Preconcentration of trace lead and iron on activated carbon functionalized by o-Anisic acid derivatives prior to their determination in environmental samples

Two solid-phase adsorbents (phase I and phase II) were synthesized successfully that o-Anisic acid derivatives were evenly functionalized on the surface of activated carbon. It was certified that the two adsorbents were applied to preconcentrate and separate trace levels of Pb(II) and Fe(III) from natural liquid samples with satisfactory results. It can be found that the adsorption capacity of the ions adsorbed on phase I and phase II was 48.3 and 85.7 mg g(-1) for Pb(II), 39.5 and 72.5 mg g(-1) for Fe(III), respectively. The detection limit (3σ) of the method separated on phase I and phase II was 0.12 and 0.09 ng mL(-1) for Pb(II), 0.23 and 0.17 ng mL(-1) for Fe(III), respectively. The relative standard deviation (R.S.D.) of the method was lower than 3.0%. The adsorption and desorption property of two kinds of adsorbents was comparatively studied, respectively. The adsorption selectivity of heavy metal ions at certain pH, the adsorption kinetics, the condition of complete elution, the effect of coexisting ions, the adsorption capacity and adsorption isotherm modes were examined. Based on the experimental datum determined by inductively coupled plasma optical emission spectrometry (ICP-OES), it was certified that the adsorption on the surface of adsorbents was in strict accordance with the monolayer adsorption principle. The structural features of series of multidentate ligand modified on adsorption matrix had been obtained. These conclusions can provide reference for synthesizing an efficient adsorbent which is specific to remove a particular kind of contaminant.

Dihydrochalcones and benzoic acid derivatives from Piper dennisii

Two new dihydrochalcones (1, 2), as well as eight known compounds, piperaduncin C (3), 2',6'-dihydroxy-4'-methoxydihydrochalcone (4), 4,2',6'-trihydroxy-4'-methoxydihydrochalcone (5), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (6), 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (7), 4-hydroxy-3-(3-methyl-2-butenoyl)-5-(3-methyl-2-butenyl)-benzoic acid (8), 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-chromene-6-carboxylic acid (9), and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid (10) were isolated from the leaves of Piper dennisii Trelease (Piperaceae), using a bioassay-guided fractionation to determine their antileishmanial potential. Among them, compound 10 exhibited the best antileishmanial activity (IC50 = 20.8 µM) against axenic amastigote forms of Leishmania amazonensis, with low cytotoxicity on murine macrophages. In the intracellular macrophage-infected model, compound 10 proved to be more active (IC50 = 4.2 µM). The chemical structures of compounds 1-10 were established based on the analysis of the spectroscopic data.

DFT, FT-Raman and FT-IR investigations of 5-methoxysalicylic acid

FT-IR and FT-Raman spectra of 5-methoxysalicylic acid (5MeOSA) have been experimentally reported in the region of 4000-10 cm(-1) and 4000-50 cm(-1), respectively. The optimized geometric parameters, conformational equilibria, normal mode frequencies and corresponding vibrational assignments of 5MeOSA (C(8)H(8)O(4)) are theoretically examined by means of B3LYP hybrid density functional theory (DFT) method together with 6-31++G(d,p) basis set. Furthermore, reliable vibrational assignments have made on the basis of potential energy distribution (PED) calculated and the thermodynamics functions, highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO) of 5MeOSA have been predicted. Calculations are employed for different conformations of 5MeOSA, both in gas phase and in solution. Solvent effects are investigated using chloroform and dimethylsulfoxide. All results indicate that B3LYP method is able to provide satisfactory results for predicting vibrational frequencies and the structural parameters, vibrational frequencies and assignments, IR and Raman intensities of 5MeOSA are solvent dependent.

Biochemical assays of immobilized oligonucleotides with mass spectrometry

This paper reports the use of mass spectrometry to characterize oligonucleotides immobilized to the surfaces of biochips. Biotinylated oligonucleotides were immobilized to self-assembled monolayers that present a streptavidin layer and then treated with a complementary strand to present short duplexes. Treatment of the surface with 5-methoxysalicylic acid and ammonium citrate matrix allows the individual oligonucleotides to be observed by matrix-assisted laser desorption/iozation and time-of-flight mass spectrometry (MALDI-TOF MS). Examples are shown wherein this method is applied to assays of hybridization, of cleavage by a deoxyribozyme, of a dephosphorylation reaction, and of the adducts formed on treatment of DNA with cis-platin. This work provides an early example of the application of mass spectrometry to DNA biochips and may substantially expand the applications of the now common oligonucleotide arrays.

A norsesquiterpene lactone and a benzoic acid derivative from the leaves of Cyclocarya paliurus and their glucosidase and glycogen phosphorylase inhibiting activities

Two novel compounds, 3-methoxypterolactone ( 1) and 2-amino-3,4-dihydroxy-5-methoxybenzoic acid ( 2), were isolated from leaves of Cyclocarya paliurus (Batal.) Iljinsk, together with nine known compounds: pterolactone ( 3), gallic acid ( 4), 4-hydroxy-3-methoxybenzoic acid ( 5), oleanolic acid ( 6), beta-boswellic acid ( 7), alpha-boswellic acid ( 8), beta-amyrin ( 9), beta-amyrone ( 10) and 3beta-O-trans-caffeoyl-morolic acid ( 11). The structure elucidation was based on spectroscopic methods, including two-dimensional NMR experiments ( (1)H- (1)H COSY, HMQC and HMBC). All isolated compounds were evaluated for their glycosidase and glycogen phosphorylase inhibitory activities. 2-Amino-3,4-dihydroxy-5-methoxybenzoic acid and gallic acid showed significant alpha-glucosidase and glycogen phosphorylase inhibitory activities.

