3 きだちろかい(Aloe arborescens Mill.)の生理活性物質

抄録

From the leaf juice of Aloe species (Aloe arborescens Mill. var. natalensis Berger), which has been widely used for a medicinal plant, we isolated a new bitter glucoside, named aloenin, together with aloe-emodin, barbaroin, magnesium lactate, succinic acid, sitosterol, n-triacontanol, n-dotriacontanol, D-glucose, potassium chloride, and sodium chloride. The presence of aloe-emodin and barbaroin has been known already, but the other components have not been reported yet in Aloe species. We now present evidences leading to structure 3 for the new bitter glucoside, aloenin. This is an unique example of naturally occurring chromene having the carbomethoxyethylidene group on C-2. The incorporation experiment of sodium malonate-2-^<14>C and phenylalanine-3-^<14>C in the Aloe plant suggested that aloenin (3) is biosynthesized by the cyclization of the polyketide as formula 14, which is formed through the acetate-malonate pathway.