Identification of a novel antibiotic from myxobacterium stigmatella eracta WXNXJ-B and evaluation of its antitumor effects In-vitro

ABSTRACT

This work was to isolate and identify the bioactive secondary metabolite which was produced by myxobacteriumStigmatella eracta WXNXJ-B, and to evaluate its antitumor and apoptosis-inducing effects. The results showed that one novel compound [molecular formula C29H25NO3] was isolated, purified by Sephadex LH-20 column chromatography and preparative RP-HPLC, and identified as 5-[6-benzyl-quinolin-3-ylmethyl]-6- phenyl-3,7-dioxa- bicycle [4.1.0] heptan-3-one [named as quinoxalone] according to its UV, IR, HRMS and NMR spectra. The compound showed strong antitumor activity on B16, HepG2, MCF-7, SGC-7901, MDA-MB231 and CT-26 six tumor cell lines in vitro. Nevertheless, it showed less cytotoxic to the mouse normal spleen cells [IC50 was 836.27 +/- 13.02 mg mL-1]. The cytotoxic study on HepG2 cellsin-vitro showed that quinoxalone could induce the change of cell nuclear and arrested the cell division in the S and G2/M phase. Our results suggest that quinoxalone could be a potential anti-cancer agent