Alkaloids from the Leaves of Uncaria rhynchophylla and Their Inhibitory Activity on NO Production in Lipopolysaccharide-Activated Microglia

详细信息    查看全文

• 作者：Dan Yuan ; Bin Ma ; Chunfu Wu ; Jingyu Yang ; Lijia Zhang ; Suiku Liu ; Lijun Wu ; Yoshihiro Kano
• 刊名：Journal of Natural Products
• 出版年：2008
• 出版时间：July 2008
• 年：2008
• 卷：71
• 期：7
• 页码：1271-1274
• 全文大小：123K
• 年卷期：v.71,no.7(July 2008)
• ISSN：1520-6025

文摘

Two new isomeric alkaloids, 18,19-dehydrocorynoxinic acid B (1) and 18,19-dehydrocorynoxinic acid (2), were isolated from the CHCl₃ 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, 1D 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 (IC₅₀: 13.7−19.0 μM). However, only weak inhibitory activity was observed for compounds 1 and 2, with a C-16 carboxylic acid group (IC₅₀: >100 μM).