In:
Chinese Journal of Chemical Physics, AIP Publishing, Vol. 22, No. 3 ( 2009-06-01), p. 275-284
Abstract:
The title compound glaucocalyxin A (1) (7, 14-dihydroxy-ent-kaur-16-en-3,15-dione) isolated from the leaves of isodon excisoides was characterized by IR, 1H NMR, 13C NMR, 1H-1H COSY, HMQC, HMBC, and EIMS, and its crystal structure was determined by single-crystal X-ray diffraction. The X-ray crystal structure revealed that the molecular backbone of the chosen crystal is a tetracyclic system, including three six-membered rings and a five-membered ring, and the three six-membered rings are in a chair-like conformation. The five-membered ring adopts a twisted envelope-like conformation, and its geometrical parameters were compared with theoretical calculations at the B3LYP and HF level of theory. The molecules form extensive networks through the intra- and intermolecular hydrogen bonds. The experimental NMR data were interpreted with the aid of magnetic shielding constant calculations, by means of the GIAO (gauge-lncluding atomic orbitals) method. Calculated and experimental results were compared with a satisfactory level of agreement. Molecular electrostatic potential map was used in an attempt to identify key features of the diterpenoid glaucocalyxin A that is necessary for its activity. Calculations of molecular electrostatic potential and stabilization energies suggest that the protonation of glaucocalyxin A will be able to occur on carbonyl oxygen atoms.
Type of Medium:
Online Resource
ISSN:
1674-0068
,
2327-2244
DOI:
10.1088/1674-0068/22/03/275-284
Language:
English
Publisher:
AIP Publishing
Publication Date:
2009
detail.hit.zdb_id:
2381472-X
SSG:
6,25
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