Lignin-Derived Syringol and Acetosyringone from Palm Bunch Using Heterogeneous Oxidative Depolymerization over Mixed Metal Oxide Catalysts under Microwave Heating

Biomass valorization to building block chemicals in food and pharmaceutical industries has tremendously gained attention. To produce monophenolic compounds from palm empty fruit bunch (EFB), EFB was subjected to alkaline hydrothermal extraction using NaOH or K2CO3 as a promotor. Subsequently, EFB-derived lignin was subjected to an oxidative depolymerization using Cu(II) and Fe(III) mixed metal oxides catalyst supported on γ-Al2O3 or SiO2 as the catalyst in the presence of hydrogen peroxide. The highest percentage of total phenolic compounds of 63.87 wt% was obtained from microwave-induced oxidative degradation of K2CO3 extracted lignin catalyzed by Cu-Fe/SiO2 catalyst. Main products from the aforementioned condition included 27.29 wt% of 2,4-di-tert-butylphenol, 19.21 wt% of syringol, 9.36 wt% of acetosyringone, 3.69 wt% of acetovanillone, 2.16 wt% of syringaldehyde, and 2.16 wt% of vanillin. Although the total phenolic compound from Cu-Fe/Al2O3 catalyst was lower (49.52 wt%) compared with that from Cu-Fe/SiO2 catalyst (63.87 wt%), Cu-Fe/Al2O3 catalyst provided the greater selectivity of main two value-added products, syringol and acetosyrigone, at 54.64% and 23.65%, respectively (78.29% total selectivity of two products) from the NaOH extracted lignin. The findings suggested a promising method for syringol and acetosyringone production from the oxidative heterogeneous lignin depolymerization under low power intensity microwave heating within a short reaction time of 30 min.

Semiochemical signatures associated with differential attraction of Anopheles gambiae to human feet

BACKGROUND

Several human-produced volatiles have been reported to mediate the host-seeking process under laboratory conditions, yet no effective lure or repellent has been developed for field application. Previously, we found a gradation of the attractiveness of foot odors of different malaria free individuals to Anopheles gambiae sensu stricto Giles. In this study, foot odor of the individual with the most attractive 'smelly' feet to the An. gambiae was collected, analyzed and attractive blend components identified.

METHODS

The foot odor of the individual with the most attractive 'smelly' feet to the An. gambiae was trapped on Porapak Q and analyzed by gas chromatography-linked mass spectrometry (GC-MS). Specific constituents perceived by the insect olfactory system were then identified by GC-linked to electro-antennography detector (GC-EAD) and characterized by GC-MS. The contribution of each constituent to the behavioral response of An. gambiae was assessed through subtractive assays under semi-field conditions in a screen-house using Counter Flow Geometry (CFG traps) baited with (i) the blend of all the EAD-active and (ii) other blends containing all components with exclusion of one component at a time. The number of mosquitoes trapped in the baited CFG traps were compared with those in the control traps.

RESULTS

Eleven major and minor constituents: 2 carboxylic acids, six aldehydes, two ketones and one phenolic compound, were confirmed to be EAD-active. The contribution of each constituent to the behavioral response of An. gambiae was assessed through subtractive assays under semi- field conditions. Exclusion/ subtraction of one of the following compounds: i-butyric acid, i-valeric acid, n-octanal, n-nonanal, n-decanal, n-dodecanal, undecanal or n-tridecanal, from each blend led to reduction in the attractiveness of all the resulting blends, suggesting that all of them are critical/important for the attractiveness of the foot odor to An. gambiae mosquitoes. However, exclusion/subtraction of 4-ethoxyacetophenone, 4-ethylacetophenone and/or 2-methylphenol, led to significant enhancements in the attractiveness of the resulting blends, suggesting that each of these compounds had repellent effect on An. gambiae ss. Undecanal exhibited kairomonal activity at low natural concentrations under semi-field conditions but repellent activity at high unnatural conditions in the laboratory. Furthermore, the comparison of the mean mosquito catches in traps baited with the nine-component blend without 4-ethoxyacetophenone, 4-ethylacetophenone and the complete foot odor collection revealed that the former is significantly more attractive and confirmed the repellent effect of the two carbonyl compounds at low natural concentration levels.

CONCLUSION

These results suggest that differential attractiveness of An. gambiae to human feet is due to qualitative and/or qualitative differences in the chemical compositions of the foot odors from individual human beings and relative proportions of the two chemical signatures (attractants versus repellents) as observed from the ratios of the bioactive components in the foot odors of the most attractive and least attractive individuals. Chemical signature means the ensemble of the compounds released by the organism in a specific physiological state. The chemical signature is emitter-dependent, but does not depend on receiver response. Thus, there is only one chemical signature for one individual or species that may eventually include inactive, attractive and repellent components for another organism. The nine-component attractive blend has a potential as an effective field bait for trapping of malaria vectors in human dwellings.

Prenylated Acetophloroglucinol Dimers from Acronychia trifoliolata: Structure Elucidation and Total Synthesis

The isolation of 12 secondary metabolites, including seven new acetophenone monomers, from the 50% CH₃OH/CH₂Cl₂ extract (N089419-L/6) of Acronychia trifoliolata was reported previously. In the present work, three new prenylated acetophenone dimers (1-3) and five known dimers (4-8) were isolated, and their structures were elucidated by using various NMR spectroscopic techniques and HRMS. Among the new dimers, an unprecedented 4-isobutyl-3-isopropyltetrahydro-2H-pyran ring was observed in the structure of 1. This study is the first to report the formation of a 2H-pyran ring between two prenylated acetophloroglucinols. Only four related dimers have been reported before, and they were formylated phloroglucinol dimers from the family Eucalypteae. Compounds 2 and 3 are acrovestone-like dimers, and the structure of 3 was confirmed by total synthesis. The evaluation of the antiproliferative activity of isolated and synthesized acrovestone-like dimers indicated that a double bond in the prenyl-like moiety as found in the more active compounds might be important for mediating activity, while the pendant isobutyl group seems to be less important.

Stainless Steel Wire Mesh Supported Molecularly Imprinted Composite Membranes for Selective Separation of Ebracteolata Compound B from Euphorbia fischeriana

Stainless steel wire mesh supported molecularly imprinted composite membranes for selective separation of Ebracteolata Compound B (ECB) were prepared based on surface polymerization using ECB separated from Euphorbia fischeriana as a template, acrylamide as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, azodiisobutyronitrile as an initiator, and stainless steel wire mesh as support. Structure and purity of ECB were characterized by nuclear magenetic resonance (¹H-NMR, 13C-NMR) and ultra high performance liquid chromatography (UHPLC). The molecularly imprinted composite membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The membrane adsorbed on the ECB reached equilibrium about 30 min later, with a maximum adsorption amount of 3.39 μmol/cm². Adsorption behavior between ECB and the molecularly imprinted composite membranes followed pseudo-second-order kinetics equation and Freundlich isotherm model. The molecularly imprinted composite membranes that could selectively identify and transport ECB in similar structures have a permeation rate of 38.71% to ECB. The ECB content in the permeation solution derived from the extract of Euphorbia fischeriana through the imprinted membrane was 87%. Overall, the obtained results demonstrated that an efficient approach with the molecularly imprinted composite membranes for selective separation of ECB from Euphorbia fischeriana.

