Structural Studies on Stilbene Oligomers Isolated from the Seeds of Melinjo (Gnetum gnemon L.)

Hiroko Tani; Hiroyuki Koshino; Tohru Taniguchi; Maiko Yoshimatsu; Susumu Hikami; Shunya Takahashi

doi:10.1021/acsomega.0c00910

Structural Studies on Stilbene Oligomers Isolated from the Seeds of Melinjo (Gnetum gnemon L.)

ACS Omega. 2020 May 19;5(21):12245-12250. doi: 10.1021/acsomega.0c00910. eCollection 2020 Jun 2.

Authors

Hiroko Tani¹, Hiroyuki Koshino², Tohru Taniguchi³, Maiko Yoshimatsu¹, Susumu Hikami¹, Shunya Takahashi²

Affiliations

¹ Institute for Bee Products & Health Science, Yamada Bee Company, Inc., 194 Ichiba, Kagamino, Okayama 708-0393, Japan.
² RIKEN Center for Sustainable Resource Science, 2-1 Wako, Saitama 351-0198, Japan.
³ Graduate School of Advanced Life Science, Frontier Research Center for Post-Genome Science and Technology, Hokkaido University, N21W11, Sapporo 001-0021, Japan.

Abstract

This paper describes the isolation and structural determination of a new stilbene dimer, named 7a-epi-gnetin C, from melinjo (Gnetum gnemon L.) seed extract. The relative structure was elucidated based on NMR spectroscopic evidence, while the absolute configuration was assigned by a combination of NMR and electronic circular dichroism spectroscopic analysis and chemical conversion. 7a-epi-Gnetin C was evaluated as an antioxidant and was shown to have a comparable activity to the known stilbene oligomers. In addition, the structural revision of gnetin L, a known stilbene dimer, was also discussed.