Linked Life Data

402208

Source:http://linkedlifedata.com/resource/pubmed/id/402208

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1977-4-15
pubmed:abstractText
The molecular structure and conformation of the cis-5,6-dihydrodiol of 7,12-dimethylbenz[a]anthracene has been determined by an X-ray crystallographic analysis. The compound crystallizes in the space group P21/a with cell dimensions a equals 17.799(6), b equals 33.211(8), c equals 5.241(1) A, beta equals 91.88(2)degrees. There are two molecules, designated A and B in the asymmetrical unit, that are not related to each other by crystallographic symmetry. Their conformations are almost identical, and there are no significant differences in their bond lengths or angles. In both molecules the 5-hydroxyl group is equatorial while the 6-hydroxyl group is axial. This conformation is probably forced by steric hindrance between the hydroxyl group, 0-6, and the hydrogen atoms of the 7-methyl group. The molecules pack in the crystal by forming hydrogen bonds between the hydroxyl groups of adjacent molecules, A with A, B, with B, and A with B. The ring system of the cis-5,6-dihydrodiol is much more buckled than is that in 7,12-dimethylbenz[a]anthracene itself. The angle between the two outermost rings is 36 degrees, the deviation from planarity being primarily a consequence of the partial saturation in the ring containing the two hydroxyl groups. Extrapolation of these results to other dihydrodiol derivatives of carcinogenic hydrocarbons permits some predictions of preferred molecular geometry. Thus, the 8,9-dihydrodiol-10,11-epoxide of 7,12-dimethylbenz]a[anthracene, analogous to the biologically active 7,8-dihydrodiol-9,10-epoxide of benzo]a[pyrene, a mutagen that is believed to be an active intermediate in carcinogenesis by benzo]a[pyrene, should probably exist preferentially in a conformation bearing the8-hydroxyl group in the axial orientation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
775-82
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
Molecular structure of the K-region cis-dihydrodiol of 7,12-dimethylbenz[a]anthracene.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.