Enhancement of the mutagenicity of Trp-P-1, Trp-P-2 and benzo[a]pyrene by bupleuri radix extract

Boiling-water extract of Korean-Saiko (Bupleuri Radix, from South Korea, Bupleurum falcatum L.) enhanced the mutagenic activity of Trp-P-1, Trp-P-2 and benzo[a]pyrene with S9mix. The boiling-water extract was fractionated with ether and then n-BuOH. Both the ether and the n-BuOH fractions also enhanced mutagenicity of Trp-P-1, respectively. The n-BuOH fraction was separated into seven fractions by silica gel chromatography and the chloroform eluate had the strongest enhancing effect on the mutagenic activity of Trp-P-1 with S9mix. The chloroform eluate fraction was further separated into five spots by thin-layer chromatography. Two of the spots had the strongest enhancing effect on the mutagenic activity of Trp-P-1. Since saikosaponin is a well known component in Bupleuri Radix, the effects of its existence were tested and saikosaponins a and c were found. The enhancement activity of saikosaponin a was very weak. The effective components are now being studied.     

N-nitroso compounds and mutagens in Chinese fermented (sour) corn pancakes

Stomach cancer rates in rural Linqu County, Shandong Province, China, are exceptionally high. A previous case-control study revealed that the risk of stomach cancer was 30% higher among those who consumed sour (fermented) corn pancakes at least daily. A previous study of the sour pancakes reported volatile nitrosamines in most specimens, and almost half reportedly showed mutagenic activity. Few households currently consume sour pancakes, and the duration of fermentation has been shortened. We tested specimens of pancake batter and sour pancakes from Linqu County for mutagenic activity using the Ames test; for N-nitroso compounds (NOC) we used the Nitrolite-thermal energy analysis (TEA) method. Results of the Ames test were inconclusive: only 1 out of 15 cooked pancakes showed a positive mutagenic response, and all 15 batter specimens were negative; however, several batter specimens showed a weakly positive trend of mutagenicity with extract concentration. Our assay for total nitroso compounds was weakly positive in only 1 out of 15 specimens of sour pancake batter. That specimen was also tested by gas chromatography-TEA for nitrosaminoacids and volatile nitrosamines, but none were detected. It seems unlikely that the Chinese sour pancakes are significantly contaminated by NOC or other mutagens.     

Direct chlorination of alcohols with chlorodimethylsilane catalyzed by a gallium trichloride/tartrate system under neutral conditions

The reaction of secondary alcohols 1 with chlorodimethylsilane (HSiMe(2)Cl) proceeded in the presence of a catalytic amount of GaCl(3)/diethyl tartrate to give the corresponding organic chlorides 3. In the catalytic cycle, the reaction of diethyl tartrate 4a with HSiMe(2)Cl 2 gives the chlorosilyl ether 5 with generation of H(2). Alcohol-exchange between the formed chlorosilyl ether 5 and the substrate alcohol 1 affords alkoxychlorosilane 6, which reacts with catalytic GaCl(3) to give the chlorinated product 3. The moderate Lewis acidity of GaCl(3) facilitates chlorination. Strong Lewis acids did not give product due to excessive affinity for the oxy-functionalities. Although tertiary alcohols were chlorinated by this system even in the absence of diethyl tartrate, certain alcohols that are less likely to give carbocationic species were effectively chlorinated using the GaCl(3)/diethyl tartrate system.     

Comparison of gas chromatography-mass spectrometry and capillary electrophoresis in analysis of phenolic compounds extracted from solid matrices with pressurized hot water

Self-constructed pressurized hot water extraction (PHWE) equipment was used in dynamic mode to extract spiked phenolic compounds (phenol, 3-methylphenol, 4-chloro-3-methylphenol and 3,4-dichlorophenol) from sea sand and soil. Phenols were analyzed by both gas chromatography-mass spectrometry (GC-MS) and capillary zone electrophoresis (CZE) to compare the techniques and to find out if CZE is a suitable tool for analysis of phenols extracted from environmental matrix. Good recoveries of phenols spiked in sea sand were achieved at all PHWE temperatures (50, 100, 200, 300 C). GC-MS studies showed that phenols were selectively extracted from soil at 50 C but various other compounds (e.g. polyaromatic hydrocarbons) were extracted along with the phenols at 300 degrees C. In the case of CZE, phenols extracted from the soil, at 300 C were separated with good resolution at pH 9.7, and co-extracted compounds did not interfere with the analysis. The analytical values obtained by GC-MS and CZE were generally of similar magnitude.     

