Synthesis and Biological Activities of 2, 3-Dimethyl-1, 4-benzoquinones Having Alkylthio and Arylthio Side Chains

Abstract

New 2, 3-dimethyl-1, 4-benzoquinones having an alkylthio or arylthio side chain at the 5-position and two alkylthio side chains at the 5-and 6-position were synthesized as possible antimetabolites of coenzyme Q. These compounds were tested for inhibition of coenzyme Q in mitochondrial succinoxidase and reduced nicotinamide adenine dinucleotide (NADH) -oxidase systems, and were found to show greater inhibition of the NADH-oxidase system than of the succinoxidase system. 5, 6-Di-octylthio-2, 3-dimethyl-1, 4-benzoquinone showed greater inhibitory activities than 5-alkylthio-2, 3-dimethyl-1, 4-benzoquinones. 5-Arylthio-2, 3-dimethyl-1, 4-benzoquinones showed potent inhibitory activities towards both enzyme systems.