Maytansinol is an ansa macrolide originally isolated from P. verrucose that has antimitotic and anticancer activities.1,2,3 It inhibits polymerization and induces depolymerization of bovine brain tubulin with EC50 values of 12 and 43 ?M, respectively.2 Maytansinol inhibits sea urchin egg mitosis when used at a concentration of 10 ?M and decreases proliferation of KB nasopharyngeal cancer cells (EC50 = 0.19 ?g/ml).3
1.Kupchan, S.M., Branfman, A.R., Sneden, A.T., et al.Novel maytansinoids. Naturally occurring and synthetic antileukemic esters of maytansinolJ. Am. Chem. Soc.97(18)5294-5295(1975) 2.Ikeyama, S., and Takeuchi, M.Antitubulin activities of ansamitocins and maytansinoidsBiochem. Pharmacol.30(17)2421-2425(1981) 3.Kupchan, S.M., Sneden, A.T., Branfman, A.R., et al.Structural requirements for antileukemic activity among the naturally occurring and semisynthetic maytansinoidsJ. Med. Chem.21(1)31-37(1978)