Pulsatile release of parathyroid hormone from an implantable delivery system

Intermittent (pulsatile) administration of parathyroid hormone (PTH) is known to improve bone micro-architecture, mineral density and strength. Therefore, daily injection of PTH has been clinically used for the treatment of osteoporosis. However, this regimen of administration is not convenient and is not a favorable choice of patients. In this study, an implantable delivery system has been developed to achieve pulsatile release of PTH. A well-defined cylindrical device was first fabricated with a biodegradable polymer, poly(l-lactic acid) (PLLA), using a reverse solid-free form fabrication technique. Three-component polyanhydrides composed of sebacic acid, 1,3-bis(p-carboxyphenoxy) propane and poly(ethylene glycol) were synthesized and used as isolation layers. The polyanhydride isolation layers and PTH-loaded alginate layers were then stacked alternately within the delivery device. The gap between the stacked PTH-releasing core and the device frame was filled with PLLA to seal. Multi-pulse PTH release was achieved using the implantable device. The lag time between two adjacent pulses were modulated by the composition and the film thickness of the polyanhydride. The released PTH was demonstrated to be biologically active using an in vitro assay. Timed sequential release of multiple drugs has also been demonstrated. The implantable device holds promise for both systemic and local therapies.

Terbium Luminescence Sensitized through Three-Photon Excitation in a Self-Assembled Unlinked Antenna

The organic-terbium hybrid compound designed with the azido molecule L, 2-methoxy benzoic acid tris-(2-methoxybenzoyl)hydrazide, exhibits three-photon-excited green emission as well as second-harmonic generation even though the antenna is unlinked from the metal center.

Synthesis and Erosion Properties of PEG-Containing Polyanhydrides

To tailor the erosion rate of polyanhydrides while retaining their surface erosion characteristics, new three-component polyanhydrides of sebacic acid, 1,3-bis(p-carboxyphenoxy)propane and poly(ethylene glycol) were synthesized. The hydrophilicity of the polymer increased and its mechanical strength decreased with increasing PEG content. Correspondingly, the erosion rate increases with increasing PEG content, whereas it decreases with increasing specimen thickness. This indicates that the incorporation of poly(ethylene glycol) into traditional two-component polyanhydrides retains their surface erosion properties while making the erosion rate tunable. The new polyanhydrides hold potential for drug delivery applications.

4-(Pyrrolidinyl)methoxybenzoic acid derivatives as a potent, orally active VLA-4 antagonist

A novel series of benzoic acid derivatives as VLA-4 antagonists were synthesized. Optimization, focusing on activity and lipophilicity needed for cell permeability, resulted in the identification of 15b and 15e with good activity (IC50 = 1.6 nM each) and moderate lipophilicity (Log D = 2.0, 1.8). Furthermore, 15e demonstrated efficacy in murine asthma model by an oral dose of 30 mg/kg.

Evaluation of Matrix Effects in Metabolite Profiling Based on Capillary Liquid Chromatography Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry

The coupling of liquid chromatography to electrospray ionization quadrupole time-of-flight mass spectrometry can be a powerful tool for metabolomics, i.e., the comprehensive detection of low molecular weight compounds in biological systems. There have, however, been doubts about the feasibility and reliability of this approach, because LC-MS--especially with electrospray ionization--can be subject to matrix effects. We evaluated matrix effects for our metabolomics platform in three ways: (i) postextraction addition of a set of reference compounds to different complex biological matrixes to determine absolute and relative matrix effects, (ii) postcolumn infusion of two reference compounds, and (iii) mixing of two complex matrixes. Our data demonstrate that there are indeed significant absolute matrix effects when comparing highly divergent samples. However, relative matrix effects are negligible--unless extremely divergent matrixes are compared--and do not compromise the relative quantification that is aimed for in nontargeted metabolomics studies. In conclusion, employing LC-coupled ESI-QTOF-MS for metabolomics studies is feasible yet rigorous validation is necessary.

Aminodeoxychorismate Synthase Inhibitors from One-Bead One-Compound Combinatorial Libraries: “Staged” Inhibitor Design

4-Amino-4-deoxychorismate synthase (ADCS) catalyzes the first step in the conversion of chorismate into p-aminobenzoate, which is incorporated into folic acid. We aim to discover compounds that inhibit ADCS and serve as leads for a new class of antimicrobial compounds. This report presents (1) synthesis of a mass-tag encoded library based on a "staged" design, (2) massively parallel fluorescence-based on-bead screening, (3) rapid structural identification of hits, and (4) full kinetic analysis of ADCS. All inhibitors are competitive against chorismate and Mg(2+). The most potent ADCS inhibitor identified has a K(i) of 360 microM. We show that the combinatorial diversity elements add substantial binding affinity by interacting with residues outside of but proximal to the active site. The methods presented here constitute a paradigm for inhibitor discovery through active site targeting, enabled by rapid library synthesis, facile massively parallel screening, and straightforward hit identification.

Qualitative and quantitative analysis of the active components of the essential oil from Brickellia veronicaefolia by nuclear magnetic resonance spectroscopy

The composition of the spasmolytic essential oil of the medicinal species Brickellia veronicaefolia was established by NMR spectroscopy in addition to GC-MS analysis and HPLC studies. Seven major compounds, representing ca. 86% of the oil, were identified as benzyl 2,6-dimethoxybenzoate (1), 2-hydroxybenzyl 2'-methoxybenzoate (2), chamazulene (3), beta-caryophyllene (4), germacrene D (5), bicyclogermacrene (6), and beta-eudesmol (7). A sensitive and accurate analytical 1H NMR method has been developed for the quantification of the major compounds in the essential oil of B. veronicaefolia. The method was validated using benzyl 2,6-dimethoxybenzoate (1) and beta-caryophyllene (4), two of the active principles in the oil, and successfully applied to the determination of these pharmacologically active compounds in three different batches of the oil collected in different geographical regions and/or seasons.

Chemical constituents of the Vietnamese inedible mushroomXylaria intracolorata

Investigation of the methanolic extract of Vietnamese inedible Xylariaceous mushroom Xylaria intracolorata resulted in the isolation of two new compounds named coloratin A [3,5-dimethoxy-2-(6-oxo-5-pentyl-6H-pyran-3-carbonyl)-benzoic acid] (1) and coloratin B (2-carbomethoxyl-3,5-dimethoxybenzoic acid) (2). Their structures were elucidated by 2D-NMR, MS, IR, and UV spectroscopy. Coloratin A (1) showed strong antimicrobial activity.

