Synthesis and insecticidal evaluation of phytoalexin phenalenones derivatives

Abstract

Phenalenone is a kind of defensive compound biosynthesized inside plants in response to the outside attack such as fungus and nematodes. A set of derivatives encompassing structural modifications on the privileged phenalenone scaffold were synthesized through introduction of phenyl and hydroxyl substitutes at 9-positon and 2-position and assessed their insecticidal activities against armyworm (Mythimna separata Walker) and cowpea aphids (Aphis craccivora). No obvious insecticidal activities of the synthesized compounds were observed against armyworm. Some of the 9-phenyl and 2-hydroxy substituted phenalenone analogues showed potential activities against cowpea aphids with 33%–41% mortality at 500mg/L.