Phytol

Phytol is an acyclic diterpene alcohol that can be used as a precursor for the manufacture of synthetic forms of vitamin E and vitamin K1. In ruminants, the gut fermentation of ingested plant materials liberates phytol, a constituent of chlorophyll, which is then converted to phytanic acid and stored in fats. In shark liver it yields pristane. Phytol is an acyclic diterpene alcohol that can be used as a precursor for the manufacture of synthetic forms of vitamin E and vitamin K1. In ruminants, the gut fermentation of ingested plant materials liberates phytol, a constituent of chlorophyll, which is then converted to phytanic acid and stored in fats. In shark liver it yields pristane. Refsum disease, an autosomal recessive disorder that results in the accumulation of large stores of phytanic acid in tissues, frequently manifests peripheral polyneuropathy, cerebellar ataxia, retinitis pigmentosa, anosmia, and hearing loss. Although humans cannot derive phytanic acid from chlorophyll, they can convert free phytol into phytanic acid. Thus, patients with Refsum disease should limit their intake of phytanic acid and free phytol. The amount of free phytol in numerous food products has been reported. Insects, such as the sumac flea beetle, are reported to use phytol and its metabolites (e.g. phytanic acid) as chemical deterrents against predation. These compounds originate from host plants. Indirect evidence has been provided that, in contrast to humans, diverse non-human primates can derive significant amounts of phytol from the hindgut fermentation of plant materials. Phytol and/or its metabolites have been reported to bind to and/or activate the transcription factors PPAR-alpha and retinoid X receptor (RXR). The metabolites phytanic acid and pristanic acid are naturally occurring ligands. In mice oral phytol induces massive proliferation of peroxisomes in several organs. Phytol is likely the most abundant acyclic isoprenoid compound present in the biosphere and its degradation products have been used as biogeochemical tracers in aquatic environments. Phytol is used in the fragrance industry and used in cosmetics, shampoos, toilet soaps, household cleaners, and detergents. Its worldwide use has been estimated to be approximately 0.1–1.0 metric tons per year.