Further isolation of glycosides from Cynanchum hancockianum

Ethnobotany, Phytochemistry and Pharmacological Effects of Plants in Genus Cynanchum Linn. (Asclepiadaceae)

Genus Cynanchum L. belongs to the family Asclepiadaceae, which comprise more than 200 species distributed worldwide. In Chinese medical practice, numerous drugs (such as tablets and powders) containing different parts of plants of this genus are used to treat snake bites, bruises, osteoblasts, rheumatoid arthritis and tumors. A search for original articles published on the cynanchum genus was performed by using several resources, including Flora of China Official Website and various scientific databases, such as PubMed, SciFinder, the Web of Science, Science Direct, and China Knowledge Resource Integrated (CNKI). Advances in the botanical, ethnomedicinal, phytochemical, and pharmacological studies of this genus are reviewed in this paper. Results showed that more than 440 compounds, including C21 steroids, steroidal saponins, alkaloids, flavonoids and terpene, have been isolated and identified from Cynanchum plants up to now. In vivo and in vitro studies have shown that plants possess an array of biological activities, including anti-tumor, neuroprotective and anti-fungal effects. Popular traditional prescription of Cynanchum sp. was also summed up in this paper. However, many Cynanchum species have received little or no attention. Moreover, few reports on the clinical use and toxic effects of Cynanchum sp. are available. Further attention should be focused on the study of these species to gather information on their respective toxicology data and relevant quality-control measures and clinical value of the crude extracts, active compounds, and bioactive metabolites from this genus. Further research on Cynanchum sp. should be conducted, and bioactivity-guided isolation strategies should be emphasized. In addition, systematic studies of the chemical composition of plants should be enhanced.

A new C21 steroidal glycoside from Cynanchum inamoenum (Maxim.) Loes

A new C21 steroidal glycoside, 5beta,6beta-epoxy-glaucogenin C-3-O-beta-D-glucopyranosyl-(1 --> 4)-beta-d-glucopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-beta-D-oleandropyranosyl-(1 --> 4)-beta-D-oleandropyranoside, named inamoside D (1), was isolated from the MeOH extract of the roots of Cynanchum inamoenum (Maxim.) Loes (Asclepiadaceae). In addition, five known compounds, including 7-demethoxytylophorine (2), dehydrodiconiferyl alcohol gamma'-O-beta-D-glucopyranoside (3), beta-d-fructofuranosyl-(2 --> 1)-alpha-D-(6-O-sinapoyl)-glucopyranoside (4), neohancoside C (5), and cuchiloside (6), have also been isolated. The structure of 1 was determined by 1D- and 2D-NMR spectroscopies. All the compounds were isolated from this plant for the first time.

High-performance liquid chromatographic determination of phenolic compounds in rice

A method has been developed for the determination of 6'-O-feruloylsucrose, 6'-O-sinapoylsucrose, ferulic acid, sinapinic acid, p-coumaric acid, chlorogenic (3-caffeoylquinic) acid, caffeic acid, protocatechuic acid, hydroxybenzoic acid, vanillic acid, and syringic acid in rice. The rice samples were extracted with 70% ethanol, filtered, and defatted. The defatted aqueous solution was subjected to solid-phase extraction using a C18 silica gel cartridge; no analyte was lost in this procedure. The 70% acidic methanol elution was analyzed directly by HPLC and HPLC-ESI-MS. Phenolic compounds were separated with a C18 reversed-phase column by gradient elution using 0.025% trifluoroacetic acid in purified water (A)--acetonitrile (B) (0 min, 5% B; 5 min, 9% B; 15 min, 9% B; 22 min, 11% B; and 38 min, 18% B) as the mobile phase at a flow rate of 0.8 ml/min. Detection limits ranged from 0.10 to 0.35 ng per injection (5 microl). Relative standard deviations of 0.22-3.95% and recoveries of 99-108% were obtained for simultaneous determination of these phenolic compounds. This method was applied to analysis of phenolic compounds in brown rice and germinated brown rice soaked in 32 degrees C water for varying durations.