Phytochemical studies of medicinal plants in Bulgaria. Prof. Dr. Stefan Nikolov D.sci.

Transcription

1 Phytochemical studies of medicinal plants in Bulgaria Prof. Dr. Stefan Nikolov D.sci.

2 TE PLANTS DIVERSITY IN BULGARIA Bulgaria is relatively small in size km2 but it is rich in biological diversity 7835 species: Algae Lichenes Bryophyta Lycopodiophyta - 7 Equisetophyta - 12 Polypodiophyta - 30 Pinophyta - 16 Magnoliophyta

3 USE OF MEDICINAL PLANTS IN BULGARIA In the practice of folk medicine about species are used. For the needs of pharmaceutical industry, phytotherapy and for export 200 species are applied more frequently.

4 In Bulgaria, phytochemical studies of medicinal plants have a long history. They have been and are still subject of scientific research units, primarily at the Institutes of BAS, Faculty of Pharmacy Sofia, the Bulgarian pharmaceutical industry and others. This presentation will present several examples of these studies in the Faculty of Pharmacy in Sofia and in the Institute of Organic Chemistry with Centre of Phytochemistry, BAS.

5 Department of Pharmacognosy, was one on the first academic units established at the Faculty of Pharmacy Sofia, 65 years ago. Since then, the discovery and characterization of biological active phytochemicals has been the most important field of scientific research at the Department.

6 The attention of the colleagues from the Department, has been focused on the following main issues: Isolation, purification, separation and structure elucidation of biological active compounds from medicinal plants; Quantitative and qualitative analyses of some active substances; Study of the content and dynamics of accumulation of some active compounds in medicinal plants; Standardization and control of herbal drug raw material;

7 Other issues of interest comprise: Biologicaly active compounds, produced via plant cells and tissue cultures; Taxonomical, chorology, ecological, biological and chemotaxonomical characteristics of Bulgarian flora species.

8 Department of Pharmacognosy Two scientific basic topics traditionally developed at the department: Saponins triterpenoids and steroids and Phenolic compounds

9 Department of Pharmacognosy Early studies on triterpene saponins have been initiated from the founder of the department, Prof. Dr. Asparukh Boychinov.

10 Department of Pharmacognosy Early studies on the steroid saponins have been initiated by prof. Dr. Diana Panova, one of the inventors of the famous Bulgarian drug "Tribestan" whose active pharmaceutical ingredient is a saponine mixture derived from Tribulus terrestris.

11 Department of Pharmacognosy The second topic are the phenol compounds, namely flavonoids. Prof. Dr. risto Ahtardzhiev was the first researcher in this field in Bulgaria. e lead the department during the period

12 Department of Pharmacognosy In 1990 a Laboratory of Pharmaceutical Biotechnology has been founded at the Department The main activities are focused on elaboration and optimization of methods for biotechnological production of saponins, and phenol compounds /e.g. flavonoids, lignans, etc./

13 Department of Pharmacognosy In order to identify new saponins and phenolic compounds (phenolic acids, xanthones, catechins, flavonoids) many species of plant genera and dozens of families from the Bulgarian and foreign flora have been explored at the department.

14 Department of Pharmacognosy Classic and state-of-the-art chromatography methods are most often used for isolation, purification and separation of compounds from the plants. The compounds are identified by the following methods: melting point; spectral (IR, UV, EI-MS, FAB-MS, 1 and C 13 and other modern NMR methods); Chemical (hydrolysis, acetylation and methylation).

15 Department of Pharmacognosy Using these methods steroid saponins, sapogenins and sterols were identified from the following species of the genera Asparagus and Ruscus (Liliaceae): Asparagus maritimus (L.) Mill. Asparagus verticillatus L. Ruscus aculeatus L. Ruscus ponticus Woronow Ruscus hypoglossum L.

16 Department of Pharmacognosy Triterpenoid saponins were isolated, purified, separated and identified as new natural compounds from plant species of the genus Astragalus (Fabaceae), Gypsophyla (Caryophyllaceae), Chenopodium (Chenopodiaceae).

17 Department of Pharmacognosy Phenolic compounds were isolated, purified, separated and identified as new natural compounds from plant species of the genus: ypericum (Guttiferae), Gentiana (Gentianaceae), Malaleuca (Myrtaceae), Stellaria (Caryophyllaceae), Ferulago (Apiaceae), Platycodon (Campanulaceae), Astragalus (Fabaceae), Potentilla (Rosaceae), Achyranthes (Amaranthaceae), Scleranthus (Caryophyllaceae), Pulsatilla (Ranunculaceae).

18 Department of Pharmacognosy Through genetic transformation in plants sells of Astragalus, Althea, Datura, yosciamus and Linum, species cell and tissue cultures have been prepared, allowing high yield production of new biologically active compounds. New technologies for their bioreactor cultivation have also been developed.

19 Department of Pharmacognosy It is important to note, that the phytochemical investigations are not ends in themselves. There has always been an emphasize on the biological activity of the compounds that have been isolated and elucidated, some of which have been found to be novel compounds.

