Different Types Of Phenols Research Articles

Influence of Harvesting Time on Phenolic and Mineral Profiles and Their Association with the Antioxidant and Cytotoxic Effects of Atractylodes japonica Koidz

Plant phytochemical accumulation is influenced by various external factors that change with the seasons (e.g., harvesting time). Atractylodes japonica, an important medicinal plant rich in bioactive compounds, is used to treat several human diseases. We analyzed the influence of harvesting time on phenolic compound concentration and antioxidant activity of A. japonica roots. We investigated the correlation between phenolic compound and minerals contents and antioxidant activity in different harvests. Total phenolic and flavonoid contents varied significantly with the harvesting time. Liquid chromatography–mass spectrometry/mass spectrometry (LC–MS/MS) analysis revealed significant changes in the concentration of various phenolics between harvests. The content of different types of phenolics were significantly higher in the samples collected in October. Among them, chlorogenic acids (133,833.30 µg/g dry weight of root extract) were the most dominant phytochemical compounds detected. Samples harvested in October had higher concentrations of flavonoids, including rutin, orientin, vitexin, and apigenin. Roots harvested in October had a significantly higher (p < 0.05) antioxidant activity than that of those harvested later. Root mineral concentrations also varied with the harvest time. The analysis revealed that macro elements such as Ca ad Mg contents were significantly increased with delaying harvesting time, whereas a different trend was observed for the microelements including Fe, Cu, Al, and As contents in the October harvest. We also found a significant relationship between antioxidant activity and phenolic compound content. The most abundant minerals (Ca, Mg, Mn, Fe, and Al) correlated positively with the antioxidant activity indicating that these elements and compounds may be associated with the A. japonica antioxidant potential. Furthermore, A. japonica root extracts inhibited NIH/3T3 cellular proliferation in a season- and dose-dependent manner. Hence, harvesting time influenced the antioxidant properties and phenolic compound accumulation of A. japonica roots. These results indicate that the harvesting time is essential for obtaining the specific phytochemicals.

Tree Nuts and Peanuts as a Source of Natural Antioxidants in our Daily Diet.

Tree nuts and peanuts are healthy foods with a proven track record of helping to reduce the incidence of chronic diseases, most notably cardiovascular disease. At the point of consumption, all nuts contain low moisture and ≥ 50% lipid contents, but this is where similarities end. The levels of key nutrients and bioactives including vitamin C, vitamin E, L-arginine, minerals (such as selenium and zinc), and phenolics can differ markedly. Distinctions in the types and quantities of phenolic constituents for tree nut species, as well as the impact of digestion, will affect the nuts' antioxidant potential in vivo. This work provides some insight into the different types of phenolics found in tree nuts and peanuts, the antioxidant potential of their phenolic extracts using in vitro chemical assays, the effect of thermal processing on the stability of the nuts' endogenous phenolics, and the impact on biomarkers of human health arising from randomized clinical trials. Key biomarkers include measures in the reduction of LDL oxidation as well as increases in the levels of vitamin E and selected phenolic compounds in blood plasma postprandially from those of baseline.

Phenolic content as Antioxidant and Antimicrobial Activities of Pistacia Atlantica Desf. (Anacardiaceae) extract from Libya

