson JH, McFarlane CS, Riendeau D. Naphthalenic lignan lactones as selective, nonredox 5-lipoxygenase inhibitors. Synthesis and biological activity of (methoxyalkyl)thiazole and methoxytetrahydropyran hybrids. J Med Chem 1994; 37:512-8. [PMID: 8120869 DOI: 10.1021/jm00030a010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Combinations of structural elements found in (methoxyalkyl)thiazole 1a and methoxytetrahydropyran 2a with a naphthalenic lignan lactone produce the potent 5-lipoxygenase (5-LO) inhibitors 3 and 4. While the nature of link Y-Z has a major effect on the in vitro activity of compounds 1 and 2, inhibitors 3 and 4 retain their potencies with either an oxymethylene (Y = O, Z = CH2) or a methyleneoxy (Y = CH2, Z = O) link. Compound 4b inhibits the oxidation of arachidonic acid to 5-hydroperoxyeicosatetraenoic acid by 5-LO (IC50 = 14 nM) and the formation of leukotriene B4 in human polymorphonuclear leukocytes (IC50 = 1.5 nM) as well as in human whole blood (IC50 = 50 nM). Compound 4b is a selective 5-LO inhibitor showing no significant inhibition of human 15-lipoxygenase or porcine 12-lipoxygenase or binding to human 5-lipoxygenase-activating protein up to 10 microM and inhibits leukotriene biosynthesis by a direct, nonredox interaction with 5-LO. Compound 15, the open form of lactone 4b, is well absorbed in the rat and is transformed into the active species 4b. In addition, 15 is orally active in the rat pleurisy model (ED50 = 0.6 mg/kg) and in the functional model of antigen-induced bronchoconstriction in allergic squirrel monkeys (95% inhibition at 0.3 mg/kg).
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Affiliation(s)
- Y Ducharme
- Merck Frosst Centre for Therapeutic Research, Pointe Claire-Dorval, Québec, Canada
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1687
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Tysklind M, Tillitt D, Eriksson L, Lundgren K, Rappe C. A toxic equivalency factor scale for polychlorinated dibenzofurans. Fundam Appl Toxicol 1994; 22:277-85. [PMID: 8005379 DOI: 10.1006/faat.1994.1031] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The ethoxyresorufin O-deethylase (EROD) induction of 20 polychlorinated dibenzofurans (PCDFs) was examined in the H4IIE rat hepatoma cell bioassay. The selection of the compounds tested was based on a multivariate chemical characterization laying the groundwork for covering the whole chemical series of PCDFs. The EROD induction potency was found to vary in ED50 values from 25 to 100,000,000 pg/mg, i.e., nearly seven orders of magnitude. The response of the bioassay was calibrated against the 2,3,7,8-tetrachlorodibenzo-p-dioxin, enabling the corresponding toxic equivalency factors (TEFs) to be calculated. In order to establish a quantitative structure-activity relationship (QSAR) for the TEF values, 37 physicochemical descriptor variables were used to chemically characterize the 87 tetra- to octachlorinated PCDFs. Using partial least-squares modeling on a training set of 10 congeners, a QSAR model with sound predictive power was obtained. The QSAR model was validated with a validation set of additional 10 congeners. The predicted TEFs indicate that a large number of congeners are potent EROD inducers.
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Affiliation(s)
- M Tysklind
- Institute of Environmental Chemistry, University of Umeå, Sweden
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1688
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Abstract
The CASE (Computer-Automated Structure Evaluation) methodology has been applied to an investigation of the basis of the genotoxicity (sfiA induction) of 79 nitroarenofurans and related molecules examined with the E. coli PQ37 genotoxicity assay (SOS chromotest). CASE identified 9 major activating structural fragments (biophores) responsible for the probability of genotoxicity (SAR). With respect to quantitative features, CASE identified 8 major molecular subunits related to the genotoxic potency (QSAR). Both the SAR as well as the QSAR analysis indicate that a nitro group on position 2 of the furan ring is important for activity provided one or more aromatic rings are attached to the furan ring, i.e. 2-nitrobenzofuran, 2-nitronaphthofuran, 2-nitroanthrafuran and 8-nitropyrenofuran. Additionally, a small substituent at position 3 of the furan ring, i.e. the methyl group of R7371, the ethyl group of R7427 and the butyl group of R7429, enhance the activity of 2-nitronaphtho[2,1-b]furan (R6597), whereas longer aliphatic chains decrease activity. Moreover, the activity of the nitro group at position 2 of the furan ring was increased by substitution of a methoxy group at position 7 of the R6597 structure. Additionally the n-octanol/water partition coefficient (log P) was found to be an important descriptor for the genotoxic potency in E. coli PQ37. Using the identified descriptors CASE correctly predicted the probability of genotoxicity of all of the genotoxicants and non-genotoxicants in the data base. The calculated genotoxic potency was equally good: 94% of all predicted results were within plus/minus one order of magnitude of the experimental result. Using CASE in the predictive mode, the program correctly predicted the probability of sfiA induction in E. coli of 95.8% of 24 "unknown" nitroarenofurans which were not part of the learning set (QSAR with r = 0.88-0.97).
