ISSN:
0192-8651
Keywords:
Computational Chemistry and Molecular Modeling
;
Biochemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Computer Science
Notes:
A conformational analysis has been performed for sixteen dimers of (+)-catechin and/or (-)-epicatechin using molecular mechanics (MM2). Monomer units are linked by 4α-6, 4α-8, 4β-6, and 4β-8 bonds. THe four possible combinations of (+)-catechin and/or(-)-epicatechin are used for each bonding pattern. The objectives are characterization of (1) the two rotational isomers at the bond between the two monomer units and (2) the conformations of the heterocyclic rings. There is a twofold rotation about the bond between monomer units. Differ4ences in the energies at the two minima range from a few tenths of a kcal/mol to several kcal/mol, depending on the dimer Heterocyclic rings occupy a range of conformations that can be described as half chairs with varying degrees of distoration toward C(2) or C(3) sofas. The more frequent distortion is toward the C(2) sofa. Interconversion between most of the heterocyclic ring conformations can be obtained by coordinated motion of C(2) and C(3), over a range of about 40 pm, with respect to the mean plane of the fused aromatic ring system.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcc.540070603
