title: Stilbenoids isolated from the seeds of Melinjo (Gnetum gnemon L.) and their biological activity.
abstract: A 50% EtOH extract of the dried endosperms of melinjo (Gnetum gnemon L.) was purified by a combination of column chromatography, including highly porous polymer, octadecylated silica (ODS), hydroxypropylated dextran (LH-20), and silica gel, resulting in the isolation of a new stilbenoid 1, named gnetin L, along with five previously identified stilbenoids 2-6 (gnetin C, gnemonosides A, C, and D, and resveratrol). All of these stilbenoids showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity similar to that of ascorbic acid and dl-alpha-tocopherol. With the exception of gnemonoside A (3), these stilbenoids showed moderate antimicrobial activity. Inhibition of lipase from porcine pancreas was recognized in four stilbenoids excluding gnemonoside A (3) and resveratrol (6). Gnetin C (2), gnemonoside C (4), and gnemonoside D (5) inhibited the hydrolysis of starch by alpha-amylase from porcine pancreas. An EtOH extract containing these stilbenoids also showed DPPH radical scavenging effect, lipase and alpha-amylase inhibition activity, and antimicrobial activity against food microorganisms and enterobacteria. The present study indicates that melinjo and extracts containing these constituents are useful as health supplements.
authors.affiliation: Hosoda SHC Company Ltd, Miyuki, Fukui, Japan.
authors.forename: Eishin
authors.initials: E
authors.lastname: Kato
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tokunaga
authors.forename: Fujio
authors.initials: F
authors.lastname: Sakan
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology; D001572:Benzofurans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D035684:Gnetum / Q000737:chemistry*; D008049:Lipase / Q000037:antagonists & inhibitors; D010179:Pancreas / Q000201:enzymology; D012639:Seeds / Q000737:chemistry*; D013267:Stilbenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000516:alpha-Amylases / Q000037:antagonists & inhibitors
chemical_list: D000890:Anti-Infective Agents; D001572:Benzofurans; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D013267:Stilbenes; C575740:gnetin C; C519613:gnetin E; C540359:gnetin L; D008049:Lipase; D000516:alpha-Amylases