Sesquiterpene Lactones from Scorzonera austriaca

Abstract

Six new sesquiterpene lactones, scorzoaustriacoside (1), scorzoaustriacin (2), scorzoaustriacin 3-O-beta-d-glucoside (3), 4-epi-dihydroestafiatol (4), 14-isovaleroxyscorzoaustricin (5), and 14-isovaleroxyscorzoaustricin sulfate (6), along with five known guaianolides, were isolated from an acetone extract of the roots of Scorzonera austriaca. The structures of the new compounds were elucidated mainly by interpretation of their 1D and 2D NMR and HRMS data. Several isolates obtained in this investigation were evaluated against a small panel of cancer cell lines.

Isolation and Structure Determination of Three New Sesquiterpenoids from Achillea millefolium

“…The positions of both methylenes were also supported by HMBC correlations. The methyl group attached to C-11 appeared at δ = 14.6 in the 13 C NMR spectrum and is α-oriented, while the methyl group at C-11, which is β -oriented, should have a chemical shift of less than 10 ppm [6,9]. The stereochemistry at all the stereogenic centers was confirmed by a NOESY experiment and by comparison with literature data (Fig.…”

“…The IR spectrum exhibited absorption bands at 3396 -3150, 1760, 1688, and 1625 cm −1 which indicated the presence of a hydroxyl group, a γ-lactone, an α, β -unsaturated cyclopentenone, and a C = C double bond, respectively. The 1 H NMR, 13 C NMR and 2D NMR data indicated that compound 3 is structurally similar to compounds 1 and 2. In compound 3 there is a lack of the side chain on C-8.…”

“…The resonances at δ = 163.3, 143.1, 60.4, and 124.6 were due to the presence of a side chain ester and could be assigned to C-16, C-17, C-18, and C-19, respectively. The point of attachment of the ester moiety at C-8 was supported by the downfield shift of H-8 (δ = 5.10 Hz) as well as by the 13 C NMR signal for C-8 at δ = 73.4. This attachment was supported by the HMBC spectrum in which H-8 showed correlations with C-16, C-9 and C-7.…”

“…This attachment was supported by the HMBC spectrum in which H-8 showed correlations with C-16, C-9 and C-7. Two signals in the 13 C NMR spectrum at δ = 62.4 and δ = 60.4 were respectively assigned to the two methylene groups C-14 and C-18 having hydroxyl groups. The positions of both methylenes were also supported by HMBC correlations.…”

New Limonoids from the Seeds of a Krishna Mangrove, Xylocarpus granatum

“…An aliphatic CH group (d(H) 3.49 (dd, J ¼ 9.5, 7.0); d(C) 48.7 (CH)), with 1 H, 1 H-COSY cross-peaks to HÀC(3) and HÀC(30) (Fig. 2), was attributed to HÀC (2). Another aliphatic CH group…”