Third calcium ion found in an inhibitor-bound phospholipase A2

The lipolytic enzyme phospholipase A2 plays a crucial role in lipid metabolism and catalyzes hydrolysis of the fatty-acid ester bond at the sn-2 position of phospholipids. Here, the crystal structure (1.7 A resolution) of the triple mutant (K53,56,121M) of bovine pancreatic phospholipase A2 complexed with an organic molecule, p-methoxybenzoic acid (anisic acid), is reported. Residues 60-70 (the surface-loop residues) are ordered and adopt conformations which are different from those normally found in structures in which a second calcium ion is present. It is interesting to note that for the first time a third calcium ion has been identified. In addition, four Tris (2-amino-2-hydroxymethyl-1,3-propanediol) molecules were located. It is believed that one of the Tris molecules plays a role in clamping the third calcium ion and that another is involved in controlling the dynamics of the surface loop through hydrogen bonds.

Kinetics of thermal decomposition of 4-carboxyl-2,6-dinitrobenzenediazonium ion (CDNBD)

The kinetics of thermal decomposition of 4-carboxyl-2,6-dinitrobenzenediazonium ion (CDNBD), an arenediazonium ion newly developed as a derivatizing reagent for drug analysis, are described. The arenediazonium ion, in an optimized concentrated sulfuric acid/orthophosphoric acid medium, was incubated for various time intervals at 30 degrees, 45 degrees, 55 degrees , 65 degrees , 75 degrees, and 85 degrees C. The amount of ion left after each time interval was quantified selectively by colorimetric assay at 490 nm, using mefenamic acid as a model diazo-coupling component. The rate constants for the decomposition were determined graphically. An Arrhenius plot was used to delineate the dependence of the rate constant on temperature and to predict the half-life at 25 degrees C and lower temperatures. The diazonium ion decomposed by first-order kinetics. The rate constants of decomposition, which increased progressively with temperature, were 3.18 +/- 0.41 x 10(-5), 1.19 +/- 0.07 x 10(-4), 4.87 +/- 0.15 x 10(-4), 12.88 +/- 0.73 x 10(-4), and 21.32 +/- 2.74 x 10(-4) (s(-1)) with corresponding half-lives of 363, 97.06, 23.72, 8.97, and 5.42 min at 30 degrees, 45 degrees, 55 degrees, 65 degrees, and 75 degrees C, respectively. CDNBD is highly stable in concentrated acid medium, with half-life values of about 10 h, 10 days, and 7.3 months at 25 degrees, 0 degrees, and -20 degrees C, respectively. The reagent stability profile shows that it could be readily adapted for routine applications in instrumental chemical analysis.

Aspergillus fumigatus CY018, an endophytic fungus in Cynodon dactylon as a versatile producer of new and bioactive metabolites

Aspergillus fumigatus CY018 was recognized as an endophytic fungus for the first time in the leaf of Cynodon dactylon. By bioassay-guided fractionation, the EtOAc extract of a solid-matrix steady culture of this fungus afforded two new metabolites, named asperfumoid (1) and asperfumin (2), together with six known bioactive compounds including monomethylsulochrin, fumigaclavine C, fumitremorgin C, physcion, helvolic acid and 5alpha,8alpha-epidioxy-ergosta-6,22-diene-3beta-ol as well as other four known compounds ergosta-4,22-diene-3beta-ol, ergosterol, cyclo(Ala-Leu) and cyclo(Ala-Ile). Through detailed spectroscopic analyses including HRESI-MS, homo- and hetero-nuclear correlation NMR experiments (HMQC, COSY, NOESY and HMBC), the structures of asperfumoid and asperfumin were established to be spiro-(3-hydroxyl-2,6-dimethoxyl-2,5-diene-4-cyclohexone-(1,3')-5'-methoxyl-7'-methyl-(1'H, 2'H, 4'H)-quinoline-2',4'-dione) and 5-hydroxyl-2-(6-hydroxyl-2-methoxyl-4-methylbenzoyl)-3,6-dimethoxyl-benzoic methyl ester, respectively. All of the 12 isolates were subjected to in vitro bioactive assays against three human pathogenic fungi Candida albicans, Tricophyton rubrum and Aspergillus niger. As a result, asperfumoid, fumigaclavine C, fumitremorgin C, physcion and helvolic acid were shown to inhibit C. albicans with MICs of 75.0, 31.5, 62.5, 125.0 and 31.5 microg/mL, respectively.

Synthesis and in vitro evaluation of (S)-2-([11C]methoxy)-4-[3-methyl-1-(2-piperidine-1-yl-phenyl)-butyl-carbamoyl]-benzoic acid ([11C]methoxy-repaglinide): a potential beta-cell imaging agent

The 11C-labeled sulfonylurea receptor 1 (SUR1) ligand (S)-2-([11C]methoxy)-4-[3-methyl-1-(2-piperidine-1-yl-phenyl)-butyl-carbamoyl]-benzoic acid ([11C]methoxy-repaglinide) was synthesized in an overall radiochemical yield of 35% after 55 min with a radiochemical purity higher than 99%. This compound is considered for the noninvasive investigation of the SUR1 receptor status of pancreatic beta-cells by positron emission tomography (PET) in the context of type 1 and type 2 diabetes. The specific activity was 40-70 GBq/micromol. In vitro testing of the nonradioactive methoxy-repaglinide was performed to characterize the affinity for binding to the human SUR1 isoform. Methoxy-repaglinide induced a complete monophasic inhibition curve with a Hill coefficient close to 1 (1.03) yielding a dissociation constant (KD) of 83 nM and an IC50 of 163 nM. Insulin secretion experiments on isolated rat islets were performed to prove biological activity, which was determined to be in the same range as that of original repaglinide.

Synthesis and characterization of polyanhydride for local BCNU delivery carriers

p-Carboxyphenoxy propane (CPP) prepolymer consisting of 4 units and sebacic acid (SA) prepolymer consisting of about 10 units were synthesized by reacting CPP and SA in the presence of excess acetic anhydride, respectively. Polyanhydride, poly(CPP-SA) copolymers were copolymerized by a melt polycondensation process with a mixture of CPP and SA prepolymer. Copolymers of average molecular weight up to 110,000 g/mol were achieved. The crystallinity of poly(CPP-SA) copolymers was decreased by the addition of the CPP homopolymer segment to SA homopolymer. Poly(CPP-SA) copolymers gradually degraded for period of 10 days. No large difference of weight loss observed according to molecular weight variation of poly(CPP-SA) copolymers. BCNU release from wafers fabricated by poly(CPP-SA) showed a sustained release pattern with no initial burst and delay of drug release.