Preliminary Quality Evaluation and Characterization of Phenolic Constituents in Cynanchi Wilfordii Radix

A new phenolic compound, 2-O-β-laminaribiosyl-4-hydroxyacetophenone (1), was isolated from Cynanchi Wilfordii Radix (CWR, the root of Cynanchum wilfordii Hemsley), along with 10 known aromatic compounds, including cynandione A (2), bungeisides-C (7) and –D (8), p-hydroxyacetophenone (9), 2′,5′-dihydroxyacetophenone (10), and 2′,4′-dihydroxyacetophenone (11). The structure of the new compound (1) was elucidated using spectroscopic methods and chemical methods. The structure of cynandione A (2), including a linkage mode of the biphenyl parts that remained uncertain, was unambiguously confirmed using the 2D ¹³C–¹³C incredible natural abundance double quantum transfer experiment (INADEQUATE) spectrum. Additionally, health issues related to the use of Cynanchi Auriculati Radix (CAR, the root of Cynanchum auriculatum Royle ex Wight) instead of CWR have emerged. Therefore, constituents present in methanolic extracts of commercially available CWRs and CARs were examined using UV-sensitive high-performance liquid chromatography (HPLC), resulting in common detection of three major peaks ascribed to cynandione A (2), p-hydroxyacetophenone (9), and 2′,4′-dihydroxyacetophenone (11). Thus, to distinguish between these ingredients, a thin-layer chromatography (TLC) method, combined with only UV irradiation detection, focusing on wilfosides C1N (12) and K1N (13) as marker compounds characteristic of CAR, was performed. Furthermore, we propose this method as a simple and convenient strategy for the preliminary distinction of CWR and CAR to ensure the quality and safety of their crude drugs.

Evaluation of Dual 5-Lipoxygenase/Microsomal Prostaglandin E2 Synthase-1 Inhibitory Effect of Natural and Synthetic Acronychia-Type Isoprenylated Acetophenones

Among the pathways responsible for the development of inflammatory responses, the cyclooxygenase and lipoxygenase pathways are among the most important ones. Two key enzymes, namely, 5-LO and mPGES-1, are involved in the biosynthesis of leukotrienes and prostaglandins, respectively, which are considered attractive therapeutic targets, so their dual inhibition might be an effective strategy to control inflammatory deregulation. Several natural products have been identified as 5-LO inhibitors, with some also being dual 5-LO/mPGES-1 inhibitors. Here, some prenylated acetophenone dimers from Acronychia pedunculata have been identified for their dual inhibitory potency toward 5-LO and mPGES-1. To gain insight into the SAR of this family of natural products, the synthesis and biological evaluation of analogues are presented. The results show the ability of the natural and synthetic molecules to potently inhibit 5-LO and mPEGS-1 in vitro. The potency of the most active compound (10) has been evaluated in vivo in an acute inflammatory mouse model and displayed potent anti-inflammatory activity comparable in potency to the drug zileuton used as a positive control.

Apocynin derivatives from Iris tectorum

Phytochemical investigation of the rhizomes of Iris tectorum resulted in the isolation and characterization of three new apocynin derivatives, apocynin-4-O-β-D-(6'-O-syringyl)glucopyranoside (1), scrophenoside C-7-ethyl ether (2, 3), together with a new naturally occurring compound but known by synthesis, apocynin-4-O-β-D-xylopyranoside (4), and five known ones (5-9). Their structures were elucidated on the basis of spectroscopic data interpretation.

Acetophenone Monomers from Acronychia trifoliolata

Seven new [acronyculatins I-O (1-7)] and four known acetophenone monomers were isolated from a CH3OH/CH2Cl2 (1:1) extract (N089419) of Acronychia trifoliolata provided by the U.S. National Cancer Institute (NCI, Frederick, MD, USA). Their structures were characterized by using various NMR and HRMS techniques. Among the known compounds, the structure of acronyculatin B (8) was revised. Some of the isolated compounds were evaluated for antiproliferative activity against human cancer cell lines. While most of the tested compounds were not cytotoxic, acronyculatins I (1) and J (2) showed moderate antiproliferative activity.

[In vitro and in vivo recoveries of cutaneous micro-dialysis probe of paeonol, eugenol and piperine]

To establish a method for detecting micro-dialysis recovery of paeonol, eugenol and piperine in Huoxue Zhitong patch, in order to provide the basis for further percutaneous pharmacokinetics studies. The concentrations of paeonol, eugenol and piperine in dialysates were determined by HPLC, and probe deliveries were calculated respectively. The effects of concentration and calibration approaches on the micro-dialysis probe deliveries of the three components were investigated, and their probe absorbability, in vitro and in vivo probe stability and repeatability were also studied.The results indicated that little paeonol, eugenol and piperine were observed in probes with 30% alcohol as the perfusate, and could be cleaned from probe in a short time. And the in vivo and in vitro probe deliveries of three components were stable within 8 h, drug-containing solution and blank perfusate were alternatively used for three times, and the in vivo and in vitro probe deliveries of three components were basically unchanged. The in vitro recoveries of paeonol, eugenol and piperine with a range of concentration were respectively (45.7±4.66)%, (27.82±2.95)%, (41.3±3.96)%, which indicated no concentration independent. Under the same conditions, the similar delivery was observed by dialysis, retrodialysis and no-net flux. Therefore, the concentrations of analyses of the collected fraction could be calibrated by in vitro or in vivo recoveries. Meanwhile, this also proved that the micro-dialysis method built by this study is applicable to the study on percutaneous pharmacokinetics of Huoxue Zhitong patch.

Chemical constituents from Melicope pteleifolia leaves

Five acetophenones bearing spiroketal-hexofuranoside rings, one di-C-glycosidic acetophenone and two benzopyrans, along with 16 known compounds were isolated from the leaves of Melicope pteleifolia. Structures of all the isolates were elucidated using extensive spectroscopic methods, including 1D, 2D-NMR and HRESIMS. All the isolates were also evaluated for their neuraminidase inhibitory activities against H1N1, H9N2, wild-type H1N1 and oseltamivir-resistant H1N1 (H274Y mutation) virus strains. Of the isolates, tamarixetin 3-robinobioside was found to exhibit the strongest enzymatic inhibition (IC50 24.93 ± 3.46, 23.19 ± 5.41, 26.67 ± 5.16 and 40.16 ± 4.50 μM, respectively). Selected candidates, kaempferol 3-robinobioside, kaempferol 3-O-β-d-glucopyranosyl (1 → 2)-α-d-xylopyranoside and tamarixetin 3-robinobioside, also showed moderate reductions in H1N1-induced cytopathic effects on MDCK cells.

Acetophenones from Acronychia pedunculata and their Cancer Chemopreventive Activity

From the roots of Acronychia pedunculata (L.) Miq. (Rutaceae) collected in Taiwan, six known and three new acetophenones have been isolated. The new compounds were named acrophenones D (1), E (2), and F (3). Of the acetophenones isolated in this study, prenylacronylin (4) and acronyculatin D. (10) exhibited significant inhibitory activity against 12-0-tetradecanoylphorbol 13-acetate-induced Epstein-Barr virus early antigen activation in Raji cells.

Acetophenone derivatives from a freshwater fungal isolate of recently described Lindgomyces madisonensis (G416)

The exploration of freshwater ascomycetes, which have undergone only limited investigation, may provide opportunities both to characterize new genera/species of fungi and to uncover new chemical diversity. In this study, seven acetophenone derivatives, madisone, 4'-methoxymadisone, dehydromadisone, 2″-methoxymadisone, dihydroallovisnaginone, dimadisone, and 4'-methoxydimadisone were characterized from an organic extract of a recently described Lindgomyces madisonensis (G416) culture, which was isolated from submerged wood collected in a stream in North Carolina. Madisone, dehydromadisone, 2″-methoxymadisone, dimadisone and 4'-demethoxydimadisone have not been reported previously, while 4'-methoxymadisone and dihydroallovisnaginone were previously unknown as natural products. Their structures were assigned on the basis of NMR and HRESIMS data, with the structure of madisone supported by X-ray crystallography. The antimicrobial activities of madisone, 4'-methoxymadisone and dihydroallovisnaginone were evaluated against a panel of bacteria and fungi. A heat map analysis of the surface of a G416 culture showed that most of the isolated compounds concentrated in the guttate compared with the vegetative mycelium of the fungus.