The aim of the work is to search for new, potentially biologically active extract .The chemical and biological investigations of different extracts of P. atlantica, resulted that the ethyl acetate extract of P. atlantica leaves contains a complicated mixture of phenolics, which includes mainly gallotannins as previously detected by 2D paper chromatographic screening. The isolation and identification of six polyphenoles (1-6) , were elucidated for the first time from this plant , including three polyphenolic acid ; gallic acid (1); ellagic acid (2) ; 3,3'-dimethoxyellagic acid (3) and three gallotannines, 2,3-di-O-galloyl-(α/β)-4C1-glucopyranose, nilocitin (4) ; 1,3-di-O-galloyl-β-D-4C1-glucopyranos (5); 1,2,3,4,6- penta-O-galloyl-b-D-4C1-glucopyranose(6).The structures of all isolated compounds were elucidated by conventional methods, spectroscopic analysis, including 1D and 2DNMR,ESIMS and HRESI mass as well. The search for new, potentially biologically active extract becomes much more efficient after identification of all compounds in that mixture. The in vitro antioxidant activity using the stable free radical DPPH (2,2-diphenyl-1-pycrylhydrazyl) method of the P. atlantica extracts proved that ethyl acetate extract possesses a distinct radical scavenging effect at the different concentrations and the extract completely inhibited DPPH absorbance at a concentration 77 μl , the percentage of inhibition obtained 96.4% can be considered as a full absorbance inhibition of DPPH . Also, the IC50 (the concentration that inhibits 50% of the absorbance of DPPH) of ethyl acetate extract of P. atlantica showed an IC50 value of 8.41±0.24 μg/ml compared with IC50 value of ascorbic acid 1.82±0.33 μg/ml. It could be concluded from the obtained results that the P. atlantica ethyl acetate extract shows a very high antioxidant capacity which is very close to the value of the reference standard used, which may be attributed to its high polyphenolic content. P. atlantica extracts demonstrated inhibitory effects against pathogenic microorganisms: Staphylococcus aureus, NCTC 7447; Bacillus subtilis, NCTC 10400; Escherichia coli, NCTC 10416; Pseudomonas aerogenasa NCIB 9016); Candida albicans, IMRU 3669.The active ethyl acetate extract shown a sensitizing effect against Staphylococcus aureus ,20mm inhibition zone while the methanolic extract effect against Bacillus Subtilis was 19.5mm inhibition zone.The present study has revealed that Pistacia Atlantica Desf. (Anacardiaceae) growing in Libya is capable of synthesizing and accumulating different types of phenolics, including mainly ellagitannins, gallotannins which were elucidated for the first time from this plant .It could be concluded from the obtained results that the P. atlantica is a promising source for bioactive compounds which have potential applications as bioactive antioxidant agents for the treatment of diseases

Application of adsorption process for phenolic compounds removal from aqueous environments: A systematic review

<p>Wastewater from various types of industries such as synthetic resins, plywood industries, paper and pulp, gas and coke oven plants, paints, coal gas, tanning, textile, plastic, rubber, pharmaceutical, petroleum and mine discharges, contain different types of phenols. Phenolic compounds are toxic substances and some are known or suspected carcinogens. Therefore it is important to remove phenol and phenolic compounds from contaminated industrial aqueous streams before discharged into any water bodies. Adsorption of phenol and its derivatives from aqueous solution by activated carbon is one of the most investigated of all liquid phase applications of carbon adsorbents. Several adsorbents have been used for treatment of wastewater and removal of phenolic compounds. Literature contains various adsorption processes and adsorbents such as pistachio nut shell ash, Moringa peregrina tree shell ash, agricultural fibers, red mud, low cost clay, olive mill waste, natural zeolites, rubber seed coat, peat, fly ash, bentonite and … which have been used for the removal of phenol and its derivatives. Any of chemical, biological and physical treatment processes has its own advantages and disadvantages. It is worth mentioning that economic aspects of these processes are important, for example biosorption were found to be effective methods with scope for further research in this field in terms of cost effectiveness and regeneration. At present study various adsorbents used by the authors of this article and other researchers for phenol and its derivatives from aqueous environments have been reported and summarized. Additionally, more research is needed to find the practical utility of low-cost adsorbents on commercial scale.</p>

The regulation by phenolic compounds of soil organic matter dynamics under a changing environment.

