Gaussian wavepacket methods have been widely employed for the investigation of nonadiabatic molecular dynamics. The Direct Dynamics variational Multi-Configurational Gaussian (DD-vMCG) method ...provides a fully quantum mechanical solution to the time-dependent Schrödinger equation for the time evolution of nuclei with potential surfaces calculated on-the-fly using a quantum chemistry program. The first strand of this research study was to develop new, more efficient algorithms and improve the existing code for DD-vMCG aiming to increase both the accuracy and efficiency of this method. Thus, a new, efficient parallel algorithm to control the DD-vMCG database of quantum chemistry points is presented along with improvements to the interpolation scheme. Benchmark calculations on butatriene, allene and formamide showed that the new scheme is a very accurate, efficient and general method to employ for full-dimensional dynamics calculations. The aforementioned algorithm was then used to describe the photodissociation dynamics of phenol including all degrees of freedom, as the second strand of this research work was to explore more complex chemical systems. Full-dimensional quantum dynamics calculations including for the first time six electronic states, along with a detailed comparison with existing 3-state and 4-state models are presented. Including the fifth singlet excited state has been shown to be vital in unravelling the photodissociation of phenol. State population and flux analysis provided new insights into the decay mechanism of phenol confirming the idea of rapid relaxation to the ground state through the ¹ππ/1¹πσ* conical intersection. Finally, an effort to further improve the accuracy of DD-vMCG was made by employing a state-of-the-art approach where a Gaussian process regression scheme is introduced and machined-learned potential energy surfaces are obtained. All the findings suggest that this method could be promising to calculate potential energy surface matrix elements. However, further development is essential to take advantage of its benefits and to deal with the computational cost.
Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial ...developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the presence of total phenolics, while spectrophotometric and chromatographic techniques are utilized to identify and quantify individual phenolic compounds. This review addresses the application of different methodologies utilized in the analysis of phenolic compounds in plant-based products, including recent technical developments in the quantification of phenolics.
Phenolic compounds, which are emitted in significant amounts from biomass burning, can undergo fast reactions in atmospheric aqueous phases to form secondary organic aerosol (aqSOA). In this study, ...we investigate the reactions of phenol (compound with formula C6H5OH)), guaiacol (2-methoxyphenol), and syringol (2,6-dimethoxyphenol) with two major aqueous-phase oxidants – the triplet excited states of an aromatic carbonyl (3C*) and hydroxyl radical (· OH). We thoroughly characterize the low-volatility species produced from these reactions and interpret their formation mechanisms using aerosol mass spectrometry (AMS), nanospray desorption electrospray ionization mass spectrometry (nano-DESI MS), and ion chromatography (IC). A large number of oxygenated molecules are identified, including oligomers containing up to six monomer units, functionalized monomer and oligomers with carbonyl, carboxyl, and hydroxyl groups, and small organic acid anions (e.g., formate, acetate, oxalate, and malate). The average atomic oxygen-to-carbon (O / C) ratios of phenolic aqSOA are in the range of 0.85–1.23, similar to those of low-volatility oxygenated organic aerosol (LV-OOA) observed in ambient air. The aqSOA compositions are overall similar for the same precursor, but the reactions mediated by 3C* are faster than · OH-mediated reactions and produce more oligomers and hydroxylated species at the point when 50% of the phenolic compound has reacted. Profiles determined using a thermodenuder indicate that the volatility of phenolic aqSOA is influenced by both oligomer content and O / C ratio. In addition, the aqSOA shows enhanced light absorption in the UV–visible region, suggesting that aqueous-phase reactions of phenols may contribute to formation of secondary brown carbon in the atmosphere, especially in regions influenced by biomass burning.