Mutagenicity tests with a permeable mutant of yeast on carcinogens showing false-negative in Salmonella assay

The mutagenicity (Trp+ reversion) of procarcinogens such as N-nitrosodimethylamine, 3,4-benzpyrene and 2-acetylaminofluorene has been detected with the permeable mutant of yeast, Saccharomyces cerevisiae C658-K42. The original strain C658, however, showed a positive response only to N-nitrosodimethylamine with S9 mix. The permeable mutant C658-K42 was employed for mutagenicity tests on 12 carcinogens which had been reported to be non-mutagenic in Salmonella/microsome tests. It was found that phenobarbital, thiourea, 1,2-dimethylhydrazine and 4-aminoantipyrine were mutagenic in the presence of S9 mix. Benzene, o-toluidine and thioacetamide were weakly mutagenic. Negative results were obtained for diethylstilbestrol, safrole, acetamide, urethane and ethionine at the concentrations used. Caprolactam did not show any mutagenic effect on C658-K42 at concentrations up to 20 mg/ml. Sodium azide, which is unlikely to be carcinogenic but is strongly mutagenic in the Ames test, showed a very weak mutagenic effect on C658-K42.     

Searching for an enhanced predictive tool for mutagenicity

The Multiple Computer Automated Structure Evaluation (MCASE) program was used to evaluate the mutagenic potential of organic compounds. The experimental Ames test mutagenic activities for 2513 chemicals were collected from various literature sources. All chemicals have experimental results in one or more Salmonella tester strains. A general mutagenicity data set and fifteen individual Salmonella test strain data sets were compiled. Analysis of the learning sets by the MCASE program resulted in the derivation of good correlations between chemical structure and mutagenic activity. Significant improvement was obtained as more data was added to the learning databases when compared with the results of our previous reports. Several biophores were identified as being responsible for the mutagenic activity of the majority of active chemicals in each individual mutagenicity module. It was shown that the multiple-database mutagenicity model showed a clear advantage over normally used single-database models. The expertise produced by this analysis can be used to predict the mutagenic potential of new compounds.     

Structural studies of organometallic compounds in solution: I. Magnesium iodide in diethyl ether and tetrahydrofuran

The structure of 2.8 M MgI₂ in diethyl ether solution and that of 1.7 M MgI₂ in tetrahydrofuran solution have been determined by large angle X-ray scattering measurements. The measurement on the diethyl ether solution was performed at 44°C, on a phase crystallizing at approximately 30°C. In diethyl ether a dimeric structure is found, arranged in a square-planar fashion. The bond lengths are: MgI 2.652(2), II (diagonal) 3.75(2) and II (linear) 5.30 Å. Three diethyl ether molecules are probably coordinated to each magnesium to complete an octahedral arrangement. In tetrahydrofuran the ion MgI⁺ from a dissociated complex predominates. In the MgI₂ complex a tetrahedral arrangement is found. In both the MgI⁺ and MgI₂ complexes the MgI distance is 2.56(2) Å. In the MgI₂ complex the II distance is 4.44(4) Å. In both solutions the MgO and MgC distances were kept fixed at 2.10 and 3.48 Å, respectively. The solubility of MgI₂ in diethyl ether has been shown to be strongly dependent on the water content of the ether; 0.2 M was the highest concentration obtained in anhydrous diethyl ether.     

西洋参中挥发油化学成分的分析

利用气相色谱－质谱－计算机联用装置分析吉林栽培西洋参挥发油中的化学成分及相对含量。由于没有按照常规的乙醚提取，而紧 ８０％的甲醇提取，因此得到的挥发油成分及含量与文献报道有很大的差别，共鉴定出２３种化合物，其中醌类及酸类约占总挥发油含量的６５％，为该部分挥发油的主要成分。     

银杏叶挥发油化学成分的研究

本文采用气相色谱以及气相色谱-质谱（GC－MS）联用技术对银杏挥发油的化学成分进行了研究，初步鉴定出其中的17种化合物。研究表明，挥发油中棕润酸和2，6-二特丁基-4-甲基苯酚的含量较高。     

