Antimicrobially active substances

Objects for medical purposes made of plastics which are to have an antimicrobially active content of metals (or metal compounds) can be economically produced in that a plastic blank in foil, granulate or fibre form is coated with the desired metal (or metal compound) by the thin-film technique. The intermediate product thus obtained is then ground and mixed and processed further as the raw material for the desired final form. Sueh objects are thus antimicrobially active all over their surfaces and also on inner surfaces. Hence the full effect of the antimicrobially active substances, in this case oligodynamically active metals (or metal compounds) is obtained with only a small fraction of the quantities formerly required when they were included in the plastic in powdered form, thus resulting in considerable cost savings. 

The number and types of micro-organisms that may develop in various pharmaceutical dosage forms is greatly influenced by the presence of substances with antimicrobial properties. Antimicrobial active substances can be divided into three groups, as follows ... 

In general, biocide-releasing polymers have no influence over their intrinsic antimicrobial activity. The polymers are simply acting as carriers for biocides or antibiotics. The biocidal molecules, which are incorporated in the polymer matrix and/or tethered to the polymer backbone, are released. One of the major advantages of these systems is that the release of the embedded antimicrobial active substances is controlled by the used polymeric system. Therefore, the rates of release are adjustable and polymers can release the biocides very close to the cell, which makes them efficient. However, the polymers still release biocides into the environment and will eventually become inactive. Polymeric biocides contain biocidal repeating units. Such macromolecules often show the same mode of action as their repeating units with somewhat lower activity, due to the steric hindrance caused by the polymeric backbone. Biocidal polymers distinguish themselves by the fact that they act as a whole molecule. Further, biocidal polymers have been found to show a lower tendency to build up bacterial resistance. ... 

The group of antimicrobially active substances known as pseudomonic acids, e.g. (152), have been the subject of considerable synthetic interest in recent years. During 1982, Snider and Phillips have described a new total synthesis of pseudomonic acid A (152) and several other research groups have outlined a variety of stereoselective approaches to key intermediates in projected syntheses of the natural metabolites. 

For a successful application it is also necessary that the antimicrobial active substance is soluble in water. The solubility of the antimicrobial formulation should be at least 10 g/1 water at 20°C. If the formulation is not water-soluble it must be capable of producing a dispersion in water. This dispersion must be stable during the whole application. 

The preparation of isothiazolidin-3-one 5-oxide and 5,5-dioxide derivatives of azetidin-3-ones was described (99EUP100069), starting from penicillanic acid sulfoxide amides in the presence of halogenating agents in anhydrous inert solvents or even without them. Through rearrangement and oxidation with conventional methods, compounds 73 could be obtained. For some derivatives the usefulness, as intermediates for the preparation of novel p-lactam analogs or active substances in formulations for antimicrobial therapy, is claimed. 

Therefore, there is substantial evidence that GA can play a positive health-related role in addition to its well-known properties as an emulsifier. Therefore, the aim of this chapter is to describe general aspects of the source, composition, and already known uses of GA as well as some new aspects of its antioxidant capacity against some reactive oxygen substances (ROS), and its antimicrobial activity (AMA). 

We wish to emphasize that our success for characterization of the substances responsible for the antimicrobial activity found in the tulip tree was due to utilization of a plan of procedure which incorporates the following elements ... 

CEFIC has estimated that more than 60% of the 2,000 biocidal active ingredients and of the 20,000 formulated biocidal products containing them currently marketed in the EU may eventually be withdrawn as a result of the implementation of the Biocidal Products Directive. Avecia believes the BPD is likely to restrict new product development and increase the costs of notifying and listing active substances, meaning that research on new actives will be difficult to justify. Avecia Protection Hygiene develops and produces antimicrobials for more than 25 applications in industrial preservation, disinfection, plastics, textiles and personal care, and it continues to develop new products. 

Maizel JV et al (1964) Avenacin, an antimicrobial substance isolated from Avena saliva. I. Isolation and antimicrobial activity. Biochemistry 3 424... 

Bishay, and A. H. Awad. Studies for DC201 determining antibiotic substances in some Egyptian plants. Part 1. Screening for antimicrobial activity. Eito-terapia 1980 51 303-308. DC202... 

The antimicrobial activity of eugenol may be associated with structural damage and alteration of the permeability mechanism of microsome, lysosome, and cell walls. The substance acts primarily on cytoplasm membranes, causing alteration of its permeability, and thus allowing leakage of essential bacterial cell constituents with subsequent death of the bacteria. 

Although biodiversity in terrestrial environments is extraordinary, oceans covering more than 70% of our planet represent a greater diversity of life. A small number of marine plants, animals, and microbes have already yielded over 12 000 novel compounds [10]. Among them, a great number of substances of marine origin have been reported to possess antimicrobial activity such as loloatins A-D, myticins A and B, psammaplin A, etc., which have been covered in several excellent reviews [10-12],... 

Lanolin has been used for many years as a vehicle for pharmacologically active substances in ophthalmic ointments and topical formulations.55-60 In addition to being a vehicle for penicillin and other antimicrobial substances, lanolin contains lipids such as 10-methyldodecanoic acid and 12-methyltridecanoic acid, which have antimicrobial activity.61,62... 

The only way for microbes to enter a healthy plant is via the stomata or at sites of injury, inflicted by herbivory, wind, or other accidents. At the site of wounding, plants often accumulate suberin, lignin, callose, gums, or other resinous substances which close off the respective areas (4.17). In addition, antimicrobial agents are produced such as lysozyme and chitinase, lytic enzymes stored in the vacuole which can degrade bacterial and fungal cell walls, protease inhibitors which can inhibit microbial proteases, or secondary metabolites with antimicrobial activity. 

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