The homolytic and heterolytic fatty acid hydroperoxide lyase-like activities of hematin

Pentenols and pentene dimers are biosynthetized in plants by homolytic fatt y acid hydroperoxide lyase (HPL) or HPL-like enzymes. It has been found tha t these compounds can modify the flavor of olive oil. Reactions between hem atin and 13-hydroperoxy-octadecatrienoic acid resulted in the formation of the same compounds via a free radical reaction in which an alkoxyl radical derived from linolenic acid hydroperoxide undergoes a beta -scission. (Z)-3 -Hexenal has also been detected as a minor product of the reaction. It is b ioconversed from the same substrate in plants by heterolytic HPL. Thanks to the redox cycle of its central iron, hematin has both homolytic and hetero lytic HPL-like activities. (C) 2001 Academic Press.