New Eremophilenolides from Senecio dianthus
Abstract
From the aerial parts of Senecio dianthus, four new eremophilenolides (1–4, resp.) and one new eremophilenolide alkaloid (5), of the relatively uncommon eremophilenoid-type sesquiterpenoid lactones, were isolated together with three known sesquiterpenoid lactones, 10β-hydroxyeremophil-7(11)-en-12,8α-olide (6), 8β,10β-dihydroxyeremophil-7(11)-en-12,8α-olide (7), and 10α-hydroxy-1-oxoeremophila-7(11),8(9)-dien-12,8-olide (8). On the basis of IR, MS, and NMR data, particularly 2D-NMR analyses, the structures of the new compounds were established as: 2β-(angeloyloxy)-10β-hydroxyeremophil-7(11)-en-12,8α-olide (1), 6β-(angeloyloxy)-10β-hydroxyeremophil-7(11)-en-12,8α-olide (2), 2β-(angeloyloxy)-8β,10β-dihydroxyeremophil-7(11)-en-12,8α-olide (3), 2β-(angeloyloxy)-8α-hydroxyeremophila-7(11),9(10)-dien-12,8β-olide (4), and 8β-amino-10β-hydroxyeremophil-7(11)-en-12,8α-olide (5). In addition, the relative configuration of 1 was corroborated by X-ray diffraction analysis.
