Interactions of carotenoids with some organophosphorus insecticides

The interactions of some organophosphorus insecticides (OPI) with carotenoids from oranges were studied in vitro. In the initial step, 5,6-epoxy (di-epoxy) xanthophylls are isomerised to 5,8-furano (di-furano) xanthophylls. This reaction can also be brought about by hydrogen ions. Degradation products of OPI or impurities present in commercial samples may be acidic. Subsequent reactions lead to complete loss of the long wavelength chromophore.