Pharmacognostic aspect, in treating of natural medicinal materials and medicinal of natural origin, is presented by very complex group of analytical and applicative methods. They are applied by means of identification, purities and quality of natural medicinal materials of vegetal, animal or mineral origin, more precisely of pharmacognostic drugs. A great number of drugs and their isolated products show the antimicrobial activities. The chemical substances, which are present in drugs, are currier of antimicrobial activities manifested by action on different bacteria, fungus, parasites and even viruses. The whole series of methods for analyzing of antimicrobial effects of drugs and the medicines in general are treated by scientific discipline microbiology. In order to complete the pharmacognostic analyses of drugs and there medicinal products, the microbiological analyses take a very important role. The antimicrobial and antifungal effects of series of plant materials, of pharmacognostic drugs against the large number of bacteria and fungus Candida have been carried out. The drugs we analyzed were treated from their chemical point of view and that is the presence of: coumarins, mucus and anthraquinones. The contents of these substances in plant material were analyzed by method of thin layer chromatography that was published preliminary. The antimicrobial effects of analyzed drugs were determinate by using dilution method in antimicrobial analyses which have been carried out with decocts of drugs.

Drugs, natural medicinal plant, animals and mineral materials, have a large and various application in official pharmacy and medicine. Carriers of multilateral pharmacological effects that those drugs shown, are chemically define as active components that are present in them. Methods of qualitative and quantitative analysis are used for the chemical investigation of components that drugs contain. Method of thin layer chromatography has been shown as very reliable. According to the chemical investigation of single drugs, it is possible to define a group of compound or single compound comparing them with standards. Relating to the usage of method of thin layer chromatography, it has been carried out investigation on presence of coumarins and flavonoids in domestic plant material that have wide everyday usage. Coumarins and flavonoids from the point of view of chemical belonging are phenol derivatives with important pharmacological effects. Applying method of thin layer chromatography, it is detected presence of coumarins and flavonoids substances in plant material that has been tested. Anethi graveolens fructus et folium (fruit and leaf of dill), Anethum graveolens L., Apiaceae, Avenae sativae fructus (fruit of oats), Avena sativa L., Poaceae and Asperulae odoratae herba (sweet woodruff), Asperula odorata L., Rubiaceae. Chromatograms are developed in systems cyclohexane-ethylacetat (13:7) and toluene-ether (1:1) saturated with 10% acetic acid, and visualisation by observing on UV lamp (254 and 366 nm), spraying with reagents KOH (10% ethanol solution) and diphenylboryloxyethylamine (1% methanol solution).