Aibrohim DramaeSutichai NithithanasilpWilunda ChoowongPranee RachtaweeSamran PrabpaiPalangpon KongsaereePattama PittayakhajonwutThailand National Center for Genetic Engineering and BiotechnologyMahidol University2018-10-192018-10-192013-09-23Tetrahedron. Vol.69, No.38 (2013), 8205-820814645416004040202-s2.0-84881183298https://repository.li.mahidol.ac.th/handle/20.500.14594/31211Two new natural products, samroiyotmycins A (1) and B (2), along with two naturally new novclobiocin 101 (3) and 4-hydroxy-3-(3-methylbut-2-enyl)benzamide (5), and five known substances including neoantimycin, clorobiocin (4), 29-O-methylabierixin, daidzein, and 1-(3-indolyl)-2,3-dihydroxypropan-1-one have been isolated from Streptomyces sp. BCC33756. Their chemical structures were determined based on NMR spectral information and the relative stereochemistry of compound 1 was determined by X-ray crystallographic data. Both samroiyotmycins A and B exhibited antimalarial activity against Plasmodium falciparum K1 - multi-drug resistant strain, with IC50values of 3.65 and 3.16 μg/mL, respectively. Compound 1 was inactive against both cancerous (MCF-7, KB) and non-cancerous (Vero) cells, while compound 2 displayed cytotoxicity against Vero cell with IC50value of 29.57 μg/mL. © 2013 Published by Elsevier Ltd.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemistryPharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1016/j.tet.2013.07.034