2',3'-Anhydroinosine;9-(2,3-Anhydro-β-D-ribofuranosyl)-1,9-dihydro-6H-purin-6-one;9-(2,3-anhydro--D-ribofuranosyl)-1,9-dihydro-6H-purin-6-one (2'',3''-anhydroinosine),;Didanosine Impurity Ⅴ:2',3'-Anhydroinosine;Inosine, 2',3'-anhydro-;Didanosine Impurity Ⅴ:2',3'-Anhydroinosine;Didanosine Impurity 5(Didanosine EP Impurity E);Didanosine EP Impurity E