The neplanocin A analogue 3-deazaneplanocin A (2b) has been synthesized. A direct SN2 displacement on the cyclopentenyl mesylate 3 by the sodium salt of 6-chloro-3-deazapurine afforded the desired regioisomer 4 as the major product. After deprotection, this material was converted to 3-deazaneplanocin A in two steps. X-ray crystallographic analysis confirmed the assigned structure. Consistent with its potent inhibition of S-adenosylhomocysteine hydrolase, 3-deazaneplanocin A displayed excellent antiviral activity in cell culture against vesicular stomatitis, parainfluenza type 3, yellow fever, and vaccinia viruses. Antiviral activity was also displayed in vivo against vaccinia virus by using a mouse tailpox assay. The significantly lower cytotoxicity of 3-deazaneplanocin A, relative to its parent compound neplanocin A, may be due to its lack of conversion to 5'-triphosphate and S-adenosylmethionine metabolites.

中文翻译：

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合成3-deazaneplanocin A，一种强大的S-腺苷同型半胱氨酸水解酶抑制剂，具有有效的体外和体内抗病毒活性。

已经合成了奈普兰球蛋白A类似物3-脱氮烷扁平球蛋白A（2b）。通过6-氯-3-去氮杂嘌呤的钠盐在环戊烯基甲磺酸酯3上的SN2直接置换提供了所需的区域异构体4作为主要产物。脱保护后，将该材料分两步转化为3-脱氮烷普莱辛A。X射线晶体学分析证实了指定的结构。与其有效抑制S-腺苷同型半胱氨酸水解酶一致，3-deazaneplanocin A在细胞培养中针对水泡性口炎，3型副流感，黄热病和牛痘病毒显示出优异的抗病毒活性。还通过使用小鼠尾痘试验在体内显示了针对牛痘病毒的抗病毒活性。相对于其母体化合物neplanocin A，3-deazaneplanocin A的细胞毒性明显降低，