Fumigant toxicity of essential oils from the Myrtaceae family and 1,8-cineole against 3 major stored-grain insects

Six out of 42 essential oils extracted from species of the family Myrtaceae found in Australia were shown to have potent fumigant toxicity against three major stored-grain insects: Sitophilus oryzae, Tribolium castaneum and Rhyzopertha dominica. These were the essential oils from Eucalyptus nicholii, E. codonocarpa, E. blakelyi, Callistemon sieberi, Melaleuca fulgens and M. armillaris. The LD₅₀ and LD₉₅ of the selected essential oils against S. oryzae adults were between 19.0–30.6 and 43.6–56.0 μl/l air, respectively. Also, these oils were approximately twice as toxic to T. castaneum and R. dominica at the LD₉₅. Fumigant effects of the essential oils rich in 1,8-cineole were considered to warrant further research into their potential for commercial use.     

Roasting effects on the distribution of tocopherols and phospholipids within each structural part and section of soybeans

To clarify the effects of microwave roasting on the distribution of tocopherols and FA of phospholipids within soybeans, whole soybeans (Glycine max) were treated by microwave and further evaluted as compared to a raw sample. Tocopherol homologs, measured using HPLC, and phospholipid profiles, quantified with GC, were determined in the seed coat, the embryonic axis, and selections of cotyledons separated from three cultivars. The tocopherols were predominantly detected in the axis, followed by the cotyledons, and then very little in the coat. As much as 25% of the individual tocopherols originally present in the coat were lost at 12 min of roasting, whereas <25% was lost in the cotyledons and the axis after 20 min of roasting. The greatest rate of phospholipid loss (P<0.05) was observed in PE, followed by PC and PI, and their changing patterns were more pronounced in the coat than in the cotyledons or the axis. Thus, tocopherol content and phospholipid profiles change with microwave roasting according to tissue.     

Composition and insecticidal activity of essential oil from Pistacia lentiscus L. against Ectomyelois ceratoniae Zeller and Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

This study reports investigations on the chemical constituents and fumigant toxicity of Pistacia lentiscus L. (Anacardiaceae) essential oil against two major stored-date insects, carob moth Ectomyelois ceratoniae Zeller and Mediterranean flour moth Ephestia kuehniella Zeller. Results showed that P. lentiscus essential oil contained terpinene-4-ol (23.32%), α-terpineol (7.12%) and β-caryophyllene (22.62%) as major compounds. Fumigant toxicity tests showed that P. lentiscus oil was more toxic to E. kuehniella (LC₅₀ = 1.84 μl/l, LC₉₅ = 5.14 μl/l) than E. ceratoniae (LC₅₀ = 3.29 μl/l, LC₉₅ = 14.24 μl/l). The fecundity and hatching rate of both insects decreased with increases in concentration or exposure time to the oil. At 136 μl/l air, fecundities and hatching rates were respectively 35 eggs/female and 42.86% for E. ceratoniae and 78 eggs/female and 29.49% for E. kuehniella.     

Biological activity and persistence of four essential oils towards the main pest of stored cowpeas, Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)

The use of essential oils extracted from native aromatic plants is perceived as a promising alternative to protect stored cowpeas in West Africa. However the optimal conditions for their efficiency remain to be determined. A study was therefore carried out to compare the biological activity and temperature-related persistence of four selected essential oils towards Callosobruchus maculatus, the main pest of stored cowpeas. Essential oil extracted from Ocimum americanum proved to be very toxic towards C. maculatus adults (LC₅₀ = 0.23 μl/l) while the oils from Hyptis suaveolens, Hyptis spicigera and Lippia multiflora exhibited higher LC₅₀ values (1.30 μl/l; 5.53 μl/l and 6.44 μl/l respectively). The persistence of the biological activity of the four oils was variable and that from O. americanum was most persistent. Fourteen days post-application, this oil was still as active on C. maculatus adults as it was immediately after its application. Exposure of this oil to a high temperature, close to temperatures occurring during storage in Burkina Faso in the dry season, however, resulted in a rapid decrease in its efficacy. Our results emphasize the need to take into account environmental factors such as temperature to optimize the use of promising essential oils for controlling stored-product pests in West Africa.     

