Synthetic glycoclusters and their related biological applications have stimulated increasing interest over the last decade. As a prerequisite to discovering active and selective therapeuticals, the development of multivalent glycoconjugates with diverse topologies is faced with inherent synthetic and structural characterisation difficulties. Here we describe a new series of molecularly-defined glycoclusters that were synthesized in a controlled manner using a robust and versatile divergent protocol. Starting from a Regioselectively Addressable Functionalized Template (RAFT) carrier, either a polylysine dendritic framework or a second RAFT, then 16 copies of βGal, αMan, βLac or cancer-related Thomsen-Freidenreich (αTF) antigen were successively conjugated within the same molecule using oxime chemistry. We thus obtained a new generation of dendri-RAFTs glycoclusters with high glycosidic density and variable spatial organizations. These compounds displaying 16 endgroups were unambiguously characterized by NMR spectroscopy and mass spectrometry. Further biological assays between a model lectin from Canavalia ensiformis (ConA) and mannosylated glycoclusters revealed a higher inhibition potency than the tetravalent counterpart, in particular for the hexadecavalent polylysine skeleton. Together with the efficiency of the synthetic and characterisation processes, this preliminary biological study provided clear evidence of promising properties that make the second generation of cyclopeptide-based glycoclusters attractive for biomedical applications.
合成糖簇及其相关
生物应用在过去十年中引起了越来越多的关注。作为发现活性和选择性治疗药物的先决条件,开发具有不同拓扑结构的多价糖簇面临着固有的合成和结构表征困难。在这里,我们介绍了一系列新的分子定义的糖团,这些糖团是通过一种稳健、多用途的分歧协议以受控方式合成的。从区域选择性可寻址功能化模板(RAFT)载体、聚赖
氨酸树枝状框架或第二个 RAFT 开始,然后使用
肟化学方法在同一分子内连续共轭 16 份 βGal、αMan、βLac 或与癌症相关的 Thomsen-Freidenreich (αTF)抗原。因此,我们获得了具有高糖苷密度和可变空间组织的新一代 dendri-RAFTs 糖簇。通过核磁共振波谱和质谱分析,这些具有 16 个末端基团的化合物得到了明确的表征。通过进一步对一种来自鲟鱼的模式凝集素(ConA)和
甘露糖基化糖簇进行
生物检测,发现其抑制效力高于四价凝集素,尤其是对十六价聚赖
氨酸骨架的抑制效力。加上合成和表征过程的高效性,这项初步
生物研究清楚地证明了第二代环肽型聚糖簇所具有的良好特性,使其在
生物医学应用中具有吸引力。