Two new 2,5-diketopiperazines produced by Streptomyces sp. SC0581

Publication date: June 2017 Source:Phytochemistry Letters, Volume 20 Author(s): Li Yang, Ahmed Mahal, Youhua Liu, Hanxiang Li, Ping Wu, Jinghua Xue, Liangxiong Xu, Xiaoyi Wei Two new diketopiperazines, cyclo(l-Phe-l-NMe-DOPA) (2) and cyclo[l-Phe-l-(NMe-3-(NMe-3-O-α-l-rhamnopyranosyl)-DOPA] (3), along with a known diketopiperazine (1), were isolated from the cultures of Streptomyces sp. SC0581. Their structures were elucidated by extensive spectroscopic analysis, single-crystal X-ray crystallographic analysis, and chemical correlation. Compounds 1 − 3 exhibited more potent ABTS radical cation scavenging activity (IC50 values: 3.7−14.6μM) than l-ascorbic acid (IC50: 17.7μM). Compounds 2 and 3 also showed remarkable DPPH radical scavenging activity. Graphical abstract

Source: Phytochemistry Letters - May 3, 2017 Category: Chemistry Source Type: research