Effects of a Novel Anti-Hyperlipidemic Agent, S-2E, on Blood Lipid Levels in Rats with Fructose-Induced Hypertriglyceridemia

Using rats with fructose-induced hypertriglyceridemia, an animal model of human hypertriglyceridemia, we investigated whether (+)-(S)-p-[1-(p-tert-butylphenyl)-2-oxo-4-pyrrolidinyl]-methoxybenzoic acid (S-2E), a novel anti-hyperlipidemic agent, reduced the elevated levels of triglyceride (TG) and non-high-density lipoprotein cholesterol (non-HDL-C), and then whether it elevated HDL-C levels. At doses of 3-30 mg/kg, S-2E reduced elevated TG levels and non-HDL-C levels simultaneously in a dose-dependent manner after a week. Furthermore, S-2E treatment at 10 mg/kg for 4 weeks showed similar effects, while the elongation of intervals between feeding periods led to further increases in these levels. Interestingly, S-2E increased blood HDL-C levels after 4 weeks of treatment. It is therefore reasonable to assume that S-2E may be useful to improve dyslipidemia such as hypertriglyceridemia and low levels of HDL-C.

Occupational Exposure to Aromatic Hydrocarbons at a Coke Plant: Part I. Identification of Hydrocarbons in Air and their Metabolites in Urine by a Gas Chromatography‐Mass Spectrometry Method

A method for the qualitative analysis of aromatic hydrocarbons in air and their various urinary metabolites is presented. The air was sampled in charcoal tubes and extracted with carbon disulfide. The hydrocarbons were identified as being aliphatic hydrocarbons (C(9)-C(19)), aromatic hydrocarbons and heterocyclic compounds. The urinary metabolites after enzymatic hydrolysis were analyzed by solid-phase extraction with a styrene-divinylbenzene resin, silylation with N,O-bis(trimethylsilyl)acetamide and GC/MS for separation and detection. Satisfactory separation of all compounds investigated was achieved without interference due to matrix peaks. The following compounds were identified in the urine of workers: dimethylphenol isomers, 4-ethyl-1,3-benzenediol, 2-ethoxybenzoic acid and methoxyphenols. Trimethylsilyl derivatives of aromatic hydroxyacids and hydroxymethoxyacids were found in the urine of occupationally exposed workers by means of a silylation procedure.

Synthesis and biological evaluation of neutrophilic inflammation inhibitors

In several non-infectious human diseases, such as ulcerous colitis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), the extravasal recruitment of neutrophils plays a crucial role in the development of tissue damage, which, when persistent, can lead to the irreversible organ dysfunction. The neutrophil activation is controlled by a number of intracellular pathways, particularly by a cAMP-dependent protein kinase A (PKA) which also acts on phosphodiesterase IV (PDE4) gene stimulating the synthesis of this enzyme, able to transform cAMP to inactive AMP. PDE4 inhibitors enhance intracellular cAMP and decrease inflammatory cell activation. Several 3-cyclopentyloxy-4-methoxybenzaldehyde and 3-cyclopentyloxy-4-methoxybenzoic acid derivatives were synthesized and studied by us to evaluate their ability to inhibit the superoxide anion production in human neutrophils. These compounds were found able to inhibit the neutrophil activation and some of them increased the cAMP level on tumor necrosis factor-alpha-stimulated neutrophils. Moreover, they also inhibited selectively the human PDE4 enzyme, although they are less potent than the reference compound Rolipram. We report here synthesis, biological studies and some SAR considerations concerning the above mentioned compounds.

Effects of a novel antihyperlipidemic agent, S-2E, on the blood lipid abnormalities in homozygous WHHL rabbits

To improve mixed hyperlipidemia in the low-density lipoprotein (LDL) receptor-deficient state, suppression of very-low-density lipoprotein (VLDL) particle production may be an important approach. We previously reported that S-2E, (+)-(S)-p-[1-(p-tert-butylphenyl)-2-oxo-4-pyrrolidinyl] methoxybenzoic acid, suppressed VLDL particle production by inhibiting the biosynthesis of both sterol and fatty acids in the liver. We therefore examined whether S-2E lowered the blood cholesterol and triglyceride (TG) levels simultaneously in homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits, which correspond to human familial hypercholesterolemia. S-2E given orally at doses of 30 to 300 mg/kg significantly lowered serum total cholesterol (TC) levels at 1 week as well as TG at 2 weeks, and the lowering of TC and TG levels by S-2E reached a maximum at 3 to 4 weeks. In contrast, oral administration of pravastatin at doses of 10 to 100 mg/kg resulted in a significant suppression of TC levels (100 mg/kg) but not TG levels. Further analysis of the TC content in fractionated serum of control and S-2E-treated animals showed that suppression of TC level by S-2E is attributable to a decrease in the proportions of VLDL, intermediate-density lipoprotein (IDL), and LDL. It is, therefore, reasonable to assume that S-2E may be useful to improve the blood lipid abnormalities in the LDL receptor-deficient state.

Tyrosinase inhibition kinetics of anisic acid

Anisic acid (p-methoxybenzoic acid) was characterized as a tyrosinase inhibitor from ani-seed, a common food spice. It inhibited the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) catalyzed by tyrosinase with an IC50 of 0.60 mM. The inhibition of tyrosinase by anisic acid is a reversible reaction with residual enzyme activity. This phenolic acid was found to be a classical noncompetitive inhibitor and the inhibition constant K(I) was obtained as 0.603 mM. Anisic acid also inhibited the hydroxylation of L-tyrosine catalyzed by tyrosinase. The lag phase caused by the monophenolase activity was lengthened and the steady-state activity of the enzyme was decreased by anisic acid.