Membrane phospholipids and sterols in microfiltered milk fat globules

Native milk fat globules of various mean diameters, ranging from d₄₃ = 2.3 µm to 8.0 µm, were obtained using microfiltration of raw whole milk. After milk fat globule washing, the milk fat globule membrane (MFGM) was separated by manual churning. After total lipid extraction and separation of polar lipids, their phospholipid (PL) and sterol composition was measured using thin‐layer chromatography, methyl ester analyses by gas chromatography, and gas chromatography coupled to mass spectrometry. The main PL species were phosphatidylethanolamine, phosphatidylcholine and sphingomyelin. The respective fatty acid composition of each PL species was measured. Many different minor bioactive sterols were detected in the MFGM, e.g. lanosterol, lathosterol, desmosterol, stigmasterol and β‐sitosterol. No significant differences in the PL and sterol profile were found between MFGM extracted from small and large milk fat globule fractions.     

Screening catalytic lipase activities with an analytical supercritical fluid extractor

Two different screenings of several commercial lipases were performed to find a lipase with superior performance for the conversion of lipid moieties to their fatty acid methyl ester (FAME) derivatives under supercritical conditions. The first screening was done under hydrolytic conditions in a buffer. The second screening was done under supercritical conditions with CO₂, utilizing some of the same lipases for the methanolysis of different lipids. For the substrates studied, there was a significant difference in lipase activity under the two above conditions. Significant hydrolytic activity was demonstrated for three different lipid types (triglycerides, sterols, and phospholipids) with Lipase PS30, but when the same lipase was immobilized on an Accurel carrier (polypropylene), the activity decreased considerably. The opposite was found for Lipase G, which showed strong activity when immobilized and under supercritical conditions. Furthermore, Chirozyme L-1 was superior under supercritical conditions. The altered substrate specificity that some of these lipases show in supercritical CO₂ suggests several interesting synthetic options and applications under these conditions.     

Composition and biological activities of essential oils from four Heracleum species

The composition of essential oils from aerial parts of Heracleum persicum, a widely used medicinal plant, and three other Heracleum species growing wild in Iran were analysed by GC and GC–MS. Myristicin (53.6%), (E)-anethole (25.0%), hexyl butanoate (29.7%) and elemicin (41.1%) were the major compounds of Heracleum pastinacifolium, H. persicum, Heracleum rechingeri and Heracleum transcaucasicum, respectively. Cytotoxic activity assessed on three human cancer cell lines (HeLa, LS180 and Raji), showed that essential oils from H. transcaucasicum (IC₅₀ values; 0.362–0.594 mg/ml) followed by H. pastinacifolium (0.497–1.398 mg/ml) had moderate antitumoral activities. In the DPPH radical scavenging assay, H. pastinacifolium and H. persicum oils showed the highest activities with IC₅₀ values of 7.3 and 7.4 mg/ml, respectively. Antioxidant activity correlated well with the total phenolic content of the oils. None of the essential oils showed significant antimicrobial activities.     

Essential oil composition of Pterospartum tridentatum grown in Portugal

The essential oils, isolated by hydrodistillation and distillation-extraction, from the aerial parts of different populations of Pterospartum tridentatum collected during the flowering phase, at different locations in Portugal, were analysed by GC and GC–MS. All the P. tridentatum populations studied afforded a yellowish oil in a yield <0.05% (v/w). cis-Theaspirane (2–14%), trans-theaspirane (2–17%) and octen-3-ol (2–37%) were, in variable amounts, the dominant components of the oils. Cluster analysis of the essential oil compositions from the nine populations studied, confirmed a major chemical variability.     

Effect of boiling and frying on the content of essential polyunsaturated fatty acids in muscle tissue of four fish species

Frozen samples of common fish species, sea trout (Salmo trutta), from Norway and Siberia, herring (Clupea harengus pallasi), rock sole (Lepidopsetta bilineata) and cod (Gadus morhua maris-albi), collected from a wholesale market in Krasnoyarsk city (Siberia, Russia) were analyzed. Special attention was paid to long-chain essential polyunsaturated fatty acids: eicosapentaenoic, 20:5ω3 (EPA) and docosahexaenoic, 22:6ω3 (DHA). Heat-treatment (cooking and frying) did not in general significantly decrease the contents of EPA and DHA compared to raw fish species, except for a modest reduction in Norwegian trout during frying. Boiled trout appeared to be a more valuable fish dish for obtaining the officially recommended appropriate daily intake of EPA + DHA for humans. Herring and sole had intermediate values, while boiled cod had a comparatively low value.