Of the many tetracycline analogues, only 4 , chlor tetracycline, oxytetracycline, te tracycline (TC) , and demethylchlortetracycline (DMCT) , are currently available for clinical -~ 1. Kunin, C. M., Finland, M., J . Clin. Invest., 2. Hirsch, H. A., Finland, M., Am.