4-(Dimethylamino)-1,5,10,11,12a-pentahydroxy-6-methyl-3,12-dioxo-3,4,4a,5,5a,6,12,12a-octahydrotetracene-2-carboximidic acid

Doxycycline is a semi-synthetic tetracycline antibiotic in which the 5beta-hydrogen is replaced by a hydroxy group and the 6alpha-hydroxy group is replaced by hydrogen. It inhibits bacterial protein synthesis and is used to treat non-gonococcal urethritis, cervicitis, exacerbations of bronchitis in patients with COPD, and adult periodontitis. It functions as an antibacterial drug, antimalarial, geroprotector, anti-inflammatory agent, and immunomodulator.