Synthesis and Biological Activity of N-Aminoethyl-terpinene-maleimidebased Thiourea Compounds

In search of novel potent bioactive compounds, a series of novel maleimide-based thiourea derivatives containing terpinene structure were designed and synthesized. Their structures were characterized by IR, MS, NMR, UV-vis and elemental analysis. The preliminary bioassay showed that the target compounds exhibited a certain fungicidal activity, in which compound 2-methoxyphenyl-Naminoethyl- terpinene-maleimide-based thiourea 5h exhibited the best inhibitory ratio of 64.2% against Alternaria solani at the concentration of 50 μg•mL-1. A few of the target compounds showed a certain growth inhibition activity against rape root (Brassica campestris), in which compound 5h exhibited the best inhibitory ratio of 82.0% (A-class activity level) at the concentration of 100 μg•mL-1. The intermediate 4 exhibited excellent growth inhibitory ratio of 92.3% (A-class activity level) against rape root at the concentration of 100 μg•mL-1. In addition, the structureantifungal activity relationship of these compounds was also discussed.