BOTANY WITH BASICS OF HYDROBOTANY (AQUATIC PLANTS OF UKRAINE) - B.Ye. Yakubenko - 2011

IV. PLANT STRUCTURE

Secondary Plant Metabolites

Antibiotics

Substances produced by microbial Cells that kill or inhibit the growth of other microorganisms are called Antibiotics. Numerous cases of antagonism are known among microorganisms, which are accompanied by the destruction or suppression of one microorganism by another due to the secretion of a specific antibiotic into the environment.

The medicinal significance of green mold (Penicillium sp.) was first highlighted as early as 1871 by Russian physicians V. Manasein and A. Polotebnov. However, this event failed to attract scientific attention, and it was not until 1929 that the Englishman A. Fleming drew attention to the ability of Penicillium notatum to inhibit the GROWTH AND REPRODUCTION of suppuration pathogens. During World War II, through the joint efforts of Fleming, Florey, Chain, and others, the industrial production of "Penicillin" was organized.

Consequently, the priority of this discovery belongs to A. Fleming. It became one of the most prominent events in 20th-century science. The therapeutic Properties of the antibiotic penicillin, extracted from the fungus, fully justified the scientist's expectations. Penicillin proved to be an effective remedy against a range of microorganisms causing severe diseases such as Pneumonia and gas gangrene. It was used to treat purulent-septic and inflammatory processes. The Effect of penicillin on microbial cells is associated with the disruption of Cell wall formation in microorganisms. Penicillin is obtained exclusively from certain species and strains of Fungi of the genus Penicillium, such as Penicillium chrysogenum.

Over the past 50 years, thousands of natural, synthetic, and semisynthetic antibiotics with various spectra of activity have been discovered; however, only a limited number of these drugs are used in clinical practice. This is mainly because most antibiotics fail to meet the requirements of practical medicine, and there is no underlying chemical regularity in their Structure.

The richest group in terms of antibiotic content is actinomycetes of the genus Actinomyces. Streptomycin is produced by soil actinomycetes Actinomyces streptomycini. It is used to treat tuberculosis (especially Tuberculous meningitis), brucellosis, tularemia, whooping cough, etc.

Chloramphenicol was isolated from the culture of the actinomycete Actinomyces venezuelae. In microbial cells, it inhibits METABOLISM/35.html">Protein Biosynthesis. It is used to combat epidemic typhus, typhoid fever, and acute intestinal infections.

Tetracyclines are metabolic products of actinomycetes: oxytetracycline from Streptomyces rimosus, and chlortetracycline from Streptomyces aureofaciens. Antibiotics of the tetracycline group are used as growth promoters in feed additives in livestock farming.

Decades of medical use of penicillin have led to The Emergence of microbial strains resistant to "first-generation" antibiotics (benzylpenicillin, streptomycin, chloramphenicol, tetracycline). This primarily concerns staphylococci and Gram-negative Bacteria, which have acquired a high degree of Antibiotic Resistance As a result of the mutagenic effect of these antibiotics upon them.

In view of these circumstances, a differentiated approach to prescribing antibiotics is necessary, utilizing the arsenal of "second-generation" drugs (new Aminoglycosides, macrolides, Semisynthetic Penicillins, Cephalosporins, lincomycin, fusidic acid, semisynthetic aminoglycosides, tetracyclines, etc.). In terms of efficacy, these antibiotics are two to three times superior to first-generation antibiotics.

Antibiotics are also used in plant cultivation. For instance, antimycin, which inhibits the growth of certain fungi, is utilized in agriculture to control fungal diseases affecting onions, peas, rice, and grapes.