ß-Thujone and Its Derivatives Modify the Probing Behavior of the Peach Potato Aphid.

Thujone is a natural biologically active monoterpene ketone component of essential oils of numerous plants. The aim of the study was to evaluate the effect of ß-thujone and ß-thujone derivatives bisulfite adduct, lactone, oxime, and lactam application on behavior of Myzus persicae (Sulz.) (Hemiptera: Aphididae) during probing and settling. The choice and no-choice tests (aphid settling and Electrical Penetration Graph (EPG), respectively) revealed that stereochemistry of thujone was important for biological activity (ß-thujone caused changes in aphid behavior while α-thujone did not) and that cyclopentane ring modifications and functional groups addition gave derivatives that possessed stronger and more durable deterrent effects. The most effective modification was the incorporation of a lactam moiety into the ß-thujone molecule. Application of ß-thujone lactam limited aphid settling for at least 24 h, caused restlessness in aphids and a delay or failure in reaching phloem phase by M. persicae. ß-Thujone lactam can be considered a deterrent of medium potency with activity expressed at preingestive phase of aphid probing. Other compounds did not restrain aphid stylet penetration in non-phloem tissues but slightly limited sap ingestion (lactone, oxime), and restrained aphid settling for a period of less than 24 h (ß-Thujone, bisulphite adduct, lactone).

Improving of hydrolases biosythesis by solid-state fermentation of Penicillium camemberti on rapeseed cake.

The study show usefulness of rapeseed cake, rich in fats and proteins byproduct generated after oil production, which may be used as a microbial medium for lipase and protease biosynthesis. Of 26 different filamentous fungi screened by solid-state fermentation, Penicillium camemberti AM83 was found to abundantly produce lipase and protease. Various process parameters were then optimized to maximize lipase and protease secretion, including carbon and nitrogen source, C/N ratio, metal ions, temperature, moisture content, initial pH, and inoculum size. Lipase production increased approximately 11.2-fold in solid-state cultures on rapeseed cake supplemented with lactose and calcium chloride, alkalinized to pH 8, hydrated to 80%, and inoculated with 1.2 × 106 spores/mL. Similarly, protease production increased approximately 8.4-fold in optimized cultures inoculated with 3.2 × 108 spores/mL, and grown on rapeseed cake with lactose and ammonium sulfate at pH 9 and moisture content 60%. The results highlight the potential economic value of solid-state fermentation on rapeseed cake to produce industrial hydrolases.

Enantioselectivity of hydroxylation of racemic piperitone by fungi.

The biotransformation of racemic piperitone ((±)-1) was investigated using four strains of fungi selected in the screening procedure. The substrate was transformed by Botrytis cinerea AM235, Absidia cylindrospora AM336, Absidia coerulea AM93, and Absidia glauca AM177 into more polar metabolites. The transformation of racemic piperitone ((±)-1) catalyzed by B. cinerea AM235 gave 7-hydroxypiperitone (2) as the only product. The biotransformation of (±)-1 by A. cylindrospora AM336 afforded mixture of three products: (-)-(R)-7-hydroxypiperitone ((-)-2), (+)-(4S,6R)-trans-6-hydroxypiperitone ((+)-3), and (+)-(4R,6R)-cis-6-hydroxypiperitone ((+)-4). The transformation of this substrate ((±)-1) by A. coerulea AM93 gave (±)-7-hydroxypiperitone ((±)-2), (-)-(4R,6S)-trans-6-hydroxypiperitone (-)-3), and (-)-(4S,6S)-cis-6-hydroxypiperitone ((-)-4). The last strain studied, A. glauca AM177, converted racemic piperitone ((±)-1) to four products: (+)-(S)-7-hydroxypiperitone (2), (+)-(4S,6R)-trans-6-hydroxypiperitone ((+)-3), (±)-cis-6-hydroxypiperitone ((±)-4), and 8-hydroxypiperitone (5).