Efficient synthesis of diverse heterobifunctionalized clickable oligo(ethylene glycol) linkers: potential applications in bioconjugation and targeted drug delivery
作者:Lalit N. Goswami、Zachary H. Houston、Saurav J. Sarma、Satish S. Jalisatgi、M. Frederick Hawthorne
DOI:10.1039/c2ob26968f
日期:——
Herein we describe the sequential synthesis of a variety of azide-alkyne click chemistry-compatible heterobifunctional oligo(ethylene glycol) (OEG) linkers for bioconjugation chemistry applications. Synthesis of these bioorthogonal linkers was accomplished through desymmetrization of OEGs by conversion of one of the hydroxyl groups to either an alkyne or azido functionality. The remaining distal hydroxyl group on the OEGs was activated by either a 4-nitrophenyl carbonate or a mesylate (–OMs) group. The –OMs functional group served as a useful precursor to form a variety of heterobifunctionalized OEG linkers containing different highly reactive end groups, e.g., iodo, –NH2, –SH and maleimido, that were orthogonal to the alkyne or azido functional group. Also, the alkyne- and azide-terminated OEGs are useful for generating larger discrete poly(ethylene glycol) (PEG) linkers (e.g., PEG16 and PEG24) by employing a Cu(I)-catalyzed 1,3-dipolar cycloaddition click reaction. The utility of these clickable heterobifunctional OEGs in bioconjugation chemistry was demonstrated by attachment of the integrin (αvβ3) receptor targeting peptide, cyclo-(Arg-Gly-Asp-D-Phe-Lys) (cRGfKD) and to the fluorescent probe sulfo-rhodamine B. The synthetic methodology presented herein is suitable for the large scale production of several novel heterobifunctionalized OEGs from readily available and inexpensive starting materials.
在此,我们描述了一系列适用于叠氮-炔烃点击化学的异双功能寡(乙烯)醇(OEG)连接子 sequential synthesis,用于生物偶联化学应用。这些生物正交连接子的合成是通过将OEG中的一个羟基转化为炔烃或叠氮功能团,进而进行去对称化来完成的。OEG上的远端羟基则通过4-硝基苯基碳酸酯或美克酸酯(–OMs)基团进行活化。–OMs功能团作为一种有用的前驱体,用于形成包含不同高度反应性末端基团的多种异双功能化OEG连接子,例如:碘、–NH2、–SH和马来酰亚胺,这些基团与炔烃或叠氮功能团具有正交性。此外,炔烃和叠氮末端的OEG可通过采用Cu(I)催化的1,3-偶极环加成点击反应生成更大的离散聚(乙烯)醇(PEG)连接子(例如,PEG16和PEG24)。通过将整合素(αvβ3)受体靶向肽环(Arg-Gly-Asp-D-Phe-Lys)(cRGfKD)和荧光探针硫酸铑胺B附着于这些可点击的异双功能OEG中,证明了它们在生物偶联化学中的实用性。本文所呈现的合成方法适合于从易得且廉价的起始材料大规模生产多种新型异双功能化OEG。