Anti-tubercular activity of novel class of spiropyrrolidine tethered indenoquinoxaline heterocyclic hybrids.

A series of structurally intriguing novel class of spiropyrrolidine tethered quinoxaline heterocyclic hybrids has been achieved in excellent yields employing ionic liquid accelerated multicomponent 1,3-dipolar cycloaddition reaction strategy. ß-Nitrostyrenes were used as dipolarophiles, while the 1,3-dipole component was the azomemthine ylide, generated in situ from indenoquinoxaline and l-phenylalanine. The reaction provided three new bonds and four contiguous stereocenter with full distereomeric control. In vitro activity of these spiroheterocyclic hybrids against Mycobacterium tuberculosis H37Rv using MABA assay revealed that the compound with nitro group on the phenyl ring is the most active candidate (1.56 µg/mL) among the other analogues of the series and has an activity similar to that of the standard drug, Ethambutol.

Discovery of spirooxindole-pyrrolidine heterocyclic hybrids with potent antifungal activity against fungal pathogens.

Fungal pathogens mainly Candida and Cryptococcus species causes serious life-threating infections to humans, especially in individuals who are immunocompromised. Increasing frequency of antifungal drug resistance along with paucity of FDA-approved drugs suggest a dire need for new antifungal drugs. Our screening of newly synthesized spirooxindole heterocyclic hybrid compounds revealed that the novel small molecule, DPA-3, has potent antifungal activity without inducing mammalian cell cytotoxicity. Furthermore, DPA-3 significantly reduced hyphal and biofilm formation of Candida albicans ATCC 10231 strain, out-competing two FDA approved antifungal drugs. The results of our study conclude that DPA-3 is a compelling candidate for further development as an antifungal drug.