Alkaloids from the leaves of Uncaria rhynchophylla and their inhibitory activity on NO production in lipopolysaccharide-activated microglia

作者：Yuan Dan^*; Ma Bin; Wu Chunfu; Yang Jingyu; Zhang Lijia; Liu Suiku; Wu Lijun; Kano Yoshihiro

来源：Journal of Natural Products, 2008, 71(7): 1271-1274.

DOI：10.1021/np8000305

Two new isomeric alkaloids, 18,19-dehydrocorynoxinic acid B (1) and 18,19-dehydrocorynoxinic acid (2), were isolated from the CHCl(3) extract of the leaves of Uncaria rhynchophylla, together with four known rhynchophylline-type alkaloids, corynoxeine (3), isocorynoxeine (4), rhynchophylline (5), and isorhynchophylline (6), and an indole alkaloid glucoside, vincoside lactam (7). The structures of compounds 1 and 2 were elucidated by spectroscopic methods including UV, IR, HREIMS, ID and 2D NMR, and CD experiments. The activity assay showed that compounds 3-6, with a C-16 carboxylic ester group, and 7 exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary cultured rat cortical microglia (IC(50): 13.7-19.0 mu M). However, only weak inhibitory activity was observed for compounds 1 and 2, with a C-16 carboxylic acid group (IC(50): > 100 mu M).

• 出版日期2008-7
• 单位沈阳药科大学