Crystal structures of the free and anisic acid bound triple mutant of phospholipase A2

Phospholipase A2 catalyses the hydrolysis of the ester bond of 3-sn-phosphoglycerides. Here, we report the crystal structures of the free and anisic acid-bound triple mutant (K53,56,120M) of bovine pancreatic phospholipase A2. In the bound triple mutant structure, the small organic molecule p-anisic acid is found in the active site, and one of the carboxylate oxygen atoms is coordinated to the functionally important primary calcium ion. The other carboxylate oxygen atom is hydrogen bonded to the phenolic hydroxyl group of Tyr69. In addition, the bound anisic acid molecule replaces one of the functionally important water molecules in the active site. The residues 60-70, which are in a loop (surface loop), are disordered in most of the bovine pancreatic phospholipase A2 structures. It is interesting to note that these residues are ordered in the bound triple mutant structure but are disordered in the free triple mutant structure. The organic crystallization ingredient 2-methyl-2,4-pentanediol is found near the active site of the free triple mutant structure. The overall tertiary folding and stereochemical parameters for the final models of the free and anisic acid-bound triple mutant are virtually identical.

Anti-hyperlipidemic action of a newly synthesized benzoic acid derivative, S-2E

A newly synthesized benzoic acid derivative, (+)-(S)-p-[1-(p-tert-butylphenyl)-2-oxo-4-pyrrolidinyl]methoxybenzoic acid (S-2E), has the capacity to inhibit the biosynthesis of both sterol and fatty acids. Here, we report the mechanism by which S-2E lowers blood cholesterol and triglyceride levels. In the liver, S-2E was converted into its active metabolite, S-2E-CoA. S-2E-CoA noncompetitively inhibited the enzymatic activities of both 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase and acetyl-CoA carboxylase at K(i)=18.11 microM and K(i)=69.2 microM, respectively. Interestingly, pharmacokinetic experiments in rats showed that the concentration of S-2E-CoA in the liver was sufficient to inhibit the activities of HMG-CoA reductase and acetyl-CoA carboxylase, for example, when orally given to rats at 10 mg/kg. Indeed, S-2E (3-30 mg/kg) given orally suppressed the secretion rate of very-low-density lipoprotein (VLDL)-cholesterol and triglyceride in Triton WR-1339-injected rats. Furthermore, S-2E lowered the blood total cholesterol and triglyceride levels simultaneously in Zucker fatty rats. Collectively, S-2E may be useful in the treatment of familial hypercholesterolemia and mixed hyperlipidemia.

Synthesis and inverse electron demand Diels-Alder reactions of 3,6-bis(3,4-dimethoxybenzoyl)-1,2,4,5-tetrazine

The synthesis of 3,6-bis(3,4-dimethoxybenzoyl)-1,2,4,5-tetrazine (2) and the scope of its reactivity in inverse electron demand Diels-Alder reactions are disclosed representing the first systematic study of the [4 + 2] cycloaddition reactions of 3,6-diacyl-1,2,4,5-tetrazines.

The comparative sealing ability of hydroxyapatite cement, mineral trioxide aggregate, and super ethoxybenzoic acid as root-end filling materials

A comparison was made of the ability of hydroxyapatite cement, mineral trioxide aggregate, and super ethoxybenzoic acid to prevent the leakage of bacteria from root canals, when used as root-end filling materials. The materials were tested in a double-chamber device in which a root segment connects the upper (delivery) chamber and the lower (receiving) chamber. The root segment was prepared by having the root canal instrumented to a #45 file, and a 3-mm-deep, root-end preparation placed at the apical foramen. The canal of each root segment was filled with gutta-percha, and the root-end preparation was filled with one of three test materials, mixed according to the manufacturer's directions. Negative controls were constructed with sticky wax sealing the apical foramen. A titered suspension of radioactively (3H-thymidine)-labeled bacteria (Enterococcus fecalis) was placed into the delivery chamber, and sterile saline was placed into the receiving chamber such that the apical third of each root section was immersed. At various time points, samples were taken from the receiving chamber, and measured for 3H activity. The results indicated that (a) all the test materials leaked significantly compared with the negative controls; and (b) there was no significant difference found between the leakage rates of the three materials tested.

Interaction between 2-ethoxybenzoic acid (EBA) and eugenol, and related changes in cytotoxicity

The liquid of 2-ethoxybenzoic acid cements is composed of 2-ethoxybenzoic acid and eugenol (4-allyl-2-methoxyphenol). Recently, eugenol was reported to produce radicals at a higher pH, which consequently directly damages cells. We examined here whether eugenol radicals are generated from the mixture of eugenol/calcium hydroxide, and also whether 2-ethoxybenzoic acid or acetylsalicylic acid scavenges radicals, using electron spin resonance spectroscopy. Radicals were generated from the mixture of eugenol/calcium hydroxide in 50% dimethylsulfoxide solution. The radical intensity of eugenol in 50% dimethylsulfoxide with 0.1 M sodium bicarbonate buffer (pH 9.5) was dose-dependently reduced by 2-ethoxybenzoic acid, whereas it was enhanced by acetylsalicylic acid. Next, we investigated the cytotoxic effect of eugenol on 2-ethoxybenzoic acid, acetylsalicylic acid, or calcium hydroxide on human pulp fibroblasts or a human submandibular gland cancer cell line. The cytotoxicity of EBA was decreased, whereas that of acetylsalicylic acid was increased by eugenol. In contrast, that of calcium hydroxide was not affected by eugenol. Human pulp fibroblast but not human submandibular gland cells showed a high resistance against calcium hydroxide. The generation of eugenol radicals in the liquid of 2-ethoxybenzoic acid cements caused by oxidation may be suppressed by 2-ethoxybenzoic acid.

