Cong WangAdeep MongerLiping WangPeng FuPawinee PiyachaturawatArthit ChairoungduaWeiming ZhuGuangxi University for NationalitiesOcean University of ChinaChinese Academy of SciencesMahidol UniversityQingdao National Laboratory for Marine Science and Technology2019-08-282019-08-282018-05-01Marine Drugs. Vol.16, No.5 (2018)166033972-s2.0-85047176616https://repository.li.mahidol.ac.th/handle/123456789/47312© 2018 by the authors. One new indolocarbazole, 3-hydroxy-K252d (3), together with the recently reported 3-hydroxyholyrine A (1) and 3-N-acetyl-3-hydroxyholyrine A (2), were obtained by feeding a culture of the marine-derived Streptomyces strain OUCMDZ-3118 with 5-hydroxy-L-tryptophan. Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 potently induced apoptosis of gastric cancer cells by inhibiting topoisomerase IIα enzyme activity and reducing the expression of antiapoptosis protein level. Compound 3 displayed moderate cytotoxicity against the A549 and MCF-7 cell lines with IC50 values of 1.2 ± 0.05 µM, 1.6 ± 0.09 µM, respectively.Mahidol UniversityPharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.3390/md16050168