Delta-7 sterols: Specificity of pumpkin seed oil

Abstract

Phytosterols belong to nonglyceridic components of the vegetable oils. They are present in very low concentrations (they belong to the minor components of the vegetable oils) and separated from the fraction of unsaponifiable matter. According to the double bond in the ring, phytosterols are usually classified as Δ5 and Δ7 sterols. For most of the plant families Δ5 sterols are typical, whereas Δ7 sterols are specific to only a few, including the Cucurbitaceae. Analytics of determination and especially identification of Δ7 sterols is very complex precisely because there are no commercial standards of this group of sterols. In the cold pressed and virgin pumpkin oil, the following sterols were identified: Δ7,22,25-stigmastatrienol, Δ7,25-stigmastadienol, spinasterol (Δ7,22-stigmastadienol), Δ7-stigmasterol and Δ7-avenasterol.

Fitosteroli pripadaju negliceridnim komponentama biljnih ulja. Prisutni su u veoma malim koncentracijama (pripadaju minornim komponentama biljnih ulja) i izdvajaju se iz frakcije neosapunjivih materija. Prema dvostrukoj vezi u prstenu, fitosteroli se obično dele na Δ5 i Δ7 sterole. Za najveći broj biljnih familija karakteristični su Δ5 steroli, dok su Δ7 steroli specifični za svega nekoliko, među kojima je i Cucurbitaceae. Analitika određivanja i posebno identifikacija Δ7 sterola je veoma složena upravo iz razloga što ne postoje komercijalni standardi ove grupe sterola. U hladno presovanom i devičanskom tikvinom ulju identifikovani su: Δ7,22,25 - stigmastatrienol, Δ7,25 - stigmastadienol, spinasterol (Δ7,22- stigmastadienol), Δ7-stigmasterol i Δ7-avenasterol.