Phenolic compounds research

There are several chemical compounds found in the waste waters of a wide variety of industries that must be removed because of the danger they represent to human health. Among the major classes of contaminants, several aromatic molecules, including phenols and aromatic amines, have been reported. Enzymatic treatment has been proposed by many researchers as an alternative to conventional methods. In this respect, PX has the ability to coprecipitate certain difficult-to-remove contaminants by inducing the formation of mixed polymers that behave similarly to the polymeric products of easily removable contaminants. Thus, several types of PX, including HRP C, LiP, and a number of other PXs from different sources, have been used for treatment of aqueous aromatic contaminants and decolorization of dyes. Thus, LiP was shown to mineralize a variety of recalcitrant aromatic compounds and to oxidize a number of polycyclic aromatic and phenolic compounds. Furthermore, MnP and a microbial PX from Coprinus macrorhizus have also been observed to catalyze the oxidation of several monoaromatic phenols and aromatic dyes (Hamid and Khalil-ur-Rehman 2009). 

Until recently, most of the chemical research on the contents of these structures was directed at the identification of the constituents of castoreum. In the late 1940s Lederer [72, 73] identified 36 compounds and some other incompletely characterized constituents in castoreum of uncertain origin. Other constituents were subsequently identified in the material [74-77]. In a reinvestigation aimed specifically at the phenol content of the material, Tang et al [69] identified 10 previously unreported phenols in the castoreum from the North American beaver, Castor canadensis. Of the 15 phenols reported elsewhere, only five were confirmed in this analysis, in addition to 10 phenolic compounds that were not reported elsewhere. It was concluded that the 10 previously identified phenols that were not found in the study by Tang et al. were either absent or were not volatile enough to be detected by the methods employed. This was most probably because a relatively low maximum column temperature of only 210 °C was employed in the GC-MS analyses. The compounds identified by Lederer,... 

Phenolic compounds can be condensed forming aryl-aryl and aryl-oxygen-aryl (ether linkages) bonds to yield diaryl and diaryl ether polymers (59). These are in many ways similar to natural humic acids, confirming earlier research by others (60-62) that humic acids are formed from the copolymerization of phenolic compounds with amino acids, peptides, and amino sugars. 

Cantarelli [332] and Montedoro and Cantarelli [333] noted the presence of phenolic compounds in olive oils and they established a set of research priorities related to these compounds that are practically still carried out nowadays. Research issues deal with the development of analytical procedures to quantify phenolic compounds in oils, the relationship between these compounds and the characteristics of the olive fruit, as determined by variety, ripeness degree, and other sonrces of variation, the relationship between the profile, concentration, and extraction technology of phenolic compounds, the biological role in the antioxidant activity in vitro and in vivo [334],... 

Cholbi MR, Paya M, Alearaz MJ. 1991. Inhibitory effects of phenolic compounds on CCKinduced microsomal lipid peroxidation. Research Articles 47 195-199. 

Stewart AJ, Mullen W, Crozier A. On-line high-performance liquid chromatography analysis of the antioxidant activity of phenolic compounds in green and black tea. Molecular Nutrition Food Research. 2005 49(1) 52-60. 

Bae, B., Autenrieth, R. L. Bonner, J. S. (1995). Kinetics of multiple phenolic compounds degradation with a mixed culture in a continuous-flow reactor. Water Environment Research, 67, 215-23. 

Among the compounds commonly determined in research laboratories are diacetyl, 2,3-butandiol, glycerol, citramalic acid, amino acids (especially proline), histamine, ammonia, succinic acid, phosphate, ash, alkalinity of the ash, ethyl, acetate, methyl anthranilate, total volatile esters, higher alcohols (both total and individually) phenolic compounds, etc. An elegant method for determining ethyl esters, capronate, caprylate, caprinate, and laurate using carbon disulfide extraction and GLC has been published (123). 

Several studies have described a relationship between the activity of PAL in iceberg lettuce leaf tissue and the development of RS symptoms [141-146]. Hyodo et al. [141] observed that an ethylene-induced increase in PAL activity parallelled the appearance of RS symptoms. These researchers also measured an increase in total phenolic compounds. It has been proposed that ethylene induces PAL activity and the resulting accumulation of phenolic compounds in cells leads to their discoloration and eventual death [141,143,145]. 

Since phenolic compounds occur in many fruits and most of them contribute to color and taste, phenolic analysis of fruits has been an active research area, especially in apple, grape, and citrus fruits and their products, such as juice, cider, and wine. 

Many of the recent studies on the BAs in wines are from the research group of Busto. In 1994 this group developed a method suitable for the determination of 19 BAs in wine (48) that involves the removal of phenolic compounds with polyvinylpirrolidone (PVP), derivatization with DNS, SPE extraction with C18 cartridges, concentration, and HPLC-UV analysis reaching DLs between 50 and 150 /rg/L. The method was applied to five different red and white wines from Catalonia. 

Reviewed previous SCWO research with model pollutants and demonstrated that phenolic compounds are the model pollutants studied most extensively under SCWO conditions Studied supercritical water oxidation of aqueous waste Explored reaction pathways in SCWO of phenol Studied catalytic oxidation in supercritical water Explored metal oxides as catalysts in SCWO Studied decomposition of municipal sludge by SCWO Investigated the SCWO kinetics, products, and pathways for CH3- and CHO-substituted phenols Determined oxidation rates of common organic compounds in SCWO... 

Phenolic compounds and flavonoids are a unique category of plant phytochemicals especially in terms of their vast po ential health-benefiting properties. They represent the most abundant and the most widely represented class of plant natural products. A substantial amount of research has been carried out over the past two decades yet large information gaps still exist. For example, the inventory of these compounds is still incomplete, although there is continuous effort to provide new structures. In addition the dissection of the metabolic pathways for certain phenolic compounds remains to be resolved. Recent reports underline that important questions that still need to be answered in the field of proanthocyanidin and tannin biosynthesis [Xie and Dixon, 2005], and even the exact nature of the biosynthetic pathway(s) leading to lignin monomers is not fully elucidated. 

Boudet AM. 2007. Evolution and current status of research in phenolic compounds. 

In association with well-known health benefits related to the consumption of fruit- and vegetable-rich diets, research on the protective effects of plant-derived phenolic compounds (polyphenols) has developed notably in recent years. In particular, their antioxidant properties have been the objective of extensive research. However these phenolics are the target of an array of chemical reactions that, if confirmed to occur in vivo, would contribute to their health promoting effects. It is now emerging that both parent compounds and their metabolites produced after ingestion can regulate cell and tissue functions by both antioxidant and nonantioxidant mechanisms. This volume provides the latest evidence supporting these concepts. 

As being part of a series launched under the umbrella of the IUBMB, the volume was planned to tackle not only the cutting edge research, but also to provide a source for basic, educational information. The target audience includes not only scientists and health professionals but also educators and students, policymakers, food and pharmaceutical developers, and many others interested in understanding how plant-derived phenolic compounds can affect human health and so, in part, explains how fruit and vegetables play a key role in enhancing human health. 

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