A new ergostanol saponin from Dioscorea deltoidea Wall var. orbiculata

From the fresh rhizomes of Dioscorea deltoidea Wall var. orbiculata , a novel ergostanol saponin, orbiculatoside A ( 1 ), was isolated and identified as 3- O - g - d -glucopyranosyl-ergost-5-ene-3 g , 26-diol-26- O - g - d -glucopyranosyl(1 M 3)-[ g - d -glucopyranosyl(1 M 2)- g - d -glucupyranosyl(1 M 6)]- g - d -glucopyranoside by various NMR techniques in combination with chemical methods. The new saponin showed strong activity against Pyricularia oryzae , with a MMDC (minimum morphological deformation concentration) value of 28.04 w mol/l and was cytotoxic to cancer cell line K562, HCT-15, A549, HT1080, and A2780a in vitro .

Keywords:

• Dioscorea Deltoidea Wall Var. orbiculata
• Orbiculatoside A
• Pyricularia Oryzae
• Cytotoxic