Search results for "Enone"

Crystal structure and absolute configuration of (4S,5R,6S)-4,5,6-trihydroxy-3-methylcyclohex-2-enone (gabosine H)

2017

The absolute configuration of the title compound, determined as 4S,5R,6S on the basis of the synthetic pathway, was confirmed by single-crystal X-ray diffraction. The mol­ecule is formed by a substituted six-membered cyclo­hexene ring adopting an envelope conformation and substituted by carbonyl, methyl and hydroxyl groups. The supra­molecular structure is mainly built by a combination of O—H⋯O and weaker C—H⋯O hydrogen bonds.

Preparation and physico-chemical study of inclusion complexes between idebenone and modified beta-cyclodextrins

1996

The inclusion properties of modifiedβ-cyclodextrins (trimethyl-β-cyclodextrin, dimethyl-β-cyclodextrin and hydroxypropyl-β-cyclodextrin) towards idebenone were compared with naturalβ-cyclodextrin. The inclusion complexes were prepared by different methods (coprecipitation, kneading, and freeze-drying) and characterized by differential scanning calorimetry, X-ray diffractometry, UV, CD and NMR spectroscopy. The results obtained by CD and NMR spectroscopy indicate a different orientation of idebenone in dimethyl-β-cyclodextrin with respect to other cyclodextrins. Stability constants of the complexes were determined in water at various temperatures and consequently thermodynamic parameters wer…

Dietary exposure to mycotoxins through the consumption of commercial bread loaf in Valencia, Spain

2017

Abstract In this study, 80 commercial samples of bread loaves were purchased from different supermarkets located in Valencia (Spain). These samples were investigated for the presence of legislated and non-legislated mycotoxins. Results showed that samples were contaminated with Aflatoxins (AFs), Zearalenone (ZEA) and Enniatins (ENs) with a frequency of 20, 96, and 65% respectively. Aflatoxin B1 (AFB1), Aflatoxin B2 (AFB2) and Aflatoxin G1 (AFG1) were detected with concentrations ranged from 0.5 to 7.1 μg/kg. The samples contaminated with AFB1 showed values exceeding the maximum limit allowed in the EU. The sum of AFs also exceeded the maximum limit allowed in 6 samples. ENs contamination da…

2016

The photochemistry of benzophenone, a paradigmatic organic molecule for photosensitization, was investigated by means of surface-hopping ab initio molecular dynamics. Different mechanisms were found to be relevant within the first 600 fs after excitation; the long-debated direct (S1 → T1) and indirect (S1 → T2 → T1) mechanisms for population of the low-lying triplet state are both possible, with the latter being prevalent. Moreover, we established the existence of a kinetic equilibrium between the two triplet states, never observed before. This fact implies that a significant fraction of the overall population resides in T2, eventually allowing one to revisit the usual spectroscopic assignm…

Evaluation of Mycotoxin Residues on Ready-to-Eat Food by Chromatographic Methods Coupled to Mass Spectrometry in Tandem

2018

Simultaneous determination of twenty-seven mycotoxins in ready-to-eat food samples using &ldquo

Climate signatures on decadal to interdecadal time scales as obtained from mollusk shells (Arctica islandica) from Iceland

2013

Abstract Pronounced decadal climate oscillations are detected in a multi-centennial record based on shell growth rates of the marine bivalve mollusk, Arctica islandica, from Iceland. The corresponding analysis of patterns in sea level pressure and temperature exhibit large-scale teleconnections with North Atlantic climate quantities. We find that the record projects onto blocking situations in the northern North Atlantic. The associated circulation shows a low-pressure signature over Greenland and the Labrador Sea and a high-pressure system over Western Europe associated with northeasterly flow towards Iceland and weakening in the westerly zonal flow over Europe. It can be speculated that s…

Human neonatal responses to androstenone

2010

Poster P327 session VII: Olfactory Psychophysics & Clinical Studies; Central Olfaction; Aims. Human newborns show equal attraction to the odors of amniotic. fluid (AF) and mothers’ colostrum [1]. As 5-a-androst-16-en-3-. one (An) has been found in both fluids [2, 3], we studied it as a. potential vector of this perinatal odor continuity and of neonatal. attraction to the smell of breast and milk [4]. Methods. Two studies. were run. 1) We recorded the behavior of 16 newborns (3 days) and. 26 adults exposed to a saturating water solution of An and to 3. reference odorants [butyric acid, B; vanilla, V; water, W]. 2) We videotaped. 26 newborns (3 days) being administered 7 stimuli: 4 dilution. …

Crystal structure and Hirshfeld surface analysis of (2E)-3-(3-bromo-4-fluorophenyl)-1-(3,4-dimethoxyphenyl)prop-2-en-1-one

2018

The title compound is constructed from two aromatic rings (3-bromo-4-fluoro­phenyl and 3,4-di­meth­oxy­phen­yl), which are linked by a C=C—C(=O)—C enone bridge and form a dihedral angle of 17.91 (17)°. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds enclosing rings of (14) graph-set motif to form layers parallel to (10).

Cytoprotective Effect of Idebenone through Modulation of the Intrinsic Mitochondrial Pathway of Apoptosis in Human Retinal Pigment Epithelial Cells E…

2022

Idebenone is a ubiquinone short-chain synthetic analog with antioxidant properties, which is believed to restore mitochondrial ATP synthesis. As such, idebenone is investigated in numerous clinical trials for diseases of mitochondrial aetiology and it is authorized as a drug for the treatment of Leber’s hereditary optic neuropathy. Mitochondria of retinal pigment epithelium (RPE) are particularly vulnerable to oxidative damage associated with cellular senescence. Therefore, the aim of this study was to explore idebenone’s cytoprotective effect and its underlying mechanism. We used a human-RPE cell line (ARPE-19) exposed to idebenone pre-treatment for 24 h followed by conditions …

An unexpected ring carboxylation in the electrocarboxylation of aromatic ketones

2006

The electrocarboxylation of various aromatic ketones, carried out in N-methyl-2-pyrrolidone (NMP) in a diaphragmless cell equipped with a carbon cathode and an aluminium sacrificial anode, yielded, among the products, the target hydroxy acids, the corresponding alcohols and pinacols and, quite surprisingly, detectable amounts of substituted benzoic acids and cycloexene carboxylic acids. These compounds arise from a never reported before electrocarboxylation on the aromatic ring, respectively, for substitution of an aromatic hydrogen and from an addition reaction. For example, the electrocarboxylation of acetophenone gave rise to the substituted benzoic acids in ortho, para and meta position…