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Affiliation(s)
- V Mersch-Sundermann
- Department of Medical Microbiology and Hygiene, Faculty of Clinical Medicine Mannheim, University of Heidelberg, Germany
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1689
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van Tellingen O, Pels EM, Henrar RE, Schaaf LJ, Padbury GE, Beijnen JH, Nooijen WJ. Fully automated high-performance liquid chromatographic method for the determination of carzelesin (U-80,244) and metabolites (U-76,073 and U-76,074) in human plasma. J Chromatogr 1994; 652:51-8. [PMID: 8014227 DOI: 10.1016/0378-4347(93)e0377-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Carzelesin (U80,244, I) is a cyclopropylpyrroloindole prodrug analog. The compound exerts its cytotoxic activity after conversion, via U-76,073 (II) to U-76,074 (III) by binding to the DNA minor groove in a sequence selective fashion. In pre-clinical investigations the drug displayed a broad spectrum activity against human xenografts in mice. To enable pharmacokinetic monitoring during the phase I clinical trials, we have developed a selective and sensitive assay for the parent compound and its two metabolites. Sample pre-treatment has been automated by using the ASPEC system and involves solid-phase extraction of the diluted plasma sample (1:3 in 20% v/v acetic acid) on an SPE-C18 precolumn followed by two consecutive washings with water and acetonitrile. The compounds are eluted with 600 microliters of dimethylacetamide and 500 microliters is injected on a Spherisorb-CN column. The sample is chromatographed using a linear gradient from 24% to 60% (v/v) acetonitrile in 20 mM phosphate buffer (pH 6.5). The eluate fraction containing the three compounds is heart-cutted in a 2-ml sample loop, switched onto a Spherisorb-ODS column and separation is accomplished using a mobile phase of acetonitrile-20 mM phosphate buffer pH 6.5 (64:36, v/v). UV detection is used with absorbance monitored at 360 nm. This highly selective method offers a lower limit of detection of less than 1 ng/ml for each of the compounds using 1000 microliters of plasma and enables the quantification of the analytes with an acceptable precision and accuracy over a range of 1 to 50 ng/ml. The assay has been implemented in a phase I clinical trial.
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Affiliation(s)
- O van Tellingen
- Department of Clinical Chemistry, Netherlands Cancer Institute, Amsterdam
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1690
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Kedderis LB, Jackson JA, Patterson DG, Grainger J, Diliberto JJ, Birnbaum LS. Chemical characterization and disposition studies with 1,2,7,8-tetrabromodibenzofuran in the rat. J Toxicol Environ Health 1994; 41:53-69. [PMID: 8277526 DOI: 10.1080/15287399409531826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Polybrominated dibenzo-p-dioxins and dibenzofurans have been identified as potential environmental contaminants. The present studies were designed to characterize the chemical disposition of a tetrabrominated dibenzofuran. The isomer-specific pattern of 1,2,7,8-tetrabromodibenzofuran (TBDF) was chemically characterized using high-pressure liquid chromatography, gas chromatography/mass spectrometry, infrared absorption, and proton nuclear magnetic resonance techniques. The absorption, distribution, and elimination of 1,2,7,8-[4,6-3H]-TBDF were examined in the rat following a single oral, dermal, or intravenous dose of 1 nmol/kg. The 1,2,7,8-TBDF was rapidly excreted in the bile (approximately 50% of the dose in 8 h). Likewise, over half of the administered dose was found in the feces and intestine contents 24 h after iv administration and in feces 72 h after oral administration. Thus, the half-life of 1,2,7,8-TBDF is approximately 1 d. Major tissue depots included the liver, adipose tissue, and skin. The decline in hepatic concentrations observed in the iv and bile studies occurred in conjunction with metabolic elimination as well as a slight accumulation in adipose tissue. Dermal absorption of 1,2,7,8-TBDF, quantified as the amount contained in tissues (excluding the skin site) and excreta at 72 h, was estimated to be 29% of the administered dose. Thus, the general disposition profile of 1,2,7,8-TBDF in the rat is similar to that of other polyhalogenated aromatic hydrocarbons. Due to its rapid elimination, which is consistent with its predicted susceptibility to metabolic elimination, acute exposure to 1,2,7,8-TBDF would not be expected to result in the degree of toxicity associated with other more persistent congeners.
