Antimicrobial activity phenolics

Silva JC, Rodrigues S, Peas X, Estevinho LM. Antimicrobial activity, phenolic profile and role in the inflammation of propolis. Food Chem Toxicol. 2012 50(5) 1790-1795. 

Because of lower toxicity and high antimicrobial activity, the phenols having the greatest use in disinfections are o-phenylphenol (Dowicide 1) [90-43-7J, C 2H qO i9-benzyl-/)-chlorophenol (Santophen 1) [120-32-1J, C H CIO and -Z fZ-amylphenol [80-46-6] They possess similar general... 

The phenols from the higher boiling point fractions have greater antimicrobial activity but must be formulated so as to overcome their poor solubility. A range of solubilized and emulsified phenolic disinfectants are available including the clear soluble fluids,... 

Many derivatives of phenol are now made by a synthetic process. Homologous series of substituted derivatives have been prepared and tested for antimicrobial activity. A combination of alkyl substitution and halogenation has produced useful derivatives including clorinated phenols which are constituents of a number of proprietary disinfectants. Two ofthe most widely used derivatives are/ -chloro-m-cresol (4-chloro-3-methylphenol, chlorocresol, Fig. 10.7C) which is mostly employed as a preservative at a concentration of 0.1%, and / -chloro-m-xylenol (4-chloro-3,5-dimethylphenol, chloroxylenol. Fig. 10.7C) which is used for skin disinfection, although less than formerly. Chloroxylenol is sparingly soluble in water and must be solubihzed, for example in a suitable soap solution in conjunction with terpineol or pine oil. Its antimicrobial capacity is weak and is reduced by the presence of organic matter. 

As is apparent from the above information, there is no ideal disinfectant, antiseptic or preservative. All chemical agents have their limitations either in terms of their antimicrobial activity, resistance to organic matter, stability, incompatibility, irritancy, toxicity or corrosivity. To overcome the limitations of an individual agent, formulations consisting of combinations of agents are available. For example, ethanol has been combined with chlorhexidine and iodine to produce more active preparations. The combination of chlorhexidine and cetrimide is also considered to improve activity. QACs and phenols have been combined with glutaraldehyde so that the same effect can be achieved with lower, less irritant concentrations of glutaraldehyde. Some... 

Some phenolic acids such as ellagic acid can be used as floral markers of heather honey (Cherchi et al., 1994 Ferreres et al., 1996a,b), and the hydroxyciimamates (caffeic, p-coumaric, and ferulic acids) as floral markers of chestnut honey (Cherchi et al., 1994). Pinocembrin, pinobanksin, and chrysin are the characteristic flavonoids of propolis, and these flavo-noid compounds have been found in most European honey samples (Tomas-Barberan et al., 2001). However, for lavender and acacia honeys, no specific phenolic compoimds could be used as suitable floral markers (Tomas-Barberan et al., 2001). Other potential phytochemical markers like abscisic acid may become floral markers in heather honey (Cherchi et al., 1994). Abscisic acid was also detected in rapeseed, lime, and acacia honey samples (Tomas-Barberan et al., 2001). Snow and Manley-Harris (2004) studied antimicrobial activity of phenolics. 

The active chloroform-soluble residue (6.2 g) was separated into tertiary phenolic and nonphenolic fractions by dissolving the residue in 250 ml of chloroform and extracting three times each with 250 ml of 5% sodium hydroxide solution. After drying, the chloroform solution was evaporated to leave 4.7 g of tertiary nonphenolic alkaloids that possessed all of the antimicrobial activity. 

The combined aqueous solution of the base layers was treated with an excess of ammonium chloride until a cloudy suspension was noted. This suspension was extracted three times with an equal volume of chloroform. The chloroform layer, after washing with water and drying (sodium sulfate), was evaporated to give 1.4 g of tertiary phenolic bases that had no antimicrobial activity. 

Pereira JA, Pereira APG, Ferreira ICFR, Valentao P, Andrade PB, Seabra R, Estevinho L and Bento A. 2006. Table olives from Portugal phenolic compounds, antioxidant potential, and antimicrobial activity. J Agric Food Chem 54(22) 8425-8431. 

Due to the antimicrobial activity of many of the phenolic compounds against different bacterial and fungal strains, several reports about the antibacterial effects of C-glycosylfla-vones have appeared. 

Randhir R, Lin Y-T, Shetty K. 2004. Stimulation of phenolic compounds, antioxidant and antimicrobial activities in dark germinated mung bean sprouts in response to peptide and phytochemical elicitors. Process Biochem 39 637-646. 

Aromatic and phenolic compounds can mediate UV-protecting activities, which might be favorable for plants living in UV-rich environments, such as high altitudes [1[. Alkaloids (such as isoquinoline, quinoline, and indole alkaloids) that derive from aromatic amino acids, such as phenylalanine, tyrosine, and tryptophan, may have UV-absorbing properties, besides antiherbivoral and antimicrobial activities. 

Secondary compounds known for their antimicrobial activity include many phenolics (e.g., flavonoids, isoflavones, and simple phenolics), glu-cosinolates, nonproteinogenic amino acids, cyanogenic glycosides, acids, aldehydes, saponins, triterpenes, mono- and disesquiterpenes, and last but not least, alkaloids (4,17,42,149,312). 

Reddy, M.K. Gupta S.K. Jacob, M.R. Khan, S.I. Ferreira, D. 2007. Antioxidant, antimalaria, and antimicrobial activity of ellagitannins and phenolic acids from punica granatum. Planta Med. 73 461 67. 

Antioxidant preservative by terminating free radicals formed during autoxidation of unsaturated lipids. It also possesses antimicrobial activity as a phenolic compound. 

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