Anacardic Acids from Knema hookeriana as Modulators of Bcl-xL/Bak and Mcl-1/Bid Interactions

Proteins of the Bcl-2 family are key targets in anticancer drug discovery. Disrupting the interaction between anti- and pro-apoptotic members of this protein family was the approach chosen in this study to restore apoptosis. Thus, a biological screening on the modulation of the Bcl-xL/Bak and Mcl-1/Bid interactions permitted the selection of Knema hookeriana for further phytochemical investigations. The ethyl acetate extract from the stem bark led to the isolation of six new compounds, three acetophenone derivatives (1-3) and three anacardic acid derivatives (4-6), along with four known anacardic acids (7-10) and two cardanols (11, 12). Their structures were elucidated by 1D and 2D NMR analysis in combination with HRMS experiments. The ability of these compounds to antagonize Bcl-xL/Bak and Mcl-1/Bid association was determined, using a protein-protein interaction assay, but only anacardic acid derivatives (4-10) exhibited significant binding properties, with Ki values ranging from 0.2 to 18 μM. Protein-ligand NMR experiments further revealed that anacardic acid 9, the most active compound, does not interact with the anti-apoptotic proteins Bcl-xL and Mcl-1 but instead interacts with pro-apoptotic protein Bid.

Mohangic Acids A-E, p-Aminoacetophenonic Acids from a Marine-Mudflat-Derived Streptomyces sp

Mohangic acids A-E (1-5) were isolated from a marine Streptomyces sp. collected from a mudflat in Buan, Republic of Korea. Comprehensive spectroscopic analysis revealed that the mohangic acids are new members of the p-aminoacetophenonic acid class. The relative and absolute configurations of the mohangic acids were determined by J-based configuration analysis and by the application of bidentate chiral NMR solvents followed by (13)C NMR analysis, chemical derivatization, and circular dichroism spectroscopy. Mohangic acid E (5), which is the first glycosylated compound in the p-aminoacetophenonic acid family, displayed significant quinone reductase induction activity.

Antiviral activity and possible mechanism of action of constituents identified in Paeonia lactiflora root toward human rhinoviruses

Human rhinoviruses (HRVs) are responsible for more than half of all cases of the common cold and cost billions of USD annually in medical visits and missed school and work. An assessment was made of the antiviral activities and mechanisms of action of paeonol (PA) and 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose (PGG) from Paeonia lactiflora root toward HRV-2 and HRV-4 in MRC5 cells using a tetrazolium method and real-time quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Results were compared with those of a reference control ribavirin. Based on 50% inhibitory concentration values, PGG was 13.4 and 18.0 times more active toward HRV-2 (17.89 μM) and HRV-4 (17.33 μM) in MRC5 cells, respectively, than ribavirin. The constituents had relatively high selective index values (3.3->8.5). The 100 μg/mL PA and 20 μg/mL PGG did not interact with the HRV-4 particles. These constituents inhibited HRV-4 infection only when they were added during the virus inoculation (0 h), the adsorption period of HRVs, but not after 1 h or later. Moreover, the RNA replication levels of HRVs were remarkably reduced in the MRC5 cultures treated with these constituents. These findings suggest that PGG and PA may block or reduce the entry of the viruses into the cells to protect the cells from the virus destruction and abate virus replication, which may play an important role in interfering with expressions of rhinovirus receptors (intercellular adhesion molecule-1 and low-density lipoprotein receptor), inflammatory cytokines (interleukin (IL)-6, IL-8, tumor necrosis factor, interferon beta, and IL-1β), and Toll-like receptor, which resulted in diminishing symptoms induced by HRV. Global efforts to reduce the level of synthetic drugs justify further studies on P. lactiflora root-derived materials as potential anti-HRV products or lead molecules for the prevention or treatment of HRV.

[Study on chemical constituents from active fraction of Cynanchum versicolor]

OBJECTIVE

To investigate the chemical constituents of active fraction of Cynanchum versicolor.

METHODS

The ethanol extract of Cynanchum versicolor was purified by macroporous resin, silica gel column and Sephadex LH-20 column chromatography, and structures of the isolated compounds were identified by spectroscopic analysis and comparison with those of literatures.

RESULTS

Six compounds were isolated and identified as glaucogenin C (I), 24-methyl-5α-cholesta-7,22-diene-3β,5,6β-triol (II), syringic acid (III), 3,4-dihydroxyacetophenone (IV), 4-hydroxyacetophenone (V), and 4-hyroxy-3-methoxyacetophenone (VI).

CONCLUSION

Compounds I, II and IV are isolated from this plant for the first time.

Paeonol protects against premature senescence in endothelial cells by modulating Sirtuin 1 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Paeonol is a phenolic compound isolated mainly from Moutan cortex, root bark of Chinese Peony tree. Moutan cortex holds a significant value in traditional Chinese medicine for alleviating various oxidative stress-related diseases mainly atherosclerosis and myocardial infarction. The present study seeks to identify the protective mechanisms of paeonol in oxidative stress-induced premature senescence in endothelial cells.

MATERIALS AND METHODS

HUVECs were pretreated with paeonol or DMSO control at different doses for 24h prior to an exposure of 200μM of reactive oxygen species (ROS) inducer, hydrogen peroxide (H2O2). The protective effects of paeonol against H2O2-induced senescence were evaluated and the activation of Sirtuin 1 pathway by paeonol pretreatment was investigated in HUVECs.

RESULTS

Paeonol attenuated H2O2-induced cell growth arrest at G0/G1 phase, reduced the percentage of SA-β-Gal positive cells and increased BrdU incorporation. In addition, enzymatic Sirt1 activation assay indicated that paeonol significantly increased lysyl deactylase activity of Sirt1 enzyme with a fold change of 2.4±0.195 (p<0.05). Furthermore, pretreatment with paeonol significantly decreased the levels of p53, acetyl H3K14 and H4K16 protein expression upregulated by H2O2 stimulation. The changes in the histone protein levels were accompanied with an increase in Sirt1 protein expression level.

CONCLUSION

These findings suggest that paeonol protects endothelial cells against oxidative stress-induced premature senescence by modulating the expressions of Sirt1 protein and its substrates.

Identification and modulatory activity assessment of 2-hydroxy-3,4,6-trimethoxyacetophenone isolated from croton anisodontus müll. Arg.(euphorbiaceae)

The n-hexane extract of the stem bark of Croton anisodontus yielded 2-hydroxy-3,4,6-trimethoxyacetophenone, a well-known substance, but isolated from this species for the first time. The antimicrobial and modulatory activities of the compound towards Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, C. krusei and C. tropicalis strains were assessed. Antibiotics such as amikacin, gentamicin and neomycin were used in a sub-inhibitory concentration. Significant activity was observed towards P. aeruginosa and S. aureus 358, with p < 0.001 in association with amikacin. The present results place C anisodontus as an alternative source of 2-hydroxy-3,4,6-trimethoxyacetophenone with antibacterial potential.

[Chemical constituents of n-BuOH extract from Phyllanthus matsumurae]

OBJECTIVE

To study the chemical constituents of n-BuOH extract from Phyllanthus matsumurae.

METHODS

Column chromatography was used for the isolation and purification. Spectroscopic methods including H-NMR, 13C-NMR and MS were used for the identification of structures.

RESULTS

Six compounds were isolated from the n-BuOH extract of 75% alcohol extract of the whole plant and identified as ellagic acid (1), phyllanthuspermin B (2), phyllanthuspermin C (3), xanthoxylin (4), hesperetin-7-O-[6-O-(alpha-L-rhamnopy ranosyl)] -beta-D-glucopyranoside (5) and 4-O-methylgallic acid (6).

