Exercise № 1. Write the words and combinations of the words in bold type and translate them.

TRADITIONAL PHARMACEUTICALS OF BIOLOGICAL ORIGIN

        A wide range of pharmaceutical substances are derived from animal sources. There are many are protein-based and detailed description of products such as insulin and other polypeptide hormones, antibody preparations, vaccines, enzymes, etc. (Many of the therapeutic proteins are now also produced by recombinant DNA technology.) Non-proteinaceous pharmaceuticals originally derived from animal sources include steroid (sex) hormones, corticosteroids and prostaglandins.Most of these substances are now prepared synthetically.

        The vast bulk of early medicinal substances were plant-derived. An estimated 3 billion people worldwide continue to use traditional plant medicines as their primary form of healthcare. At least 25% of all prescription drugs sold in North America contain active substances which were originally isolated from plants (or are modified forms of chemicals originally isolated from plants). Many of these were discovered by a targeted knowledge-based ethnobotanical approach. Researchers simply recorded plant-based medical cures for specific diseases and then analysed the plants for their active ingredients. Plants produce a wide array of bioactive molecules via secondary metabolic pathways. Most of these probably evolved as chemical defence agents against infections or predators. While some medicinal substances continue to be directly extracted from plant material, in many instances plant-derived drugs can now be manufactured, at least in part, by direct chemical synthesis. In addition, chemical modification of many of these plant ‘lead’ drugs have yielded a range of additional therapeutic substances. The bulk of plant-derived medicines can be categorized into a number of chemical families, including alkaloids, flavonoids, terpenes and terpenoids, steroids (e.g. cardiac glycosides), as well as coumarins, quinines, salicylates and xanthines.

           Microorganisms produce a wide variety of secondary metabolites, many of which display actual or potential therapeutic application. Antibiotics are by far the most numerous such substances and this family of pharmaceuticals arguably has had the greatest single positive impact upon human healthcare in history.Antibiotics are generally defined as low molecular mass microbial secondary metabolites which, at low concentrations, inhibit the growth of other microorganisms. To date, well in excess of 10 000 antibiotic substances have been isolated and characterized. Overall, antibiotics are a chemically heterogeneous group of molecules, although (as described later) many can be classified into different families based upon similarity of chemical structure.Today there are in excess of 100 antibiotics available on the market. Due to the availability of such a wide range, many pharmaceutical companies cut back or abandoned ongoing antibiotic screening programmes during the 1980s. However, the emergence of microbial strains resistant to most antibiotics threatens medical reversion effectively to a pre-antibiotic era. These developments have rejuvenated interest in discovering new antibiotics and many pharmaceutical companies have recommenced antibiotic screening programmes.

        Most major life form families (microorganisms, plants and animals) have each yielded a host of valuable therapeutic substances. Many pharmaceutical companies and other institutions continue to screen plants and microbes in the hope of disovering yet more such therapeutic agents. However, in recent years, more and more emphasis is being placed upon developing the ‘body’s own drugs’ as commercially produced pharmaceutical substances. Most such drugs are protein-based, and these biopharmaceuticals represent an exciting new family of pharmaceutical products. The number of such drugs gaining approval for general medical use continues to grow, as does their range of therapeutic applications.

Exercise № 3. Fill the second column.