4'-Acetylchrysomycin A is a bacterial metabolite and derivative of chrysomycin A that has been found inStreptomycesand has antibacterial and anticancer activities.1It is active against strains of methicillin-resistantS. aureus(MRSA) and vancomycin-resistant strains ofE. faecalisandE. faecium(MICs = 0.5-2 μg/ml for all). 4'-Acetylchrysomycin A is cytotoxic against a panel of human cancer cell lines, including doxorubicin-sensitive or -resistant cells (IC50s = 0.085-0.26 and 3.4-16 ng/ml, respectively). 1.Wada, S.-I., Sawa, R., Iwanami, F., et al.Structures and biological activities of novel 4'-acetylated analogs of chrysomycins A and BJ. Antibiot. (Tokyo)70(11)1078-1082(2017)