title: Alkaloids from the leaves of Uncaria rhynchophylla and their inhibitory activity on NO production in lipopolysaccharide-activated microglia.
abstract: 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 (IC 50: 13.7-19.0 microM). However, only weak inhibitory activity was observed for compounds 1 and 2, with a C-16 carboxylic acid group (IC 50: >100 microM).
authors.affiliation: Department of Traditional Chinese Medicines, Shenyang Pharmaceutical UniVersity, 103 Wenhua Road, Shenyang 110016, People's Republic of China. yuandan_kampo@163.com
authors.forename: Dan
authors.initials: D
authors.lastname: Yuan
authors.forename: Bin
authors.initials: B
authors.lastname: Ma
authors.forename: Chunfu
authors.initials: C
authors.lastname: Wu
authors.forename: Jingyu
authors.initials: J
authors.lastname: Yang
authors.forename: Lijia
authors.initials: L
authors.lastname: Zhang
authors.forename: Suiku
authors.initials: S
authors.lastname: Liu
authors.forename: Lijun
authors.initials: L
authors.lastname: Wu
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kano
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000818:Animals; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D017628:Microglia / Q000187:drug effects; D015394:Molecular Structure; D009569:Nitric Oxide / Q000096:biosynthesis*; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D051381:Rats; D032070:Uncaria / Q000737:chemistry*
chemical_list: C531543:18,19-dehydrocorynoxinic acid; C531542:18,19-dehydrocorynoxinic acid B; D000470:Alkaloids; D004365:Drugs, Chinese Herbal; D008070:Lipopolysaccharides; D009569:Nitric Oxide