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Affiliation(s)
- L B Kedderis
- Curriculum in Toxicology, University of North Carolina at Chapel Hill
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1691
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Hongo K, Konishi M, Kurihara S. Cytoplasmic free Mg2+ in rat ventricular myocytes studied with the fluorescent indicator furaptra. Jpn J Physiol 1994; 44:357-78. [PMID: 7869599 DOI: 10.2170/jjphysiol.44.357] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To estimate cytoplasmic Mg2+ concentration ([Mg2+]i), ventricular myocytes enzymatically isolated from rat hearts were loaded with the fluorescent indicator, furaptra, and the fluorescence signals of single quiescent myocytes were measured at 32 degrees C. The excitation spectrum of furaptra measured in the myocytes was well-fitted by the spectra obtained in vitro; thus it was possible to calibrate the fluorescence signal in terms of [Mg2+]i. The analysis implied that about 20% of the indicator molecules were Mg(2+)-bound. Considering that the indicator likely reacts with Mg2+ with a larger KD value in cytoplasm than in vitro (by a factor of 1.2-2 as suggested for mouse and frog skeletal muscles), the [Mg2+]i for the resting single myocytes was estimated to be within 0.8-1.3 mM. Superfusion with a high extracellular Mg2+ concentration (20 mM) caused a slow and slight elevation in [Mg2+]i over a period of a few hours. Other experimental interventions, including application of a low extracellular Na+ concentration and isoproterenol, and CO2 acidosis, did not cause a detectable change in [Mg2+]i, whereas the application of an uncoupler, a blocker of oxidative phosphorylation in mitochondria, caused a rapid and large increase in [Mg2+]i. It is suggested that the [Mg2+]i is tightly maintained at around 1 mM, unless intracellular ATP is depleted.
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Affiliation(s)
- K Hongo
- Department of Physiology, Jikei University School of Medicine, Tokyo, Japan
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1692
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Mennear JH, Lee CC. Polybrominated dibenzo-p-dioxins and dibenzofurans: literature review and health assessment. Environ Health Perspect 1994; 102 Suppl 1:265-74. [PMID: 8187718 PMCID: PMC1566873 DOI: 10.1289/ehp.94102s1265] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Polybrominated dibenzo-p-dioxins (PBDDs) and dibenzofurans (PBDFs) occur as trace (ppb) contaminants in brominated flame retardants and are produced during combustion of these chemicals. They are also formed when organics are incinerated in the presence of bromine, e.g., in municipal and industrial incinerators and in internal-combustion engines. Combustion of organics in the presence of both bromine and chlorine results in the formation of mixed (i.e., bromo, bromo/chloro and chloro) halogenated dibenzo-p-dioxins and dibenzofurans (HDDs and HDFs). There are 4600 potential mixed congeners. The biological effects of PBDDs and PBDFs are similar, if not identical, to those of PCDDs and PCDFs. Both groups of compounds induce hepatic aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin-o-deethylase (EROD) in rats and cause wasting and thymic atrophy in rats and guinea pigs. Tetrabrominated dinenzo-p-dioxin (TBDD) and dibenzofuran (TBDF) are reproductive toxins in mice and produce skin lesions in the rabbit-ear acnegenic test. The brominated compounds appear to bind to the same cytosolic receptors believed to mediate the toxicities of the chlorinated analogs. When compared on a molar-concentration basis, the brominated compounds are equipotent to the chlorinated analogs. TBDD is absorbed after oral, dermal, or intratracheal administration in rats, stored in the liver and adipose tissue, and eliminated in the feces through biliary excretion. The biological half-lives of the brominated compounds appear to be somewhat shorter than those of the corresponding chlorinated species. The brominated compounds, like their chlorinated congeners, have the potential to cause dermal, hepatic, and gastrointestinal toxicities in humans.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J H Mennear
- Campbell University, School of Pharmacy, Buies Creek, NC 27506
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1693
