[Photometric determination of microsomal epoxide hydrase activity by the 4-(p-nitrobenzyl)pyridine test]

In the present paper, a simple photometric assay of microsomal epoxide hydrolase activity using the 4-NBP test is described. The outline of this method is the reaction of 4-NBP with the unreacted oxide extracted from incubation medium in separated ethyl-acetate layer, followed by measurement of absorbancy at 560 nm. The usefulness of this assay can be in application to all epoxides enough alkylating and it can be used for routine analyses which don't request either particular instruments or suitable standards of synthesis.