hydroxy fatty acid lactone polyunsaturated fatty acid very long-chain fatty acid tetracosanoic acid branched-chain fatty acid leptomycin A complex, very long chain, polyunsaturated fatty acid whose core structure comprises 8-oxononadeca-2,10,12,16,18-pentaenoic acid having methyl substituents at positions 3, 5, 7, 9, 11 and 15 and a 3,6-dihydropyran-6-one-2-yl group at position 19. CHEBI:52651 chebi_ontology leptomycins oxo fatty acid alpha,beta-unsaturated monocarboxylic acid