The Constituents Relate to Anti-oxidative and α-Glucosidase Inhibitory Activities in Yacon Aerial Part Extract

• Published in: YAKUGAKU ZASSHI Vol. 126; no. 8; pp. 665 - 669
• Main Authors: TERADA, Sumio, ITO, Kikuo, YOSHIMURA, Akira, NOGUCHI, Naoto, ISHIDA, Takashi
• Format: Journal Article
• Language: Japanese
• Published: The Pharmaceutical Society of Japan 01.08.2006
• Subjects: antioxidant; Smallanthus sonchifolia; tricaffeoylaltraric acid; Yacon; α-glucosidase inhibitory activity
• ISSN: 0031-6903; 1347-5231
• DOI: 10.1248/yakushi.126.665

Hot water extract of the aerial part of Yacon (Smallanthus sonchifolia, Compositae) showed potent free radical-scavenging activity and inhibitory effects on lipid peroxidation in rat brain homogenate. The most potent antioxidative activity focused on the 50% MeOH-eluted fraction on DIAION HP-20 column chromatography. The structure of the major component in the fraction was identified as 2,3,5-tricaffeoylaltraric acid (TCAA) based on spectroscopic evidence. The antioxidative activity of TCAA is superior to that of natural antioxidants such as (±)-catechin, α-tocopherol, and ellagic acid, and TCAA also showed selective maltase-inhibitory activity (IC50 49 μg/ml). As the hypoglycemic activity of Yacon extract was described in a previous report, the present results showing that the aerial part of Yacon has strong antioxidative activity may encourage its potential use as a food supplement to prevent type II diabetes.