title: New flavanol and cycloartane glucosides from Landoltia punctata.
abstract: Chemical investigation on the constituents of Landoltia punctata led to the isolation and identification of 17 compounds, four of which were new and identified as (3b,24S)-9,19-cycloartane-3,22,24,25-tetraol 3-O-[b-D-glucopyranosyl-(1→2)]-[b-D-glucopyranosyl-(1→6)]-b-D-glucopyranoside (1), (3b,24S)-9,19-cycloartane-3,24,25-triol 3-O-[b-d-glucopyranosyl-(1→2)]-[b-D-glucopyranosyl-(1→6)]-b-D-glucopyranoside (2), 3,4'-dihydroxy-7,3'-dimethoxyflavan-5-O-b-D-glucopyranoside (3) and 3,4'-dihydroxy-4,7,3'-trimethoxyflavan-5-O-b-D-glucopyranoside (4). Their structures were elucidated by spectroscopic, chemical, and biochemical methods. Thus, cycloartane triterpenoids were discovered in the Lemnaceae family for the first time. Compound 3 showed antioxidant capacity in the positively charged 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical (ABTS+•) and superoxide anion radical scavenging assays.
authors.affiliation: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
authors.forename: Nini
authors.initials: N
authors.lastname: Wang
authors.affiliation: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
authors.forename: Guobo
authors.initials: G
authors.lastname: Xu
authors.affiliation: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.affiliation: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China. zhaohai@cib.ac.cn.
authors.forename: Hai
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China. ligy@cib.ac.cn.
authors.forename: Guoyou
authors.initials: G
authors.lastname: Li
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D029064:Araceae / Q000737:chemistry*; D001234:Aspergillus niger / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry; D015394:Molecular Structure; D012441:Saccharomyces cerevisiae / Q000187:drug effects; D014315:Triterpenes / Q000737:chemistry
chemical_list: D000890:Anti-Infective Agents; D000975:Antioxidants; D005419:Flavonoids; D005960:Glucosides; D014315:Triterpenes; C085352:cycloartane