Abstract
Eight new eremophilenolides, 6β-angeloyloxy-3β, 9α-dihydroxyeremophil-7(11)-en-12, 8β-olide (1), 6β-angeloyl-oxy-3β, 9β-dihydroxyeremophil-7(11)-en-12, 8β-olide (2), 6β-angeloyloxy-3β, 8β, 9β-trihydroxyeremophil-7(11)-en-12, 8α-olide (3), 6β-(3'-chloro-2'-hydroxy-2'-methylbutyloyloxy)-3β-hydroxyeremophil-7(11)-en-12, 8β-olide (4), 6β-epoxyangeloyloxy-3β-hydroxyeremophil-7(11)-en-12, 8β-olide (5), 3β-hydroxy-6α-methoxyeremophil-7(11)-en-12, 8β-olide (6), 3β-hydroxy-6β-methoxyeremophil-7(11)-en-12, 8α-olide (7) and 8β-hydroxy-3-oxoeremophil-7(11)-en-12, 8α-olide (8) were isolated from the dried rhizomes of Petasites japonicus MAXIM. (Compositae) together with a new eremophilane-type sesquiterpenoid, 3β-hydroxy-8-oxoeremophil-6-en-12-oic acid methyl ester (9). Compound 4 is the first chlorine-containing eremophilenolide derivative isolated from natural sources. The structures of these compounds were elucidated by spectroscopy.
