Abstract
Novel one-pot multicomponent synthesis of 2-pyrimidinamine derivatives can be achieved via green chemistry, using Cu(II)-tyrosinase enzyme (Cu-Tyr) as a catalyst. This method offers mild reaction conditions and a high yield of derivatives. We synthesised several compounds in this manner and evaluated their larvicidal, and antifeedant activities. Out of the synthesised derivatives, compound 3, with a median lethal dose (LD50) of 21.43 ?g/mL, was highly active against Culex quinquefasciatus, compared to compounds 1a?m and 2, and the control, hydantocidin. Compounds 1j, 1d, and 1e were low active against C. quinquefasciatus with LD50 values of 78.46, 78.59, and 79.54 ?g/mL, respectively. In antifeedant screening, compounds 1j, 1l, and 2 generated 100% mortality within 24 h against Oreochromis mossambicus at 100 ?g/mL, where toxicity was determined as the ratio of the number of dead and live fingerlings (%) at 24 h. In contrast, compounds 1a?f, 1i, 1m, and 3 were less toxic to O. mossambicus as compared to the control, dibromoisophakellin. Therefore, compound 3 had high larvicidal activity against C. quinquefasciatus and was less toxic to non-target aquatic species. Molecular docking studies also supported the finding that compound 3 was an effective larvicide with more inhibition ability than the control hydantocidin (-9.6 vs. -6.1 kcal/mol).