CONCLUSION

Compounds 2 - 6 are obtained from this plant for the first time.

Inhibitory effects of stilbene derivatives from Parthenocissus tricuspidata on adipocyte differentiation and pancreatic lipase

Obesity, which is characterized by excessive fat accumulation, occurs by fat absorption by lipase and sequential fat accumulation in adipocytes through adipocyte differentiation. Thus, inhibition of pancreatic lipase activity and adipocyte differentiation would be crucial for the prevention and treatment of obesity. Investigation of anti-obesity compounds from Parthenocissus tricuspidata stems resulted in the isolation of nineteen compounds including five acetophenones, five flavonoids and nine stilbene derivatives. Among them, the stilbene derivatives showed the most potent anti-obesity effects. Stilbene monomers showed strong inhibitory activity on both adipocyte differentiation and pancreatic lipase, followed by stilbene dimer and trimer. Flavonoids showed mild inhibition on adipocyte differentiation, whereas acetophenones showed little effect in our assay system. Taken together, P. tricuspidata might be a new candidate for the development of obesity treatment.

[Study on the chemical constituent from the dichloromethane extract of the pine needle of Cedrus deodara (II)]

OBJECTIVE

To study the chemical constituents of the dichloromethane extract from pine needles of Cedrus deodara.

METHODS

The chemical constituents were isolated and purified from the dichloromethane extract of pine needles by chromatography on silica gel and Sephadex LH-20. Their structures were elucidated by analysis of spectral data and chemical properties.

RESULTS

Seven compounds were isolated and their chemical structures were identified as ferulic acid (1), osthole (2), beta-phenylacrylic acid (3), paeonol (4), beta-sitosterol (5), magnolol (6) and honokiol (7).

CONCLUSION

Compounds 1 - 4, 6 and 7 are isolated from this plant for the first time.

Anti-inflammatory and antimicrobial properties of pyrroloquinazoline alkaloids from Adhatoda vasica Nees

Adhatoda vasica Nees, Acanthaceae, is well known plant in Ayurveda and Unani medicine. The purpose of this study was to characterize the most bioactive phytochemicals viz., vasicine, vasicinone, vasicine acetate, 2-acetyl benzyl amine, vasicinolone present in the chloroform fraction having anti-inflammatory and antimicrobial activities. The anti-inflammatory activity was tested by using carrageenan and CFA-model induced paw oedema. The antimicrobial activity of isolated compounds was assessed by using the microdilution method. The observed results revealed that vasicine showed most potent anti-inflammatory effects (59.51%) at the dose of 20.0mg/kg at 6h after carrageenan injection and maximum inhibition rate was observed of vasicinone (63.94%) at the dose of 10.0mg/kg at 4 days after CFA injection. The strong antibacterial activity was exhibited by vasicine at 20μg/ml dose against E. coli and also demonstrated maximum antifungal activity against C. albicans at the dose of >55μg/ml. All the five alkaloids demonstrated significant anti-inflammatory and antimicrobial activities.

Aqueous ionic liquid based ultrasonic assisted extraction of four acetophenones from the Chinese medicinal plant Cynanchum bungei Decne

In this study, an aqueous ionic liquid based ultrasonic assisted extraction (ILUAE) method for the extraction of the four acetophenones, namely 4-hydroxyacetophenone (1), 2,5-dihydroxyacetophenone (2), baishouwubenzophenone (3) and 2,4-dihydroxyacetophenone (4) from the Chinese medicinal plant Cynanchum bungei was developed. Three kinds of aqueous l-alkyl-3-methylimidazolium ionic liquids with different anion and alkyl chain were investigated. The results indicated that ionic liquids (ILs) showed remarkable effects on the extraction efficiency of acetophenones. In addition, the ILUAE, including several ultrasonic parameters, such as the ILs concentration, solvent to solid ratio, power, particle size, temperature, and extraction time have been optimized. Under these optimal conditions (e.g., with 0.6M [C(4)MIM]BF(4), solvent to solid ratio of 35:1, power of 175 W, particle size of 60-80 mesh, temperature of 25 ° C and time of 50 min), this approach gained the highest extraction yields of four acetophenones 286.15, 21.65, 632.58 and 205.38 μg/g, respectively. The proposed approach has been evaluated by comparison with the conventional heat-reflux extraction (HRE) and regular UAE. The results indicated that ILUAE is an alternative method for extracting acetophenones from C. bungei.

Cholinesterase inhibitory constituents from Ficus bengalensis

Bengalensinone (22β-hydroxylup-12,20-dien-3-one; 1), a new lupane triterpene, and benganoic acid (2), a new apocarotenoid, together with lupanyl acetate, 3-acetoxy-9(11),12-ursandiene, stigmasterol, alpinumisoflavone, 4-hydroxyacetophenone, 4-hydroxybenzoic acid, 4-hydroxymellein, and p-coumeric acid were isolated from the methanolic extract of the aerial roots of Ficus bengalensis. The structures of these compounds were established by the combination of 1D NMR (¹H and ¹³C NMR) and 2D NMR (HMQC, HMBC, and COSY) analyses, and mass spectrometry (EI-MS and HR-EI-MS), and in comparison with literature data of the related compounds. Compounds 1 and 2 displayed inhibitory potential against enzyme cholinesterase in a concentration-dependent manner with IC₅₀ values 194.5 and 154.5 μM for acetylcholinesterase and 224.9 and 120.0 μM for butyrycholinesterase, respectively.

A new prenylated acetophenone from the root bark of Derris indica

A new acetophenone, 1-[2,4-dihydroxy-5-(3-methylbut-2-enyl)phenyl]ethanone (1) was isolated from the root bark of Derris indica, along with 3,7,-dimethoxy-3',4'-methylenedioxyflavone (desmethoxykanugin) (2), 5-methoxyfurano[4",5":6,7]flavone (pinnatin) (3), and 3'-hydroxyfurano[4",5":7,8]flavone (pongol) (4). The structures of these compounds were established by means of chemical and spectral studies. The occurrence of this prenylated acetophenone in D. indica is of biogenetic and chemotaxonomic significance.

[Study on chemical constituents of Carthamus tinctorius]

OBJECTIVE

To investigate the chemical constituents in water-soluble fraction of Carthamus tinctorius.

METHODS

Compounds were isolated and purified by macroporus resin, silica gel, Sephadex LH-20 column chromatography and preparative HPLC. The structures were identified by spectral analysis.

RESULTS

Twelve compounds were isolated and identified as 4-Hydroxybenzaldehyde (1); E-1-(4'-hydroxypheny) -but-1-en-3-one (2); 3-Formylindole (3); 2-Acetyl-5-hydroxymethylfuran (4); p-Hydroxycinnamic acid (5); (6R, 7E, 9R) -9-hydroxy-4,7-megastigmandien-3-one (6); 4-hydroxyacetophenone (7); 5-(hydroxymethyl) -2-furaldehyde (8); 4-Hydroxybenzoic acid (9); Stigmasterol-3-O-beta-D-glucopyranoside (10); Daucosterol (11); beta-sitosterol (12).

CONCLUSION

Compounds 1 - 4, 6, 7, 10 are isolated from this plant for the first time.

