Enzymatic synthesis and biological activities of validoxylamine A ester derivatives

Validoxylamine A is an important biopesticide intermediate with bacteriostatic and insecticidal activities. To discover new green pesticides, 9 novel compounds were synthesized by lipase esterification reaction using validoxylamine A as the lead compound. Their structures were characterized by ^ⅠH NMR, ¹³C NMR and HRMS. The biological activities results showed that most of those compounds retained their inhibitory activity against Rhizoctonia solani. Compound Ⅰ had the best inhibitory effect, with the EC₅₀ value of 13.03 μmol/L. Compound Ⅶ had a lethality of 64.60% to Aphis craccivora at 500 mg/L. This class of derivatives has fungicidal and insecticidal activities and is worthy of further study.