Synthetic phenolic antioxidants (SPAs) are widely used in various industrial and commercial products to retard oxidative reactions and lengthen product shelf life. In recent years, numerous studies ...have been conducted on the environmental occurrence, human exposure, and toxicity of SPAs. Here, we summarize the current understanding of these issues and provide recommendations for future research directions. SPAs have been detected in various environmental matrices including indoor dust, outdoor air particulates, sea sediment, and river water. Recent studies have also observed the occurrence of SPAs, such as 2,6-di-tert-butyl-4-methylphenol (BHT) and 2,4-di-tert-butyl-phenol (DBP), in humans (fat tissues, serum, urine, breast milk, and fingernails). In addition to these parent compounds, some transformation products have also been detected both in the environment and in humans. Human exposure pathways include food intake, dust ingestion, and use of personal care products. For breastfeeding infants, breast milk may be an important exposure pathway. Toxicity studies suggest some SPAs may cause hepatic toxicity, have endocrine disrupting effects, or even be carcinogenic. The toxicity effects of some transformation products are likely worse than those of the parent compound. For example, 2,6-di-tert-butyl-p-benzoquinone (BHT-Q) can cause DNA damage at low concentrations. Future studies should investigate the contamination and environmental behaviors of novel high molecular weight SPAs, toxicity effects of coexposure to several SPAs, and toxicity effects on infants. Future studies should also develop novel SPAs with low toxicity and low migration ability, decreasing the potential for environmental pollution.
In the artificial breeding of Pampus argenteus (Euphrasen, 1788), female fish spawn before male release sperm, which indicates rapid ovarian development. In fish, aromatase is responsible for ...converting androgens into estrogens and estrogen plays a crucial role in ovarian development. In this study, we aimed to investigate the potential role of brain-type and ovarian-type aromatase to study the rapid ovarian development mechanism. The results showed that cyp19a1a was mainly expressed in the ovary and could be classified as the ovarian type, whereas cyp19a1b could be considered as the brain type for its expression was mainly in the brain. During ovarian development, the expression of cyp19a1a in the ovary significantly increased from stage IV to stage V and Cyp19a1a signals were present in the follicle cells, while cyp19a1b expression in the pituitary gland decreased from stage IV to stage V. To further investigate the function of Cyp19a1a, recombinant Cyp19a1a (rCyp19a1a) was produced and specific anti-Cyp19a1a antiserum was obtained. The expressions of cyp19a1a, estrogen receptors 2 alpha (esr2a), and androgen receptor alpha (arα) were significantly upregulated in the presence of rCyp19a1a. Meanwhile, cyp19a1a was expressed significantly after E2 treatment in both ovarian and testicular tissue culture. Taken together, we found two forms of aromatase in silver pomfret. The ovarian-type aromatase might play an important role in ovarian differentiation and maturation, and participate in E2 synthesis through co-regulation with esr2a. The brain-type aromatase cyp19a1b might be involved in the regulation of both brain and gonadal development.
•p-Coumaric and chlorogenic acids were predominant phenolic acids in barnyard millet.•Barnyard millet phenolics prevented oxidative DNA damage and protein fragmentation.•Millet phenolics inhibited ...protein glycation, crosslinks and AGEs formation.•Reactive carbonyl intermediates were effectively scavenged by millet phenolics.•Millet phenolics protected glycoxidation-induced protein conformational changes.
Protein glycation plays a vital role in the progression of various diabetes complications. Therefore, inhibition of protein glycation could be a key strategy to prevent these diabetic abnormalities. Evaluation of phenolic compositions and their antiglycation activity revealed that p-coumaric and chlorogenic acids were major phenolic acids in barnyard millet. These phenolics exhibited multiple antioxidant activities in various mechanisms and protected the oxidative DNA damage and hydroxyl radical-induced protein fragmentation. Millet phenolics were very effective in scavenging >78% reactive carbonyl intermediates in the reaction and protected protein thiol group oxidation. Furthermore, 68.3% inhibition of protein glycation and reduced formation of protein aggregates were also observed with millet phenolics. Besides, fluorescence intensity measurements indicated a significant decrease in advance glycated end products and protection against glycoxidation-induced protein conformational changes at 100 µg/ml phenolics. These results suggest the potential utility of barnyard millet as an ingredient in functional foods for controlling protein glycation associated diabetic complications.
