In the present paper, a fast and economical HPLC method [on a Phenomenex Polar-RP column with a solution of (phosphoric acid:triethylamine:dibutylamine:water = 0.40:0.1:0.2:499.3) and methanol] is developed, and applied for the determination of norephedrine, norpseudoephedrine, ephedrine (E), pseudoephedrine (PE) and methylephedrine (ME) in 64 samples of three species from main habitats in China. Quantitation data showed that total alkaloid content in Ephedra equisetina Bge. (2.708 ± 0.642%) is higher than that in E. sinica Stapf. (1.365 ± 0.624%) and E. intermedia Schrenk et C. A. Mey. (1.537 ± 0.746%), but the range of total alkaloid content in each species is so wide that the ranges of the three species greatly overlap. The contents of E, PE and ME are different among the three species. The ratio E/total alkaloid content and ratio E/PE as well as E and ME contents can be used for identification of E. sinica, E. intermedia and E. equisetina from one another.
An HPLC-PAD-MS(n) method was employed to profile the phenolic compounds of the aerial part of Artemisia pectinata (Neopallasia pectinata), a plant with no previous reports concerning its phenolic constituents. Three isomers of trans-caffeoylquinic acid accompanied by cis-5-caffeoylquinic acid, six isomers of trans-dicaffeoylquinic acid, two isomers of methyl trans-dicaffeoylquinate (including one new isomer), a trans-caffeoylferuloylquinic acid and three flavanoids were identified unambiguously by analysis of their UV and MS(n) spectra in comparison with standard compounds that were isolated from natural sources, or synthesised, or were surrogate standards (green coffee extract). Other compounds were identified by analysis of their UV and MSn data in comparison with those reported in the literature. MS(n) experiments also suggested the presence of groups of dicaffeoylquinic acid glycosides, caffeoylquinic acid diglycosides, caffeoylquinic acid glycosides and quinic acid diglycosides.
Three new cardenolides, 3-O-beta-D-fucopyranosylstrophanthidin (1), 3-O-beta-D-quinovopyranosylperiplogenin (2), and 3-O-beta-D-glucopyranosyl-(1 --> 4)-alpha- l-rhamnopyranosylcannogenin (3), together with seven known cardenolides (4- 10), were isolated from a cytotoxic ethanol extract of the whole dried plants of Saussurea stella. The structures of these compounds were established by spectroscopic and chemical methods. When the cytotoxicity of compounds 2- 10 toward Bel-7402 human hepatoma cells and BGC-823 human gastric cancer cells was evaluated, all compounds showed IC 50 values of<1 microM for both cell lines. This is the first report of cardenolides occurring in a species of the family Asteraceae.
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