Diterpenes and sesquiterpenes from Osteospermum species

Sesquiterpene Glycosides fromCalendula persica

“…The isolation of these glycosides may be of chemotaxonomic importance as similar compounds are present in Osteospermum (9) which is also a member of the tribe Calendulaceae. After isolation of larger quantities, biological tests may show whether these glycosides are responsible for the observed activities of these species.…”

New Cadinane Sesquiterpenes from the Stems of Kadsura heteroclita

“…The relative configuration of 2 was assigned by detailed analysis of its NOESY spectra and the 1 H-NMR coupling constants. The observed NOESY correlations between H 3 -14 (δ H 1.24) and H-7 (δ H 3.09) indicated that H 3 -14 and H-7 were co-facial, while H 3 -14 and 1,2-isopropanediol group were trans to each other [34,35,36,37], unlike the cis conformations [31,32,33]. The above deductions were further proved by the NOESY cross peaks between H-10 (δ H 2.64) and H 3 -13 (δ H 1.14).…”

“…The relative configuration of 3 was assigned by detailed analysis of its NOESY spectra, in which H 3 -14 (δ H 1.57) was correlated with H-7 (δ H 2.79, t, J = 2.7), illustrating the β-orientation of H-7, while the 1,2-isopropanediol group was α -oriented. The absence of correlations between H 3 -14, H 3 -13 and H 2 -12 also suggested that H 3 -14 and the 1,2-isopropanediol group were in trans conformation [34,35,36,37]. The 1 H coupling constant between H 2 -8 and H-7 were 2.7 Hz in triplicate, indicating that H-7 and H-8α, H-8β are in ee and ae formation.…”

Diterpenoids

“…Some aspects of the photochemistry of this series have also been examined. X -Ray analysis was also ~s e d ~~* ~~ to establish the structure of helioscopinolide A (60), which was obtained from Euphorbiu helioscopia. Its 3-epimer is helioscopinolide B and the 3-ketone is helioscopinolide C. Some diterpenes of the cassane skeleton, e.g.…”