1.Content of carotenoids, tocopherols, sterols, triterpenic and aliphatic alcohols, and volatile compounds in six walnuts (Juglans regia L.) varieties.
Abdallah IB1, Tlili N2, Martinez-Force E3, Rubio AG3, Perez-Camino MC3, Albouchi A4, Boukhchina S2. Food Chem. 2015 Apr 15;173:972-8. doi: 10.1016/j.foodchem.2014.10.095. Epub 2014 Oct 25.
The aim of this work was to study the content of tocopherols, sterols, triterpenic and aliphatic alcohols, carotenoids, and volatile compounds in the kernel oils from six walnut (Juglans regia L.) varieties. The levels of β-carotene ranged between 0.22 and 0.62 mg/kg, followed by lutein (0.01-0.06 mg/kg). The total content of tocopherol ranged from 186.5 to 436.2 mg/kg of the extracted oil and the major isoform in all samples was γ-tocopherol. The most abundant phytosterol was β-sitosterol (974-1494 mg/kg) followed by campesterol then Δ-5-avenasterol. The major triterpenic alcohol was cycloartenol (226.4-532.1 mg/kg). Hexacosanol (9.71-28.15 mg/kg) was the major aliphatic alcohol. The detected volatile compounds were pentanal, hexanal, nonanal, 2-decenal and hexanol. The statistical analysis showed significant differences between varieties, which are probably due to genetic factors.
2.Angiotensin II modification by decomposition products of linoleic acid-derived lipid hydroperoxide.
Takahashi R1, Goto T1, Oe T2, Lee SH3. Chem Biol Interact. 2015 Sep 5;239:87-99. doi: 10.1016/j.cbi.2015.06.029. Epub 2015 Jun 22.
Polyunsaturated fatty acids are highly susceptible to oxidation induced by reactive oxygen species and enzymes, leading to the formation of lipid hydroperoxides. The linoleic acid (LA)-derived hydroperoxide, 13-hydroperoxyoctadecadienoic acid (HPODE) undergoes homolytic decomposition to reactive aldehydes, 4-oxo-2(E)-nonenal (ONE), 4-hydroxy-2(E)-nonenal, trans-4,5-epoxy-2(E)-decenal (EDE), and 4-hydroperoxy-2(E)-nonenal (HPNE), which can covalently modify peptides and proteins. ONE and HNE have been shown to react with angiotensin (Ang) II (DRVYIHPF) and modify the N-terminus, Arg(2), and His(6). ONE-derived pyruvamide-Ang II (Ang P) alters the biological activities of Ang II considerably. The present study revealed that EDE and HPNE preferentially modified the N-terminus and His(6) of Ang II. In addition to the N-substituted pyrrole of [N-C4H2]-Ang II and Michael addition products of [His(6)(EDE)]-Ang II, hydrated forms were detected as major products, suggesting considerable involvement of the vicinal dihydrodiol (formed by epoxide hydration) in EDE-derived protein modification in vivo.
3.Unveiling chemical defense in the rice stalk stink bug against the entomopathogenic fungus Metarhizium anisopliae.
da Silva RA1, Quintela ED2, Mascarin GM3, Pedrini N4, Lião LM5, Ferri PH5. J Invertebr Pathol. 2015 May;127:93-100. doi: 10.1016/j.jip.2015.03.009. Epub 2015 Mar 21.
Eggs, nymphs (1st-5th instar) and adults of Tibraca limbativentris were challenged by conidial suspensions of its major fungal pathogen Metarhizium anisopliae in order to assess their susceptibility. The role of chemical defensive compounds from exocrine secretions produced by both nymphs and adults were examined for their participation on M. anisopliae infection. Although insect susceptibility to M. anisopliae followed a dose-dependent manner, adults followed by older nymphs displayed the highest resistance. Eggs were highly susceptible showing >96% fungal infection. Crude extracts isolated from metathoracic scent gland and dorsal abdominal glands of adults and nymphs, respectively, showed fungistatic effects by impairing spore germination, vegetative growth and sporulation. Gas chromatography-mass spectrometry analysis of these extracts revealed that the major components were short-chain hydrocarbons (C10-13) and unsaturated aldehydes.
4.Behavioral responses to mammalian blood odor and a blood odor component in four species of large carnivores.
Nilsson S1, Sjöberg J1, Amundin M2, Hartmann C3, Buettner A3, Laska M1. PLoS One. 2014 Nov 10;9(11):e112694. doi: 10.1371/journal.pone.0112694. eCollection 2014.
Only little is known about whether single volatile compounds are as efficient in eliciting behavioral responses in animals as the whole complex mixture of a behaviorally relevant odor. Recent studies analysing the composition of volatiles in mammalian blood, an important prey-associated odor stimulus for predators, found the odorant trans-4,5-epoxy-(E)-2-decenal to evoke a typical "metallic, blood-like" odor quality in humans. We therefore assessed the behavior of captive Asian wild dogs (Cuon alpinus), African wild dogs (Lycaon pictus), South American bush dogs (Speothos venaticus), and Siberian tigers (Panthera tigris altaica) when presented with wooden logs that were impregnated either with mammalian blood or with the blood odor component trans-4,5-epoxy-(E)-2-decenal, and compared it to their behavior towards a fruity odor (iso-pentyl acetate) and a near-odorless solvent (diethyl phthalate) as control. We found that all four species displayed significantly more interactions with the odorized wooden logs such as sniffing, licking, biting, pawing, and toying, when they were impregnated with the two prey-associated odors compared to the two non-prey-associated odors.