20 Department of Pharmacognosy There have been several research projects aimed at bioactivity-guided fractionation and identification of phytochemicals with antineoplastic activity, in collaboration with the department of Phrmacology. For example saponins from Astragalus corniculatus Bieb., Fabaceae, pholoroglucinols from ypericum species, diverse phenolic compounds (e.g. flavonoids, benzophenones, xanthones, etc.)

21 Department of Pharmacognosy Astragalus corniculatus Bieb., Fabaceae

22 Department of Pharmacognosy Three novel triterpenoid saponins have been identified from the species: 3-O-β-[4-oxo-β-pentopyranosyl-(1 2)-β-Dglucopyranosyl]-21 -hydroxy oleanolic acid; 3β-4-oxo-β-pentopyranosyl-21 - hydroxy oleanolic acid; 3-O-β-D-xylopyranosyl-3β,19 - dihydroxyоlеаn-12-ene-28, 21β olide

23 Department of Pharmacognosy O O COO O O O O O O O O O 3-O-β-[4-oxo-β-pentopyranosyl-(1 2)-β-D-glucopyranosyl]- 21 -hydroxy oleanolic acid Krasteva, I., S. Nikolov, M. Kaloga, G. Mayer. Triterpenoid saponins from Astragalus corniculatus. Z. Naturforsch., 61b, 2006, 9, IF 2006 =0.825

24 Krasteva, I., S. Nikolov, M. Kaloga, G. Mayer. Triterpenoid saponins from Astragalus corniculatus. Z. Naturforsch., 61b, 2006, 9, IF Department of Pharmacognosy O COO O O O O O 3β-4-oxо-β-pentopyranosyl-21 - hydroxy oleanolic acid

25 Department of Pharmacognosy O O C O O O O O O 3-O-β-D-xylopyranosy-3β,19 -dihydroxyоlеаn, 21β olide Krasteva, I., S. Nikolov, M. Kaloga. A new saponin lactone from Astragalus corniculatus. Natural Product Research, 21, 2007, 10, IF 0.683

26 In the Department of Immunology, Institute of Experimental Pathology and Parasitologi, BAS, was studied purified saponin mixture from Astragalus corniculatus containing mainly these three new triterpene saponins as was proven strong immunomodulating and immunostimulating effect.

27 migration (mm 2 ) percent mortality Mortality percent in Graffi tumor bearing hamsters treated with PSM days after tumor transplantation T +PSM 1 T +PSM 2 T 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0 PSM+T T PSM Control Migration area (mm 2 ) of peritoneal macrophages from normal and tumor bearing hamsters treated w ith PSM days Sap+T T Sap Control Toshkova, R. A., I. N. Krasteva, D.W. Wesselinova, I. Ivanov, S. D. Nikolov. Influence of purified saponin mixture from Astragalus corniculatus Bieb. on phagocytic cells in Graffi tumor bearing hamsters. Journal of Ethnopharmacology, 109, 2007, 3, IF Toshkova, R. A., I. N. Krasteva, S. D. Nikolov. Immunorestoration and augmentation of mitogen lymphocyte response in Graffi tumor bearing hamsters by purified saponin mixture from Astragalus corniculatus. Phytomedicine, 15, 2008, 10, IF 2.330

28 The Department Natural Product Chemistry has been a part of the Institute of Organic Chemistry since its opening in Slide 1

29 Natural Products Characterization of the chemical diversity and health promoting potential of Bulgarian flora Isolation of new biologically active natural compounds (alkaloids, terpenoids,, flavonoids and other phenolics) Development of methods for standardization and quality control of Bulgarian medicinal plants and propolis

30 Sesquiterpene Lactones and Other Phytochemicals in Asteraceaen Plants: New compounds, bioactivity, analysis, chemotaxonomy Anthemis Achillea Artemisia Tanacetum Xanthium Over 35 publications in the last 20 years

31 Propolis research Chemical composition of propolis from different locations Biologically active constituents from propolis New propolis types: Mediterranean propolis (With the group of Prof. inou) Standardization of poplar propolis Over 40 publications in the last 20 years

32 Alkaloids: structure, analysis, chemical transfromations and biological activity Thalictrum Berberis Papaver Datura Isopyrum Potent antiviral substance:oxoglaucin Over 20 publications in the last 20 years

33 Other important subjects Tribulus terrestris: new bioactive constituents, analysis and standardization Essential oils of Bulgarian aromatic plants Sideritis: : chemical constituents, biological activity Iridoids and flavonoids from Bulgarian medicinal plants: Lamiaceae, Scrofulariaceae Modern methods for extraction of bioactive compounds from plant material Phytochemical studies of Black Sea algae

34 The Balkan region is rich in endemic species and is one of the most important centers of plant biodiversity in Europe. Therefore, responsibility and obligation of every Bulgarian phytochemists is to explore the Bulgarian flora as a source of new biologically active structures.

35 Thank you for your attention!