基于不同萃取剂的生物油常压蒸馏研究

选用乙酸乙酯、二氯甲烷、乙醚和甲苯四种溶剂,分别与生物油按一定质量比混合萃取。将萃取相蒸馏得到的四种油相层与原始生物油进行对比,研究不同萃取剂对生物油萃取-蒸馏后各馏分的产率、水分及高附加值酚类组分变化的影响。结果表明,经萃取-蒸馏后,生物油残渣比例减少,水分含量降低。在四种溶剂中,甲苯萃取率较低,蒸馏后酚类绝对峰面积较小;乙酸乙酯和乙醚萃取效率较高,但两者萃取相蒸馏后酚类含量低;二氯甲烷萃取酚类能力强,其馏分中愈创木酚及其衍生物相对含量为34.11%,比生物油高出15.52%,富集程度高,更有利于后续进一步提纯愈创木酚及其衍生物等高附加值化学品。     

Separation and identification of bioactive compounds in Anabasis articulata (Forsk) Moq. roots

In the present paper, for the first time, we are interested to separate and identify some bioactive fractions isolated from the roots of a Saharan plant Anabasis articulata, which is widely used in traditional medicine against cancer. The crude methanolic extract of the roots was fractionated on column chromatography, and eluted with dichloromethane/methanol each time with increasing polarity of methanol; 17 fractions were separated. One of these fractions named F12 showed more antioxidant activity to scavenge DPPH free radical with percentage inhibition of 95.29%. F12 was separated by thin-layer chromatography (TLC) to give 12 compounds. A second preparative TLC of compound 2, which has antioxidative activity of 74.92%, provided the three phenolic acids M1, M2 and M3, analysed by high-performance liquid chromatography and UV–visible spectrophotometry.     

Mutagenicity of flavonoids assayed by bacterial reverse mutation (Ames) test

The mutagenicity of ten flavonoids was assayed by the Ames test, in Salmonella typhimurium strains TA98, TA100 and TA102, with the aim of establishing hydroxylation pattern-mutagenicity relationship profiles. The compounds assessed were: quercetin, kaempferol, luteolin, fisetin, chrysin, galangin, flavone, 3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone. In the Ames assay, quercetin acted directly and its mutagenicity increased with metabolic activation. In the presence of S9 mix, kaempferol and galangin were mutagenic in the TA98 strain and kaempferol showed signs of mutagenicity in the other strains. The absence of hydroxyl groups, as in flavone, only signs of mutagenicity were shown in strain TA102, after metabolization and, among monohydroxylated flavones (3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone), the presence of hydroxyl groups only resulted in minor changes. Luteolin and fisetin also showed signs of mutagenicity in strain TA102. Finally, chrysin, which has only two hydroxy groups, at the 5-OH and 7-OH positions, also did not induce mutagenic activity in any of the bacterial strains used, under either activation condition. All the flavonoids were tested at concentrations varying from 2.6 to 30.7 nmol/plate for galangin and 12.1 to 225.0 nmol/plate for other flavonoids. In light of the above, it is necessary to clarify the conditions and the mechanisms that mediate the biological effects of flavonoids before treating them as therapeutical agents, since some compounds can be biotransformed into more genotoxic products; as is the case for galangin, kaempferol and quercetin.     

Identification of some polycyclic nitrogen-containing compounds in coal-derived oil

A systematic method for the identification of aza-arenes in coal-derived oil was developed. The basic nitrogen-containing substances were extracted with 6 M hydrochloric acid and fractionated sequentially by using gel chromatography and thin-layer chromatography (TLC) on an alumina plate. The aza-arenes in these fractions were separated by using glass capillary gas chromatography. Individual compounds in the column effluent were trapped in a system consisting of a valve for flow switching and a trapping tube made from a glass capillary. The fluorescence spectra of nanogram to subnanogram amounts of trapped compounds were measured. Some attempts were made to identify components based on their TLC RF values and their fluorescence spectra, in addition to their mass spectra.     

