Abrusosides A-D, Four Novel Sweet-Tasting Triterpene Glycosides from the leaves of Abrus precatorius

In addition to abrusoside A [1], abrusosides B [2], C [3], and D [4], three further sweet glycosides based on the novel cycloartane-type aglycone, abrusogenin [5], were isolated from an n-BuOH-soluble extract of the leaves of Abrus precatorius. Using a combination of spectral methods, the structures of compounds 1-4 were assigned, respectively, as the 3-O-beta-D-glucopyranosyl, the 3-O-beta-D-glucopyranosyl-(1----2)-beta-D-6-methylglucuronopyranosyl+ ++, the 3-O-beta-D-glucopyranosyl-(1----2)-beta-D-glucopyranosyl, and the 3-O-beta-D-glucopyranosyl-(1----2)-beta-D-glucuronopyranosyl derivatives of compound 5. After it established that compounds 1-4 were neither acutely toxic with mice nor mutagenic with Salmonella typhimurium strain TM677, they were found by a human taste panel to exhibit sweetness potencies in the range 30-100 times greater than sucrose.