Dual HIV-1 Reverse Transcriptase and Integrase Inhibitors from Arrigoni, an Endemic Species of Sardinia (Italy)

During our search for potential templates of HIV-1 reverse transcriptase (RT) and integrase (IN) dual inhibitors, the methanolic extract obtained from aerial parts of was investigated. Repeated bioassay-guided chromatographic purifications led to the isolation of the following secondary metabolites: myricetin, myricetin 3--rutinoside, myricetin-3--(6″--galloyl)-β-d-galactopyranoside, (-)-epigallocatechin 3--gallate, tryptamine, ferulic and phloretic acids. The isolated compounds were tested on both HIV-1 RT-associated RNase H and IN activities. Interestingly, (-)-epigallocatechin-3--gallate and myricetin-3--(6″--galloyl)-β-d-galactopyranoside potently inhibited both enzyme activities with IC values ranging from 0.21 to 10.9 μM. Differently, tryptamine and ferulic acid exhibited a significant inhibition only on the IN strand transfer reaction, showing a selectivity for this viral enzyme. Taken together these results strongly support the potential of this plant as a valuable anti HIV-1 drugs source worthy of further investigations.