Application： 2-Hydroxyisoquinoline-1,3(2H,4H)-dione was recently discovered as a scaffold for the inhibition of HIV-1 integrase and the RNase H function of HIV-1 reverse transcriptase. Its interaction with Mg2+ and Mn2+ was investigated using different spectroscopic techniques and it was reported that 2-hydroxyisoquinoline-1,3(2H,4H)-dione forms a 1:1 complex with Mg2+ but a 1:2 complex with Mn2+. Antiviral agent.