The molecule is the conjugate base of ketomycolic acid type-2 (XII). A class of mycolic acids characterized by the presence of a proximal alkenyl group with a trans C=C double bond and a distal oxo group and a (CH-CH3) fragment of (S) stereochemistry in the meromycolic chain.
(E,2R,3R,10S)-2-ethyl-3-hydroxy-5,10-dimethyl-9-oxododec-6-enoate