iridoids and actinidine

Actinidine, a methylcyclopentane monoterpenoid pyridine alkaloid, has been found in many iridoid-rich plants and insect species. In a recent research on a well-known actinidine- and iridoid-producing ant species,

Topics: Actinidia; Alkaloids; Animals; Ants; Gas Chromatography-Mass Spectrometry; Hot Temperature; Iridoids; Molecular Structure; Nepeta; Pyridines; Terpenes

Detecting danger is one of the foremost tasks for a neural system. Larval parasitoids constitute clear danger to Drosophila, as up to 80% of fly larvae become parasitized in nature. We show that Drosophila melanogaster larvae and adults avoid sites smelling of the main parasitoid enemies, Leptopilina wasps. This avoidance is mediated via a highly specific olfactory sensory neuron (OSN) type. While the larval OSN expresses the olfactory receptor Or49a and is tuned to the Leptopilina odor iridomyrmecin, the adult expresses both Or49a and Or85f and in addition detects the wasp odors actinidine and nepetalactol. The information is transferred via projection neurons to a specific part of the lateral horn known to be involved in mediating avoidance. Drosophila has thus developed a dedicated circuit to detect a life-threatening enemy based on the smell of its semiochemicals. Such an enemy-detecting olfactory circuit has earlier only been characterized in mice and nematodes.

Topics: Alkaloids; Animals; Animals, Genetically Modified; Behavior, Animal; Bridged Bicyclo Compounds, Heterocyclic; Drosophila melanogaster; Drosophila Proteins; Female; Iridoids; Larva; Mutant Proteins; Nerve Tissue Proteins; Odorants; Olfactory Bulb; Oviposition; Protein Isoforms; Pyridines; Receptors, Odorant; Sensory Receptor Cells; Signal Transduction; Terpenes; Wasps

Iridodial beta-monoenol acetate, isolated from the essential oil of Nepeta leucophylla Benth, and actinidine from N. clarkei Benth were screened for antifungal activities against Aspergillus flavus, Aspergillus ochraceus, Penicillium citrinum, and Penicillium viridicatum, all known mycotoxin-producing taxa, and Sclerotium rolfsii and Macrophomina phaseolina, potential soybean pathogens. Iridodial beta-monoenol acetate was most effective against S. rolfsii, while actinidine was highly active against M. phaseolina.

Topics: Alkaloids; Antifungal Agents; Aspergillus flavus; Aspergillus ochraceus; Drugs, Chinese Herbal; Fungi; Glycine max; Iridoids; Microbial Sensitivity Tests; Mitosporic Fungi; Mycotoxins; Penicillium; Plant Oils; Plants, Medicinal; Pyrans; Pyridines; Terpenes