LARVICIDAL ACTIVITY OF THE SYNTHESISED LIGNANS, NEOLIGNANS, AND COUMARIN AGAINST Crocidolimia binotalis 2nd INSTAR LARVAE

Five compounds comprising 8-O-4’-neolignan (7), two arylnaphthalene lignans (5, 8), aryldihydrobenzofuran neolignan (4), and lignan (6) were synthesised by enzymatic coupling reaction using horseradish peroxidase (HRP) between vanillin (1) with methyl ferulate (2) or sinapate (3). All of these compounds, as well previously palladium-catalysed products (9), 8-O-4'-neolignan (10), arylcoumarin (11), (12), examined for larvicidal activity against Crocidolomia binotalis 2nd instar larvae. It revealed that seven out nine had a mortality rate more than 90% after 24 hours exposure. Neolignan (10) demonstrated the strongest LD50 = 2.218 mg/L 1.678 mg/L, respectively compared to standard azadirachtin (LD50 =2.818 mg/L). The results showed have high potential use in control C. larvae could be used development new effective larvicides.