Convenient Synthesis of a Propargylated Cyclic (3′-5′) Diguanylic Acid and Its “Click” Conjugation to a Biotinylated Azide

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• 作者：Andrzej Grajkowski ; Jacek Cielak ; Alexei Gapeev ; Christian Schindler ; Serge L. Beaucage
• 刊名：Bioconjugate Chemistry
• 出版年：2010
• 出版时间：November 17, 2010
• 年：2010
• 卷：21
• 期：11
• 页码：2147-2152
• 全文大小：218K
• 年卷期：v.21,no.11(November 17, 2010)
• ISSN：1520-4812

文摘

The ribonucleoside building block, N²-isobutyryl-2′-O-propargyl-3′-O-levulinyl guanosine, was prepared from commercial N²-isobutyryl-5′-O-(4,4′-dimethoxytrityl)-2′-O-propargyl guanosine in a yield of 91%. The propargylated guanylyl(3′-5′)guanosine phosphotriester was synthesized from the reaction of N²-isobutyryl-2′-O-propargyl-3′-O-levulinyl guanosine with N²-isobutyryl-5′-O-(4,4′-dimethoxytrityl)-2′-O-tert-butyldimethylsilyl-3′-O-[(2-cyanoethyl)-N,N-diisopropylaminophosphinyl] guanosine and isolated in a yield of 88% after P(III) oxidation, 3′-/5′-deprotection, and purification. The propargylated guanylyl(3′-5′)guanosine phosphotriester was phosphitylated using 2-cyanoethyl tetraisopropylphosphordiamidite and 1H-tetrazole and was followed by an in situ intramolecular cyclization to give a propargylated c-di-GMP triester, which was isolated in a yield of 40% after P(III) oxidation and purification. Complete N-deacylation of the guanine bases and removal of the 2-cyanoethyl phosphate protecting groups from the propargylated c-di-GMP triester were performed by treatment with aqueous ammonia at ambient temperature. The final 2′-desilylation reaction was effected by exposure to triethylammonium trihydrofluoride affording the desired propargylated c-di-GMP diester, the purity of which exceeded 95%. Biotinylation of the propargylated c-di-GMP diester was easily accomplished through its cycloaddition reaction with a biotinylated azide derivative under click conditions to produce the biotinylated c-di-GMP conjugate of interest in an isolated yield of 62%.