Background: Nucleoside analogues are well-known antitumor, antiviral, and chemotherapeutic agents. Alterations on both their sugar and the heterocyclic parts may lead to significant changes in the spectrum of their biological activity and the degree of selective toxicity, as well as in their physicochemical properties.

Methods: C5-arylalkynyl-β-D-ribofuranonucleosides 3-6, 3΄-deoxy 12-15, 3΄-deoxy-3΄-C-methyl- β-D-ribofurananucleosides 18-21 and 2΄-deoxy-β-D-ribofuranonucleosides 23-26 of uracil, were synthesized using a one-step Sonogashira reaction under microwave irradiation and subsequent deprotection.

Results: All newly synthesized nucleosides were tested for their antitumor or antiviral activity. Moderate cytostatic activity against cervix carcinoma (HeLa), murine leukemia (L1210) and human lymphocyte (CEM) tumor cell lines was displayed by the protected 3΄-deoxy derivatives 12b,12c,12d, and the 3΄-deoxy-3΄-methyl 18a,18b,18c. The antiviral evaluation revealed appreciable activity against Coxsackie virus B4, Respiratory syncytial virus, Yellow Fever Virus and Human Coronavirus (229E) for the 3΄-deoxy compounds 12b,14, and the 3΄-deoxy-3΄-methyl 18a,18c,18d, accompanied by low cytotoxicity.

Conclusion: This report describes the total and facile synthesis of modified furanononucleosides of uracil, with alterations on both the sugar and the heterocyclic portions. Compounds 12b,14 and 18a,c,d showed noticeable antiviral activity against a series of RNA viruses and merit further biological and structural optimization investigations.

背景：核苷类似物是众所周知的抗肿瘤药，抗病毒药和化学治疗药。它们的糖和杂环部分的改变都可能导致其生物学活性和选择性毒性程度以及其理化性质发生重大变化。

方法：C5-芳基炔基-β-D-呋喃核糖核苷3-6、3′-脱氧12-15、3′-脱氧-3′-C-甲基-β-D-呋喃核糖核苷18-21和2′-脱氧-β尿嘧啶的-D-呋喃核糖核苷23-26，是通过一步一步Sonogashira反应在微波辐射下并随后脱保护而合成的。

结果：测试所有新合成的核苷的抗肿瘤或抗病毒活性。受保护的3′-脱氧衍生物12b，12c，12d和3′-脱氧-3′-显示出对宫颈癌（HeLa），鼠白血病（L1210）和人淋巴细胞（CEM）肿瘤细胞系的中等抑制作用。甲基18a，18b，18c。抗病毒评估显示，该化合物对3 Co-脱氧化合物12b，14和3΄-脱氧-3΄-甲基18a，18c具有明显的抗柯萨奇病毒B4，呼吸道合胞病毒，黄热病毒和人冠状病毒（229E）的活性， 18d，伴有低细胞毒性。

结论：该报告描述了尿嘧啶修饰的呋喃呋喃核苷的完整合成，并且糖和杂环部分均发生了改变。化合物12b，14和18a，c，d对一系列RNA病毒显示出明显的抗病毒活性，值得进一步进行生物学和结构优化研究。