Isolation and characterization of efficient isoxaben-transforming Microbacterium sp strains from four European soils

Nutrient-agar plates containing isoxaben (500 mg litre(-1)) were used to isolate isoxaben-metabolising bacteria from four European soils incubated with the herbicide under laboratory conditions. In flask experiments, inoculation of a basal salts medium containing nitrogen and [phenyl-U-14C]isoxaben with an isolate (B2b) resulted in 33% recovery of the initial radioactivity as [14C]carbon dioxide after 2 weeks. A major metabolite identified by GC-MS and NMR analysis as 3-(1-ethyl-1-methylpropyl)isoxazol-5-ylamine accumulated both in basal salts and nutrient broth media. 2,6-Dimethoxybenzoic acid, a suspected metabolite of isoxaben, was not detected in either liquid media. However, the capability of the B2b isolate to use 2,6-dimethoxybenzoic acid as a source of carbon was demonstrated. Soil inoculation with the B2b strain resulted in an increase in the recovery of [14C] carbon dioxide from both [phenyl-U-14C] and [isoxazole-5-14C]isoxaben. The metabolite identified as 3-(1-ethyl-1-methylpropyl)isoxazole-5-ylamine only accumulated if the soil was autoclaved before inoculation. This metabolite was rapidly mineralized by the microflora of a natural soil without history of isoxaben treatment. Homology patterns of sequenced 16S rDNA between isoxaben-transforming isolates and reference strains showed that the four isolates identified belonged to the genus Microbacterium.

Two diphenylpropan-1,2-diol syringates from the roots of Erythrina variegata

Two new diphenylpropan-1,2-diols, eryvarinols A (1) and B (2), were isolated from the roots of Erythrina variegata. Their structures were elucidated as 1-(4-hydroxy-2-methoxyphenyl)-2-(4-hydroxy-3,5-dimethoxybenzoyloxy)-3-(4-hydroxyphenyl)propan-1-ol (1) and its 3"-prenyl derivative (2) on the basis of spectroscopic and chemical evidence. Both these compounds are unusual diphenylpropan-1,2-diols with a syringyl group.

A retrospective study of pulpal response in vital adult teeth prepared for complete coverage restorations at ultrahigh speed using only air coolant

STATEMENT OF PROBLEM

The dental literature has shown a 3% to 25% pulpal necrosis rate as a result of tooth preparation for complete coverage restorations.

PURPOSE

The purpose of this retrospective study was to examine clinical and radiographic records for evidence of pulpal necrosis in teeth prepared for complete coverage restorations at ultrahigh speed when air coolant alone was used.

MATERIAL AND METHODS

The 1847 teeth in this study (182 fixed partial denture abutment teeth and 1665 single teeth restored with 21 all-ceramic, 1095 metal-ceramic, and 731 all-metal restorations) were prepared with diamond instruments (burs) in a sweeping or painting motion with the use of light pressure (1-3 oz) at ultrahigh speed with air coolant alone from the handpiece. New burs were used for each patient and then discarded. Each bur was used on no more than 4 teeth. All impressions were made with reversible hydrocolloid. Provisional restorations were fabricated on a stone cast and cemented with zinc oxide and eugenol cement. Provisional restorations were removed at 3 to 4 weeks and definitive restorations placed. Between 1970 and 1989, 6 different luting agents (zinc phosphate, resin, glass ionomer, ortho-ethoxybenzoic acid, carboxylate, and polycarboxylate) were used to place definitive restorations. All patients were questioned about symptoms of tooth sensitivity, tenderness, or pain at their regular (4- to 6-month) hygiene recall appointments. Success was defined as any definitively restored teeth that remained free of radiographic evidence of periapical radiolucency and clinical signs and symptoms of pulpal sensitivity or pain recorded in the clinical record. The results were compared with rates of pulpal necrosis for teeth prepared with water coolant as reported in the dental literature published between 1970 and 1997.

RESULTS

Of 638 teeth prepared between 1970 and 1979, the pulpal necrosis rate was 2.19% (14 teeth: 12 single teeth and 2 fixed partial denture abutment teeth) (97.81% success rate). Of 1209 teeth prepared between 1980 and 1989, the pulpal necrosis rate was 0.66% (8 teeth: 7 single crown teeth and 1 partial denture abutment tooth) (99.34% success rate). Of 1825 teeth prepared between 1970 and 1989, radiographic evidence of pulpal necrosis was found in 0% (100% success rate). No clinical symptoms of pain or sensitivity were recorded in the patient records for the surviving teeth during the time period of this study, which was conducted in May 2001. No crowns were repaired or removed as a result of carious lesions. No higher incidence of pulpal necrosis relative to the type of luting agent was observed.

CONCLUSION

Within the limitations of this retrospective study, it is suggested that tooth reduction procedures can be completed with minimal damage to the pulp when only air coolant from the dental handpiece is used.

Four new compounds from the seeds of Cassia fistula

Four new compounds, 5-(2-hydroxyphenoxymethyl)furfural (1), (2'S)-7-hydroxy-5- hydroxymethyl-2-(2'-hydroxypropyl)chromone (2), benzyl 2-hydroxy-3,6-dimethoxybenzoate (3), and benzyl 2beta-O-D-glucopyranosyl-3,6-dimethoxybenzoate (4), together with four known compounds, 5-hydroxymethylfurfural, (2'S)-7-hydroxy-2-(2'-hydroxypropyl)-5-methylchromone, and two oxyanthraquinones, chrysophanol and chrysophanein, were isolated and identified from the seeds of Cassia fistula. The structures of 1-4 were determined on the basis of spectral data explanation, and the synthesis of compound 1 was carried out.

New furanoid diterpenes from Caesalpinia pulcherrima

Four new cassane-type furanoditerpenoids (1-4) were isolated from the air-dried leaves of Caesalpinia pulcherrima. Their structures were elucidated by spectral data interpretation. The exocyclic methylene compound 1 readily isomerized and oxidized to the benzofuran 4. Benzyl 2,6-dimethoxybenzoate (5) was also identified in this study. Antimicrobial tests on 1-5 indicated that they were active against several bacteria (S. aureus, E. coli, P. aeruginosa, and B. subtilis) and fungi (C. albicans and T. mentagrophytes).

