Sterol compositions of seeds and mature plants of family cucurbitaceae

Abstract

Abstract The sterol fractions of the unsaponifiable lipids obtained from 32 seed and mature plant (leaves and stems, pericarp of the fruit, and roots) materials from the 12 genera Apodanthera, Benincasa, Citrullus, Coccinea, Cucumis, Cucurbita, Gynostemma, Lagenaria, Luffa, Momordica, Sechium and Trichosanthes , of the family Cucurbitaceae were investigated by gas liquid chromatography (GLC) on an OV‐17 glass capillary column. Among the 23 sterols with Δ 5 ‐, Δ 7 ‐ and Δ 8 ‐skeletons identified by GLC, the Δ 7 ‐sterols were found to be the major sterols of most of the Cucurbitaceae investigated. The seed materials contained 24‐ethyl‐Δ 7 ‐sterols possessing Δ 25 ‐bonds, i.e. 24‐ethylcholesta‐7,25‐dienol and 24‐ethylcholesta‐7,22,25‐trienol, whereas the mature plant materials contained 24‐ethyl‐Δ 7 sterols without a Δ 25 ‐bond, i.e. 24‐ethylcholest‐7‐enol and 24‐ethylcholesta‐7,22‐dienol, as the most predominant sterols, with a few exceptions. The isolation and identification of 24α‐ethylcholesta‐8(14),22‐dienol from the aerial parts of Cucumis sativus also is described.