Phenols, Acetylenes, and Sesquiterpene Lactones from Inulanthera nuda

Five new compounds, the sesquiterpene lactones 1 and 2 , the 2 H ‐pyran‐2‐one 9 , the flavone glycoside 10 , and the organic diacid 11 were isolated from the CH 2 Cl 2 extract ( 1 and 2 ) and from the BuOH part of the MeOH extract ( 9  –  11 ) of the aerial parts of Inulanthera nuda Källersjö (Asteraceae). The structures were established by spectroscopic methods, including UV, IR, EI‐MS, D/CI‐MS and TSP‐MS, 1 H‐ and 13 C‐NMR as well as two‐dimensional NMR techniques. The sesquiterpene lactones were identified as 1 α ,4 β ,10 β ‐trihydroxyguaia‐2,11(13)‐dieno‐12,6 α ‐lactone ( 1 ) and 4 β ,10 β ‐dihydroxy‐1 α ‐methoxyguaia‐2,11(13)‐dieno‐12,6 α ‐lactone ( 2 ), while 9 was found to be 4‐( β ‐ D ‐glucopyranosyloxy)‐6‐methyl‐2 H ‐pyran‐2‐one, 10 was determined as luteolin 7‐(2″‐ O ‐acetyl‐ β ‐ D ‐glucuronoside) and 11 as ( Z )‐2‐(4‐hydroxybenzyl)butenedioic acid. The new compounds were accompanied by six more compounds ( 3  –  8 ) from the CH 2 Cl 2 extract and ten compounds from the BuOH extract (including 12  –  16 ). Compounds 3 and 4 were identified as ( E )‐ and ( Z )‐ O ‐acetyldendranthemenol, while the structures of 5  –  8 were elucidated as the flavones salvigenin, 5‐hydroxy‐3′,4′,6,7‐tetramethoxyflavone, eupatorin, and cirsilineol, respectively, from their spectroscopic data (EI‐ and D/CI‐MS, UV, 1 H‐ and 13 C‐NMR). Compounds 12  –  16 were determined as scopolin, maltol 3‐glucoside, and the flavone glycosides luteolin 7‐glucuronide, apigenin 7‐glucuronide, and scutellarein 7‐glucuronide based on spectral evidences (D/CI‐ and TSP‐MS, UV, 1 H‐ and 13 C‐NMR). The additional five compounds from the BuOH extract were identified on‐line by HPLC‐MS as chlorogenic acid, 3,4‐dicaffeoylquinic acid, 1,5‐dicaffeoylquinic acid, 4,5‐dicaffeoylquinic acid, and 3,4‐dicaffeoylisoquinic acid. The identification was based on comparison of retention times and UV and mass spectra with authentic samples.