ISOLATION OF PROLYCOPENE AND PRO-γ-CAROTENE FROM EVONYMUS FORTUNEI

Abstract

It has been reported (1) that the ripe seeds of Evonymus europaeus L. (Celastraceae) contain unesterified zeaxanthin, C40H56O2, as the main polyene pigment. The same statement is valid for Evonymus fortunei, var. color., Rehd., commonly termed “winter-creeper euonymus,” from 1 kilo of which 1300 mg. of zeaxanthin were isolated. Upon evaporation of its saponified ether extract and addition of petroleum ether, abundant quantities of zeaxanthin crystallize. This paper describes an investigation of some of the pigments (about 200 mg. per kilo, of which one-fourth is β-carotene) which remain in the mother liquor. The mixture can be resolved by chromatographic analysis. In addition to some twenty less interesting pigments, two representatives of a stereochemically new class of natural carotenoids (2) were separated; viz., prolycopene, C40H56, and pro-γ-carotene, C40H66. The yields of pure crystals were 11 mg. and 0.5 mg. per kilo of seeds respectively. Hence, Evonymus fortunei may serve as a source of prolycopene while it does not offer any larger yield of pro-γ-carotene than does the fruit of Butia capitata (3). According to the foregoing paper (4) Pyracantha angustifolia is the best starting material for the isolation of pro-γ-carotene at the present time.