PRODRUGS OF PEPTIDES .9. BIOREVERSIBLE N-ALPHA-HYDROXYALKYLATION OF THE PEPTIDE-BOND TO EFFECT PROTECTION AGAINST CARBOXYPEPTIDASE OR OTHER PROTEOLYTIC-ENZYMES

被引:21
作者
BUNDGAARD, H
RASMUSSEN, GJ
机构
[1] Royal Danish School of Pharmacy, Department of Pharmaceutical Chemistry, Copenhagen, DK-2100
关键词
PEPTIDES; PRODRUG; 5-OXAZOLIDINONES; N-ALPHA-HYDROXYALKYLATION; PROTEOLYTIC ENZYMES; PEPTIDE ABSORPTION;
D O I
10.1023/A:1015833229554
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Various N-alpha-hydroxyalkyl derivatives of N-acyl amino acids and di- and tripeptides were prepared by hydrolysis or aminolysis of N-acyl 5-oxazolidinones. The stability of these derivatives was studied in aqueous solution as a function of pH. The compounds were all degraded quantitatively to their parent N-acylated amino acid or peptide and aldehyde but with vastly different rates. At pH 7.4 and 37-degrees-C the half-lives of decomposition ranged from 4 min to 1500 hr. The structural factors influencing the stability included both steric and polar effects within the acyl and N-alpha-hydroxyalkyl moieties as well as within the amino acid attached to the N-alpha-hydroxyalkylated N-acyl amino acid. Whereas the N-benzyloxycarbonyl (Z) derivatives of the dipeptides Gly-L-Leu and Gly-L-Ala were readily hydrolyzed by carboxypeptidase A, the N-hydroxymethylated compounds, i.e., Z-Gly(CH2OH)-Leu and Z-Gly(CH2OH)-Ala, were resistant to cleavage by the enzyme as revealed by their similar rates of decomposition in the presence or absence of the enzyme at pH 7.4 and 37-degrees-C. The results suggest that N-alpha-hydroxyalkylation of a peptide bond protects not only this bond but also an adjacent peptide bond against proteolytic cleavage. Since the N-alpha-hydroxyalkyl derivatives are readily bioreversible, undergoing spontaneous hydrolysis at physiological pH, this prodrug approach promises to overcome the enzymatic barrier to absorption of various peptides.
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页码:313 / 322
页数:10
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