Structure Identification: |
J Nat Prod. 2003 Oct;66(10):1378-81. | Cassane diterpenoids of Caesalpinia pulcherrima.[Pubmed: 14575441 ] | METHODS AND RESULTS:
Five new cassane diterpenoids (1-5) were isolated from the roots of Caesalpinia pulcherrima, along with the known Isovouacapenol C (6), pulcherrimin A (11), and 6beta-cinnamoyl-7beta-hydroxyvouacapen-5alpha-ol (12). Compounds 3-5 possess the alpha,beta-butenolide moiety, whereas compounds 1 and 2 contain a more usual 2,3-disubstituted furan unit. Compounds 7 and 8 were derived from hydrolysis of 6, while 9 and 10 were derived from acetylation and oxidation of 6, respectively.
CONCLUSIONS:
The (1)H and (13)C NMR spectra of all compounds were completely assigned using a combination of 2D NMR experiments, including (1)H-(1)H COSY, HSQC, HMBC, and T-ROESY sequences. | Acta Crystallogr Sect E Struct Rep Online. 2010 Jul 17;66(Pt 8):o2059-60. | Absolute configuration of isovouacapenol C.[Pubmed: 21588364 ] | METHODS AND RESULTS:
The title compound, C(27)H(34)O(5) {systematic name: (4aR,5R,6R,6aS,7R,11aS,11bR)-4a,6-dihy-droxy-4,4,7,11b-tetra-methyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca-hydro-phenanthro[3,2-b]furan-5-yl benzoate, Isovouacapenol C}, is a cassane furan-oditerpene, which was isolated from the roots of Caesalpinia pulcherrima. The three cyclo-hexane rings are trans fused: two of these are in chair conformations with the third in a twisted half-chair conformation, whereas the furan ring is almost planar (r.m.s. deviation = 0.003 Å). An intra-molecular C-H⋯O inter-action generates an S(6) ring. The absolute configurations of the stereogenic centres at positions 4a, 5, 6, 6a, 7, 11a and 11b are R, R, R, S, R, S and R, respectively.
CONCLUSIONS:
In the crystal, mol-ecules are linked into infinite chains along [010] by O-H⋯O hydrogen bonds. C⋯O [3.306 (2)-3.347 (2) Å] short contacts and C-H⋯π inter-actions also occur. |
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