| Nouelia insignis Franch belongs to the family of Compositae; it is an endemic and rare plant as well as a monotype species of the genus Nouelia Franch in china. The in vitro activity-test indicated that the 95% ethanolic extract of the aerial parts of Nouelia insignis Franch showed a-amylase inhibitory activity. In order to further investigate chemical constituents and active compounds, the aerial parts of Nouelia insignis Franch was phytochemically studied for the first time. Twenty-eight compounds were isolated, two of which were new compounds and one was a new artifact.The extract of 95% ethanol at room temperature was suspended in hot water and extracted successively with petroleum ether, EtOAc and n-BuOH to give corresponding four fractions, respectively. Twenty-eight compounds were isolated predominantly by silica gel and Sephedex LH-20 column chromatography and identified by spectral methods, chemical reaction, X-ray crystallographic analysis or comparing them with authentic samples.Two new ent-kaurene-type diterpenes were identified as ent-14β, 15α-dihydroxykaur-16-en-19-oic acid (1) and ent-14β-hydroxy-15-oxokaur-16-en-19-oic acid (2); the new artifact was identified as ent-15α-hydroxykaur-16-en-19-oic acid 11,12-acetonide (3); twenty-five known compounds were ent-11α,16α-epoxy-15α-hydroxy-16S-kaur-19-oic acid (4), ent-15α-hydroxykaur-16-en-19-oic acid (5), ent-11α, 12α, 15α-trihydroxykaur-16-en-19-oic acid (6), ent-12α,15α-dihydroxykaur-16-en-19-oic acid (7), 8β,9-dihydro-onoseriolide (8), taraxerone (9),β-taraxerol (10),α-taraxerol (11), taraxeryl acetate (12), 2,6-dimethoxy-l,4-benzoquinone (13), stigmasterol (14), 3-O-β-D-glucopyranosyl stigmasterol (15),β-sitosterol (16),β-daucosterol (17), 2,3-dihydroxypropyl hexadecoate (18), palmitic acid (19), tetracosanoic acid (20), pentacosan-1-ol (21), taraxasteryl acetate (22), pseudo taraxasteryl acetate (23), caffeic acid (24), sucrose (25), rutin (26), glutinol (27), and onoseriolid (28).
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