Helenanolides, guaianolide glucosides and other constituents of two Helenium donianum varieties

Antiplasmodial and Antiproliferative Pseudoguaianolides of Athroisma proteiforme from the Madagascar Dry Forest

“…Its 1 H NMR spectrum in CDCl 3 showed signals for two methyl singlets at δ H 2.10 and 0.98, three methyl doublets at δ H 1.14, 1.14, and 1.02, three methylene multiplets, two of which were olefinic (δ H 2.66, 1.53; 2.42, 1.41; 5.53, 6.40), and eight methines (δ H 1.98, 2.24, 2.50, 3.04, 4.41, 4.64, 4.90, and 5.02), four of which were oxygenated (Table ). Inspection of the 1 H and 13 C NMR data of 2 in CDCl 3 showed a close similarity with the data of the previously isolated (l S ,2 S ,4 R ,5 R ,6 R ,7 S ,8 S ,l0 R )-2,4-diacetoxy-6-hydroxyguai-11­(13)-en-8,12-olide ( 7 ) . It differed from 7 in the presence of a 2-methylpropanoyl group at C-2 of 2 compared to an acetate group at C-2 of 7 .…”

“…Inspection of the 1 H and 13 C NMR data of 2 in CDCl 3 showed a close similarity with the data of the previously isolated (l S ,2 S ,4 R ,5 R ,6 R ,7 S ,8 S ,l0 R )-2,4-diacetoxy-6-hydroxyguai-11(13)-en-8,12-olide ( 7 ). 15 It differed from 7 by the presence of a 2-methylpropanoyl group at C-2 of 4 compared to an acetate group at C-2 of 7 . HMBC correlations from H-2 to C-1', and of the methine septet at H-2' and of H 3 -3' and H 3 -4' to C-1', and from H-4 to C-1” indicated that the 2-methylpropanoyl group was located at C-2 and the acetate group at C-4.…”

“…Its 1 H NMR spectrum in CDCl 3 showed signals for three methyl singlets ( δ H 1.27, 1.26 and 1.07), one methyl doublet ( δ H 1.41 d, J = 7.2 Hz), two olefinic methyl groups ( δ H 1.78 m; 1.94 dq, J = 7.3, 1.5 Hz), one singlet methylene ( δ H 2.49), and three methines ( δ H 3.55 m, 3.19 m, and 2.43 m). Three oxygenated methines were also observed at δ H 5.48 br s, 5.34 (d, J = 3.7 Hz), and δ H 4.66 br s. Signals for five olefinic methines were observed at δ H 7.60 dd ( J = 6.0, 1.6 Hz), 6.80 s, 6.12 s, 6.12 m, and 6.10 m. The 13 C NMR spectrum displayed a set of signals ascribable to a ( Z )-2-methyl-2-butenoyl (angeloyl) group ( δ C 166.1, 127.0, 139.7, 15.7, 20.4) 15 and a 3-hydroxy-3-methylbutanoyl group ( δ C 171.6, 46.4, 69.2, 29.3, 29.2) 18 together with 15 signals of a sesquiterpene lactone [two quaternary carbons at δ C 55.3 and 130.8; a lactone carbonyl at δ C 162.4, and a conjugated carbonyl at δ C 207.7; one quaternary and one secondary methyl ( δ C 18.8 and 19.2, respectively); two olefinic methines ( δ C 161.0 and 130.3); three oxygen-bearing methines ( δ C 88.5, 76.0, and 64.7); three methines ( δ C 50.5, 45.5, and 50.5); and an exocyclic methylene ( δ C 134.4), as indicated by the HMQC spectrum (Table 1)]. The complete 1 H and 13 C NMR assignments and connectivities were established from a combination of COSY, HMQC, and HMBC data.…”

Cytotoxic and Anti-Inflammatory Sesquiterpenes from the Whole Plants of Centipeda minima

“…Comparison of the NMR data (Tables 3 and 4) of 9 with those of 8 indicated that both compounds are closely related, differing in their substituents at C-2 and C-4. Detailed analysis of the 2D NMR spectroscopic data indicated that the isobutyryl moiety in 8 was replaced by a tigloyl moiety [δ H 6.85 (1H, qq, J = 7.2, 1.5 Hz, H-3″), 1.80 (3H, dq, J = 7.2, 1.1 Hz, H-4″), 1.83(3H, m, H-5″)] 23 in 9, which was affirmed by the HMBC correlation from H-2 to C-1″. Likewise, the isovaleryl moiety in 8 was replaced by an angeloyl moiety [δ H 6.06 (1H, qq, J = 7.2, 1.5 Hz, H-3′), 1.97 (3H, dq, J = 7.2, 1.5 Hz, H-4′), 1.85 (3H, m, H-5′)] in 9, as supported by the HMBC correlation from H-4 (δ H 4.86) to C-1′.…”

Natural sesquiterpenoids

“…Known eudesmanolides have been isolated from Ophryosporus piquerioides"' and Sonchus n y m ~n i i . ~~' Saussureal (298), a sesquiterpene lactone with a new modified eudesmane skeleton, has been found in the roots of Saussurea lappa. This compound possessed plant growth regulator…”