Antimicrobial properties complexes

Although a few mechanisms have so far been proposed to explain the antimicrobial properties exhibited by proanthocyanidins (e.g., inhibition of extracellular enzymes) [86], Jones et al. [83] postulated that their ability to bind bacterial cell coat polymers and their abihty to inhibit cell-associated proteolysis might be considered responsible for the observed activity (Table 1). Accordingly, despite the formation of complexes with cell coat polymers, proanthocyanidins penetrated to the cell wall in sufficient concentration to react with one or more ultra-structural components and to selectively inhibit cell wall synthesis. Decreased proteolysis in these strains may also reflect a reduction of the export of proteases from the cell in the presence of proanthocyanidins [83]. 

Because of structural uncertainties and confusing nomenclature, much of the early literature is, frankly, of little more than historical interest. However, after 1930, when most authors adopted the present Chemical Abstracts naming (see Note on Nomenclature that follows), a reliable body of literature gradually accumulated on all six systems, albeit at very different rates. For example, data on the 1,8-naphthyridines greatly outnumbered those on the other systems, probably as a result of the discovery of significant antimicrobial properties associated with nalidixic acid as well as the intrinsic suitability of the 1,8-system for metal complexation. 

Some antioxidants possess antimicrobial properties, such as propyl gallate and butylated hydroxy anisole, which are somewhat effective against bacteria. Butylated hydroxy toluene has demonstrated some antiviral activity. Compatibility of antioxidants with the drug, packaging system and the body should be studied carefully. For example, tocopherols may be absorbed onto plastics ascorbic acid is incompatible with alkalis, heavy metals, and oxidizing materials such as phenylephrine, and sodium nitrite and propyl gallate forms complexes with metal ions such as sodium, potassium and iron. 

Ross, D.L. and Riley, C.M. Physicochemical properties of the fluoroquinolone antimicrobials III. Complexation of lomefloxacin with various metal ions and the effect of metal complexation on aqueous solubility. Int. J. Pharm.,... 

The implication of microbial infection as an etiological agent in arthritis has been the main stimulus for the investigation of the antimicrobial properties of gold complexes. The... 

CS, which is natural polymer containing active groups, such as -NH2, can be functionalised to introduce new positively charged N-atoms. The CS-iodine complexes exhibit better antimicrobial properties. 

In recent years, there are several reports to deal with the effect of CDs on the antimicrobial properties of AITC in a liquid-state condition [12,13]. To clearly illustrate the effect of CDs on AITC in real food systems, a practical example has been drawn below to follow the preparation, releasing properties and use of CD-AITC inclusion complexes for the meat and baking products preservation. 

Remarkably, the presence in solution of the dmg of I2 molecules and 13 ions affect drug s biological properties such as toxicity, irritation [44, 46]. Selection of equilibrium concentrations of molecular iodine and triiodide can reduce toxicity while retaining antimicrobial properties. The reviewed studies could shed a light on such phenomena. One assumes that involvement of a-dextrins in the mixture ensure the presence of the three active centers located within the a-dextrin helix molecular iodine coordinated lithium halogenides and polypeptides, triiodide and lithium halogenides. We believe that the existence of two complexes of iodine and triiodide reduces toxicity of the dmgs [17-20]. 

Mahae N, Chalat C, Muhamud P et al (2011) Antioxidant and antimicrobial properties of chitosan-sugar complex, hit Food Res J 18 1543-1551... 

Ag(I) ions have long been known to possess potent antimicrobial properties, but the use of silver compounds as pharmaceuticals has been hampered by their unfavourable chemical properties. For example, many Ag(I) complexes are light sensitive, and the insolubility of AgCl often presents problems when compounds come into contact with physiological fluids. Over 100 silver compounds have been evaluated for anticancer activity by the National Cancer Institute, and only 5 have shown at best marginal activity. The burn-treatment compound silver sulphadiazene is insoluble and applied topically to burn wounds. Its antibacterial action may be attributable to the slow release of Ag at the wound site ). 

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