Synthesis of new uracil-5-sulphonamide-p-phenyl derivatives and their effect on Biomphalaria alexandrina snail's nucleoproteins

In continuation of the previous work (Fathalla, 1992) on the synthesis of s ome heterocycles containing uracil moiety, we report herein the incorporati on of uracil moiety into cyanopyridine thione, thiosemecarbazone, semicarba zone, cyanopyridine, aminocyano pyridine, isoxazoline, pyrazoline, pyrimidi ne, triazolo pyrimidine, pyran, selena and thiazole derivatives which might modify their biological activities. The biological studies revealed that the chemical compound III f showed hig h molluscicdal activity than other compounds. The profile of the nucleoprot ein extracted from chemically (compound IIIc, e, f and g) treated or UV-irr adiated B. alexandrina snails did not show appreciable differences when com pared to non-treated (native) snails by using SDS-PAGE, where no obvious qu alitative or quantitative differences were observed. Immunization of experi mental animals with the nucleoprotein extracted from native, chemically (co mpound III f St g) treated or physically treated B. alexandrina snails indu ced significant protection against challenge with normal S. mansoni cercari ae, as compared to the non-immunized challenged control. As well as, a decr ease in the number of granuloma formation and the size range of granuloma w as also observed in immunized animals. It is concluded that, compounds III f and g have a potent molluscicidal activity. They also induced chemical mo dification comparable to that induced by physical treatment in the snail's nucleoprotein, which could possibly be used in immunization against S. mans oni infection.