Stereoisomeric acylamidomorpholinium carnitine analogues: Selective inhibitors of carnitine palmitoyltransferase I and II

Acylamidomorpholinium carnitine analogues, 6-(tetradecanamidomethyl- and -hexadecanamidomethyl)-4,4-dimethylmorpholin-4-ium-2-acetate, 1, synthesized as complete sets of stereoisomers, were assayed as inhibitors for isozymes of carnitine palmitoyltransferase (CPT). Microsomal CPT isozymes showed modest discrimination among the stereoisomer; while rat-liver mitochondrial CPT-I and CPT-II showed distinct differences. The tetradecanamidomethyl analogue of (2R,6S)-1 activated CPT-I but inhibited CPT-II.