Tetracycline antibiotics

Tetracycline antibiotics

Tetracyclines have a ring system of four linear annelated six-membered rings and are characterized by a common octahydronaphthacenes skeleton. They are potent, broad-spectrum antibacterial agents effective against gram-positive and gram-negative aerobic and anaerobic bacteria. As a result, the tetracyclines are drugs of choice or well-accepted alternatives for a variety of infectious diseases. Among these, they also play a role in the treatment of sexually transmitted and gonococcal diseases, urinary tract infections, bronchitis, and sinusitis remain prominent.

The majority of the marketed tetracyclines (tetracycline, chlorotetracycline, oxytetracycline, and demeclocycline) are naturally occurring compounds obtained by the fermentation of Streptomyces spp. broths. The semisynthetic tetracyclines (methacycline, doxycycline, minocycline) have the advantage of longer duration of antibacterial action. However, all these tetracyclines exhibit a similar profile in terms of antibacterial potency. In general, their activity encompasses many strains of gram-negative E. coli, Proteus, Klebsiella, Enterobacter, Niesseria, and Serratia spp., as well as gram-negative Streptococci and Staphylococci of particular interest is the potency of tetracylines against Haemophilus, Legionella, Chlamydia, and Mycoplasma.

Classes of tetracyclines

I.Natrual tetracyclines (biosynthetic)

II. Semisynthetic tetracyclines

III. Protetracyclines