Phenolics are the most abundant plant metabolites and are believed to decompose slowly in soils compared to other soil organic matter (SOM). Thus, they have often been considered as a slow carbon (C) pool in soil dynamics models. Here, however, we review changes in our concept about the turnover rate of phenolics and quantification of different types of phenolics in soils. Also, we synthesize current research on the degradation of phenolics and their regulatory effects on decomposition. Environmental changes, such as elevated CO2, warming, nitrogen (N) deposition, and drought, could influence the production and form of phenolics, leading to a change in SOM dynamics, and thus we also review the fate of phenolics under environmental disturbances. Finally, we propose the use of phenolics as a tool to control rates of SOM decomposition to stabilize organic carbon in ecosystems. Further studies to clarify the role of phenolics in SOM dynamics should include improving quantification methods, elucidating the relationship between phenolics and soil microorganisms, and determining the interactive effects of combinations of environmental changes on the phenolics production and degradation and subsequent impact on SOM processing.

Reduction of the Variety of Phenolic Compounds in Bio-oil via the Catalytic Pyrolysis of Pine Sawdust

The objective of this study was to evaluate phenolic compounds produced from the catalytic pyrolysis of pine sawdust by commercial catalysts. Eight types of commercial catalysts consisting of SiO2, montmorillonite, α-Fe2O3, HZSM-5 (Si:Al = 25:1), ZnO, γ-Fe2O3, HZSM-5 (Si:Al = 50:1), and nano-HZSM-5 (Si:Al = 50:1) were screened in a fixed bed reactor at a reaction temperature of 500 °C and a vapor residence time of 3 s. All the tested commercial catalysts exhibited different catalytic performances for the adjustment of the composition of the bio-oil. HZSM-5 (Si:Al = 25:1) significantly increased hydrocarbon production in the bio-oil, which is helpful for improving its heating value. The different types of phenols were reduced significantly from 17 to 7 with nano-HZSM-5 (Si:Al = 50:1); however, the phenols content also decreased from 32.6% to 23.28% compared with non-catalytic pyrolysis. Meanwhile, the addition of nano-HZSM-5 (Si:Al = 50:1) to the raw material provided the highest amount of furans (up to 38.8%) among the tested commercial catalysts. The inexpensive ZnO and γ-Fe2O3 also were surprisingly effective for the reduction of the variety of phenolic compounds detected by GC/MS, reducing that number from 17 to 10.

Comparative analysis of phenolic profile of Monodora myristica and Monodora tenuifolia

This study sought to identify phenolics present in the seeds of Monodora myristica and Monodora tenuifolia by Gas chromatography (GC) coupled to Flame ionization detector (FID). GC-FID analysis identified fifty-three different types of phenolics in both M. myristica and M. tenuifolia seeds. Predominant phenolics are Myristicin (RT: 13.78), Caffeic acid (RT: 14.16), Safrole (RT: 11.37), Methyl Eugenol (RT: 12.32), Catechin (RT: 3.63), Elemicin (RT: 13.69), Quercetin (RT: 25.05), Kaempherol (RT: 21.52), Methyl Isoeugenol (RT: 12.69) and Eugenol (RT: 11.70). It was observed that M. myristica is rich in Myristicin (42.60%), Caffeic acid (23.39%), Elemicin (3.82%) and Eugenol (1.02%), while M. tenuifolia is rich in Safrole (11.86%), Methyl Eugenol (6.28%), Catechin (5.27%), Quercetin (2.97%), Kaempherol (2.27%) and Methyl Isoeugenol (1.45%). However, the two species of Monodora contained virtually the same kinds of phenolics but in varying quantities with M. myristica having a higher total phenolic content (1478.32 mg/100 g) than M. tenuifolia (1171.52 mg/100 g). Both species are promising sources of phenolics. Key words: Monodora myristica, Monodora tenuifolia, phenolics.

