Linked Life Data

8691470

Source:http://linkedlifedata.com/resource/pubmed/id/8691470

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1996-8-26
pubmed:abstractText
5-fluorouracil (5-FU) seco-nucleosdies having as the "sugar" moiety a two-carbon (C2) side chain carrying a N-(2-chloroethyl)-N-nitrosourea group were designed as molecular combinations of antimetabolite and alkylating agent, but hydrolytic release of free 5-FU was not fast enough for significant contribution to the high activity they showed against colon and breast tumors in mice. In the present study of the synthesis of the more reactive C3 seco-nucleosides, it emerged that, of various groups attached to the aldehydic center in the precursor phthalimides, only the alkoxy/uracil-1-yl type was conveniently obtained by the standard method. The methylthio/uracil-1-yl analog required relatively large amounts of reagent methanethiol, and exploration of alternatives involving alpha-chlorination of alkyl methyl sulfide or Pummerer rearrangement of its S-oxide, or successive hydrolysis and methylation of isothiouronium bromide, gave disappointing yields. For successful preparation of the alkoxy/uracil-3-yl compounds, the route used for C2 homologs required considerable experimental modification. In addition to these O,N- and S,N-acetals, some N,N-acetals bearing two 5-FU residues were prepared. The new drugs have been tested against a panel of experimental tumors in mice. Although it is evident from a parallel study that even these C3 seco-nucleosides release free 5-FU too slowly in vivo, several of them have shown impressive anticancer activity. Reviewing their performance in comparison with earlier molecular combinations, a short list of seven [B.4152 (6), B.4015 (5), B.4030 (10), B.3999 (4), B.3995 (2), B.4083 (3), and B.3996 (the N 3-substituted analog of 1)] should be investigated further. This is particularly appropriate in light of the present understanding of the mode of action of chloroethylating agents. Following a prolonged period of clinical impatience with nitrosoureas because of limited selectivity action, a new era is confidently anticipated as these powerful drugs are increasingly studied in combination with O6-benzylguanine and other more efficient inhibitors of repair enzymes like O6-alkylguanine-DNA-alkyltransferase now being developed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1403-12
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Nucleoside analogs. 14. The synthesis of antitumor activity in mice of molecular combinations of 5-fluorouracil and N-(2-Chloroethyl)-N-nitrosourea moieties separated by a three-carbon chain.
pubmed:affiliation
Screening and Pharmacology Group, EORTC, and University Chemical Laboratory, Trinity College, Dublin, Ireland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't