<unk>  (INN) is a broad-spectrum polyketide antibiotic produced by the Streptomyces genus of Actinobacteria, indicated for use against many bacterial infections. It is a protein synthesis inhibitor. It is commonly used to treat acne today, and, more recently, rosacea, and is historically important in reducing the number of deaths from cholera.<unk>  is marketed under the brand names Sumycin, Tetracyn, and Panmycin, among others. Actisite is a thread-like fiber formulation used in dental applications. It is also used to produce several semisynthetic derivatives, which together are known as the<unk>  antibiotics.  The term<unk> " is also used to denote the four-ring system of this compound;<unk> s" are related substances that contain the same four-ring system.
Tetracycline hydrochloride
Oxytetracycline hydrochloride
Doxycycline monohydrate
Minocycline hydrochloride
Oxytetracycline
Doxycycline Hyclate
Chloramphenicol succinate 
Doxycycline 