The enzymatic conversion of glucose into ATP, GTP, UTP, and CTP with several different isotopic labeling patterns is described. Enzymes of the pentose phosphate pathway and enzyme-catalyzed hydrogen exchange were used to convert three types of isotopically labeled glucose into [1',2',3',4',5',5'-H-2(6)]NTPs (1-4), [3',4',5',5'-H-2(4)]UTP (5), [1',2',3',4',5'-C-13(5)]NTPs (6-9), and [3',4',5',5'-H-2(4)-1',2',3',4',5'-C-13(5)]NTP (10-13), which were then used to synthesize a 30 nucleotide HIV TAR RNA. Representative NOESY and HSQC spectra were acquired to demonstrate the utility of the new labeling-patterns. The spectral editing afforded by H-2 and C-13 labeling dramatically simplifies the-crowded NOESY and HSQC spectra of RNA molecules. The synthetic methods described here will permit the preparation of several specifically deuterated and/or C-13-labeled forms of RNA which should be useful in NMR structural studies of large RNAs.