Cytotoxic prenylated acetophenone dimers from Acronychia pedunculata

Three new acetophenone dimers or Acronychia-type acetophenones, acropyrone (1), acropyranol A (2), and acropyranol B (3), were isolated from the trunk bark of Acronychia pedunculata and structurally characterized, together with four known acetophenone dimers, acrovestone (4), acrovestenol (5), acrofolione A (6), and acrofolione B (7), the acetophenone monomer acronyline (8), and four furoquinoline alkaloids. The chemical structures of the new isolated compounds were elucidated unambiguously by spectroscopic data analysis. The cytotoxic activities of the isolated acetophenone dimers were evaluated against the DU145 prostate and A2058 melanoma human cancer cell lines as well as the NHDF normal cell line. Acrovestone (4) and acrovestenol (5) exhibited substantial cytotoxicity, with IC(50) values of 0.38 and 2.8 μM against A2058 melanoma cells as well as 0.93 and 2.7 μM against DU145 prostate cancer cells, respectively.

[Study on secondary metabolites of marine fungus Penicillium sp. FS60 from the South China Sea]

OBJECTIVE

To study the secondary metabolites of the marine fungus Penicillium sp. FS60 from the South China Sea and their cytotoxicities.

METHODS

The compounds were isolated from the culture of strain FS60 by various chromatographic methods (silica gel, reverse silica gel, Sephadex-LH20, preparative TLC, HPLC and PTLC) and recrystallization. Their structures were identified by extensive analysis of their spectroscopic data. Compounds were tested for their cytotoxicities against SF-268, MCF-7, and NCI-H460 cell lines by SRB method. While, Compounds were tested for their antibacterial activities against S. aureus, E. coli and P. aeruginosa.

RESULTS

Seven compounds were isolated from the culture and identified as methyl 2,4-dihydroxy-3,5,6-trimethylbenzoate (1), 4-hydroxyacetophenone (2), 5-hydroxymethyl-furoic acid (3), isochromophilones VIII (4), ergosterol (5), ergosterol peroxide (6), and cerevisterol (7).

CONCLUSION

Compound 1 is isolated from the genus Penicillium for the first time. Compound 3 is demonstrated to have significant inhibition against S. aureus and P. aeruginosa. Compound 4 is demonstrated to have significant inhibition against the three cell lines.

Stereoselective bioreduction of 1-(4-methoxyphenyl)ethanone by whole cells of marine-derived fungi

Nine strains of marine-derived fungi (Aspergillus sydowii Ce15, A. sydowii Ce19, Aspergillus sclerotiorum CBMAI 849, Bionectria sp. Ce5, Beauveria felina CBMAI 738, Cladosporium cladosporioides CBMAI 857, Mucor racemosus CBMAI 847, Penicillium citrinum CBMAI 1186, and Penicillium miczynskii Gc5) were screened, catalyzing the asymmetric bioreduction of 1-(4-methoxyphenyl)ethanone 1 to its corresponding 1-(4-methoxyphenyl)ethanol 2. A. sydowii Ce15 and Bionectria sp. Ce5 produced the enantiopure (R)-alcohol 2 (>99% ee) in accordance with the anti-Prelog rule and, the fungi B. felina CBMAI 738 (>99% ee) and P. citrinum CBMAI 1186 (69% ee) in accordance with the Prelog rule. Stereoselective bioreduction by whole cells of marine-derived fungi described by us is important for the production of new reductases from marine-derived fungi.

Acaricidal toxicity of 2'-hydroxy-4'-methylacetophenone isolated from Angelicae koreana roots and structure-activity relationships of its derivatives

The acaricidal activities of 2'-hydroxy-4'-methylacetophenone derived from Angelica koreana roots and its derivatives against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Tyrophagus putrescentiae were examined by vapor phase and contact toxicity bioassays. In the vapor phase toxicity bioassay, 2'-methylacetophenone (1.25 μg/cm(2)) was 8.0 times more toxic against D. farinae than benzyl benzoate (10.00 μg/cm(2)), followed by 3'-methylacetophenone (1.26 μg/cm(2)), 4'-methylacetophenone (1.29 μg/cm(2)), 2'-hydroxy-4'-methylacetophenone (1.75 μg/cm(2)), and 2'-hydroxy-5'-methylacetophenone (1.96 μg/cm(2)). In the contact toxicity bioassay, 3'-methylacetophenone (0.58 μg/cm(2)) was 17.24 times more effective against D. farinae than benzyl benzoate (7.52 μg/cm(2)), followed by 2'-methylacetophenone (0.64 μg/cm(2)), 2'-hydroxy-4'-methylacetophenone (0.76 μg/cm(2)), 4'-methylacetophenone (0.77 μg/cm(2)), and 2'-hydroxy-5'-methylacetophenone (1.16 μg/cm(2)). The acaricidal activities of 2'-hydroxy-4'-methylacetophenone derivatives against D. pteronyssinus and T. putrescentiae were similar to those against D. farinae. In terms of structure-activity relationships, acaricidal activity against the three mite species changed with the introduction of hydroxyl and methyl functional groups onto the acetophenone skeleton. Furthermore, some of 2'-hydroxy-4'-methylacetophenone derivatives could be useful for natural acaricides against three mite species.

An application of high-speed counter-current chromatography for separation and purification of bungeiside-A, bungeiside-B and baishouwubenzophenone from Cynanchum bungei Decne

INTRODUCTION

Cynanchum bungei Decne (Baishouwu in China), is a famous traditional Chinese medicine that has been widely used as a tonic medicine or health food for centuries. Bungeiside-A, bungeiside-B and baishouwubenzophenone, as the major bioactive constituents in C. bungei, are challenging to separate and purify since bungeiside-A and -B are present in very low concentrations and have similar structures and high polarity.

OBJECTIVE

To develop a method of isolation and purification of bungeiside-A and -B and baishouwubenzophenone from the Chinese medicinal plant Cynanchum bungei Decne by high-speed counter-current chromatography (HSCCC).

METHODOLOGY

The roots of C. bungei were extracted with light-petroleum (60-90 °C) and chloroform to remove the lipid substance. Then the residuals were extracted with methanol. The methanol extract was prepared for the subsequent HSCCC separation. The simple HSCCC method of separation and purification of bungeiside-A and -B and baishouwubenzophenone was established according to the solvent system, which was selected according to the measurement of partition coefficient (K). The purities of target compounds were test by HPLC and the structure was identified by ¹H NMR and ¹³C NMR.

RESULTS

Bungeiside-A (9.4 mg), bungeiside-B (8.6 mg) and baishouwubenzophenone (5.7 mg) were obtained from 1.5 g of the methanol extract with purities of 93.2, 98.7 and 95.4%, respectively.

CONCLUSION

These results clearly demonstrate that HSCCC is a powerful tool for isolating and purifying components with similar structures, low concentration and high polarity from medicinal plant, such as bungeiside-A and -B and baishouwubenzophenone.

Autotoxicity and allelopathy of 3,4-dihydroxyacetophenone isolated from Picea schrenkiana needles

Bioassay-guided fractionation of the diethyl ether fraction of a water extract of Picea schrenkiana needles led to the isolation of the phenolic compound 3,4-dihydroxy- acetophenone (DHAP). The allelopathic effects of DHAP were evaluated under laboratory conditions on P. schrenkiana, rice (Oryza sativa L.), wheat (Triticum aestivum L.), radish (Raphanus sativus L.), lettuce (Latuca sativa L.), cucumber (Cucumis sativus L.) and mung bean (Phaseolus radiatus L.). DHAP significantly inhibited seed germination and seedling growth of P. schrenkiana at concentrations of 2.5 mM and 0.5 mM (p < 0.05). Soil analysis revealed that P. schrenkiana forest soils contained exceptionally high DHAP concentrations (mean = 0.51 ± 0.03 mg/g dry soil), sufficient to inhibit natural P. schrenkiana recruitment. DHAP also exhibited strong allelopathic potential. It significantly inhibited wheat and lettuce seed germination at concentrations of 1 mM and 0.5 mM (p < 0.05). The active compound also completely inhibited root growth of the six test species at high concentrations. Our results suggest a dual role of DHAP, both as an allelochemical and as an autotoxicant. The potential for a single plant needle-leached compound to influence both inter- and intra-specific interactions emphasized the complex effects that plant secondary metabolites might have on plant population and community structure.

