Hastifolins A–G, antifeedant neo-clerodane diterpenoids from Scutellaria hastifolia

Clerodane diterpenes: sources, structures, and biological activities

“…Many compounds in this subtype contain the typical functional groups of neo-clerodane diterpenoids, including a C-4/C-18 (e.g., 505) or C-3/C-4 epoxide (e.g., 515, 516) and cis C-17a and C-20a methyl groups. [192][193][194][195][196][197][198][199][200][201][202][203][204][205][206][207][208][209] Among them, hastifolin A (505) from Scutellaria hastifolia showed signicant antifeedant activity against larvae of Spodoptera littoralis at a concentration of 100 ppm; its feeding index was 60 AE 15.2 and FI 50 concentration was 45 ppm. 204 Seguiniilactones A and B (515-516) from Colquhounia seguinii differ structurally only in where the butenolide ring is connected to C-12.…”

Acylated neo -clerodanes and 19- nor - neo -clerodanes from the aerial parts of Scutellaria coleifolia (Lamiaceae)

“…The 1 H and 13 C NMR spectra of 7 and 8 were closely correlated with those of hastifolins E and D (Raccuglia et al, 2010), respectively, indicating they were also a pair of C-13 epimers of 8b,13-epoxy-4,18-dihydroxy-neo-cleradane-15,16-olides. Analysis of 1 H and 13 C NMR spectra of 7 and 8 indicated the presence of two tigloyl groups and one oxymethine instead of the cinnamoyl group and one methylene seen in hastifolins E and D. The locations of the two tigloxy groups were elucidated to be C-6 and C-7 from the 1 H-1 H COSY correlation of H-6/H-7, as well as the HMBC correlations of H-6 with C-1 0 , H-7 with C-1 00 , H 3 -17 with C-7, and of H 3 -19 with C-6 ( Fig.…”

“…The 1 H and 13 C NMR spectroscopic data were similar to those of 1 except for the chemical shifts ascribable to H-6, H 2 -18, C-4 and C-18. In contrast, the chemical shifts of H 2 -18 [d H 2.41 (d, J = 4.3 Hz), 3.28 (dd, J = 1.9, 4.3 Hz)], C-4 (d C 64.8) and C-18 (d C 50.8) were well correlated with those of neo-clerodanes with an oxyrane moiety at C-4 (Bozov et al, 1993;de la Torre et al, 1995;Malakov and Papanov, 1996;Muñoz et al, 1997;Esquivel et al, 2001;Raccuglia et al, 2010). These data implied that 6 had a 4,18;8b,13-diepoxy-neo-clerodane-15,16-olide structure.…”

“…More than 100 neo-clerodanes have been isolated from this genus, and have been classified into 8b-hydroxy-neo-clerod-13-en-15,16-olides (Cole et al, 1990;Miyaichi et al, 1994;de la Torre et al, 1997;Hussein et al, 1996;Malakov and Papanov, 1996;Kizu et al, 1997;Rodríguez et al, 1997;Esquivel et al, 2001;Nguyen et al, 2009;Shang et al, 2010;Raccuglia et al, 2010;Wang et al, 2012), 8b,13-epoxy-neo-clerodane-15,16-olides (Bozov et al, 1993;Malakov and Papanov, 1996;Kizu et al, 1997;Esquivel et al, 2001;Nguyen et al, 2009;Shang et al, 2010;Raccuglia et al, 2010;Lee and Shim, 2011;Wang et al, 2012) and 11,16;15,16-diepoxy-neo-clerodanes (Cole et al, 1990;de la Torre et al, 1995de la Torre et al, , 1997Rodríguez et al, 1997;Ohno et al, 1996Ohno et al, , 1997Kizu et al, 1998;Bruno et al, 2000;Wang et al, 2012), respectively. These neo-clerodanes have attracted interest of researchers for their biological activities, which include anti-feedant (Cole et al, 1990;Muñoz et al, 1997;Raccuglia et al, 2010), anti-oxidant (Nguyen et al, 2009) and anti-cancer activities (Wang et al, 2012).…”

Neopierisoids A and B, Two New Chlorinated 3,4-seco-Grayanane Diterpenoids with Antifeedant Activity from Flowers of Pieris japonica

“…Antifeedants are found among all of the major classes of secondary metabolites: alkaloids, phenolics, and terpenoids . Many diterpenoids, an important subclass of terpenoids, show antiviral, antibacterial, and allelopathic effects, and are obvious phytoalexins with a defensive function against generalist and specialist insect and mammalian herbivores. − Grayanane diterpenoids, the main poisonous constituents of toxic species in the family Ericaceae, exhibit remarkable antifeedant and insecticidal activities. − …”