The trans-anethole degradation pathway in an Arthrobacter sp

A bacterial strain (TA13) capable of utilizing t-anethole as the sole carbon source was isolated from soil. The strain was identified as Arthrobacter aurescens based on its 16 S rRNA gene sequence. Key steps of the degradation pathway of t-anethole were identified by the use of t-anethole-blocked mutants and specific inducible enzymatic activities. In addition to t-anethole, strain TA13 is capable of utilizing anisic acid, anisaldehyde, and anisic alcohol as the sole carbon source. t-Anethole-blocked mutants were obtained following mutagenesis and penicillin enrichment. Some of these blocked mutants, accumulated in the presence of t-anethole quantitative amounts of t-anethole-diol, anisic acid, and 4,6-dicarboxy-2-pyrone and traces of anisic alcohol and anisaldehyde. Enzymatic activities induced by t-anethole included: 4-methoxybenzoate O-demethylase, p-hydroxybenzoate 3-hydroxylase, and protocatechuate-4,5-dioxygenase. These findings indicate that t-anethole is metabolized to protocatechuic acid through t-anethole-diol, anisaldehyde, anisic acid, and p-hydroxybenzoic acid. The protocatechuic acid is then cleaved by protocatechuate-4,5-dioxygenase to yield 2-hydroxy-4-carboxy muconate-semialdehyde. Results from inducible uptake ability and enzymatic assays indicate that at least three regulatory units are involved in the t-anethole degradation pathway. These findings provide new routes for environmental friendly production processes of valuable aromatic chemicals via bioconversion of phenylpropenoids.

New 4-methoxybenzoyl derivatives from the ascidian Polycarpa aurata

From the hydrophilic extract of the ascidian Polycarpa aurata three new compounds, N-(4-methoxybenzoyl)-N'-methylguanidine (1), butyl 2-(4-methoxyphenyl)-2-oxoacetate (2), and 2-(4-methoxyphenyl)-N-methyl-2-oxoacetamide (3), together with the known compounds methyl 2-(4-methoxyphenyl)-2-oxoacetate (4) and 4-methoxybenzoic acid were isolated. The structures of all isolates were determined from their spectroscopic data (NMR, MS, IR, UV).

Aniracetam enhances cortical dopamine and serotonin release via cholinergic and glutamatergic mechanisms in SHRSP

Aniracetam, a cognition enhancer, has been recently found to preferentially increase extracellular levels of dopamine (DA) and serotonin (5-HT) in the prefrontal cortex (PFC), basolateral amygdala and dorsal hippocampus of the mesocorticolimbic system in stroke-prone spontaneously hypertensive rats. In the present study, we aimed to identify actually active substances among aniracetam and its major metabolites and to clarify the mode of action in DA and 5-HT release in the PFC. Local perfusion of mecamylamine, a nicotinic acetylcholine (nACh) and N-methyl-D-aspartate (NMDA) receptor antagonist, into the ventral tegmental area (VTA) and dorsal raphe nucleus (DRN) completely blocked DA and 5-HT release, respectively, in the PFC elicited by orally administered aniracetam. The effects of aniracetam were mimicked by local perfusion of N-anisoyl-gamma-aminobutyric acid [corrected] (N-anisoyl-GABA), one of the major metabolites of aniracetam, into the VTA and DRN. The cortical DA release induced by N-anisoyl-GABA applied to the VTA was also completely abolished by co-perfusion of mecamylamine. Additionally, when p-anisic acid, another metabolite of aniracetam, and N-anisoyl-GABA were locally perfused into the PFC, they induced DA and 5-HT release in the same region, respectively. These results indicate that aniracetam enhances DA and 5-HT release by mainly mediating the action of N-anisoyl-GABA that targets not only somatodendritic nACh and NMDA receptors but also presynaptic nACh receptors.

Heliotropium huascoense resin exudate: chemical constituents and defensive properties

From the resinous exudate of Heliotropium huascoense a new compound, rel-(8R,9R)-carrizaloic acid, (1) (3-[rel-(8R,9R-9-hydroxy-9,13,13-trimethyl-12-oxo-10-cyclohexenyl)methyl]-4-methoxybenzoic acid), and three known flavonoids, [3-methylgalangin, 3,7-dimethylgalangin, and (-)-alpinone] have been isolated. The structure of 1 was determined by spectral and chemical methods. Several plant defensive properties of 1 (insecticidal and antifungal) have been evaluated.

Degradation of o-methoxybenzoate by a two-member consortium made up of a gram-positive Arthrobacter strain and a gram-negative Pantotea strain

Aromatic carboxylic acids substituted with methoxylated groups are among the most abundant products in "alpechin", the wastes resulting from pressing olives to obtain olive oil. Degradation of o-methoxybenzoate by an stable consortium made of a gram positive bacterium, Arthrobacter oxydans, and gram negative one, Pantotea agglomerans, was shown to mineralize this compound efficiently. The concerted action of both microorganisms was needed for the two first steps in the process, namely, the conversion of o-methoxybenzoate into salycilate, and the hydroxylation of the latter to gentisate. Gentisate was further degraded by the Arthrobacter strain.

5-Methoxysalicylic acid and spermine: a new matrix for the matrix-assisted laser desorption/ionization mass spectrometry analysis of oligonucleotides

5-Methoxysalicylic acid (MSA) is demonstrated to be a useful matrix for matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry of oligonucleotides, when desorption/ionization without fragmentation is desired. When MSA is combined with the additive spermine, the need for desalting is reduced. The MSA/spermine matrix yields linear TOF mass spectra with improved resolution, less fragmentation, and less intense alkali ion adduct peaks than those spectra obtained using 3-hydroxypicolinic acid and 6-aza-2-thiothymine with spermine or diammonium hydrogen citrate as additives. Instrumental conditions are discussed to improve the spectral resolution, specifically the use of longer delay times in the delayed-extraction ion source.

Identification and effects of interaction phytotoxic compounds from exudate of Cistus ladanifer leaves

Eleven allelochemicals (ferulic acid, cinnamic acid, 4-hydroxybenzoic acid, hydroxycinnamic acid, methyl propionate, oxalic acid, methylmalonic acid, p-anisic acid, butyric acid, 3-hydroxybutyric acid, and azulene) were identified in the exudate of Cistus ladanifer L. We studied the effect of each on germination, cotyledon emergence, root length, and cotyledon length of Rumex crispus. Three groups were distinguished with respect to phytotoxic activity: compounds with low activity (ferulic acid, 4-hydroxybenzoic acid, oxalic acid, methylmalonic acid, p-anisic acid, hydroxybutyric acid, and azulene), with intermediate activity (cinnamic acid and hydroxycinnamic acid), and with high activity (methyl propionate and butyric acid). The effect of the interaction of the compounds was studied. When acting conjointly, all combinations tested produced a more negative effect on both germination and seedling growth than when acting alone. The interaction affected cotyledon emergence and root length more negatively than germination and cotyledon length. When hydroxycinnamic acid and cinnamic acid were added to these mixtures there was an enhancement in the phytotoxic activity, accentuating the effect of the other allelochemicals.