The 2',4',6'-trihydroxyacetophenone isolated from Myrcia multiflora has antiobesity and mixed hypolipidemic effects with the reduction of lipid intestinal absorption

This study evaluated the hypolipidemic and antiobesity effects of phloroacetophenone (2',4',6'-trihydroxyacetophenone, THA) isolated from Myrcia multiflora and their relationship with triglyceride (TG) intestinal absorption and pancreatic lipase activity inhibition. The hypolipidemic effect of THA was evaluated by acute (Triton WR-1339 treatment) and chronic assay (high-fat diet treatment), the antiobesity effect was evaluated by chronic assay (high-fat diet treatment), while the inhibition of enzymatic activity of pancreatic lipase was measured in the intestinal tissue of mice treated with high olive oil concentration. In the acute assay, THA caused greater total cholesterol (37 %) and triglyceride (46 %) serum level reduction than lovastatin (32 and 1 %), a HMG-CoA reductase inhibitor or orlistat (26 and 34 %), a gastrointestinal lipase inhibitor. In addition, in the chronic assay with a high-fat diet, THA reduced cholesterol and triglyceride levels (32 and 61 %, respectively) while lovastatin showed a decrease of 35 and 49 %, respectively. THA also caused a reduction in weight gain very similar to orlistat (40 and 38 %, respectively) when the animals were submitted to a high-fat diet. Moreover, THA showed a stronger and continuous pancreatic lipase inhibitory activity when compared with orlistat, causing inhibition of this enzyme during 6 hours associated to a significant reduction of triglyceride serum levels. The IN VIVO antiobesity and hypolipidemic effects of THA may be partly mediated by delaying the intestinal absorption of dietary fat by inhibiting pancreatic lipase activity.

p-hydroxyacetophenone amides from Cystobacter ferrugineus, strain Cb G35

A family of six novel p-hydroxyacetophenone amides, 1-6, was isolated from Cystobacter ferrugineus, strain Cb G35. Their structures were elucidated by ESI-TOF mass spectrometry and NMR spectroscopy. Feeding experiments with labeled [¹³C₉,¹⁵N]-tyrosine and [d₁₀]-leucine identified the biosynthetic precursors of 1.

Phenolic compounds from Eucalyptus gomphocephala with potential cytotoxic and antioxidant activities

Two new phenolic compounds, 2,4,6-trihydroxy-5-methyl-acetophenone 2-O-beta-D-glucopyranoside (3), and benzyl alcohol 7-O-(3',4',6'-tri-O-galloyl)-beta-D-glucopyranoside (8), together with eight known phenolic compounds, were isolated from the 70% aqueous acetone extract of Eucalyptus gomphocephala DC. (Myrtaceae). The isolated compounds were elucidated based on their 1H, 13C, DQF-COSY, selective 1D-TOCSY, HSQC, and HMBC NMR spectroscopic and ESI-MS data. The antioxidant effect of the phenolic compounds was tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical and super oxide anion radical scavenging assays. The cytotoxicity of the isolated compounds was evaluated using HeLa cell line.

[Study on the chemical constituents from fresh roots of Euphorbia fischeriana]

OBJECTIVE

To study the chemical constituents in ethyl acetate fraction from the Euphorbia fischeriana.

METHODS

The compounds were isolated by silica gel column chromatography and HPLC, and their structures were elucidated by means of spectral analyses.

RESULTS

Fourteen compounds were identified as 2,4-dihydroxy-6-methoxy-3-methylacetophenone (1), 12-deoxyphorbol-13-hexadecanoate (2), ethylgallate (3), esculetin (4), 2,4-dihydroxy-6-methoxy-acetophenone (5), 12-deoxyphorbol-13-acetate (6), 12-deoxyphorbol-13,20-diacetete (7), jolkinolide B (8), 17-hydroxyjolkinolide B (9), 17-hydroxy-jolkinolide A (10), langduin C (11), 3-methylp-hydroxybenzoic acid (12), methyl gallate (13), 3, 3'-diacetyl-pyridine-4,4'-dimethoxy-2, 2', 6, 6'-tetrahydroxydiphenylmethane (14).

CONCLUSION

Compounds 3, 5, 12, 13 are isolated from this plant for the first time.

The novel anti-hyperglycemic effect of Paeoniae radix via the transcriptional suppression of phosphoenopyruvate carboxykinase (PEPCK)

The antidiabetic actions of Paeoniae Radix involve stimulating glucose uptake and reducing glucose absorption. However, the importance of this herb in the transcriptional regulation of hepatic gluconeogenesis has not previously been investigated, although hepatic gluconeogenesis contributes the most to fasting hyperglycemia. Using rats with streptozotocin-induced diabetes and db/db mice, the dose- and time-dependent suppressive effects of the ethanol extract of Paeoniae Radix (PR-Et) on diabetic hyperglycemia and phosphoenopyruvate carboxykinase (PEPCK) transcription are first demonstrated. Second, by employing H4IIE cells, the inhibitory action of PR-Et on both dexamethasone- and 8-bromo-cAMP-induced-PEPCK expression was also confirmed without causing any cytotoxicity. In addition, this inhibitory effect could be sustained for over 24 h with repeated treatment. Most importantly, PR-Et's action was unaffected by either insulin desensitization or palmitate stimulation. Finally, paeonol and paeoniflorin, two well-known constituents in Paeoniae Radix, did not suppress PEPCK expression at testing concentration. In conclusion, it was clearly demonstrated that transcriptional inhibition of gluconeogenesis is one of the important antidiabetic actions of Paeoniae Radix. Future development of this herb as a dietary supplement or drug should bring substantial benefits for the diabetic population.

Chemical constituents of Saxifraga stolonifera (L.) Meeb

To study the chemical constituents of Saxifraga stolonifera (L.) Meeb., chromatographic techniques were applied to separate and purify the compounds, and their structures were confirmed on the basis of physicochemical properties and spectral data. Ten compounds were isolated and identified as 5-O-methylnorbergenin (1), 3, 4-dihydroxyallylbenzene-4-O-beta-D-glucopyranoside (2), (7R, 8S)-4, 9, 9'-trihydroxyl-3-methoxyl-7, 8-dihydrobenzofuran-1'-propylneolignan-3'-O-beta-D-glucopyranoside (3), quercetin-3-O-beta-D-xylopyranosyl-(1 --> 2)-beta-D-galactopyranoside (4), kaempferol-3-O-alpha-L-rhamnopyranoside (5), (3S, 5R, 6R, 7E, 9R)-3, 5, 6, 9-tetrahydroxy-7-megastigmane (6), benzyl-O-alpha-L-rhamnopyranosyl-(1 --> 6)-beta-D-glucopyranoside (7), p-hydroxyacetophenone (8), pyrogallic acid (9) and p-hydroxyphenol (10). Compound 1 is a new compound. Compounds 2-10 were isolated from this plant for the first time.

p-Aminoacetophenonic acids produced by a mangrove endophyte Streptomyces sp. (strain HK10552)

Four new p-aminoacetophenonic acids, named (2E)-11-(4′-aminophenyl)-5,9-dihydroxy-4,6,8-trimethyl-11-oxo-undec-2-enoic acid (1), 9-(4′-aminophenyl)-3,7-dihydroxy-2,4,6-trimethyl-9-oxo-nonoic acid (2), (2E)-11-(4′-aminophenyl)-5,9-O-cyclo-4,6,8-trimethyl-11-oxo-undec-2-enoic acid (3) and 9-(4′-aminophenyl)-3,7-O-cyclo-2,4,6-trimethyl-9-oxo-nonoic acid (4), were isolated from an endophyte Streptomyces sp. (strain HK10552) of the mangrove plant Aegiceras corniculatum. The structures of 1–4 were elucidated by using spectroscopic analyses. The relative stereoconfigurations of compounds 3 and 4 were determined by NOESY experiments. In the bioassay test, 1–4 showed no cytotoxicity against the Hela cell lines. Compound 4 also showed no inhibitory bioactivity on HCV protease and SecA ATPase and wasn’t active against VSVG/HIV-luc pseudotyping virus.

