Chemistry of emeriamine and its analogs and their inhibitory activity in long-chain fatty acid oxidation

Abstract
Emericedins A, B, and C, new betaines having inhibitory activity of long chain fatty acid oxidation, were isolated from the culture both of Emericella quadrilineata IFO 5859. Their structures were determined by spectroscopic analyses as (R)-3-(acylamino)-4-(trimethylammonio)butyrate (acyl: A, acetyl; B, propionyl; C, n-butyryl). Structural confirmation and assignment of absolute configuration were made by chemical synthesis from L-asparagine. Deacylation of emericedin gave a potent derivative, (R)-3-amino-4-(trimethylammonio)butyrate, designated as emeriamine. In order to study the structure-activity relations, various analogues of emeriamine, including a stereoisomer, were prepared. Among them, N-palmitoyl and N-myristoyl derivatives showed much stronger inhibition of fatty acid oxidation than emeriamine.