Palladium-Catalyzed Direct Synthesis and Insecticidal Activity of Arylmatrine Derivatives

Pd­(OAc)2/NiXantphos efficiently catalyzed
the direct
arylation at the C-14 position of matrine, leading to 38 arylmatrine
derivatives (1a–19a and 1b–19b) in good yields. Most of these matrine analogues
showed enhanced insecticidal effects superior to the parent compound
matrine. Among them, the 3,5-diphenylbenzene analogue (8b) exhibited the most potent in vivo antifeedant activity (EC50 = 0.19 mg/mL) against Spodoptera exigua (Hübner), with approximately 25-fold more activity than matrine,
for which the preliminary mechanism of action was verified through
enzyme inhibition activities and molecular docking. Compound 8b as well displayed in vitro antiproliferation activity on
Sf9 insect cells (IC50 = 8.1 μM), and its apoptotic
induction effect was illustrated by morphological observation and
DNA fragment analysis. Overall, the above results provide further
information on the potential of arylmatrine-type lead compounds for
the prevention and control of insect pests.