7-Aryl substituted furo[3,2-h]quinoliniums have been synthesised in two steps from 5-chloro-8-hydroxy-7- iodo-quinoline through a tandem Sonogashira alkynylation-cyclization pathway using aryl acetylenes followed by quaternisation reaction with alkyl halides under microwave irradiation. The compounds have been characterized spectroscopically and assessed for their sperm-immobilizing efficacy in vitro by modified Sander–Cramer test. Most of the derivatives showed potent spermicidal effect with minimum effective concentration (MEC) ranging from 125g/ml – 1mg/ml. The results were further confirmed by double fluoroprobe staining with syber14/PI (Propidium Iodide). The mode of spermicidal action was assessed by (a) Hypo-osmotic swelling tests and (b) Scanning electron microscopy. The compounds have been found to be nontoxic to lactobacillus in 36 hours of culture whereas mild to moderately effective on common vaginal pathogens. Taken together it can be inferred that the water-soluble salts prepared from facile technique are potential candidates for spermicides and could further be utilized for the preparation of vaginal contraceptives.
Keywords: Furo[3, 2-h]quinoliniums, Spermicide, Microwave, Contraceptive, Scanning electron microscopy.