Use of chiral malonates to determine the absolute configuration of the hydrogen atoms eliminated during the formation of 6-methylsalicylic acid by 6-methylsalicylic acid synthase from Penicillium patulum

Abstract

When acetoacetyl-CoA was used as the starter molecule together with chiral malonyl-CoA derivatives, prepared from (R)- and (S)-[1-¹³C; 2-²H]malonates, for the biosynthesis of 6-methylsalicylic acid using 6-methylsalicylic acid synthase from Penicillium patulum, mass spectrometric analysis of the products established that the hydrogen atom incorporated at the 3-position of 6-methylsalicylic acid originates from H_Re of malonyl-CoA allowing the deduction that the hydrogen atom at the 5-position must originate from H_Si.