#Trimethoprim (#C14H18N4O3), also known as 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine, is an antibiotic used to treat #bacterial infections. The molecular structure of trimethoprim consists of a pyrimidine ring and three methoxy (-OCH3) functional groups. The carbon atoms in the methoxy groups are sp3 hybridized, and the carbon atoms in the pyrimidine ring are sp2 hybridized.