2,10,12,16,18-Nonadecapentaenoic acid, 19-(3,6-dihydro-3-methyl-6-oxo-2H-pyran-2-yl)-6-hydroxy-3,5,7,9,11,15,17-heptamethyl-8-oxo- 87081-36-5 LEPTOMYCIN A NSC369326