Discovery and development of direct Xa inhibitors Xa was identified as a promising target for the development of new anticoagulants in the early 1980s. In 1987 the first factor Xa inhibitor, the naturally occurring compound antistasin, was isolated from the salivary glands of the Mexican leech "Haementeria officinalis". Antistasin is a polypeptide and a potent Xa inhibitor. In 1990 another naturally occurring Xa inhibitor was isolated, tick anticoagulant peptide (TAP) from extracts of the tick "Ornithodoros moubata". TAP and antistasin were used to estimate factor Xa as a drug target. Blood coagulation is a complex process by which the blood forms clots. It is an essential part
Bicyclomycin Bicyclomycin Bicyclomycin (Bicozamycin) is a broad spectrum antibiotic active against Gram-negative bacteria and the Gram-positive bacterium, "Micrococcus luteus" that was isolated from "Streptomyces sapporonesis" and "Streptomyces aizumenses" in 1972. It belongs to a class of naturally occurring 2,5-diketopiperazines, that are among the most numerous of all the naturally occurring peptide antibiotics. This clinically useful antibiotic is rapidly absorbed in man when given intramuscularly, has low toxicity and has been used to treat diarrhea in humans and bacterial diarrhea in calves and pigs. Bicyclomycin is the only known selective inhibitor of Rho, a RecA-type ATPase, which is a transcription termination factor