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Biomedical subjects

V Opletalová

Publications and source records attributed to V Opletalová.

9 recordsLinked to original sources

[Chalcones (1,3-diarylpropen-1-ones) and their analogs as potential therapeutic agents in cardiovascular system diseases].

At the beginning of a new millennium, several important questions have come to the fore connected with the utilization of natural resources for the investigation of new medicaments (necessity of cooperation of both highly developed and developing countries in the protection of natural resources, necessity to justly evaluate and reward the contributions of the individual cultures in the case that a knowledge of traditional medicine was employed in the development of a new medicament, necessity to achieve the maximal chemical variety of real and virtual libraries of substances from which potential drugs are selected for screening tests). The research of chalcones and its analogues which are relatively easily available not only by isolation from natural material, but also by the methods of classical and combinatorial synthesis should not be substantially affected by the above-described changes. The present communication links up with previous papers (Opletalová, V., Sedivý, D.: Ces. slov. Farm. 48, 252 (1999); Opletalová, V.: Ces. slov. Farm. 49, 278 (2000); Opletalová, V. et al.: Folia Pharm. Univ. Carol. 25, 21 (2000)) and is devoted to the stabilizing action of chalcones on the vascular wall, vasodilating and anti-aggregating effects, and a favourable effect of their antioxidative activity on the functions of the cardiovascular system. The introduction also briefly discusses the nomenclature of this group of compounds.

Animals↗

Conformational analysis of 2-hydroxy-2',5'-diazachalcones.

Spatial arrangement of 2-hydroxy-2',5'-diazachalcones was studied by means of infrared and NMR spectral data and molecular models calculations. The models were calculated in vacuum using semi-empirical AM1 method (software HyperChem 5.1). The initial geometries of the molecules were built by means of standard parameters and then optimized by Polak-Ribiere geometrical optimization. It was found that (E)-s-cis-conformers with synperiplanar arrangement of C-alpha and C-6 have the lowest heats of formation (standard heat of formation).

Chalcone↗

[Chalcones and their heterocyclic analogs as potential therapeutic agents in bacterial diseases].

Chalcones and their heterocyclic analogues possess a number of biological effects. Their antifungal effects were reported in the previous communication (Opletalová V., Sedivý D.: Ces. a Slov. Farm. 48, 252 (1999)). The present review is devoted to the antibacterial activity of these compounds. For antibacterial activity, the presence of the enone aggregate in the molecule is important. Hydrogenated analogues are less effective or ineffective, saturated brominated analogues are effective probably after a metabolic transformation into unsaturated alpha-bromochalcone. In the rings, substitution with a hydroxyl is advantageous, in some cases also substitution with a lipophilic substituent, e.g. a halogen or an alkyl, proved to be advantageous. On the other hand, substitution with amino groups often results in a decrease in effectiveness. Effectiveness of chalcones and their derivatives against gram-positive microorganisms is usually higher than against gram-negative bacteria. Some analogues, however, inhibited also the growth of gram-negative strains. With regard to increased incidence of tuberculosis in recent years, antimycobacterial effectiveness of chalcones and their derivatives is especially interesting.

Anti-Bacterial Agents↗

[Chalcones and their heterocyclic analogs as potential antifungal chemotherapeutic agents].

Chalcones and their heterocyclic analogues show various biological effects, e.g. anti-inflammatory, antitumour, antibacterial, antituberculous, antiviral, antiprotozoal, gastroprotective, and others. The present review discusses in greater detail the fungistatic and fungicide properties of these compounds and presents also their chemical structures. The mechanism of antifungal effects of chalcones and their analogues has not been investigated in greater detail. Due to the presence of a reactive ketovinyl moiety in the molecule the compounds of this type are able to react with the thiol groups of enzymes. It cannot be excluded that chalcones interfere with the normal function of the membranes of fungi and moulds. Further investigation of chemical, physical, and biological properties of chalcones and their analogues could lead to the elucidation of the mechanism of their action and finding of effective fungicidal and fungistatic agents in this group of organic substances.

Antifungal Agents↗

[Substances affecting the synthesis and activity of leukotrienes].

Leukotrienes play an important role in inflammation and asthma. This paper briefly deals with compounds influencing leukotriene biosynthesis and activity. 5-Lipoxygenase inhibitors (e.g., zileuton) and FLAP inhibitors (e.g., quiflapon) hinder biosynthesis of all leukotrienes. LTB4 production may be limited by LTA4-hydrolase inhibitors. Attention is also paid to leukotriene receptor antagonists. LTB4 antagonists (e.g., SC-51146) should be useful in the treatment of diseases in which a prominent neutrophil infiltrate is present, especially psoriasis and inflammatory bowel disease. Peptidoleukotriene (LTC4, LTD4, LTE4) antagonists, such as zafirlukast and pranlukast, are currently being developed as antiasthmatics.

Asthma↗

[Legal and ethical problems in drug advertising and their resolution in practice].

Advertising of drugs and other preparations with an impact on human health is an integral part of the present time. The presented paper deals with different types of advertisements and legal and ethical problems associated with them. The authors in more detail discuss principles laid down in directive 92/28/EEC, which are mandatory from January 1993 for countries of the EEC.

Advertising↗