Lycopersene and Prelycopersene Pyrophosphate

This paper reports the enzymatic synthesis of lycopersene and prelycopersene pyrophosphate from [4,8,12,16-14C]geranylgeranyl pyrophosphate by soluble enzyme systems obtained from yeast and tomato fruit plastids. Incubation of a soluble extract of an acetone powder of tomato fruit plastids, or a purified squalene synthetase of yeast, with [4,8,12,16-14C]geranylgeranyl pyrophosphate and NADPH yields a product which co-chromatographs with authentic lycopersene on thin layer, column, and gas-liquid chromatographic systems. These enzyme systems also form prelycopersene pyrophosphate from [4,8,12,16-14C]geranylgeranyl pyrophosphate in the absence of NADPH. Both of the above compounds, lycopersene and prelycopersene pyrophosphate, are converted to phytoene and lycopene on incubation with the above soluble tomato enzyme system, NADP and FAD. Hence, it is concluded that these compounds are intermediates in the biosynthesis of acyclic and cyclic carotenes from geranylgeranyl pyrophosphate.