摘要
在固相多肽合成中,Dmab作为羧基保护基具有脱保护条件温和、步骤简便、选择性高的特点,但有时脱保护效率并不稳定.为此,基于Fmoc/t Bu/Dmab三维正交保护策略,利用固相多肽合成技术设计并合成了4个肽树脂,对固相多肽合成中Glu和Asp主链和侧链羧基的Dmab保护基脱除规律进行了研究.结果显示,树脂上α-ODmab的脱保护快速、完全,β-ODmab和γ-ODmab脱保护反应较慢,可以检测到相应的中间产物(4-氨基苄酯肽),推测脱保护效率由快到慢依次为α-ODmab>β-ODmab>γ-ODmab.该结果表明Dmab作为α-COOH保护基具有较高的应用价值,但用于β-COOH和γ-COOH保护时,其脱保护条件尚不成熟.
Dmab was a protecting group of carboxyl with the advantages of rapid and chemoselective removal in solid phase peptide synthesis( SPPS),but the efficiency of deprotection of Dmab was not stable sometimes. Therefore, based on the Fmoc/t Bu/Dmab orthogonal protection strategy, four peptide resins were synthesized by SPPS,and the deprotection reaction condition of Dmab in SPPS was studied. The results showed that the α-ODmab of Glu and Asp could be removed quickly and completely on the peptide resin,but the intermediate product of 4-aminobenzyl ester peptide could be detected after the deprotective reaction of β-ODmab of Asp and γ-ODmab of Glu. The efficiency of deprotection of Dmab could be deduced as α-ODmab > β-ODmab > γ-ODmab. In conclusion,the Dmab protecting group held promise in SPPS,especially in the synthesis of head-to-tail cyclic peptides,but was not enough ideal in the synthesis of side-chain cyclic peptides or modified peptides.
引文
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