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Sonnenbichler J, Dietrich J, Schäfer W, Zetl I. Secondary fungal metabolites and their biological activities, IV. Synthesis of compounds with structural similarities to the toxic metabolites of the pathogenic fungus Heterobasidion annosum and investigation of their antibiotic activities. Biol Chem Hoppe Seyler 1993; 374:1047-55. [PMID: 8292264 DOI: 10.1515/bchm3.1993.374.7-12.1047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A series of synthetic analogues of fomannoxin and fomajorin S, the toxic metabolites of the basidiomycete Heterobasidion annosum, was prepared in order to investigate which partial structures of the molecules are responsible for their biological activities. Of the compounds synthesized the five indane-2-acid derivatives 5-acetylindane-2-carboxylic acid (2), (+/-)5-formylindane-2-carboxylic acid (3), (+/-)indane-2,5-dicarboxylic acid (4), (+/-)formyl-2-methylindane-2-carboxylic acid (7) and 5-acetyl-indane-2,2-dicarboxylic acid (10) and 4-(2'-ethylbutyloxy)benzaldehyde (18) have not yet been described. Different biological test systems were employed to investigate the antibiotic activities of the synthesized analogues. The experimental results suggest that in the case of fomajorin S, the structural element essential for its toxicity is the 2-H- or 2-methylindane 2-acid. From the results obtained with the synthetic analogues of fomannoxin, it is now evident that the toxicity of this fungal metabolite can be attributed to an aromatic ring with a carbonyl or carboxyl substituent combined with a branched lipophilic side chain in p-substitution.
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1694
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Abstract
Bioactivity-directed fractionation of the CHCl3 extract of the bark of Erythrina burana afforded phaseollidin [1] and cristacarpin [2]. Both 1 and 2 exhibited moderate but selective activity towards DNA repair-deficient yeast mutants, whereas only 1 was found to be cytotoxic. 13C-nmr spectra of both compounds were assigned.
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Affiliation(s)
- E Dagne
- Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg 24061-0212
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1695
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Jackson JA, Diliberto JJ, Birnbaum LS. Estimation of octanol-water partition coefficients and correlation with dermal absorption for several polyhalogenated aromatic hydrocarbons. Fundam Appl Toxicol 1993; 21:334-44. [PMID: 8258387 DOI: 10.1006/faat.1993.1106] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
n-Octanol-Water partition coefficients (K(ow)) were experimentally estimated for: 2,3,7,8-tetrachloro-and 2,3,7,8-tetrabromodibenzo-p-dioxin; 2,3,7,8-tetrachloro-, 2,3,7,8-tetrabromo-, and 1,2,7,8-tetrabromodibenzofuran; 1,2,3,7,8-pentachloro-, 1,2,3,7,8-pentabromo-, 2,3,4,7,8-pentachloro-, and 2,3,4,7,8-pentabromodibenzofuran; 1,2,4,6,8,9-hexachlorodibenzofuran (HxCDF), and 3,4,3',4'-tetrachlorobiphenyl (3,4,3',4'-TCB). The method involved correlation of literature K(ow) with reverse-phase high-performance liquid chromatography (RP-HPLC) retention time for a series of 23 calibration standards and estimation of K(ow) for test compounds from measured RP-HPLC retention. Retention times for all standards and test chemicals were measured in duplicate on the same octadecasilane (C18) reverse-phase column with an isocratic 85:15 methanol:water mobile phase; solutes were detected by uv absorbance (254 nm). Literature log K(ow) values used for the calibration standards had been measured exclusively by the generator column method. Log K(ow) estimates for the test compounds in the present study ranged from 5.45 for 3,4,3',4'-TCB to 6.81 for HxCDF. K(ow) estimates were then plotted against laboratory data for the in vivo 3-day dermal absorption of single equimolar doses (200 pmol and 20 nmol, or approximately 1 nmol/kg and approximately 0.1 mumol/kg) of selected test compounds in male F344 rats. Strong inverse correlations were found between octanol-water partition coefficient estimates and single-dose dermal absorption for most of the compounds studied. In addition, RP-HPLC retention time itself appeared to be as equally suited as K(ow) to such correlations with dermal absorption. The structure-activity relationships suggested in this study were sought in order to explain observed differences in the dermal absorption of polyhalogenated dibenzo-p-dioxin, dibenzofuran, and biphenyl congeners differing in number, position, and/or type (Cl or Br) of halogen substituents. Moreover, these results should be of predictive value in the risk assessment of dermal exposure to polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, and their brominated analogues.
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Affiliation(s)
- J A Jackson
- ManTech Environmental Technology, Inc., Research Triangle Park, North Carolina 27709
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1696
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Imai K, Fukushima T. Derivatization with fluorogenic benzofurazan reagents of amino acid enantiomers and their separation on a Pirkle type column. Biomed Chromatogr 1993; 7:275-6. [PMID: 8305859 DOI: 10.1002/bmc.1130070508] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
L- and D-Amino acids (Leu or Phe) were derivatized with fluorogenic reagents, 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F), 4-aminosulfonyl-7-fluoro-2,1,3-benzoxadiazole (ABD-F) and 5-(N,N-dimethylamino)naphthalene-1-sulfonylchloride (DNS-CI), and separated on a Pirkle type column, Sumichiral OA 2500 (S) ((S)-1-naphthylglycyl-3,5-dinitrophenylamide silica gel) with a mobile phase of 20 mM ammonium acetate in methanol. The fluorometric detection of the derivatives was made at 530 nm, 590 nm, 590 nm and 530 nm with excitation at 470 nm, 450 nm, 450 nm and 350 nm, respectively. The former three derivatives of the enantiomers were separated well from each other; The alphas for each NBD-, DBD- and ABD-derivative of L- and D-Leu were 1.10, 1.11 and 1.10, respectively. However, the DNS derivatives of L- and D-Leu were not separated (separation factor, alpha = 1.0). All NBD-, DBD- and ABD-derivatives of L- and D-Phe were also well separated (alphas were 1.18, 1.17 and 1.16, respectively), while DNS-L- and -D-Phe were barely separated (alpha = 1.04). These data suggest that the 2,1,3-benzoxadiazole (benzofurazan) moiety is very effective and preferable to the dimethylaminonaphthalene sulfonyl (DNS) structure for the separation of enantiomers of amino acids derivatized with benzofurazan reagents.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K Imai
- Branch Hospital Pharmacy, University of Tokyo, Japan
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1697
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Lans MC, Klasson-Wehler E, Willemsen M, Meussen E, Safe S, Brouwer A. Structure-dependent, competitive interaction of hydroxy-polychlorobiphenyls, -dibenzo-p-dioxins and -dibenzofurans with human transthyretin. Chem Biol Interact 1993; 88:7-21. [PMID: 8330325 DOI: 10.1016/0009-2797(93)90081-9] [Citation(s) in RCA: 283] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Previous results from our laboratory indicated specific and competitive interactions of hydroxylated metabolites of 3,3', 4,4'-tetrachlorobiphenyl with the plasma thyroid hormone transport protein, transthyretin (TTR), in rats in vivo and with human TTR in vitro. In the present study the structural requirements for competition with thyroxine (T4) for TTR-binding were investigated in more detail. Several hydroxylated polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were tested in an in vitro competitive binding assay, using purified human TTR and [125I]T4 as a displaceable radioligand. All hydroxylated PCBs, but not the single PCB tested, competitively displaced [125I]T4 from TTR with differential potency. The highest competitive binding potency was observed for hydroxylated PCB congeners with the hydroxygroup substituted on meta or para positions and one or more chlorine atoms substituted adjacent to the hydroxy group on either or both aromatic rings (IC50 range 6.5-25 nM; Ka range: 0.78-3.95 x 10(8) M-1). The relative potency of all meta or para hydroxylated PCBs was higher than that of the physiological ligand, T4 (relative potency range: 3.5-13.6 compared to T4). There were no marked distinctions in TTR-T4 competitive binding potencies between the ortho- and non-ortho-chlorine substituted hydroxy-PCB congeners tested. Marked differences in TTR-T4 binding competition potency were observed between the limited number of hydroxylated PCDDs and PCDFs tested. The hydroxy-PCDD/Fs, with chlorine substitution adjacent to the hydroxy-group, i.e. 7-OH-2,3,8-trichlorodibenzo-p-dioxin, 2-OH-1,3,7,8-tetrachlorodibenzo-p-dioxin and 3-OH-2,6,7,8-tetrachlorodibenzofuran, all showed a similar or higher relative binding potency, i.e. 1, 4.4 and 4.5 times higher, respectively, than T4. No detectable [125I]T4 displacement was observed with 2-OH-7,8-dichlorodibenzofuran, 8-OH-2,3,4-trichlorodibenzofuran and 8-OH-2,3-dichlorodibenzo-p-dioxin, which did not contain chlorine substitution adjacent to the OH-group. These results indicate a profound similarity in structural requirements for TTR binding between hydroxy-PCB, -PCDD and -PCDF metabolites and the physiological ligand, T4, e.g. halogen substitution adjacent to the para hydroxy group, while planarity does not seem to influence the ligand-binding potency.
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Affiliation(s)
- M C Lans
- Department of Toxicology, Agricultural University Wageningen, The Netherlands
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1698
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Abstract
In this paper, it is hypothesized that the distinction between certain active and inactive cannabinoids is that the inactive analogs possess extra volume associated with their carbocyclic rings that may be responsible for an unfavorable interaction at the cannabinoid receptor. Using the active analog approach, a model is developed of a region of steric interference at this receptor using the active cannabinoids (-)-trans-delta 9-tetrahydrocannabinol, (-)-trans-delta 8-tetrahydrocannabinol, (-)-11-hydroxy-beta-hexahydrocannabinol, and a (-)-trans-11-hydroxy-delta 8-tetrahydrocannabinol dimethylheptyl derivative and the inactive cannabinoids (9S,6aR)-trans-delta 10,10a-tetrahydrocannabinol and a (+)-trans-11-hydroxy-delta 8-tetrahydrocannabinol dimethylheptyl derivative. Each of these molecules satisfy the cannabinoid pharmacophoric requirements, i.e., a phenolic oxygen at C1 and a side chain of acceptable length at C3. Accessible conformers of each molecule were identified by using the method of molecular mechanics as encoded in the MMP2(85) program. The MAP facility within the Chem-X molecular modeling program was then used to calculate the region of steric interference (termed the receptor essential volume, REV) from these accessible conformers. The calculations revealed an REV region located near the top of the carbocyclic ring in the bottom face of the molecule. In order to explore the use of this REV to account for the activities of other cannabinoids, the minimally active classical cannabinoid (-)-11-hydroxy-alpha-hexahydrocannabinol, an active benzofuran cannabinoid, and the active nonclassical cannabinoid CP-47,497 were then studied. In each case, the activity or minimal activity of each compound can be explained on the basis of the ability of one or more accessible conformer of each molecule to clear the REV calculated here. The results of this study provide an explanation at the molecular level for observed activity differences between cannabinoids that exhibit shape differences associated with their carbocyclic rings.
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Affiliation(s)
- P H Reggio
- Department of Chemistry, Kennesaw State College, Marietta, Georgia 30061
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1699
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Abstract
New beta-1,3-glucan synthase inhibitor (BU-4794F) was isolated from the culture broth of Gilmaniella sp. FA4459. Structural studies indicated that it was a novel member of the papulacandin group of antibiotics.
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Affiliation(s)
- M Aoki
- Bristol-Myers Squibb Research Institute, Tokyo, Japan
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1700
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Pieters L, de Bruyne T, Claeys M, Vlietinck A, Calomme M, vanden Berghe D. Isolation of a dihydrobenzofuran lignan from South American dragon's blood (Croton spp.) as an inhibitor of cell proliferation. J Nat Prod 1993; 56:899-906. [PMID: 8350090 DOI: 10.1021/np50096a013] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Dragon's blood is a red viscous latex extracted from the cortex of various Croton spp. (Euphorbiaceae), most commonly Croton lechleri, Croton draconoides (or Croton palanostigma), and Croton erythrochilus. It is used in South American popular medicine for several purposes, including wound healing. Bioassay-guided fractionation of dragon's blood, using an in vitro test system for the stimulation of human umbilical vein endothelial cells, has resulted in the isolation of a dihydrobenzofuran lignan, 3',4-O-dimethylcedrusin or 4-O-methyldihydrodehydrodiconiferyl alcohol [2-(3',4'-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-7-methoxybenzo furan-5- propan-1-ol] [1] as the biologically active principle. A related compound, 4-O-methylcedrusin [2-(3',4'-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro-7-hydroxybenzo furan-5- propan-1-ol] [2], and the alkaloid taspine [3], also isolated from dragon's blood, were not active in the same assay. A cell proliferation assay, measuring the incorporation of tritiated thymidine in endothelial cells, showed that compound 1 did not stimulate cell proliferation, but rather inhibited thymidine incorporation, while protecting cells against degradation in a starvation medium.
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