4,24-Dioxa-9,22-diazatetracyclo[19.3.1.110,14.03,5]hexacosane, maytansine deriv. 66547-10-2 Ansamitocin P 4 MAYTANSINE DERIV Maytansine, 3-de(2-(acetylmethylamino)-1-oxopropoxy)-3-(3-methyl-1-oxobutoxy)- Maytansine, 3-de[2-(acetylmethylamino)-1-oxopropoxy]-3-(3-methyl-1-oxobutoxy)- Maytansine, O3-de[2-(acetylmethylamino)-1-oxopropyl]-O3-(3-methyl-1-oxobutyl)- Maytansinol isovalerate NSC292223 TAM-340 Tam 340