Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1988-3-18
pubmed:abstractText
The pentapeptide lactone Cbz-(Thr-D-Val-Pro-Sar-MeAla-) was synthesized in order to observe the behavior of the unprotected lactone resulting from its hydrogenolytic deprotection. Closely related peptide lactones have been reported as intermediates in total syntheses of actinomycin D and its analogues, despite the fact that unprotected and unprotonated O-peptides of serine and threonine are known to undergo rapid O,N-acyl shift. In the present study the peptide lactone was seen to undergo a slow O,N-acyl shift, in a matter of hours, to the known cyclic pentapeptide. This contrasted with the rapid rearrangement of a model O-peptide, O-hippuryl-L-threonine methyl ester. This slowness of an O,N-acyl shift in a cyclic system presumably results from higher energy barriers of conformational origin. It explains the suitability of unprotected peptide lactones for the syntheses of actinomycins and other peptide lactone antibiotics which have appeared in the literature.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0367-8377
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
481-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Slow O,N-acyl shift in an actinomycin-related peptide lactone.
pubmed:affiliation
Research Foundation of the Washington Healthcare Corporation, Washington, D.C.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.