Leupeptins, leupeptin Pr and leupeptin Ac, strongly inhibit proteolysis by plasmin, trypsin and papain, but do not inhibit proteolysis by <#-chymotrypsin. The inhibition is competitive with substrates. The inhibitory effect on esterolysis by plasmin and trypsin is weaker than on proteolysis. The results with derivatives of leupeptins which contain carboxyl or alcohol instead of aldehyde and of ...

Emetine is a natural product alkaloid from ipecac species. It is one of the main active ingredients in ipecac syrup used as emetic, and has been used extensively in phytomedicine as an antiparasitic drug. It inhibits both ribosomal and mitochondrial protein synthesis and interferes with the synthesis and activities of DNA and RNA. For this reason, it has been a vital tool to pharmacologists and...

Complement is a system of serum proteins whose main function is to defend the body against infection. Although it has a reputation as a dauntingly complex system, this results chiefly from confusion in the nomenclature, which has varied considerably with time as more components were discovered, for example as ‘component C3’ became subdivided into several components one of which is still called ...

Stilbenoids are a group of naturally occurring phenolic compounds found in various plant species. They share a common backbone structure known as stilbene, but differ in the nature and position of substituents. Stilbenoids are classified as phytoalexins, which are antimicrobial compounds produced de novo in plants to protect against fungal infection and toxins. In this review, the biological ef...

most active with MICs (μg/ml) against B. subtilis (1-2), MRSA (2-4), M. catarrhalis (4) and VRE (2-64). Effects on macromolecular synthesis and membrane functions were tested in B. subtilis. Pyrone I nonspecifically inhibited incorporation of radiolabeled precursors into DNA, RNA and protein within 5 minutes of drug exposure, similar to that of triclosan. Both compounds also inhibited the cellu...