(A commercial mixture of Actinomycin C1 5%, C2 30% and C3 65% is available). Actinomycin C1 (native) crystallises from EtOAc as red crystals, is soluble in CHCl3, *C6H6 and Me2CO, and has m 246-247o(dec), [] 20D -328o (0.22, MeOH) and max 443nm ( 25,000) and 240nm ( 34,000). Actinomycin C2 (native) crystallises as red needles from EtOAc and has m 244-246o(dec), [] D -325o (c 0.2, MeOH), max 443nm ( 25,300) and 240nm ( 33,400). Actinomycin C3 (native) recrystallises from cyclohexane, or *C6H6/MeOH/cyclohexane as red needles with m 238-241o (dec), [] D -321o (c 0.2, MeOH), max 443nm ( 25,000) and 240nm ( 33,300). [Brockman & Lackner, Chem Ber 101 1312 1968.] Itis light sensitive.[Beilstein 27 III/IV 9642.]
