Activity of the diastereoisomers of 13,23‐dimethylpenta‐triacontane, the sex pheromone of Glossina pallidipes, and comparison with the natural pheromone

Abstract

All three synthetic diastereoisomers of 13,23-dimethylpentatriacontane, the pheromone of Glossina pallidipes (Austen), have been tested in the G.pa1lidipes sex pheromone bioassay, together with one of the four diastereoisomers of 13,17-dimethylpentatriacontane, originally proposed as a candidate pheromone of G.pallidipes. Of the three isomers of 13,23-dimethylpentatriacontane only the (13R,23S) isomer was active with an ED-50 of 4.47f1.09yg (meankSD). The (13R,17R)-13,17-dimethylpentatriacontane was inactive. The diastereoisomeric mixtures of 13,17-and 13,23-dimethylpentatriacontane were active with ED-50 values of 17.88k1.25 yg and 8.88k1.15 yg respectively. The natural pheromone was active with an ED-50 of 8.07-t 1.17 p g indicating it to be a diastereoisomeric mixture.

Semiochemicals – Synthesis, Stereochemistry, and Bioactivity

“…Thus, (13R,23S)-53 was active as the sex-stimulant pheromone of the female tsetse fly, Glossina pallidipes. Neither the (13R,23R) nor the (13S,23S) isomer was bioactive [81] . The ten categories described above were only found through experiments.…”

Chirality and insect pheromones

“…Thus, (13R,23S)-41 was ac- tive as the sex-stimulant pheromone of the female tsetse fly, Glossina pallidipes. 51,52 Neither (13R,23R)-nor (13S,23S)-isomer was bioactive. 52 The above-described 10 categories were found only through experiments.…”

“…51,52 Neither (13R,23R)-nor (13S,23S)-isomer was bioactive. 52 The above-described 10 categories were found only through experiments. In all cases synthesis of pure enantiomers and stereoisomers was followed by bioassay to clarify the matter.…”

Chirality and insect pheromones

“…51,52 Neither (13R,23R)-nor (13S,23S)-isomer was bioactive. Thus, (13R,23S)-41 was ac- tive as the sex-stimulant pheromone of the female tsetse fly, Glossina pallidipes.…”