Structure and Absolute Configuration of Diterpenoids from Hymenaea stigonocarpa

Abstract

Chemical investigations of the ethanolic extracts from the flowers and leaves of Hymenaea stigonocarpa Mart. ex Hayne afforded one new ent-halimane diterpenoid, 18-hydroxy-ent-halima-1(10),13-(E)-dien-15-oic acid (1), together with five known compounds (2-6). The structural elucidation was performed by means of NMR (COSY, HSQC, HMBC, and NOESY) and MS analyses. Complete (1)H and (13)C NMR data assignments are also reported for labd-13-en-8β-ol-15-oic (2) and labd-7,13-dien-15-oic (3) acids. The absolute configurations of 1 and 2 were established by comparison of experimental and calculated Raman optical activity spectra.

Halimane diterpenoids: sources, structures, nomenclature and biological activities

“…This journal is © The Royal Society of Chemistry 2018 The study of genus Halimium plants has made possible to determine the presence of ve chemotypes of Halimiun viscosum, known in accordance with the harvesting place: Villarino de los Aires, (Salamanca, Spain), 17 La Fregeneda, (Salamanca, Spain), 26,27 Valparaiso, (Zamora, Spain), 28 Celorico da Beira, (Portugal) 29 and San João da Pesqueira, (Portugal). 30 In this group, the Euphorbiaceae, 78,108,109,[111][112][113][114] Cistaceae, 17,26,27,29,30,110,[115][116][117][118] Leguminoseae, 48,119,120 Compositae, 21,24 Jungermanniaceae, 121 Velloziaceae 52 and Annonaceae 122,123 plant families have been studied together with marine organisms of genus Spurilla 124 and Agelas. 74,125 The most numerous compounds of this group (Fig.…”

Conformational distortion of α-phenylethyl amine in cryogenic matrices – a matrix isolation VCD study

“…The rotation along a for the conformers c1 and c2 passes through the transition states TS 11 and TS 22 before arriving at the identical conformations. The area encircled by the 0.25 kcal mol À1 contour line spans more than 25 degrees along the phenyl ring rotational motion and also about 25 degrees along the amine rotation.…”

“…of little populated conformers. [11][12][13] Furthermore, VCD spectroscopy has been shown to be a very powerful technique to study intermolecular interactions such as solutesolvent [14][15][16][17] or solute-solute [18][19][20][21][22] interactions as well as chirality transfer phenomena. Slight warming of the solid matrix also enables the diffusion controlled generation of larger molecular clusters.…”

Three new diterpenoids from Marrubium aschersonii

“…The 13 C NMR spectrum (Table 2) in combination with DEPT experiments resolved 22 carbon resonances attributable to two keto carbonyl groups, an acetyl group, two tetrasubstituted double bonds, a trisubstituted double bond, two sp 3 quaternary carbons, six sp 3 methylenes (two oxygenated), and four methyls. According to aforementioned information, to satisfy eight degrees of unsaturation, compound 1 was suggested to be a bicyclic diterpenoid, structurally similar to the type of halimane diterpenoids (Monteiro et al, 2015).…”