New Glucosides of a 4-Hydroxy-5-methylcoumarin and a Dihydro-α-pyrone from Gerbera jamesonii hybrida

Abstract

Two new glucosides, 2, C₁₆H₁₈O₉, mp 202-203°C, [α]²⁰_D-96.4°(MeOH) and gerberin (5), C₁₂H₁₈O₈, [α]¹⁹_D +11.2°(MeOH), were isolated from the aerial part of Gerbera jamesonii hybrida (Compositae). On methanolysis, 2 yielded 6-hydroxy-4-methoxy-5-methylcoumarin. The tetraacetate of 5 yielded tetraacetylparasorboside on catalytic hydrogenation. The chemical structures of 2 and 5 were established as 4-β-D-glucopyranosyloxy-6-hydroxy-5-methylcoumarin and (6S)-5, 6-dihydro-4-β-D-glucopyranosyloxy-6-methyl-2H-pyran-2-one, respectively. The yield of gerberin (5) was quite high, amounting to about 3.7% based on the weight of the dried plant material.