Abstract
This review summarises patents claiming novel tetracyclines specified for antibacterial or antimicrobial use published from January 1998 to October 2002. A brief overview of the mode of action and important resistance mechanisms of the tetracycline class is presented. All of the novel tetracyclines cited were prepared through application of known chemistry to a small number of core tetracyclines with major focus upon the aromatic ring positions C-7, C-8 and C9; metal-catalysed aryl coupling reactions such as the Suzuki, Stille and Heck couplings were cited in numerous examples. Core tetracyclines used to derive novel chemical matter include tetracycline, doxycycline, sancycline and minocycline, among others, and the chemistry is claimed for alternative tetracycline templates. Novel tetracyclines were claimed for use against Gram-negative and Gram-positive bacteria including strains exhibiting tetracycline-specific efflux and ribosomal protection resistance. Tetracyclines were also claimed for use against cryptosporidium and as antifungal agents. In all cases, limited detailed information on biological profiles was cited.