Linked Life Data

7760694

Source:http://linkedlifedata.com/resource/pubmed/id/7760694

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-6-23
pubmed:abstractText
To investigate the metabolism and possible deleterious effects of 4-methyl and 4,4-dimethyl steroids in Manduca sexta, the 4,4-dimethyl sterols lanosterol and cycloartenol, the 4-methyl sterol obtusifoliol and the 4,4-dimethyl pentacyclic triterpenoid alpha-amyrin were fed in an artificial agar-based diet at various concentrations. Utilization and metabolism of these four compounds were compared with sitosterol, stigmasterol, brassicasterol, ergosterol and 24-methylenecholesterol, 24-alkyl sterols that are readily dealkylated and converted to cholesterol in Manduca and in most phytophagous insects. None of the 4-methylated compounds significantly inhibited development except at very high dietary concentrations. The delta 24-bonds of lanosterol and cycloartenol were effectively reduced by the Manduca delta 24-sterol reductase enzyme, as is the delta 24-bond of desmosterol which, in most phytophagous insects, is an intermediate in the conversion of sitosterol, stigmasterol and other C28 and C29 phytosterols to cholesterol. On the other hand, the 24-methylene substituent of obtusifoliol was not dealkylated. Each of the 4-desmethyl C28 and C29 sterols was readily converted to cholesterol, and a significant amount of 7-dehydrocholesterol was derived from ergosterol metabolism. The reason for the differences in substrate specificity of these sterols is not clear, but the information may be useful in the development of new, specific, mechanism-based inhibitors of sterol metabolism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0024-4201
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
91-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Comparative studies of metabolism of 4-desmethyl, 4-monomethyl and 4,4-dimethyl sterols in Manduca sexta.
pubmed:affiliation
Insect Neurobiology & Hormone Laboratory, ARS, USDA, Beltsville, Maryland 20705, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't