High value-added application of natural forest product α-pinene: design, synthesis and 3D-QSAR study of novel α-campholenic aldehyde-based 4-methyl-1,2,4-triazole-thioether compounds with significant herbicidal activity

For exploring novel natural product-derived herbicides, 16 novel alpha-campholenic aldehyde-based 4-methyl-1,2,4-triazole-thioether compounds were designed, synthesized, and characterized by FT IR, H-1 NMR, C-13 NMR, ESI-MS and elemental analysis. The preliminary bioassay showed that, at 100 mu g/mL, most of the target compounds displayed significant inhibition activity against rootgrowth of rape(Brassica campestris L.), with inhibition rates of 85.0% (similar to)98.2%(A-class activity level), much better than that of the positive control flumioxazin. In addition, an effective and reason-able 3D-QSAR model was established by CoMFA method in SYBYL-X 2.1.1 software. It was found that, the steric field was the major factor towards the herbicidal activity of the target compounds against B. campestris L., and the introduction of bulky groups into m- and p-position of the benzene ring was favourable to increase the herbicidal activity. This kind of title compounds deserved further study as potential leading compounds for the discovery and development of novel herbicidal agents.