Chemical constituents from stems of Uncaria scandens / 中草药

ABSTRACT

Objective: To study the chemical constituents from the stems of Uncaria scandens. Methods: The compounds were isolated and purified by silica gel column chromatography, Sephadex LH-20, RP18, and HPLC. The structures were identified by spectroscopic methods and physicochemical properties. The contents of rhynchophylline and isorhynchophylline were detected by HPLC method. Results: Seventeen compounds were isolated and identified from 95% ethanol extract of the stems of U. scandens and characterized as 5α-carboxystrictosidine (1), 3β-isodihydrocadambine (2), strictosamide (3), 3α-dihydrocadambine (4), mitraphylline (5), uncarine F (6), 3β-isodihydrocadambine 4-oxide (7), isodihydrocdambine (8), nauclefine (9), cadambine (10), calyxamine B (11), methyl chlorogenate (12), 3,4,5-trimethoxyphenol (13), α-tocopherylquinone (14), quinovic acid (15), methyl caffeate (16), and hyperoside (17). The contents of rhynchophylline and isorhynchophylline from U. scandens were 0.72 and 0.38 μg/g. Conclusion: Compounds 7-9 and 11-14 are isolated from Uncaria genus for the first time. Compounds 1-6 and 16, 17 are isolated from U.scandens for the first time. The contents of rhynchophylline and isorhynchophylline is low and the reasonable use of them as U. scandens in some areas needs to be further verified.