Methyl Esters of ( E )-Cinnamic Acid: Activity against the Plant-Parasitic Nematode Meloidogyne incognita and In Silico Interaction with Histone Deacetylase.

( E )-Cinnamaldehyde is very active against Meloidogyne incognita but has low persistence in soil. To circumvent this problem, esters of cinnamic acid were evaluated as a substitute for ( E )-cinnamaldehyde. The best results under assays with M. incognita second-stage juveniles (J2) were obtained for the methyl esters of ( E )- p -fluoro- ( 13 ), ( E )- p -chloro- ( 14 ), and ( E )- p -bromocinnamic acid ( 15 ), which showed lethal concentrations to 50% (LC 50 ) J2 of 168, 95, and 216 μg/mL, respectively. Under the same conditions, the LC 50 values for the nematicides carbofuran and fluensulfone were 160 and 34 μg/mL, respectively. Substances 13 - 15 were also active against nematode eggs, which account for most of the M. incognita population in the field. According to an in silico study, substances 13 - 15 can act against the nematode through inhibition of histone deacetylase. Therefore, esters 13 - 15 and histone deacetylase are potentially useful for the rational design of new nematicides for the control of M. incognita .