This review summarizes and systematizes the literature on the anti-HIV activity of plant coumarins with emphasis on isolation and the mechanism of their antiviral action. This review summarizes the information on the anti-HIV properties of simple coumarins as well as annulated furano- and pyranocoumarins and shows that coumarins of plant origin can act by several mechanisms: inhibition of HIV reverse transcriptase and integrase, inhibition of cellular factors that regulate HIV-1 replication, and transmission of viral particles from infected macrophages to healthy ones. It is important to note that some pyranocoumarins are able to act through several mechanisms or bind to several sites, which ensures the resistance of these compounds to HIV mutations. Here we review the last two decades of research on the anti-HIV activity of naturally occurring coumarins.

A new method for the direct metal-free C–H functionalization of electron-deficient triazines with fragments of naturally occurring and synthetic 5,7-dihydroxycoumarins is reported. It has been found that the reaction of 5,7-dihydroxycoumarins with triazines proceeds under mild conditions, showing a high chemo- and regioselectivity.

A new synthetic protocol for nucleophilic substitution of hydrogen­ in quinoxalones and pteridinones by the action of 5,7-di­hydroxycoumarins and related m-dihydroxybenzene compounds has been developed. The C–C coupling reaction proved to proceed smoothly under rather mild conditions, thus giving the corresponding C–H functionalized products in good yields. The advantages of this environmentally benign protocol are high regio- and chemoselectivity, and an easy workup procedure. Direct incorporation of the coumarin moiety into the pyrazine ring in pteridines or quinoxalines provides a short pathway to pyrazine-coumarin hybrid compounds.

A total of 21 novel xanthone and acridone derivatives were synthesized using the reactions of 1,2,4-triazine derivatives with 1-hydroxy-3-methoxy-10-methylacridone, 1,3-dimethoxy-, and 1,3-dihydroxanthone, followed by optional dihydrotiazine ring aromatization. The synthesized compounds were evaluated for their anticancer activity against colorectal cancer HCT116, glioblastoma A-172, breast cancer Hs578T, and human embryonic kidney HEK-293 tumor cell lines. Five compounds (7a, 7e, 9e, 14a, and 14b) displayed good in vitro antiproliferative activities against these cancer cell lines. Compounds 7a and 7e demonstrated low toxicity for normal human embryonic kidney (HEK-293) cells, which determines the possibility of further development of these compounds as anticancer agents. Annexin V assay demonstrated that compound 7e activates apoptotic mechanisms and inhibits proliferation in glioblastoma cells.