4-Nitrophenyl butyrate

4-Nitrophenyl butyrate is a nitro-substituted phenolic ester compound. 4-Nitrophenyl butyrate is water-soluble and is tolerated as a substrate by lipase enzymes, making it a useful probe for lipase activity. Hydrolysis of 4-Nitrophenyl butyrate by the enzyme produces p-nitrophenoxide which can be monitored by UV-Vis spectrophotometry at 400 nm. This approach has specifically been used to assess the activities of both cholesterol esterase and lipoprotein lipase and 4-Nitrophenyl butyrate has also been employed as a probe for screening the lipolytic activity of novel microorganism strains.