Zur enzymatischen Bildung von Steringlykosiden durch Partikelfraktionen aus Blättern von Lattich und Spinat

Abstract

Particulate fractions from lettuce (Lactuca sativa L.) and spinach (Spinacia oleracea L.) leaves incorporate glucose-¹⁴C from UDP- glucose-¹⁴C into steryl glycosides and esterified steryl glycosides. The activity of the enzyme was found to be optimal at pH 8.5 (Tris/HCl). The reaction, which is stimulated by ATP, depends on the presence of free sterols. Spinach leaf preparations, which were lyophilized and extracted with petroleum ether, convert not only α-spinasterol, which is the major sterol of this plant, but also β-sitosterol and cholesterol into glucosides. There is good evidence that both reactions, glycosylation and acylation, are associated with the same particles.