[CuO-Ru/Al2O3 catalytic ozonation of acetophenone in water]

Two-component CuO-Ru based on active Al2O3 (CuO-Ru/Al2O3) catalyst was prepared by incipient wetness impregnation and used to catalytic ozonation of acetophenone (AP). The results showed that doping Ru could significantly improve the catalytic activity of CuO/Al2O3. For example, the COD removal rates of AP solution after 30 min by ozonation alone, CuO/Al2O3/O3, and CuO-Ru/Al2O3/O3 were 6.3%, 20.0% and 54.0%, respectively. The change of pH almost had no affect on degradation efficiency of AP. However, a comparison of COD removal between ozonation alone and catalytic ozonation indicated that CuO-Ru/Al2O3 catalyst was more suitable for application in neutral or acidic condition. CuO-Ru/Al2O3 catalyst could accelerate decomposition rate of ozone in water, and its decomposition rate constant reached 2.58 x 10(-3) s(-1) while that of ozone alone in double-water was 1.19 x 10(-3) s(-1). The experimental result of t-butanol indicated that CuO-Ru/Al2O3 catalytic ozonation of AP followed a radical-type mechanism.

[Paeonol attenuates oxygen-glucose deprivation injury and inhibits NMDA receptor activation of cultured rat hippocampal neurons]

The purpose of this study is to determine if paeonol can protect hippocampal neurons against injury due to oxygen-glucose deprivation (OGD) injury. The rat neurons were cultured in an OGD environment and the model of OGD injury was established. Paeonol and MK-801, a positive control drug, were added before deprivation. Neuron viability was measured by the reduction of MTT; glutamate was analyzed by amino acid analyzer; binding activity of NMDA receptor was evaluated by liquid scintillation counting and the expression of NMDA receptor NR1 subunit mRNA was semiquantitatively determined by RT-PCR. Compared with OGD injury group, paeonol treatment obviously increased cell survival rate and reduced the binding activity of NMDA receptors and the release of glutamate; and down-regulating the expression of NR1 subunit. These results suggest that paeonol may exhibit its protective effect against OGD injury by the action on NMDA receptor of rats.

Polygonophenone, the first MEM-substituted natural product, from Polygonum maritimum

An unprecedented natural acetophenone, polygonophenone (1), and a new resorcinol, polygonocinol (2), were isolated from the dichloromethane and methanol extracts of Polygonum maritimum and identified as 2-hydroxy-4-[(2-methoxyethoxy)methoxy] acetophenone and 2-methyl-5-nonadecylresorcinol, respectively. In addition, 11 known compounds were identified, namely, the sesquiterpenoid (+)-8-hydroxycalamene, four ferulic acid esters (tetracosyl, hexacosyl, octacosyl, and triacontyl ferulate), the arylpropane broussonin B, the flavonoids quercetin, quercitrin, and (+)-catechin, the hydroquinone glucoside isotachioside, and beta-sitosterol. The structures of the new compounds were elucidated on the basis of their NMR and MS data. It is noteworthy that polygonophenone (1) is the first naturally methoxyethoxymethyl (MEM)-substituted natural product, and its isolation gives support for the use of MEM protection in biomimetic synthetic schemes.

Benzoic acid derivatives, acetophenones, and anti-inflammatory constituents from Melicope semecarpifolia

Two new benzoic acid derivatives, (E)-3-acetyl-6-(3,7-dimethylocta-2,6-dienyloxy)-2,4-dihydroxybenzoic acid (1) and (E)-3-acetyl-4-(3,7-dimethylocta-2,6-dienyloxy)-2,6-dihydroxybenzoic acid (2), and three new acetophenones, (E)-1-(5-(3,7-dimethylocta-2,6-dienyloxy)-7-hydroxy-2,2-dimethyl-2 H-chromen-8-yl)ethanone (3), (E)-1-(5-(3,7-dimethylocta-2,6-dienyloxy)-7-hydroxy-2-methyl-2-(4-methylpent-3-enyl)-2 H-chromen-8-yl)ethanone (4), and (R,E)-1-(5-(3,7-dimethylocta-2,6-dienyloxy)-3,7-dihydroxy-2,2-dimethylchroman-8-yl)ethanone (5), have been isolated from the fruits of Melicope semecarpifolia, together with eight known compounds. The structures were determined through in-depth NMR and mass spectrometric analyses. Among the isolated compounds, 2-(1'-geranyloxy)-4,6,beta-trihydroxyacetophenone (8), 4-(1'-geranyloxy)-2,6,beta-trihydroxyacetophenone (9), 5-hydroxy-3,7,3',4'-tetramethoxyflavone (10), 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (11), and 5,4'-dihydroxy-3,7-dimethoxyflavone (12) exhibited potent inhibition (IC50<4 microg/mL) on superoxide anion generation and elastase release by human neutrophils in response to fMet-Leu-Phe/cytochalasin B.

[Study on microwave-assisted extraction technology for active ingredients in different parts of traditional Chinese medicine]

OBJECTIVE

To study the optimization process of microwave-assisted extraction for active ingredients in different parts of TMC.

METHOD

Using the uniform design, the optimization processes of microwave-assisted extraction for Flavonoids and Paneonolum in Bidens and Cortex Moutan were gained.

RESULT

The optimization process of extraction for Flavonoids in Bidens can be described as following: microwave power was 850 W, radiation time was 30 min, solvent concentration was 40%, solvent volume was 13 times as the proportion of raw material, and dipping time was 60 min. The optimization process of extraction for Paneonolum in Cortex Moutan has also been gained which could be shown as following: 340 W as microwave power, 20 min as radiation time, 85% as solvent concentration, 1:5 as the proportion of raw material to solvent, and 30 min as the dipping time.

CONCLUSION

These can prove it reasonable to get active ingredients in Bidens and Cortex Moutan with microwave-assisted extraction technology.

Thermodynamic studies of the interaction of molecular micelles and copolymerized molecular micelles with benzodiazepines and alkyl phenyl ketones using MEKC

In this study, polymers of sodium 10-undecenoyl L-leucinate (SUL) and sodium undecenyl sulfate (SUS) as well as their copolymerized molecular micelles (CoPMMs) were applied in MEKC as pseudostationary phases to separate benzodiazepines and alkyl phenyl ketones. SDS, a common pseudostationary phase used in MEKC, was also used for comparison. The van't Hoff relationship was applied to compute the temperature dependence of the MEKC retention factors of the test solutes to estimate the enthalpy, entropy, and the Gibbs free energy. Nonlinear van't Hoff plots were obtained with the majority of benzodiazepines indicating that the thermodynamic parameters were temperature-dependent in all surfactant systems for these solutes. In contrast, all alkyl phenyl ketones resulted in linear van't Hoff plots.

[Rapid identification of compounds in cortex moutan by liquid chromatography-tandem mass spectrometry]

AIM

To analyze the chemical constituents of cortex moutan by liquid chromatography coupled with electrospray ionization mass spectrometry.

METHODS

An on-line optimized HPLC-DAD/MS2 technique was employed.