Spectroscopic [IR and Raman] Analysis and Gaussian Hybrid Computational Investigation- NMR, UV-Visible, MEP Maps and Kubo Gap on 2,4,6-Nitrophenol

In the present methodical study, FT-IR and FT-Raman of the 2,4,6-Nitrophenol (TNP) called as picric acid are recorded and the observed vibrational frequencies are assigned. The hybrid computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31+G(d,p) and 6-311++G(d,p) basis sets and the corresponding results are tabulated. The alternation of structure of nitro phenol due to the subsequent substitutions of NO2 is investigated. The vibrational sequence pattern of the molecule related to the substitutions is analyzed. Moreover, 13C NMR and 1H NMR are calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra are simulated and the chemical shifts related to TMS are compared. A study on the electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, are performed by HF and DFT methods. The calculated HOMO and LUMO energies and the kubo gap analysis show that the occurring of charge transformation within the molecule. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. NLO properties related to Polarizability and hyperpolarizability are also discussed. The thermodynamic properties (thermal energy, heat capacity and entropy) of the title compound are calculated in gas phase and are interpreted with different types of phenols.

A Continuous Base-Catalyzed Methylation of Phenols with Dimethyl Carbonate

We have found that the use of a conventional, heated, standard 316 stainless steel or steel-braided PTFE tube reactor is a good and easily scalable alternative to the use of continuous microwave-heated reactors. The heat-up is almost as fast as with microwave heating, and the reactors can easily be scaled towards large-scale production. The transfer of the reported microwave procedure to the continuous flow method went very smoothly, and we found that we could further optimize the reaction to a catalytic procedure where only 10 mol % of DBU is needed with only 3 equiv of DMC. The reaction can be run neat in cases where the starting material is soluble in DMC as phenol is, or with a small amount of DMF (2–3 vol). The reaction is efficient for different types of phenols, giving a clean reaction in high yields.

Identification and quantification of flavonoids in traditional cultivars of red and white onions at harvest

Onions are rich in different types of phenolics, mainly flavonols, and in red varieties anthocyanins are also present. This is significant because these classes of phenolics are antioxidants and hence may impart important functional properties to onions. The aim of the present work was to simultaneously determine flavonol and anthocyanin concentrations in different onion varieties, two white (Branca da Póvoa and the hybrid SK409) and three red (landrace Vermelha da Póvoa, a selected line of Vermelha da Póvoa and Red Creole). Flavonols (quercetin 7,4-diglucoside, quercetin 3,4-diglucoside, isorhamnetin 3,4-diglucoside, quercetin 3-glucoside, quercetin 4-glucoside and isorhamnetin 4-glucoside) were the predominant polyphenolic compounds. White cultivars had the lowest total flavonol content, with values of 89.3 ± 38.5 and 101.0 ± 18.9 mg quercetin/kg fresh weight for Branca da Póvoa and the hybrid SK409, respectively. The red onions had the highest levels of flavonols, especially the selected population of Vermelha da Póvoa and Red Creole, with values of 280.2 ± 41.5 and 304.3 ± 81.2 mg quercetin/kg fresh weight, respectively. Red onions are not only richer in flavonols, but also contain anthocyanins. Four anthocyanins (cyanidin 3-glucoside, cyanidin 3-laminaribioside, cyanidin 3-(6″-malonylglucoside), and cyanidin 3-malonylaminaribioside) were quantified in all red onions, with Red Creole presenting the highest concentration (28.6 ± 8 mg cyanidin/kg fresh weight). Red onions may be recommended for their major potential functional properties. A distinct gradient in total flavonoid content was found between the outer, central and inner edible scales and along the longitudinal axis of the bulb. Differences in flavonol levels between small- and large-sized onions were also found. All of these factors are of paramount importance for sampling and characterizing onions with regard to flavonoids.

