Phenolic compounds and

The aqueous sodium naphthenate phase is decanted from the hydrocarbon phase and treated with acid to regenerate the cmde naphthenic acids. Sulfuric acid is used almost exclusively, for economic reasons. The wet cmde naphthenic acid phase separates and is decanted from the sodium sulfate brine. The volume of sodium sulfate brine produced from dilute sodium naphthenate solutions is significant, on the order of 10 L per L of cmde naphthenic acid. The brine contains some phenolic compounds and must be treated or disposed of in an environmentally sound manner. Sodium phenolates can be selectively neutralized using carbon dioxide and recovered before the sodium naphthenate is finally acidified with mineral acid (29). Recovery of naphthenic acid from aqueous sodium naphthenate solutions using ion-exchange resins has also been reported (30). 

Some examples of metal ion indicators. Numerous compounds have been proposed for use as pM indicators a selected few of these will be described. Where applicable, Colour Index (C.I.) references are given.12 It has been pointed out by West,11 that apart from a few miscellaneous compounds, the important visual metallochromic indicators fall into three main groups (a) hydroxyazo compounds (b) phenolic compounds and hydroxy-substituted triphenylmethane compounds (c) compounds containing an aminomethyldicarboxymethyl group many of these are also triphenylmethane compounds. 

PO performs vitally important functions in the plant cell and is mainly associated with the oxidation of phenolic compounds and with the formation and strengthening of the cell wall (Passardi et al., 2004). PO is involved in the oxidative transformation of molecules in growth-regulating or signalling activities and - as a result - can also perform regulatory functions in the cell. Plant POs are represented by genetically different proteins with the same enzymatic activity (Welinder et al., 2002). 

Alvarez-Suarez, J. M., TuUpani, S., Romandini, S., Vidal, A., and Battino, M. (2009). Methodological aspects about determination of phenolic compounds and in vitro evaluation of antioxidant capacity in the honey A review. Curr. Ami. Client. 5, 293-302. 

Nutrient deficiencies may also influence the production of allelochemics. The compounds studied in great detail have been the phenolic compounds and scopolin-related chemicals. Deficiencies of boron, calcium, magnesium, nitrogen, phosphorus, potassium, and sulfur have all been reported to enhance the concentration of chlorogenic acids and scopolin in a variety of plants (4). In other species, chlorogenic acids have decreased in plants that are deficient in magnesium or potassium. 

Crossing the boundaries of phenolic compounds and amino acids in coffee, caffeoyl tryptophan, and p-coumaiyl-(L)-tryptophan have both been identified recently in green Robusta coffee beans.51 A... 

Many toxic pollutants were detected in the process wastewaters from metal molding and casting processes. The toxic pollutants detected most frequently in concentrations at or above 0.1 mg/L were phenolic compounds and heavy metals. The pollutants include 2,4,6-trichlorophenol, 2,4-dimethyl-phenol, phenol, 2-ethylhexyl, cadmium, chromium, copper, lead, nickel, and zinc. Each type of operation in the foundry industry can produce different types of pollutants in the wastewater stream. Also, because each subcategory operation often involves different processes, pollutant concentrations per casting metals may vary. 

Other aquatic weeds such as reed mat, mangrove (leaves), and water lily (Nymphaceae family plants) have been found to be promising biosorbents for chromium removal. The highest Cr(III) adsorption capacity was exhibited by reed mat (7.18 mg/g), whereas for Cr(VI), mangrove leaves showed maximum removal capacity (8.87 mg/g) followed by water lily (8.44 mg/g). It is interesting to mention that Cr(VI) was reduced to Cr(III), with the help of tannin, phenolic compounds, and other functional groups on the biosorbent, and subsequently adsorbed. Unlike the results discussed previously for the use of acidic treatments, in this case, such treatments significantly increased the Cr(VI) removal capacity of the biosorbents, whereas the alkali treatment reduced it.118... 

For kraft pulp mills, the Cluster Rules add toxic and nonconventional pollutants to the list of regulated pollutants only for bleached papergrade kraft mills. Effluent limitations guidelines and standards were added for the following BAT and PSES pollutants (and NSPS/PSNS for new sources) chloroform, 2,3,7,8-TCDD, 2,3,7,8-TCDF, 12 chlorinated phenolic compounds, and AOX. All of the... 

Phenolic compounds may enhance the rate of decomposition of aromatic ether, because the phenoxy radical may be stabilized by solvation (18) or hydrogen bonding (19) with phenolic compounds and may result in the subsequent hydrogen transfer reaction from hydrogen donating solvent or phenols (20). 

Reported redox potentials of laccases are lower than those of non-phenolic compounds, and therefore these enzymes cannot oxidize such substances [7]. However, it has been shown that in the presence of small molecules capable to act as electron transfer mediators, laccases are also able to oxidize non-phenolic structures [68, 69]. As part of their metabolism, WRF can produce several metabolites that play this role of laccase mediators. They include compounds such as /V-hvdi oxvacetan i I ide (NHA), /V-(4-cyanophenyl)acetohydroxamic acid (NCPA), 3-hydroxyanthranilate, syringaldehyde, 2,2 -azino-bis(3-ethylben-zothiazoline-6-sulfonic acid) (ABTS), 2,6-dimethoxyphenol (DMP), violuric acid, 1-hydroxybenzotriazole (HBT), 2,2,6,6-tetramethylpipperidin-iV-oxide radical and acetovanillone, and by expanding the range of compounds that can be oxidized, their presence enhances the degradation of pollutants [3]. 

