Anita M. Sutedja, Emiko Yanase, Irmanida Batubara, Dedi Fardiaz, Hanifah N. Lioe
Although the intake of jack bean (Canavalia ensiformis (L.) DC.), an underutilized tropical legume, can potentially decrease the risk of several chronic diseases, not much effort has been directed at profiling the polyphenolics contained therein. Hence, this work aimed to identify and quantify the dominant jack bean polyphenolics, which are believed to have antioxidant and other bioactivities. Four major compounds were detected and identified as kaempferol glycosides with three or four glycoside units. Their structures were established based on UV-visible, 1D, 2D NMR, and HR-ESI-MS analyses. Specifically, kaempferol 3-O-α-l-rhamnopyranosyl (1→6)-β-d-glucopyranosyl (1→2)-β-d-galactopyranosyl-7-O-[3-O-o-anisoyl]-α-l-rhamnopyranoside was detected for the first time, while the other three compounds have already been described in plants other than jack bean. This new compound was found to have a higher α-glucosidase inhibition activity compared to acarbose. © 2020 by the authors.
Faculty of Applied Biological Sciences, Graduate School of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu City, Gifu, 501-1193, Japan; Department of Food Science and Technology, Faculty of Agricultural Engineering and Technology, IPB University, Kampus IPB Dramaga, Bogor, West Java, 16680, Indonesia; Department of Food Technology, Faculty of Agricultural Technology, Widya Mandala Catholic University Surabaya, Jalan Dinoyo 42-44, Surabaya, East Java, 60265, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Science, IPB University, Kampus IPB Dramaga, Bogor, West Java, 16680, Indonesia; Tropical Biopharmaca Research Center, IPB University, Kampus IPB Taman Kencana No 3, Bogor, 16128, West Java, Indonesia