Muramic acid is an amino sugar acid. In terms of chemical composition, it is the ether of lactic acid and glucosamine. It occurs naturally as N-acetylmuramic acid in peptidoglycan, whose primary function is a structural component of many typical bacterial cell walls. Muramic acid is an amino sugar acid. In terms of chemical composition, it is the ether of lactic acid and glucosamine. It occurs naturally as N-acetylmuramic acid in peptidoglycan, whose primary function is a structural component of many typical bacterial cell walls.