seco-Cyclothialidines: new concise synthesis, inhibitory activity toward bacterial and human DNA topoisomerases, and antibacterial properties

seco-Cyclothialidines are a promising class of bacterial DNA gyrase B subunit inhibitors. A new seco-cyclothialidine derivative containing a dioxazine moiety, BAY 50-7952, was synthesized through a new concise pathway. One key step of the synthesis is the straightforward formation of the 2-aminothiazole derivative of S-tritylcysteine. In biological tests, BAY 50-7952 and other known seco-cyclothialidines exhibited high and selective activity toward bacterial DNA gyrase and toward Gram-positive bacteria. The dioxazine moiety and other similar groups were found to be important for the ability of the seco-cyclothialidines to penetrate bacterial membranes. The opposite enantiomer ((S)-form) of BAY 50-7952 was also synthesized, and neither significant target activity nor in vitro antibacterial activity were found, suggesting a highly selective fit of the (R)-form. Despite promising in vitro activity, only poor activity was found in the murine infection model.

Tissue reactions after subcutaneous and intraosseous implantation of mineral trioxide aggregate and ethoxybenzoic acid cement

Biocompatibility of mineral trioxide aggregate and ethoxybenzoic acid cement was investigated by subcutaneous and intraosseous implantation of the materials in rats. Tissue reactions were studied at 15, 30, and 60 days after implantation. Subcutaneous implantation of mineral trioxide aggregate initially elicited severe reactions with coagulation necrosis and dystrophic calcification; the reactions, however, subsided to mostly moderate with time. Subcutaneous implantation of ethoxybenzoic acid cement initially elicited mostly moderate reactions that subsided to mild in time. Osteogenesis was not observed with either material upon subcutaneous implantation indicating that neither material is osteoinductive. Reactions to intraosseous implants of both materials were less intense than with subcutaneous implantation. Osteogenesis occurred in association with intraosseous implants indicating that both materials are osteoconductive.

Substrate and solvent isotope effects on the fate of the active oxygen species in substrate-modulated reactions of putidamonooxin

Using 4-methoxybenzoate monooxygenase from Pseudomonas putida, the substrate deuterium isotope effect on product formation and the solvent isotope effect on the stoichiometry of oxygen uptake, NADH oxidation, product and/or H2O2 (D2O2) formation for tight couplers, partial uncouplers, and uncouplers as substrates were measured. These studies revealed for the true, intrinsic substrate deuterium isotope effect on the oxygenation reaction a k1H/k2H ratio of < 2.0, derived from the inter- and intramolecular substrate isotope effects. This value favours a concerted oxygenation mechanism of the substrate. Deuterium substitution in a tightly coupling substrate initiated a partial uncoupling of oxygen reduction and substrate oxygenation, with release of H2O2 corresponding to 20% of the overall oxygen uptake. This H2O2 (D2O2) formation (oxidase reaction) almost completely disappeared when the oxygenase function was increased by deuterium substitution in the solvent. The electron transfer from NADH to oxygen, however, was not affected by deuterium substitution in the substrate and/or the solvent. With 4-trifluoromethylbenzoate as uncoupling substrate and D2O as solvent, a reduction (peroxidase reaction) of the active oxygen complex was initiated in consequence of its extended lifetime. These additional two electron-transfer reactions to the active oxygen complex were accompanied by a decrease of both NADH oxidation and oxygen uptake rates. These findings lead to the following conclusions: (a) under tightly coupling conditions the rate-limiting step must be the formation time and lifetime of an active transient intermediate within the ternary complex iron/peroxo/substrate, rather than an oxygenative attack on a suitable C-H bond or electron transfer from NADH to oxygen. Water is released after the monooxygenation reaction; (b) under uncoupling conditions there is competition in the detoxification of the active oxygen complex between its protonation (deuteronation), with formation of H2O2 (D2O2) and its further reduction to water. The additional two electron-transfer reactions onto the active oxygen complex then become rate limiting for the oxygen uptake rate.

Molecular mechanism of lung hemorrhage induction by VRV-PL-VIIIa from Russell's viper (Vipera russelli) venom

The basic phospholipase A(2) (VRV-PL-VIIIa) from Vipera russelli venom induces multiple toxic effects including neurotoxicity, myotoxicity, edema and hemorrhage. This phospholipase A(2) has been extensively characterized for its pharmacological properties except for hemorrhagic activity. In the present investigation, the lung hemorrhagic activity was assayed using lung dye diffusion method. The investigations to understand the mechanism of lung hemorrhage induction by VRV-PL-VIIIa was followed by chemical modification studies and also by interaction with an antihemorrhagic factor p-anisic acid (4-methoxy benzoic acid). In presence of 1:2 mol:mol PLA(2): anisic acid, the lung hemorrhagic and edema inducing activities were completely neutralized in experimental animals; however, catalytic and anticoagulant activities were not neutralized. Carbamylation of VRV-PL-VIIIa resulted in the loss of lung hemorrhage and edema inducing activities. In contrast, carbamylation of VRV-PL-VIIIa in the presence of anisic acid could not neutralize the lung hemorrhage and edema inducing activities. The anticoagulant and enzyme activities were only partially neutralized when carbamylated both in the presence and absence of anisic acid.

Reduction of aryl acids by white-rot fungi for the biocatalytic production of aryl aldehydes and alcohols

Ligninolytic basidiomycetes were screened for their ability to reduce aryl acids to the corresponding aldehydes and alcohols. Seven fungal strains converted p-anisic acid in high molar yields to the reduced products. The white-rot fungus Bjerkandera sp. strain BOS55 was one of the best reducing strains and was highly tolerant towards high concentrations of different aromatic acids. It was tested for the reduction of p-anisic, veratric, 3-chloro-4-methoxybenzoic, 3,5-dichloro-4-methoxybenzoic, 3,4-dichlorobenzoic, 4-fluorobenzoic, and 3-nitrobenzoic acids. All of these compounds were reduced to their corresponding aldehydes and alcohols.