Linked Life Data

16190750

Source:http://linkedlifedata.com/resource/pubmed/id/16190750

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2005-9-29
pubmed:abstractText
The limited efficacy and considerable side effects of currently available therapies for the treatment of hepatitis C virus (HCV) infection have prompted significant efforts toward the development of safe and effective new therapeutics. The pentapeptide alpha-ketoamides of type 1 were weak HCV inhibitors with a binding constant, Ki, above 5 microM. We envisioned that cyclization of a P2 phenyl side chain to a P3 capping group could enhance binding through an interaction of the resulting macrocycle with the methyl group of Ala156 on the enzyme backbone. The macrocyclic dipeptide moiety would also decrease the peptidic nature of the inhibitors. The synthesis of macrocyclic HCV inhibitors started from m-tyrosine methyl ester. Two consecutive couplings, first, with Boc-cyclohexylglycine and, then, with hept-6-enoic acid, provided compound 6. The alkene was converted to an alcohol via hydroboration. The key macrocyclization of phenol alcohol 7 was achieved through a Mitsunobu reaction. Both 16- and 17-membered macrocycles (8 and 21) were prepared. After hydrolysis, the macrocyclic acids (15 and 22) were coupled to the right-hand tripeptide (14) to afford alpha-hydroxyamides, which upon Dess-Martin periodinane oxidation furnished the desired alpha-ketoamides. Esters, acids, and amides were incorporated at the C-terminal of these peptides. These inhibitors were tested in an HCV protease continuous assay. The binding constants (Ki) indicated that the 16-membered macrocyclic inhibitors (23 and 24) were less potent than the 17-membered analogues (16-19). It was also evident that C-terminal acids (i.e., 17) and amides (18 and 19) (Ki range: 0.16-0.31 microM) were much better inhibitors than tert-butyl esters (16 and 23). The X-ray crystal structure of compound 17 bound to the enzyme revealed that the macrocycle formed a "donut"-shaped ring around the methyl group of Ala156. P2' phenyl and P1 propyl groups wrapped around the Lys136 side chain, forming a "C"-shaped clamp. The 17-membered macrocyclic inhibitors 17-19 were significantly more potent than the acyclic pentapeptide 1.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6229-35
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Design, synthesis, and biological activity of m-tyrosine-based 16- and 17-membered macrocyclic inhibitors of hepatitis C virus NS3 serine protease.
pubmed:affiliation
Schering-Plough Research Institute, 2015 Galloping Hill Road, K-15-3-3545, Kenilworth, New Jersey 07033, USA. kevin.chen@spcorp.com
pubmed:publicationType
Journal Article