Characterization and insecticidal activity of sucrose octanoates

Sucrose esters, a new class of biopesticides related to the Nicotiana family, were synthesized efficiently under vacuum and isolated by column chromatography (CC). The isolations were characterized with mass spectrometry (MS) and nuclear magnetic resonance (NMR). Their insecticidal activities against Lymantria dispar grubs were determined. Thin-layer chromatography ultraviolet (TLC-UV) spectrophotometric analyses showed that the ratio of the monoesters to others in the reaction product was 1.48:1. After isolation by CC, three groups, which had polarity from weak to strong, were obtained in high purity. Both electrospray ionization (ESI)-MS and H-1 NMR analyses proved that these groups were triesters, diesters and monoesters, respectively. According to their peak areas of gas chromatographic (GC) analyses, the monoester content was 61.72%. Among these esters, the reaction product and monoesters presented the highest insecticidal activities. The Lymantria dispar grub mortality reached 79.2% after being treated for 5 days with 12 mg/mL of the reaction products. The results indicate the synthesized sucrose octanoate product under vacuum is a good insecticide candidate.