4H,6H-[1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7-dione 1-oxide (1) and 6-methyl-4H,6H-[1,2,5]- oxadiazolo[3,4-d]pyrimidine-5,7-dione 1-oxide (2) are nitric oxide (NO) donors. Their glycosidation, with peracetyl ribofuranose, xylfuranose and glucopyranose respectively, under solvent-free and fusion reaction conditions gives corresponding oxadiazolo[3,4-d]pyrimidine nucleoside derivatives 7, 9～12. The O-acetyl groups in nucleoside 7 are removed by the use of methanolic ammonia to yield compound 8. These new nucleosides may be as potential NO donors. Initial bioactivity tests show that pyrimidofuroxan-nucleosides have antivirus and anticancer effects. The research results provide new candidate molecules for study of antivirus and anticancer drugs.

Key words: oxadiazolo[3,4-d]pyrimidine nucleoside, antivirus, anticancer