Catalytic alkylation of aryl Grignard reagents by iron(III) amine-bis(phenolate) complexes

Reaction of n-propylamino-N,N-bis(2-methylene-4-tert-butyl-6-methylphenol), H(2)L1, n-propylamino-N,N-bis(2-methylene-4,6-di-tert-butylphenol), H(2)L2, and benzylamino-N,N-bis(2-methylene-4-tert-butyl-6-methylphenol), H(2)L3, with anhydrous ferric chloride in the presence of base yields the products, [FeL1(μ-Cl)](2) (1), [FeL2(μ-Cl)](2) (2) and [FeL3(μ-Cl)](2) (3). In the solid state, these complexes exist as chloride-bridged dimers giving distorted trigonal bipyramidal iron(III) ions. Reaction of H(2)L1 with FeBr(3), however, results in the formation of a tetrahedral iron(III) complex possessing two bromide ligands. The amine-bis(phenolate) ligand is bidentate in this complex and bonds to the iron(III) ion via the phenolate O-donors. The central amine donor is protonated, resulting in a quaternized ammonium fragment and the iron(III) centre possesses a negative formal charge. As a result, this complex is zwitterionic and formulated as FeBr(2)L1H (4). Complex 1 is an air-stable, non-hygroscopic, single-component catalyst for C-C cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides, including chlorides. Good to excellent yields of cross-coupled products are obtained in diethyl ether at room temperature. In some cases where low yields are obtained under these conditions, the use of microwave-assisted heating of the reaction mixture can improve yields.     

Gas chromatographic-mass spectrometric determination of oxolinic acid in fish using selected ion monitoring

A gas chromatographic-mass spectrometric (GC-MS) method is described for the determination of oxolinic acid in fish tissues. oxolinic acid is reduced with sodium tetrahydroborate to permit GC analysis. The sample is homogenized with phosphate buffer (pH 6) and extracted with ethyl acetate. The extract is partitioned between sodium hydrogencarbonate solution and the aqueous phase is acidified and re-extracted with ethyl acetate. The residue from the ethyl acetate extract is dissolved in methanol and reduced with sodium tetrahydroborate. The reduction product is extracted with diethyl ether and analysed by GC-MS in the selected ion monitoring mode for the ions at m/z 204, 219 and 176. The detection limit is 0.001 mg/kg and the recoveries were 95.6% [relative standard deviation (R.S.D.) 7.7%] at 0.1 mg/kg and 72.9% (R.S.D. 13.3%) at 0.01 mg/kg fortification levels in fish.     

The Phenolic Compounds Profile and Cosmeceutical Significance of Two Kazakh Species of Onions: Allium galanthum and A. turkestanicum

Numerous species of Allium genus have been used in the traditional medicine based on their vast biological effects, e.g., antimicrobial, digestion stimulant, anti-sclerotic, soothing, antiradical or wound healing properties. In this work, unpolar and polar extracts from two lesser-investigated species of Allium growing in Kazakhstan, Allium galanthum Kar. & Kir. (AG) and A. turkestanicum Regel. (AT), were studied for their composition and biological effects. In the HPLC-ESI-QTOF-MS/MS analyses of water and alcoholic extracts simple organic acids, flavonoids and their glycosides were found to be the best represented group of secondary metabolites. On the other hand, in the GC-MS analysis diethyl ether, extracts were found to be rich sources of straight-chain hydrocarbons and their alcohols, fatty acids and sterols. The antimicrobial activity assessment showed a lower activity of polar extracts, however, the diethyl ether extract from AT bulbs and AG chives showed the strongest activity against Bacillus subtilis ATCC 6633, B. cereus ATCC 10876, some species of Staphylococcus (S. aureus ATCC 25923 and S. epidermidis ATCC 12228) and all tested Candida species (Candida albicans ATCC 2091, Candida albicans ATCC 10231, Candida glabrata ATCC 90030, Candida krusei ATCC 14243 and Candida parapsilosis ATCC 22019) with a minimum inhibitory concentration of 0.125–0.5 mg/mL. The highest antiradical capacity exhibited diethyl ether extracts from AG bulbs (IC50 = 19274.78 ± 92.11 mg Trolox eq/g of dried extract) in DPPH assay. In ABTS scavenging assay, the highest value of mg Trolox equivalents, 50.85 ± 2.90 was calculated for diethyl ether extract from AT bulbs. The same extract showed the highest inhibition of mushroom tyrosinase (82.65 ± 1.28% of enzyme activity), whereas AG bulb ether extract was the most efficient murine tyrosinase inhibitor (54% of the enzyme activity). The performed tests confirm possible cosmeceutical applications of these plants.     

