Search results for "Ester"
showing 10 items of 4273 documents
Experimental contact zones reveal causes and targets of sexual selection in hybridizing lizards
2016
Divergence in sexually selected traits in allopatry should affect the degree and direction of hybridization. However, few studies have established the causes and targets of sexual selection during secondary contact. Common wall lizards (Podarcis muralis) from north-central Italy have highly exaggerated male sexual traits compared to populations in Western Europe. Using experimental populations, we show that this creates asymmetries in male dominance, spatial habitat use and reproductive success upon secondary contact. Hybridization occurred almost exclusively between males of the Italian lineage and females of the Western European lineage. We provide evidence to suggest stronger ongoing sel…
Life history evolution in social insects: a female perspective
2016
Social insects are known for their unusual life histories with fecund, long-lived queens and sterile, short-lived workers. We review ultimate factors underlying variation in life history strategies in female social insects, whose social life reshapes common trade-offs, such as the one between fecundity and longevity. Interspecific life history variation is associated with colony size, mediated by changes in division of labour and extrinsic mortality. In addition to the ratio of juvenile to adult mortality, social factors such as queen number influence life history trajectories. We discuss two hypotheses explaining why queen fecundity and lifespan is higher in single-queen societies and sugg…
Molecular phylogeny and forms of photosynthesis in tribe Salsoleae (Chenopodiaceae).
2016
Evolution of C3–C4 intermediate and C4 lineages are resolved in Salsoleae (Chenopodiaceae), and a model for structural and biochemical changes for the evolution of the Salsoloid form of C4 is considered.
Characterization and purification of a bacterial chlorogenic acid esterase detected during the extraction of chlorogenic acid from arbuscular mycorrh…
2016
International audience; A Gram-negative bacterium able to grow using chlorogenic acid (5-caffeoylquinic acid) as sole carbon source has been isolated from the roots of tomato plants inoculated with the arbuscular mycorrhizal fungus Rhizophagus irregularis. An intracellular esterase exhibiting very high affinity (K-m = 2 mu M) for chlorogenic acid has been extracted and purified by FPLC from the chlorogenate-grown cultures of this bacterium. The molecular mass of the purified esterase determined by SDS-PAGE was 61 kDa and its isoelectric point determined by chromatofocusing was 7.75. The esterase hydrolysed chlorogenic acid analogues (caffeoylshikimate, and the 4- and 3-caffeoylquinic acid i…
Marine Cryptophytes Are Great Sources of EPA and DHA
2017
Microalgae have the ability to synthetize many compounds, some of which have been recognized as a source of functional ingredients for nutraceuticals with positive health effects. One well-known example is the long-chain polyunsaturated fatty acids (PUFAs), which are essential for human nutrition. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the two most important long-chain omega-3 (-3) PUFAs involved in human physiology, and both industries are almost exclusively based on microalgae. In addition, algae produce phytosterols that reduce serum cholesterol. Here we determined the growth rates, biomass yields, PUFA and sterol content, and daily gain of eight strains of marine…
Extraction of lipids from wet microalga Auxenochlorella protothecoides using pulsed electric field treatment and ethanol-hexane blends
2017
Abstract Pulsed Electric Field (PEF) treatment was used as pre-treatment on the microalgae strain Auxenochlorella protothecoides (A.p.) prior to organic solvent extraction of lipids. Experiments were performed on fresh biomass from mixotrophic or autotrophic culture which both had an evaluated lipid content of 30–35% of cell dry weight. Lipid yield was determined gravimetrically and compared to the reference lipid content assessed by bead-milling and subsequent Soxhlet extraction. The biomass was concentrated at 10% w/w solids prior to PEF-treatment and further dewatered afterwards to approximately 25% w/w before extraction. PEF-treatment with an energy input of 1.5 MJ per kilogram of dry m…
Boric acid toxicity to the German cockroach, Blattella germanica: Alterations in midgut structure, and acetylcholinesterase and glutathione S-transfe…
2006
0048-3575 doi: DOI: 10.1016/j.pestbp.2005.05.002; Oral toxicity of boric acid, an inorganic insecticide, was evaluated on German cockroach, Blattella germanica L. (Dictyoptera, Blattellidae). Newly emerged adults were exposed to various concentrations of boric acid incorporated into the diet. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. Histological study of midgut revealed alterations in the epithelial cells and a signiWcant increase in the epithelium thickness. In a second series of experiments, the compound was investigated on the activities of acetylcholinesterase (AChE) and glutathione S-transferases (GSTs). Data showed that the compound…
The antioxidant 2,3‐dichloro,5,8‐dihydroxy,1,4‐naphthoquinone inhibits acetyl‐cholinesterase activity and amyloid β 42 aggregation: A dual target the…
2020
Alzheimer's disease is characterized by amyloid β aggregation and cholinergic neurodegeneration. In the present study, pure DDN (2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone) was examined, for the first time, for its dual potential as inhibitor of acetylcholinesterase (AChE) and Aβ42 aggregation. Such investigation was encouraged by the in vitro high antioxidant potential of DDN. Indeed, it revealed interesting antioxidant activity with IC50 values of 9.8 and 4.3 µM for ABTS and reducing power, respectively. The ability of DDN to counteract Aβ42 aggregation was evaluated by thioflavine-T assay. Strong inhibition of Aβ42 aggregation of more than 90% at 25 µM was measured. Moreover, results …
Effect of methylparaben in Artemia franciscana.
2017
In this study, the toxicity of methylparaben (MeP) an emerging contaminant, was analysed in the sexual species Artemia franciscana, due to its presence in coastal areas and marine saltworks in the Mediterranean region. The acute toxicity (24 h-LC50) of MeP in nauplii was tested and its chronic effect (9 days) evaluated by measuring survival and growth under two sublethal concentrations (0.0085 and 0.017 mg/L). Also, the effect on several key enzymes involved in: antioxidant defences (catalase (CAT) and gluthathion-S-transferase (GST)), neural activity (cholinesterase (ChE)) and xenobiotic biotransformation (carboxylesterase (CbE), was assessed after 48 h under sublethal exposure. The result…
Anti-Inflammatory and Cytoprotective Effect of Plant Sterol and Galactooligosaccharides-Enriched Beverages in Caco-2 Cells
2019
Plant sterol (PS) (1 g/100 mL) enriched milk-based fruit beverages with or without galactooligosaccharides (GOS) (1.8 g/100 mL) were used in differentiated Caco-2 cells. Their potential cytopreventive effect against oxidative stress induced by cholesterol oxidation products (COPs) and their anti-inflammatory properties were evaluated. Preincubation (24 h) with bioaccessible fractions from beverages without and with GOS (MfB and MfB-G) completely prevented the COPs (60 μM/4 h) induced oxidative stress independent to GOS presence with exception to calcium influx and GSH content, where a partial protective effect was observed. Besides, MfB produced a significant (p < 0.05) reduction of IL-8 (4…