Conferring antimicrobial activity

Novel Methods of Conferring Antimicrobial Activity on Cotton... 

The pH of the finished product may have a strong influence on the type of preservative used. A good example of this can be seen with the use of organic acids which may exist in a predominantly dissociated or an undissociated form as a consequence of the product pH. The undissociated form is considered to confer the antimicrobial activity and the effect of pH on benzoic, sorbic and dehydroacetic acid is described in the graph below. It can be seen that, at the normal pH of most personal care products ie. 5.5 to 7.0, there is little activity remaining. Hence organic acids would be suitable preservatives for predominantly acidic products, such as astringent washes made with lemons. 

Crooks, C. and Lamb, C. (2001). Identification of a host-pathogen specific gene conferring protection from a preformed antimicrobial activity in Arabidopsis. In "10th International Congress on Molecular Plant-Microbe Interactions University of Wisconsin", Madison, USA. 

However the mechanism of the antimicrobial effect of silver nanoparticles is not well understood. It has been recently reported that Nanosilver represents a special physicochemical system which confers its antimicrobial activities via Ag-t [11]. According to Morones et al., the bactericidal effect of silver nanoparticles on microorganisms is connected not merely with the release of silver ions in solution [12]. Silver nanoparticles can also be attached to the surface of the cell membrane and drastically distnrb its proper function [12]. They could also penetrate inside the bacteria and canse farther damage by interacting with sulfur and phosphorus-containing componnds snch as DNA. 

L-Ascorbic acid is not normally considered a bacteriostat, yet in aqueous solution at the higher concentrations used in the aqueous phase of ascorbic acid treated foods, it appears that it can confer some limited antimicrobial activity. Arafa and Chen (727), increased refrigerated... 

A. Classification All penicillins are derivatives of 6-aminopenicillanic acid and contain a beta-lactam ring structure that is essential for antibacterial activity. PeniciUin subclasses have additional chemical substituents that confer differences in antimicrobial activity, susceptibility to acid and enzymic hydrolysis, and biodisposition. 

Chantana, V. Juree, C. Thawatchaj, P. Effect of hydroxypropylmethyl eeUulose and polyvinyl pyrrol-idone on physical properties of Yahom buccal tablets and the antimicrobial activity of Yahom. In The Fourth Thailand Materials Science Technology Conference, Khong Wan Bangkok, Thailand, PPOl/1-PPOl/3, 2006. 

The third group ccmsists of excipients with collateral antimicrobial activity that are principally added to dosage forms for reasons unrelated to their (sometimes weak) antimicrobial activity. For example, sodium lauiyl sulfate is known to inactivate some gram-positive bacteria. Similarly, edetate has weak antimicrobial activity, and it confers synergistic antimicrobial properties when combined with quaternary anmumium substances. In... 

S.L.G. Yamini, Green synthesis of silver nanoparticles from Cleome viscosa Synthesis and antimicrobial activity. International Conference on Bioscience., 5 334-338,2011. 

N-acetylasimilobine, thaliporphine, predicentrine, iV-methylaurotetanine, lirioferine, liriotuliperine, corunnine. The authors indicate that some of these compounds are probably phytoalexins conferring resistance to the wood from microorganisms. Glaucine in particular has antimicrobial activity (115). 

Guerreiro et al recently described the expression of AMPs (antimicrobial peptides) fused with a CBM3 from C. thermocellum in a bacterial host. AMPs are cationic molecules with a wide range of antimicrobial activities. The authors suggested CBM3 as a good candidate to overcome difficulties related to the expression of these molecules, namely associated to the small size and potential toxicity for host [189]. Furthermore the authors suggested the possible use of the fusion CBM-AMP to confer antimicrobial properties to cellulosic materials. 

Antimicrobial peptides have also been postulated to play a central role in the plant innate immune response to microbial infection and include the thionins, the defensins, and the cyclotides. It has been demonstrated that physiological concentrations of the thionins are active against bacteria and fungi in vitro and the heterologous expression of thionins in a transgenic plant model confer protection against bacterial challenge. ... 

Inoue M, Mitsuhashi S. (1996) Antibacterial activity of new carbapenem S-4661 and stability to beta-lactamase. In Program and Abstracts of the Thirty-sixth Interscience Conference on Antimicrobial Agents and Chemotherapy, New Orleans, p. FI 12. American Society for Microbiology, Washington, DC, USA. 

Tisdale M, Parry NR, Cousens D, St. Clair MH and Boone LR. Anti-HIV activity of (lS-4R)-4-[2-amino-6-cyclopropylamino-9H-purin-9-yl]-2-cyclopentene-l-methanol (1592U89). In Abstracts of the 34th Interscience Conference on Antimicrobial Agents and Chemotherapy. Orlando, Florida, 1994 92. 

Otani T, et al. DK-507k, a New 8-Meth-oxyquinolone In Vitro and In Vivo Antibacterial Activities. In 41st Interscience Conference on Antimicrobial Agents and Chemotherapy, Abstract F-547. Chicago, 2001. 

Petersen U, et al. BAY Y 3118, a novel 4-quinolone Synthesis and in vitro activity. In 32nd Interscience Conference on Antimicrobial Agents and Chemotherapy, Abstract No. 642. Anaheim, 1992. 

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