Inulevs-A, a new sesquiterpene lactone from the leaves of Inula racemosa Hook. f."

The Himalayan herb Inula racemosa has long been valued for its therapeutic benefits, which are largely attributed to the bioactive compounds present in its roots. However, the chemical and medicinal potential of its leaves has remained largely unexplored. This study addresses this gap by isolating one new (2) and ten known (1, 3-11) sesquiterpene lactones from leaves of Inula racemosa. Inulevs-A (2) was identified as the 11,13-dihydro analogue of the leaf major metabolite 4,5-epoxy-11(13)-guaien-12,8-olide (1) through 1D/2D NMR and mass data. The biological activity of 1 and 2 are analysed for regulating GLUT4 expression, a key protein involved in insulin-dependent glucose uptake.