Semisynthesis of A23187 (calcimycin) analogs. II. Introduction of a methyl group on the benzoxazole ring.

Abstract
Semisynthesis of 2 demethylamino A23187 with a methyl group in the 4- or 5-position on the benzene ring were carried out via the cleavage of A23187 oxazole ring and rebuilding of modified benzoxazoles. These compounds release Ca2+ and Mg2+ from [rat liver] mitochondria and keep in part the antibacterial activity of the natural metabolite.