Glycosylated Flavonoids from Psidium guineense as Major Inhibitors of HIV-1 Replication in vitro

Abstract

Flavonoids are present in practically all plants and many biological activities have been described for them. The flavonoid quercetin is a common molecule for which anti-HIV activity has been demonstrated. Avicularin and guajaverin are derivatives of quercetin with a glycoside substituent in their structure. In this work, a mixture of both derivatives was purified from an extract of Psidium guinense. The mixture exhibited activity against HIV-1 in vitro, with an IC₅₀ of approximately 8.5 μg/mL, which compares favorably with the IC₅₀ of 53 μg/mL of quercetin. The mixture also inhibited HIV-1 reverse transcriptase (RT), with an IC₅₀ of 7.2 μM, compared to 0.6 μM for quercetin. These results are in agreement with the in silico prediction for the interaction of these flavonoids with RT and suggest that the glycosylic moiety could favor the transport of the compound into the cell. However, the glycosidic moiety might be cleaved intracellularly, being the resultant quercetin responsible for the antiviral activity.