Hirudin Hirudin Hirudin is a naturally occurring peptide in the salivary glands of blood-sucking leeches (such as "Hirudo medicinalis") that has a blood anticoagulant property. This is fundamental for the leeches’ alimentary habit of hematophagy, since it keeps the blood flowing after the initial phlebotomy performed by the worm on the host’s skin. During his years in Birmingham and Edinburgh, John Berry Haycraft had been actively engaged in research and published papers on the coagulation of blood, and in 1884, he discovered that the leech secreted a powerful anticoagulant, which he named hirudin, although it was not isolated until the 1950s,
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