Validated Reversed-Phase Column High-Performance Liquid Chromatographic Method for Separation and Quantification of Polyphenolics and Furocoumarins in Herbal Drugs

A rapid column high-performance liquid chromatographic-photodiode array method has been developed for the separation and identification of secondary metabolites, especially different types of phenols and furocoumarins, in a 35 min chromatographic run. The method has been optimized and validated for selectivity, precision, recovery, and robustness with the aim of application for standardization of selected herbal drugs. Almost all of the tested compounds had linearity of >98%, with relative standard deviation <10% in terms of variation of retention time. Interday and intraday variability was <5%. The developed method has been successfully applied in identification and quantification of phenols and furocoumarins present in different plants, viz., Artemisia pallens (whole plant), Hibiscus rosa-sinensis DC (flower), Heracleum candicans DC (fruit), and Ficus carica Linn (bark). The results indicate that the method is rapid, accurate, and robust for the analysis of different types of phenols and furocoumarins and, hence, can be successfully used in the quality control and standardization of plant extracts and herbal drugs.

Optimization of a High-Performance Liquid Chromatography Method for the Separation and Identification of Six Different Classes of Phenolics

Flavonoids are chemical moieties widely distributed in certain plants that are important biologically active constituents of a daily human diet, with significant pharmacological potential (anti-hepatotoxic, anti-allergic, anti-inflammatory, anti-osteoporotic, and anti-tumor activities). Thus keeping in view the importance of this class of compounds, a rapid method for the separation and identification of fifteen phenols belonging to six different types of phenolics in a sole analysis has been developed and validated using selectivity, precision, recovery, and robustness as parameters. The method developed, which is rapid, accurate, and robust for the analysis of different classes of phenols, can be used in the quality control and standardization of plant extracts as well as herbal drugs, including compound herbal formulations.

Peroxidase-catalyzed oxidation of beta-carotene in HL-60 cells and in model systems: involvement of phenoxyl radicals.

Recent studies provide extensive evidence for the importance of carotenoids in protecting against oxidative stress associated with a number of diseases. In particular, reactions of carotenoids with phenoxyl radicals generated by peroxidase-catalyzed one-electron metabolism of phenolic compounds may represent an important antioxidant function of carotenoids. To further our understanding of the antioxidant mechanisms of carotenoids, we used in the present work two different phenolic compounds, phenol and a polar homologue of vitamin E (2,2,5,7,8-pentamethyl-6-hydroxychromane, PMC), as representatives of two different types of phenols to study reactions of their respective phenoxyl radicals with carotenoids in cells and in model systems. We found that phenoxyl radicals of PMC did not oxidize beta-carotene in either HL-60 cells or in model systems with horseradish peroxidase (HRP)/H2O2. In contrast, the phenoxyl radicals generated from phenol (by native myeloperoxidase in HL-60 cells or HRP/H2O2 in model systems) effectively oxidized beta-carotene and other carotenoids (canthaxanthin, lutein, lycopene). One-electron reduction of the phenoxyl radical by ascorbate (assayed by electron spin resonance-detectable formation of semidehydroascorbyl radicals) prevented HRP/H2O2-induced oxidation of beta-carotene. PMC, but not phenol, protected beta-carotene against oxidation induced by a lipid-soluble azo-initiator of peroxyl radicals. No adducts of peroxidase/phenol/H2O2-induced beta-carotene oxidation intermediates with phenol were detected by high-performance liquid chromatography-mass spectrometry analysis of the reaction mixture. Since carotenoids are essential constituents of the antioxidant defenses in cells and biological fluids, their depletion through the reaction with phenoxyl radicals formed from endogenous, nutritional and environmental phenolics, as well as phenolic drugs, may be an important factor in the development of oxidative stress.

Patch‐Size Effects on Plant Phenolics in Successional Openings of the Southern Appalachians

We examined the seasonal changes in plant chemical defenses of key tree species (Robinia pseudoacacia, Liriodendron tulipifera, Acer rubrum, and Cornus florida) regenerating during early succession in different patch sizes within Southern Appalachian forests. Trees of each species were sampled from five sizes of forest openings (0.016, 0.08, 0.4, 2.0, and 10 ha; two replicates each) and from the understory of surrounding forests. Leaves of rapidly growing, pioneer species (Robinia and Liriodendron) were slightly less tough and contained lower levels of hydrolyzable tannins and total phenolics, but higher condensed tannin concentrations than the slower growing, more shade—tolerant species (Acer and Cornus). These results generally support earlier findings indicating the evolutionary development of greater levels of constitutive phenolics in slow—growing than fast—growing species. The differential use of condensed and hydrolyzable tannins by slow— and fast—growing species may reflect adaptive trade—offs in the allocation of different types of phenolics. Regenerating trees often had tougher leaves and contained higher levels of phenolics in large than small openings by midsummer. The differences in phenolics were more pronounced for condensed tannins and when comparing the smallest canopy openings with larger patch sizes. Plant phenolics were also generally lower in understory trees than in conspecific sprouts in openings. These findings may reflect phenotypic carbon/nutrient adjustments as light availability changes across the patch—size gradient. The greater sunlight in large than small openings apparently promotes excess carbon production and a metabolic buildup of phenolic compounds. Independent measures of phenolic compounds peaked at different times during the growing season. Hydrolyzable tannins reached peak levels quite early whereas condensed tannins increased later in the growing season. Total phenolics peaked in midsummer. Herbivore damage was consistently high (5—9%) on Robinia sprouts in all openings. Insect herbivory on the remaining three species (1—5%) was significantly lower in large than small patch sizes. Tree species regenerating in the high sunlight of larger openings in Southern Appalachian forests thus tend to have tougher leaves, contain greater phenolics, and experience less herbivore damage than conspecifics in small openings.

Direct liquefaction of different lignocellulosics and their constituents: 2. Molecular weight determination, gas chromatography, i.r. spectroscopy

Oils derived by thermochemical conversion of different lignocellulosic feedstocks have been comparatively characterized. The average molecular weights (MW) were determined of oils and their SESC-fractions by use of high performance gel permeation chromatography. The MW of the oils varied between 230 (spruce holocellulose) and 540 Dalton (spruce organosolv lignin), while those of the SESC fractions increased with increasing polarity. Capillary g.c. was used to quantify monomeric phenols. No aromatic compounds could be detected in the oil from pure cellulose. I.r. spectra of the oils were evaluated quantitatively; multiple linear regression analysis revealed that the amounts of different types of phenols and the oxygen content can be calculated approximately from the i.r. data.

On the complexation of uranyl with phenolic ligands

Following a previous paper (1) further complex systems involving uranyl and phenols were studied by potentiometric methods in dilute aqueous solutions containing an excess of the phenolic reagent. Equilibrium constants are given and some general rules for uranyl complexing with different types of phenols are outlined.

Reactions between amino acid compounds and phenols during oxidation

About 30 per cent of organic soil nitrogen can be hydrolized with HCl to amino acids; about 30 per cent is nonhydrolizable. In contrast to this high content of amino acid nitrogen is the small availability of the nitrogen to micro-organisms. In light of the theory proposing a reaction between the α-amino group of amino acids or peptides and quinones formed during oxidation of lignin degradation products or other phenolic compound, different types of phenols were oxidized by phenolases in presence of amino acid compounds. It could be shown that the reaction of binding of nitrogen started at pH values higher than 6.5, and that only such phenols reacted which had no methoxylated hydroxyl groups. The reaction of some phenols during oxidation in presence of amino acids was accompanied by deamination and decarboxylation of the latter. The reaction products of phenols with amino acids were stable against hydrolysis. Using peptides it was found that all amino acids, except the N-terminal which is bound to oxidized phenols, could be hydrolyzed normally. With serum albumin it could be shown that there is a reaction with the amino group of the N-terminal amino acid and also with the e-amino group of lysine residues with phenols during oxidation. The reacted protein seemed to be degraded normally with a protease ofBacillus subtilis.