Dykes L, Rooney LW, Waniska RD, and Rooney WL (2005), Phenolic compounds and... 

Leser, C. and Treutter, D. (2005). Effects of nitrogen supply on growth, contents of phenolic compounds and pathogen (scab) resistance of apple trees , Physiologia Plantarum, 123, 49-56. 

The allelopathic effects of dominant plants on other plants in phytocoenosis are caused by phenolic phytotoxins present in all parts of plants, but the highest amount of these compounds is accumulated in the leaves. Leaves of dominant trees represent the main components of the litter in the forest, thus analysis of phenolic compounds and measurements of their content in leaves and leaf litter is considered as very important. 

Ishikura, N. (1976). Seasonal changes in contents of phenolic compounds and sugar in Rhus, Euonymus and Acer leaves with special reference to anthocyanin formation in autumn. Botanical Magazine, Tokyo 89 251-257. 

Burda S, Oleszek W and Lee CY. 1990. Phenolic compounds and their changes in apples during maturation... 

Robards K, Prenzler PD, Tucker G, Swatsitang P and Glover W. 1999. Phenolic compounds and their role in oxidative processes in fruits. Food Chem 66 4014-36. 

Sellappan S, Akoh CC and Krewer G. 2002. Phenolic compounds and antioxidant capacity of Georgia-grown blueberries and blackberries. J Agric Food Chem 50(8) 2432-2438. 

Tomas-Barberan FA and Espin JC. 2001. Phenolic compounds and related enzymes as determinants of quality in fruits and vegetables. J Sci Food Agric 81(9) 853-876. 

Plant metabolism can be separated into primary pathways that are found in all cells and deal with manipulating a uniform group of basic compounds, and secondary pathways that occur in specialized cells and produce a wide variety of unique compounds. The primary pathways deal with the metabolism of carbohydrates, lipids, proteins, and nucleic acids and act through the many-step reactions of glycolysis, the tricarboxylic acid cycle, the pentose phosphate shunt, and lipid, protein, and nucleic acid biosynthesis. In contrast, the secondary metabolites (e.g., terpenes, alkaloids, phenylpropanoids, lignin, flavonoids, coumarins, and related compounds) are produced by the shikimic, malonic, and mevalonic acid pathways, and the methylerythritol phosphate pathway (Fig. 3.1). This chapter concentrates on the synthesis and metabolism of phenolic compounds and on how the activities of these pathways and the compounds produced affect product quality. 

Stewart RJ, Askew EW, McDonald CM, Metos J, Jackson WD, Balon TW and Prior RL. 2002. Antioxidant status of young children response to an antioxidant supplement. J Am Diet Assoc 102(11) 1652—1657. Stratil P, Klejdus B and Kuban V. 2006. Determination of total content of phenolic compounds and their antioxidant activity in vegetables evaluation of spectrophotometric methods. J Agric Food Chem... 

Stratil P, Klejdus B and Kuban V. 2007. Determination of phenolic compounds and their antioxidant activity in fruits and cereals. Talanta 71 (4) 1741—1751. 

STAFFORD, H.A., Possible multi-enzyme complexes regulating the formation of Cg-C3 phenolic compounds and lignins in higher plants, Rec. Adv. Phytochem., 1974, 8, 53-79. 

Perry, N.B., Burgess, E.J., and Glennie, V.L., Echinacea standardization Analytical methods for phenolic compounds and typical levels in medicinal species, J Agric Food Chem, 49, 1702, 2001. 

Pauly Sulphanilic acid (9 g l-1) in cone. HC1. Mix 1 volume with 10 volumes of watei 1 volume sodium nitrite (50 g l-1) and 1 volume sodium carbonate (100 g 1 1) His Tyr Red Light orange Some imidazoles and phenolic compounds and ammonium salts react. Colours vary — red, brown, yellow. Use after ninhydrin, isatin or Ehrlich in multiple-dip sequences... 

RP-HPLC has been employed for the determination of flavonoids and other phenolic compounds in cranberry juice. The neutral and acidic analytes were preconcentrated octadecyl silica SPE cartridges conditioned with distilled water (neutral analytes) or with 0.01 M HC1 (acidic compounds). Hydrolysis of samples was carried out in aqueous methanol solution acidified with 6 M HC1 at 35°C for 16h. Chromatographic separation was performed in an ODS column (150 X 4.6mm i.d. particle size 5/.an). Solvents A and B were water-acetic acid (97 3, v/v) and methanol, respectively. The gradient started with 0 per cent B (flow rate, 0.9 ml/min), reached 10 per cent B in lQmin (flowrate, 1.0 ml/min) and increased to 70 per cent B in 40min (flowrate, 1.0 ml/min). Analytes were detected at 280 and 360 nm. Some typical chromatograms are presented in Fig. 2.71. The concentrations of flavonoids and phenolic acids are compiled in Table 2.69. It was stated that the SPE-HPLC procedure makes possible the simultaneous determination of phenolic compounds and flavonoids, therefore, it can be employed for the measurement of these classes of analytes in other fruit juices [188],... 

Pool PL, Lin PZ. 1982. Mutagenicity testing in the Salmonella typhimurium assay of phenolic compounds and phenolic fractions obtained from smokehouse smoke condensates. Food Chem Toxicol 29 383-391. 

Oufedjikh H, Mahrouz M, Amiot MJ, Lacroix M (2000) Effect of gamma-irradiation on phenolic compounds and phenylalanine ammonia-lyase activity during storage in relation to peel injury from peel of Citrus Clementina Hort. ex. Tanaka. J Agric Food Chem 48(2) 559-565... 

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