Non-communicable diseases (NCDs) have become the largest contributor to worldwide morbidity and mortality. Among them, cancer and cardiovascular diseases (CVDs) are responsible for a 47% of worldwide ...mortality. In general, preventive approaches modifying lifestyle are more cost-effective than treatments after disease onset. In this sense, a healthy diet could help a range of NCDs, such as cancer and CVDs. Traditional Mediterranean Diet (MD) is associated by the low-prevalence of certain types of cancers and CVDs, where olive oil plays an important role. In fact, different epidemiological studies suggest that olive oil consumption prevents some cancers, as well as coronary heart diseases and stroke incidence and mortality. Historically, the beneficial health effects of virgin olive oil (VOO) intake were first attributed to the high concentration of monounsaturated fatty acids. Nowadays, many studies indicate that phenolic compounds contained in olive oil have positive effects on different biomarkers related to health. Among them, phenolic compounds would be partially responsible for health benefits. The present work aims to explore, in studies published during the last five years, the effects of the main phenolic compounds isolated from olive oil on different cancer or CVD aspects, in order to clarify which compounds have more potential to be used as nutraceuticals with preventive or even therapeutic properties.
The incidence of diabetes mellitus (DM) is reaching alarming proportions worldwide, particularly because it is increasingly affecting younger people. This reflects the sedentary lifestyle and ...inappropriate dietary habits, especially due to the advent of processed foods in modern societies. Thus, unsurprisingly, the first medical recommendation to patients with clinically evident DM is the alteration in their eating behaviour, particularly regarding carbohydrates and total energy intake. Despite individual and cultural preferences, human diet makes available a large amount of phytochemicals with therapeutic potential. Phenolic compounds are the most abundant class of phytochemicals in edible plants, fruits and beverages. These compounds have strong antioxidant and anti-inflammatory activities that have been associated with specific features of their chemical structure. Among others, such properties make them promising antidiabetic agents and several mechanisms of action have already been proposed.
Herein, we discuss the recent findings on the potential of dietary phenolic compounds for the prevention and/or treatment of (pre)diabetes, and associated complications.
A broad range of studies supports the innate potential of phenolic compounds to protect against DM-associated deleterious effects. Their antidiabetic activity has been demonstrated by: i) regulation of carbohydrate metabolism; ii) improvement of glucose uptake; iii) protection of pancreatic β-cells; iv) enhancement of insulin action and v) regulation of crucial signalling pathways to cell homeostasis. Dietary phenolic compounds constitute an easy, safe and cost-effective way to combat the worrying scenario of DM. The interesting particularities of phenolic compounds reinforce the implementation of a (poly)phenolic-rich nutritional regime, not only for (pre)diabetic patients, but also for non-diabetic people.
•The bio-residues from the wine industry were explored for their bioactivities.•The seeds showed the highest amount of phenolic compounds.•The skins presented the highest levels of ...anthocyanins.•Highest antioxidant, cytotoxic and antibacterial potential was observed by seeds.•Strong correlations were observed between polyphenols and bioactivities.
The bio-residues resulting from the wine industry (grape pomace made up of skins, seeds and stems) are often undervalued but constitute a potential source of bioactive phenolic compounds that can be applied in several industries. In this context, the aim of the present study was to evaluate the phenolic profile of Vitis vinifera L. grape pomace (skins, seeds and their mixture), and correlate them with its antioxidant, cytotoxic and antibacterial activities. The seeds showed the highest amount of phenolic compounds and also the highest antioxidant, cytotoxic and antibacterial activities. The skins revealed the highest levels of anthocyanins and p-coumaric acid hexoside. Strong correlations were observed between the presence of phenolic compounds and all the bioactivities studied. These by-products are good sources of phenolic compounds with high antioxidant and antibacterial activity, and also presenting a moderate cytotoxicity activity. These added-value by-products have great applicability in food, pharmaceutical and cosmetic industries.
Information on the physicochemical variability in rapeseed oil from different varieties during each refining process is lacking. Our purpose was to investigate the physicochemical properties, ...micronutrients and oxidative stability of the oil extracted from the five varieties of rapeseeds during their different stages of refining process. Increase in the acid value, peroxide value and p-anisidine value were detected in the refining, while content of tocopherols, sterols, β-carotene and phenols, which are regarded as important nutritional compounds diminished. Moreover, the loss rate of total phytosterols of all oils during neutralization (9.23-7.3%) and deodorization (9.97-8.27%) were higher than that of degumming (3.01-0.87%) and bleaching (2.75-1.18%). Deodorization affected total tocopherols contents the most, followed by bleaching, neutralization and degumming. There was a remarkable reduction in total content of phenol, β-carotene and oxygen radical absorbance of all oils during refining. The accumulated information can be used in looking for the optimum condition to meet the basic requirements for oil and minimize micronutrients losses so as to increase their market value.
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