摘要:

AbstractSialyl‐T‐glycopeptides were synthesized by solid‐phase techniques, using a PEGA resin as the solid support. An appropriately protected building block containing α‐Neu5Ac‐(2→3)‐β‐Gal‐(1→3)‐α‐GalN3‐(1→) attached to Fmoc‐Thr/Ser‐OPfp was employed in a solid‐phase glycopeptide assembly of a 10‐mer glycopeptide, using a general Fmoc/OPfp‐ester strategy. Reduction of the azido group of the GalN3residue was effected on solid‐phase, using DTT and DBU. After acidolytic cleavage from the resin, the methyl ester of the sialic acid residue and acetyl groups were removed with 30% NaOMe/MeOH in MeOH and water pH 14, at −30°C for 2 h. At this low temperature, the highly basic conditions did not result in any detectable β‐elimination. However, one O‐acetyl group, located at the 2‐position of the Gal was resistant to hydrolysis. To remove this remaining acetyl group, reaction with hydrazine hydrate in CHCl3and MeOH at room temperature for 2.5 h was successful. The two target sequences of sialyl‐T‐glycopeptides were obtained in good yield. In contrast to the the analogs carrying the T‐antigen, the Sial‐T‐glycopeptides were non‐immunogenic, supporting the idea that the sialylation is a method of circumventing the recogni

ISSN:1075-2617    

DOI:10.1002/1099-1387(200012)6:12<585::AID-PSC274>3.0.CO;2-0

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY

摘要:

AbstractSeveral new α‐azido acids have been synthesized and their use in solid‐phase peptide synthesis has been demonstrated. The azido group allows for high activation of the carboxyl group as an acid chloride without formation of byproducts and with no detectable racemization. An analog of Leu‐enkephalin has been prepared and tested in the mouse vas deferens and guinea pig ileum bioassays: it displays moderate activity at the δ‐opiod receptor. Copyright © 2000 European Peptide Society and John Wiley

ISSN:1075-2617    

DOI:10.1002/1099-1387(200012)6:12<594::AID-PSC276>3.0.CO;2-X

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY

摘要:

AbstractFour diamino acid‐Nα‐substituted oligopeptide (DNO) oligomers substituted with pyrenyl as photophysical probes were synthesized. The excimer formation and ground‐state association of the pyrenyl groups were investigated by means of absorption and steady‐state fluorescence spectroscopy together with time‐resolved fluorescence techniques. The photophysical parameters obtained from the different derivatives reflect the secondary structural properties of the DNO backbones. Copyright © 2000 European Peptide Society and John Wile

ISSN:1075-2617    

DOI:10.1002/1099-1387(200012)6:12<603::AID-PSC281>3.0.CO;2-J

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY

摘要:

AbstractAn efficient synthesis of the cyclic decapeptide MEN 11270 [H‐

ISSN:1075-2617    

DOI:10.1002/1099-1387(200012)6:12<612::AID-PSC291>3.0.CO;2-K

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY

摘要:

AbstractThis paper describes the synthesis of two diastereoisomers of an imidazoline dipeptide mimetic (a 4,5‐dihydroimidazole‐4‐carboxylic acid), suitably protected for incorporation into solid phase peptide synthesis (SPPS) using the Fmoc protocol, from a phenylalanine‐derived thioimidate and an α,β‐diaminopropanoic acid ester, followed by protecting group manipulation. Copyright © 2000 European Peptide Society and John Wil

ISSN:1075-2617    

DOI:10.1002/1099-1387(200012)6:12<621::AID-PSC298>3.0.CO;2-1

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY