Characterization and Identification of Bioactive Polyphenols in the Trapa
bispinosa Roxb. Pericarp Extract |
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| Authors: | Yuji Iwaoka Shoichi Suzuki Nana Kato Chisa Hayakawa Satoko Kawabe Natsuki Ganeko Tomohiro Uemura Hideyuki Ito |
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| Institution: | 1.Department of Nutritional Science, Faculty of Health and Welfare Sciences, Okayama Prefectural University, Okayama 719-1197, Japan; (Y.I.); (S.S.); (N.K.); (C.H.); (S.K.); (N.G.);2.Hayashikane Sangyo Co., Ltd., 2-4-8 Yamatomachi, Shimonoseki 750-8608, Japan; |
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| Abstract: | In this study, we present the isolation and characterization of the structure of six gallotannins (1–6), three ellagitannins (7–9), a neolignan glucoside (10), and three related polyphenolic compounds (gallic acid, 11 and 12) from Trapa bispinosa Roxb. pericarp extract (TBE). Among the isolates, the structure of compound 10 possessing a previously unclear absolute configuration was unambiguously determined through nuclear magnetic resonance and circular dichroism analyses. The α-glucosidase activity and glycation inhibitory effects of the isolates were evaluated. Decarboxylated rugosin A (8) showed an α-glucosidase inhibitory activity, while hydrolyzable tannins revealed stronger antiglycation activity than that of the positive control. Furthermore, the identification and quantification of the TBE polyphenols were investigated by high-performance liquid chromatography coupled to ultraviolet detection and electrospray ionization mass spectrometry analysis, indicating the predominance of gallic acid, ellagic acid, and galloyl glucoses showing marked antiglycation properties. These findings suggest that there is a potential food industry application of polyphenols in TBE as a functional food with antidiabetic and antiglycation activities. |
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| Keywords: | Trapa bispinosa Roxb polyphenol ellagitannin gallotannin α -glucosidase inhibitor advanced glycation end products (AGEs) antiglycation effect LC/UV/ESIMS analysis |
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