Isolation of Two Quinones with Coenzyme Q Activity from Alfalfa.

Abstract

Procedures are described for the isolation of 2 quinones from alfalfa. The 1st quinone has an absorption maximum at 275 m[mu] and is identical with coenzyme Q10 which previously has been isolated from animals. It is 2,3-dimethoxy-5-methyl benzoquinone with 10 mono-unsaturated isoprenoid units in a side chain at the 6-position. The 2d quinone has an absorption maximum at 255 m[mu]. This compound has been referred to as Q254, but the name plastoquinone is not proposed to avoid confusion with the coenzyme Q group and to emphasize its concentration in the plastids of higher plants. The alfalfa coenzyme Q10 is fully active in the enzymatic assay for coenzyme Q (restoration of succinic oxidase in beef heart mitochondria after solvent extraction), whereas plastoquinone has only partial activity.