摘要:

AbstractA new water‐solubleN‐protecting group, 2‐[phenyl(methyl)sulfonio]ethyloxycarbonyl tetrafluoroborate, has been prepared and its application to solid phase peptide synthesis in water has been studied. Leu‐enkephalin amide was successfully synthesized in water by the solid phase method using this protecting group. Copyright © 2001 European Peptide Society and John Wiley&S

ISSN:1075-2617    

DOI:10.1002/psc.361

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

Abstract(R,S)‐Methionine was transformed intoCα‐hydroxymethyl methionine by a route involvingCα‐hydroxymethylation of 2‐phenyl‐4‐methylthioethyl‐5‐oxo‐4,5‐dihydro‐1,3‐oxazole. The absolute configuration of (−)‐Cα‐hydroxymethyl methionine was elucidated to be (S) by chemical correlation with (S) (−)‐Cα‐ethyl serine. Absolute structure determination (by single crystal X‐ray diffraction) onNα‐benzoyl‐Cα‐hydroxymethyl methionine confirmed the (R)‐configuration for the (+)‐enantiomer. In addition, the X‐ray diffraction analysis showed that theCα,α‐disubstituted glycyl residue adopts the fully extended (C5) conformation. Copyrig

ISSN:1075-2617    

DOI:10.1002/psc.360

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThree linear Thr6‐bradykinin analogues in which either one or both the two phenylalanine residues in the peptide sequence have been substituted byN‐benzylglycine (BzlGly) and their head‐to‐tail cyclic analogues were synthesized and tested on an isolated rat duodenum preparation. The linear (BzlGly5,Thr6‐BK, BzlGly8,Thr6‐BK and BzlGly5,8,Thr6‐BK) and the cyclic (cycloBzlGly5,Thr6‐BK,cycloBzlGly8,Thr6‐BK andcycloBzlGly5,8,Thr6‐BK) peptoid‐like analogues were characterized by amino acid analysis, optical rotation, analytical HPLC and MALDI‐TOF mass spectroscopy. The conformational features of both the linear and cyclic derivatives were investigated by FT‐IR and CD measurements. Preliminary molecular mechanics calculations were also performed on some synthetic peptides. Pharmacological screening using the relaxation of the isolated rat duodenum preparation showed that incorporation ofN‐benzylglycine at positions 5 and/or 8 in the linear Thr6‐BK causes a substantial decrease in potency. Comparable incorporation incycloThr6‐BK, at position 8, or 5 and 8, resulted in nearly inactive analogues. However,cycloBzlGly5,Thr6‐BK showed a potency which is of the same order of magnitude as forcyclo‐BK andcycloThr6‐BK. Copyright © 2001 European Pe

ISSN:1075-2617    

DOI:10.1002/psc.358

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThis article illustrates the successful and efficient solid phase assembly of hydrophobic difficult sequence peptides following botht‐Boc and Fmoc chemistry. The peptides were synthesized on an optimized 1,4‐butanediol dimethacrylate‐crosslinked polystyrene support (BDDMA‐PS). Four difficult sequence test peptides, VAVAG, VIVIG, QVGQVELG and VQAAIDYING, were synthesized in relatively good yield and purity without any aggregation problems. The peptides were assembled on chloromethylated and 4‐hydroxymethylphenoxymethyl (HMP) BDDMA‐PS resins. The peptides were fabricated using Boc amino acid 1‐hydroxybenzotriazolyl and Fmoc amino acid pentafluorophenyl active esters in coupling reactions. The peptides after synthesis were cleaved from the polymeric support by exposing the peptidyl resin to 90% trifluroacetic acid/5% thioanisole/5% EDT mixture. The HPLC and MALDI TOF MS studies of the peptides revealed the high homogeneity of the synthesized peptides. Chloromethylated resin having a functional group loading of 1.14 mmol Cl/g was used for the synthesis. The yield and homogeneity of these peptides synthesized using the new support were high when compared with the conventional DVB‐PS resin. Copyright © 2001 European Peptide Society and John

ISSN:1075-2617    

DOI:10.1002/psc.355

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY