Demeclocycline
Demeclocycline is a semi-synthetic, broad-spectrum naphthacene antibiotic produced by the bacterium Streptomyces aureofaciens. Demeclocycline binds to bacterial 30S ribosomal subunit and prevents binding of aminoacyl-tRNA to the mRNA-ribosome complex, thereby inhibiting protein synthesis. Demeclocycline also inhibits the effect of vasopressin on the renal tubules, thereby causing diuresis.