Search results for " aroma"
showing 10 items of 370 documents
Synthesis of aryl azides: A probe reaction to study the synergetic action of ultrasounds and ionic liquids
2011
Abstract The combined effect of ultrasounds and ionic liquids was used to perform the synthesis of aryl azides by nucleophilic aromatic substitution in ionic liquid/[1-butyl-3-methylimidazolium][N 3 ] binary mixtures. The ultrasounds efficiency was analyzed as a function of the substrate and of the ionic liquid structure. In the first case, both 6π and 10π electrons aryl halides were considered. As far as the ionic liquid structure is concerned, both aromatic and aliphatic ionic liquids were taken into account. Among aromatic cations, the effects due to different ability in giving hydrogen bond or π–π interactions were considered. The use of a geminal ionic liquid having an aromatic spacer …
On-surface Synthesis of a Chiral Graphene Nanoribbon with Mixed Edge Structure.
2020
Abstract Chiral graphene nanoribbons represent an important class of graphene nanomaterials with varying combinations of armchair and zigzag edges conferring them unique structure‐dependent electronic properties. Here, we describe the on‐surface synthesis of an unprecedented cove‐edge chiral GNR with a benzo‐fused backbone on a Au(111) surface using 2,6‐dibromo‐1,5‐diphenylnaphthalene as precursor. The initial precursor self‐assembly and the formation of the chiral GNRs upon annealing are revealed, along with a relatively small electronic bandgap of approximately 1.6 eV, by scanning tunnelling microscopy and spectroscopy.
Studies of the binding of diolepoxide metabolites of polycyclic aromatic hydrocarbons to DNA using electrofluorescence polarization spectroscopy
1996
In the electrofluorescence method, a solution of DNA with covalently bound polycyclic hydrocarbons is placed in an electric field, and changes in the intensity of polarized fluorescence are observed. Under the correct conditions, these charges can be used to determine a value for the angle psi between the long axis of the hydrocarbon molecule and the axis of the DNA helix. For DNA or poly(dA-dT) treated with each stereoisomer of anti-benzo[c]phenanthrene diolepoxide, psi ranged from 55 degrees to 61 degrees, consistent with a mixture of quasi-intercalated adenine adducts and externally bound guanine adducts. Similar results were obtained with another set of 'fjord-region' diolepoxides, deri…
Matching beer with food : pairing principles, underlying mechanisms and a focus on aromatic similarity
2018
Pairing between beer and dishes emerges as a new trend in France. Beer promoters or gastronomy professionals need to offer high-quality advices in terms of beer and food pairing to their customers. Within this context, the objective of the research was to identify pairing principles and to better understand the underlying perceptual mechanisms. Determinants of food and beverage pairing were first analysed from experts’ discourses. Results showed that food and beverage pairings are governed by perceptual, conceptual and affective features, related to physio-chemical, perceptual and cognitive processes. Experts often mentioned “Aromatic Similarity” as one of the main pairing principles. This …
Synthesis and characterisation of N-glycosyl amines from the reaction between 4,6-O-benzylidene-D-glucopyranose and substituted aromatic amines and a…
2001
Twelve N-glycosyl amines were synthesised using 4,6-O–benzylidene-D-glucopyranose and different substituted aromatic amines, including some diamines that resulted in bis-glycosyl amines. Another set of six N–glycosyl amines was synthesised using different hexoses and pentoses and 2–(o–aminophenyl)benzimidazole. All compounds were isolated as solid products and purified, their elemental compositions were established, and these were characterised by NMR (1H and 13C), UV–Vis, and FTIR spectroscopy, by FAB mass spectrometry (molecular-ion peaks gave molecular weights), and by their optical rotations. While the protected saccharide, 4,6-O-benzylidene-D-glucopyranose, exists as a mixture of β and…
Non-starter lactic acid bacteria used to improve cheese quality and provide health benefits
2010
Non-starter lactic acid bacteria (NSLAB) dominate cheese microbiota during ripening. They tolerate the hostile environment well and strongly influence the biochemistry of curd maturation, contributing to the development of the final characteristics of cheese. Several NSLAB are selected on the basis of their health benefits (enhancement of intestinal probiosis, production of bioactive peptides, generation of gamma-aminobutyric acid and inactivation of antigenotoxins) and are employed in cheese-making. This review describes the ecology of NSLAB, and focuses on their application as adjunct cultures, in order to drive the ripening process and promote health advantages. The scopes of future dire…
Palladium-Catalyzed Arylation of Linear and Cyclic Polyamines.
2005
Synthetic protocols for the palladium-catalyzed arylation of various linear and cyclic polyamines and polyoxapolyamines has been worked out. Pd(0) and Pd(II) complexes with such phosphine ligands as dppf, BINAP, PPF-OMe, P(tBu) 3 , 2-ditert-butylphosphino- 1,1'-biphenyl have been explored in the catalytic amination reactions. Monoamination of chloro-, bromo-, and iodoarenes with di-, tri-, and tetraamines have been carried out, condi- tions for di- and polyarylation of linear polyamines have been elaborated. Successful aryla- tion of 1,4,7,10-tetraazacyclododecane (cyclene) and 1,4,8,11-tetraazacyclotetradecane (cy- clam) have been conducted. Intramolecular diamination of dihaloarenes such …
Branched-Chain and Aromatic Amino Acids Are Associated With Insulin Resistance During Pubertal Development in Girls.
2018
Cross-sectional studies in children show branched-chain and aromatic amino acids are associated with insulin resistance, but whether these associations persist from childhood to adulthood is not known. This study aimed to assess whether circulating amino acids associate with insulin resistance during pubertal development.This was a 7.5-year longitudinal study from childhood to early adulthood. A total of 396 nondiabetic Finnish girls aged 11.2 ± .8 years at baseline participated in the study which was conducted at the Health Science Laboratory, University of Jyväskylä. Serum concentrations of glucose and insulin were determined by enzymatic photometric methods and amino acids by nuclear mag…
Estimation of the degrading genetic potential of soil bacterial communities: a new tool for evaluating and predicting soil contamination by organic m…
2007
During the last two centuries, industrialisation has led to increasing contamination of the environment by xenobiotics, notably aromatic compounds (i.e. PAHs, pesticides). These widespread pollutants are a major threat affecting soil quality and human health. In this context, numerous policies have been drawn up notably in Europe, to monitor the threats of pollution to ecosystems and to detect and implement measures to counterbalance the damage. Nevertheless, the European Commission and scientific community are still confronted with a lack of appropriate tools to monitor biodiversity in relation to environmental processes affecting global warming and soil protection. This study proposes too…
The impact of lactic acid bacteria with antimicrobial properties on biodegradation of polycyclic aromatic hydrocarbons and biogenic amines in cold sm…
2017
The influence of surface treatment with lactic acid bacteria (LAB), previously cultivated in an alternative substrate, on the formation of polycyclic aromatic hydrocarbons (PAHs) and biogenic amines (BAs) in cold smoked pork meat sausages was investigated. Moreover, sausages treatment with LAB after the smoking on PAHs content changes was evaluated. Additionally, the inhibitory effects of LAB metabolites on food spoilage bacteria was determined using the agar well diffusion assay method. The metabolites of Pediococcus acidilactici KTU05-7, Pediococcus pentosaceus KTU05-9 and Lactobacillus sakei KTU05-6 strains showed good inhibitory properties against tested pathogenic and food spoilage bac…