Composition of essential oils. Part 7. Bulgarian oil of rose (Rosa Damascena mill.)

Abstract

A first-quality Bulgarian oil of rose was analysed. After classical group separation, the neutral part was further subdivided by "group displacement chromatography" on deactivated silica gel into non-polar, slightly polar and polar parts. Acids and phenols were analysed as methoxy and ethoxy derivatives. The individual groups were first distilled. Pure components were isolated from the distillation fractions by preparative gas chromatography. Fractions isolated on a hydrocarbon-type stationary phase (Apiezon L) were further separated on a poly(ethylene glycol) (Emulphor-O) to give the pure components. In a second analysis, the oil was separated in a continuous counter-current separator with 680 cells in order to isolate the fraction containing those compounds which are responsible for the "honey note" of the oil. The enriched part (ca. 1% of the oil) was then separated as described above. As a result, 127 compounds were isolated and identified, representing 98.6% of the volatile part. Of these only 40 had previously been reported. The compound mainly responsible for the sweet odor ("honey note") was shown to be a dehydroisoionone comprising 0.1% of the oil. Because of its organoleptic importance, damascenone is proposed as common name for this substance. © 1987.