Composition of semivolatile compounds of 10 Cinnamomum species from China and Myanmar

The semivolatile composition of stem-bark of 10 Cinnamomum species, collected from China and Myanmar, were obtained by extraction with diethyl ether and analyzed by GC-FID and GC-MS. Identification of the substances was made by comparison of standards, mass spectra, and retention indices with literature records. Total of 74 compounds were identified. All data were statistically processed with principal component analysis and cluster analysis. Cinnamaldehyde and alpha-cubebene were found as the common constituent of the investigated population. Except Cinnamomum multiflorum, volatile terpenoids were the main constituents of all taxa. Major constituent of C. multiflorum was phenylpropanoid. Cluster subset gave the information that chemical components variation was influenced by geographical sources. Here, the first information on the semivolatile composition of six never investigated species viz. C. multiflorum, C. obtusifolium, C. inunctum, C. chartophyllum, C. pathenoxylon, and C. glanduliferum. Furthermore, those species could be alternative source of bioactive compounds.     

Development of a test system for mutagenicity of photosensitizers using Drosophila melanogaster

In the past few years, there has been an increase in the application of photosensitizers for medical purposes. A good standardized test system for the evaluation of the mutagenic potentials of photosensitizers is therefore an indispensable device. In the standard Ames test, white light itself was proven to be mutagenic and the result influenced by the light source. Lack of a reliable positive control is another problem in many genotoxicity test systems used for the evaluation of mutagenicity of photosensitizers. Based on the validated somatic mutation and recombination test, known as SMART, and using Drosophila melanogaster, we developed the Photo-SMART and demonstrated that methylene blue, known to induce photomutagenicity, can act as a positive control in the presented test system. The SMART scores for the loss of heterozygosity caused predominantly by homologous mitotic recombination. The Photo-SMART can be used to detect photogenotoxicity caused by short-lived photoproducts or by stable photoproducts or both. We demonstrated the Photo-SMART to be a good standardized test system for the evaluation of mutagenic potentials of the photosensitizer 5,10,15-tris(4-methylpyridinium)-20-phenyl-[21H,23H]-porphine trichloride (TPP). We demonstrated that TPP was mutagenic using the Photo-SMART. For hematoporphyrin, the results of the Photo-SMART indicate the absence of mutagenicity.     

Comparative Studies of the (Anti) Mutagenicity of Baccharis dracunculifolia and Artepillin C by the Bacterial Reverse Mutation Test

Baccharis dracunculifolia is a plant native from Brazil, commonly known as 'Alecrim-do-campo' and 'Vassoura' and used in alternative medicine for the treatment of inflammation, hepatic disorders and stomach ulcers. Previous studies reported that artepillin C (ArtC, 3-{4-hydroxy-3,5-di(3-methyl-2-butenyl)phenyl}-2(E)-propenoic acid), is the main compound of interest in the leaves. This study was undertaken to assess the mutagenic effect of the ethyl acetate extract of B. dracunculifolia leaves (Bd-EAE: 11.4-182.8 μg/plate) and ArtC (0.69-10.99 μg/plate) by the Ames test using Salmonella typhimurium strains TA98, TA97a, TA100 and TA102, and to compare the protective effects of Bd-EAE and ArtC against the mutagenicity of a variety of direct and indirect acting mutagens such as 4-nitro-O-phenylenediamine, sodium azide, mitomycin C, benzo[a]pyrene, aflatoxin B1, 2-aminoanthracene and 2-aminofluorene.The mutagenicity test showed that Bd-EAE and ArtC did not induce an increase in the number of revertant colonies indicating absence of mutagenic activity. ArtC showed a similar antimutagenic effect to that of Bd-EAE in some strains of S. typhimurium, demonstrating that the antimutagenic activity of Bd-EAE can be partially attributed to ArtC. The present results showed that the protective effect of whole plant extracts is due to the combined and synergistic effects of a complex mixture of phytochemicals, the total activity of which may result in health benefits.     

Structural and Quantitative Analyses of 4-Chloroaniline-Derived Oligomers

Abstract

The oxidation of 4-chloroaniline by a peroxidase resulted in eight oligomeric products. A reverse-phase high performance liquid chromatography (HPLC) method was developed so that substrate disappearance and the corresponding product formations could be quantitatively monitored. The product mixture was isolated from the aqueous reaction solution with solid-phase extraction and the extract components were separated by thin-layer chromatography (TLC). The individual TLC bands were extracted for mass spectrometric and proton nuclear magnetic resonance analyses. The product mixture was found to contain dimers, trimers, and tetramers with benzoquinone monoimine, benzopuinone di-mine, diaminobenzene, and azobenzene structures. Analytical methodologies were specific for the study of the oxidative transformation of 4-chloroaniline, but they should be applicable to other anilinederived oligomers.