Simultaneous determination of four anthraquinones in Polygonum multiflorum by QAMS / 中国中药杂志

A simple, specific and selective quantitative analysis of multi-components by single marker(QAMS) method for simultaneous determination of anthraquinones and anthraquinone glycosides in Polygonum multiflorum was developed. Four main anthraquinones and its glycosides, emodin, emodin-8-O-β-D-glucoside, physcion and physcion-8-O-β-D-glucoside were selected as analytes to evaluate the quality of P. multiflorum. Emodin was used as the internal standard, and the relative correction factors(RCFs) between emodin and the other three anthraquinones were calculated. Comparison of the contents of the four components in 30 batches of P. multiflorum from different regions and 12 batches decoction pieces from different manufacturers by QAMS and external standard method(ESM) showed that there was no significant difference between QAMS and ESM for quantification of the four main components by using relative error results, and the QAMS method was accurate and reliable, and had a good repeatability. In addition, compared with the results calculated by the difference method between total anthraquinone and free anthraquinone in the content determination of P. multiflorum in Chinese Pharmacopoeia, the results of direct determination combined anthraquinone by QAMS were very close to that by measured the external standard method. Therefore, simultaneous quantification of four main anthraquinones by using QAMS is suitable to evaluate the quality of P. multiflorum. Then the optimized assay method of the combined anthraquinone contents showed simple and feasible, which could be replaced and improved the quantification method of the combined anthraquinone in the current Chinese Pharmacopeia.

Evaluation of chemical quality profile of Polygoni Multiflori Radix at different processing degrees based on its classic processing method "nine-steaming and nine-sun-curing" / 中国中药杂志

Based on the ancient method of nine-steaming and nine-sun-curing,the chemical composition changes and quality profiles in different processes of Polygoni Multiflori Radix were studied. Their contents of stilbene glycoside,anthraquinones and polysaccharides were determined by nine-steaming and nine-sun-curing with black bean juice and pharmacopoeia method. HPLC chemical fingerprints were established,and orthogonal partial least squares-discriminant analysis( OPLS-DA) was performed on different processed products using SIMCA 14. 1 software to evaluate the quality difference between samples. The results of content determination show that,with the increase of the number of processing and steaming times,the stilbene glycoside and the combined anthraquinone showed a decreasing trend,and the free anthraquinone,total anthraquinone and polysaccharide showed an upward trend in the different preparations of Polygoni Multiflori Radix and Pharmacopoeia. Six-steamed and six-sun-cured products can be used as the finishing point for the classic steaming. Fingerprint results showed that there were significant differences in chemical composition in Polygoni Multiflori Radix at different processing processes. It can be identified stilbene glycoside( peak 13),emodin( peak 21),and physcion( peak 24). By comparing the relative peak areas of the 26 chromatographic peaks in the sample after normalization( the reference is peak 7),it was found that the relative peak areas of 12 peaks in the processed products were higher than the raw products,13 peaks were reduced; according to statistical analysis of OPLS-DA,Polygoni Multiflori Radix at different processing degrees was further divided into three categories,sample S1 was class I,S2-S5 were class Ⅱ,and S6-S11 were class Ⅲ． And 8 peaks with the VIP value higher than 1. 0 were peak 13,21,4,3,11,14,5,and 24 in order. The eight chemical components were the main components to distinguish the difference between Polygoni Multiflori Radix in the process of nine-steaming and nine-sun-curing,suggesting that it was rational to use stilbene glycoside,emodin and emodin methyl ether as quality control indicators of Polygoni Multiflori Radix. The method established in this experiment conformed to the methodological verification requirements,established a method of multi-component content determination combined with fingerprint,and clarified that six-steaming and six-sun-curing was used as an improved classical processing technology,and more clearly defined the whole dynamic change of chemical composition in Polygoni Multiflori Radix by nine-steaming and ninesun-curing process. It provides a basis for the chemical quality evaluation model about different processed products of Polygoni Multiflori Radix.

Phytochemical and toxicological investigations of crude methanolic extracts, subsequent fractions and crude saponins of Isodon rugosus

BACKGROUND: Isodon rugosus is used traditionally in the management of hypertension, rheumatism, tooth-ache and pyrexia. Present study was arranged to investigate I. rugosus for phytoconstituents, phytotoxic and cytotoxic activities to explore its toxicological, pharmacological potentials and to rationalize its ethnomedicinal uses. Briefly, qualitative phytochemical analysis of the plant extracts were carried out for the existence of alkaloids, flavonoids, saponins, oils, glycosides, anthraquinones, terpenoids, sterols and tannins. Plant crude methanolic extract (Ir.Cr), its subsequent fractions; n-hexane (Ir.Hex), chloroform (Ir.Chf), ethyl acetate (Ir.EtAc), aqueous (Ir.Aq) and saponins (Ir.Sp) in different concentrations were tested for phytotoxic and cytotoxic activities using radish seeds and brine shrimps (Artemia salina) respectively. The phytotoxic activity was determined by percent root length inhibition (RLI) and percent seeds germination inhibition (SGI) while the cytotoxicity was obtained with percent lethality of the brine shrimps. RESULTS: Ir.Cr was tested positive for the presence of alkaloids, glycosides, flavonoids, oils, terpenoids, saponins, tannins and anthraquinones. Among different fractions Ir.Sp, Ir.Chf, Ir.EtAc, and Ir.Cr were most effective causing 93.55, 89.32, 81.32 and 58.68% inhibition of seeds in phytotoxicity assay, with IC50 values of 0.1, 0.1, 0.1 and 52 µg/ml respectively. Similarly, among all the tested samples, Ir.Sp exhibited the highest phytotoxic effect causing 91.33% root length inhibition with IC50 of 0.1 µg/ml. Ir.Sp and Ir.Chf were most effective against brine shrimps showing 92.23 and 76.67% lethality with LC50 values of 10 and 12 µg/ml respectively. CONCLUSIONS: It may be inferred from the current investigations that I. rugosus contains different secondary metabolites and is a potential source for the isolation of natural anticancer and herbicidal drug molecules. Different fractions exhibited phytotoxic and cytotoxic activities, thus providing pharmacological basis for ethnomedicinal uses of this plant.

Phytochemical and antioxidant studies of Laurera benguelensis growing in Thailand

The aim of this study was to investigate metabolites of the lichen Laurera benguelensis. A high-performance liquid chromatographic (HPLC) method has been developed for the characterization of xanthones and anthraquinones in extracts of this lichen. Lichexanthone, secalonic acid D, norlichexanthon, parietin, emodin, teloschistin and citreorosein were detected in the lichen samples, which were collected from two places in Thailand. Components of the lichen were identifed by relative retention time and spectral data. This is the frst time that a detailed phytochemical analysis of the lichen L. benguelensis was reported and this paper has chemotaxonomic signifcance because very little has been published on the secondary metabolites present in Laurera species. Some of the metabolites were detected for the frst time in the family Trypetheliaceae. The results of preliminary testing of benzene extract and its chloroform and methanol fractions showed that all samples showed a weak radical scavenging activity. The chloroform extract showed the highest antioxidant activity.