RESULTS

In the negative ion detection mode, 38 components such as monoterpene glucosides, galloylglucoses and acetophenones were isolated. Among them, over thirty compounds were identified, including paeonol, paeonilflorin, oxypaeoniflorin, benzoylpaeoniflorin, benzoyloxypaeoniflorin, galloylpaeoniflorin, galloyloxypaeoniflorin, mundanpioside A, C, D, E, H, etc. by the high performance liquid chromatography with diode-array detection in parallel with electrospray ionization and quadrupole-time of flight tandem mass spectrometry (HPLC-DAD/ESI-MS2).

CONCLUSION

This method can be used to rapidly determine the constituents of cortex moutan.

Paeonol reduced cerebral infarction involving the superoxide anion and microglia activation in ischemia-reperfusion injured rats

Both Moutan cortex of Paeonia suffruticosa Andrews (MC) and the root of Paeonia lactiflora Pall (PL) are important Traditional Chinese herbs used commonly to treat inflammatory and pyretic disorders. Paeonol, a common component of MC causes anti-platelet aggregation and scavenges free radicals. Therefore, the aim of the present study is to investigate the effects of Paeonol on cerebral infarct. A total of 60 male Sprague-Dawley (SD) rats were studied. An animal model of cerebral infarct was established by occluding both common carotid arteries and the right middle cerebral artery for 90 min, followed by a 24 h period of reperfusion. The percentage of cerebral infarction area to total brain area in each piece of brain tissue, and neuro-deficit score were measured. Superoxide anion was determined by the number of lucigenin-chemiluminescence (CL) counts. ED1 (mouse anti rat CD68) and interleukin-1beta (IL-1beta) immunostaining in the cerebral infarction region were also investigated for activation of microglia. The results indicated that Paeonol 15 and 20 mg/kg pretreatment and 20 mg posttreatment reduced the cerebral infarction area; Paeonol 15 and 20 mg/kg pretreatment reduced the neuro-deficit score. In addition, Paeonol 20 mg/kg pretreatment reduced the lucigenin-CL counts at 2 h period of reperfusion. The number of ED1 and IL-1beta immunoreactive cells also reduced in the cerebral infarction region; there were no significant changes in blood sugar levels. The results show that Paeonol reduced cerebral infarct and neuro-deficit in rat, suggesting Paeonol might play a similar role in reducing cerebral infarction in humans. Paeonol suppresses and scavenges superoxide anion, and inhibit microglia activation and IL-1beta in ischemia-reperfusion injured rats.

Inhibitory kinetics of paeonol on the activity of mushroom tyrosinase oxidizing L-dopa

AIM

To evaluate the effect of paeonol on the activity of tyrosinase and provide experimental evidence for the treatment of hyperpigmentation disorders.

METHODS

Tyrosinase activity was estimated by measuring the oxidation rate of L-3,4-dihydroxyphenylalanine (L-Dopa). The inhibitory effects of paeonol on the activity of mushroom tyrosinase and Michaelis-Menten kinetics were deduced from the Lineweaver-Burk plots.

RESULTS

The inhibitory concentration of paeonol leading to 50% enzyme activity lost (IC50) was estimated to be 0.60 mmol x L(-1). The inhibition constants for paeonol binding free enzyme, K(I), and substrate-enzyme, K(IS), are 0.084 and 0.12 mmol x L(-1), respectively.

CONCLUSION

Paeonol is a potential mixed inhibitor of mushroom tyrosinase. The mixed inhibition function may originate from its ability to form a Schiff base with a primary amino group and to chelate copper at the active site of tyrosinase.

Acaricidal activities of paeonol and benzoic acid from Paeonia suffruticosa root bark and monoterpenoids against Tyrophagus putrescentiae (Acari: Acaridae)

The acaricidal activities of paeonol (2'-hydroxy-4'-methoxyacetophenone) and benzoic acid identified in the root bark of tree peony, Paeonia suffruticosa Andrews, against copra mite, Tyrophagus putrescentiae (Schrank), adults were examined using direct contact and vapour phase toxicity bioassays and compared with those of cinnamyl acetate, cinnamyl alcohol and 37 monoterpenoids as well as the acaricides benzyl benzoate, dibutyl phthalate and N,N-diethyl-m-toluamide (DEET). Based on LD(50) values in fabric piece contact toxicity bioassays, the acaricidal activities of benzoic acid (4.80 microg cm(-2)) and paeonol (5.29 microg cm(-2)) were comparable to that of benzyl benzoate (4.46 microg cm(-2)) but more pronounced than those of DEET (30.03 microg cm(-2)) and dibutyl phthalate (25.23 microg cm(-2)). In vapour phase toxicity bioassays, paeonol and benzoic acid were much more effective in closed containers than in open ones, indicating that the effects of these compounds were largely due to action in the vapour phase. As judged by 24 h LD(50) values, (1S)-(-)-verbenone (7.42 mg per disc) was the most toxic fumigant, followed by (1S)-(-)-camphor, (S)-(+)-carvone, (R)-(-)-linalool and (+/-)-camphor (10.45-18.18 mg). Potent fumigant toxicity was also observed with paeonol, (2S,5R)-(-)-menthone, (+/-)-citronellal, benzoic acid, (1S,4R)-(-)-alpha-thujone and (R)-(+)-pulegone (25.10-34.63 mg). Neither benzyl benzoate, DEET nor dibutyl phthalate caused fumigant toxicity. Paeonia root bark-derived materials, particularly paeonol and benzoic acid, as well as the monoterpenoids described, merit further study as potential acaricides or as leads for the control of T. putrescentiae.

Preparation of glycerol dimethacrylate-based polymer monolith with unusual porous properties achieved via viscoelastic phase separation induced by monodisperse ultra high molecular weight poly(styrene) as a porogen

The preparation of polymer-based monolith capillary was examined by the use of glycerol dimethacrylate (GDMA) as monomer and monodisperse standard polystyrene (PS) solution in chlorobenzene as porogen. Poly-GDMA monoliths were prepared in situ in test tubes with standard PS having the variety of molecular weight (defined as Mw hereafter) from 50,000 to 3,840,000, and their morphology was compared to that of poly-GDMA monolith prepared in situ with a poor porogenic solvent of GDMA. According to scanning electron micrograph (SEM) observation, the structure of poly-GDMA monolith prepared in situ with toluene as a poor porogenic solvent showed a typical agglomerated globular structure, whereas the morphology of poly-GDMA monolith prepared in situ with the polymer (PS) porogenic solution was transformed from the aggregated globule form to three dimensionally (3D) continuous skeletal structure with the increase of Mw of standard PS utilized. Along with this morphological transformation or change, in the case of poly-GDMA monolith prepared in situ with ultra high Mw standard PS porogenic solution, the pore size distribution showed a sharp bimodal distribution, with one peak being located around 4 nm in the mesopore range (2-50 nm) and the other peak located around 1-2 microm in the macropore range (>50 nm), respectively. The poly-GDMA capillaries were prepared in situ with toluene, low Mw (50,000, 600,000) PS solution in chlorobenzene and the above mentioned ultra high Mw PS solution in chlorobenzene as a porogen, respectively, and measured by mu-HPLC with benzene and n-alkyl phenyl ketone as solutes for the evaluation in aqueous methanol (MeOH/H(2)O = 50/50-80/20, v/v). The permeability of capillaries prepared in situ with ultra high Mw standard PS polymer porogenic solution was much larger, compared to those of the capillaries prepared in situ with low Mw standard PS polymer porogenic solution or with toluene as porogen. On the other hand, the column efficiency was better in the case of the capillary prepared in situ with the ultra high Mw PS solution than in the latter capillaries. Those observations indicated that the ultra high Mw standard PS polymer porogenic solution should delay dynamically the phase separation of polymerizing mixture because of its visco-elasticity and should contribute to the creation of three dimensionally continuous skeletal monolith structure better to afford high separation efficiency.