The goal of part I of this thesis was to isolate pure anti cancer compounds from the Russian plant Sanguisorba officinalis. This plant was selected for investigation because it showed 100% activity against leukemia (L1210 mouse leukemia cells) during the preliminary screening of approximately 100 Russian plant extracts. This work has resulted in the isolation of novel compound 11 using traditional chromatography techniques. Compound 11 was characterized with spectroscopic techniques such as IR, 1H NMR, 13C NMR, DEPT, DQCOSY and MS. Compound 11 was assigned the structure dipentyl 2-(4-(pentan-3-yl) phenyl) malonate. The goal of part II of this thesis was to synthesize novel ethers of podocarpic acid. Ethers are of great interest in biological studies and pharmaceutical applications because of their wide variety of uses in the treatment of various diseases. A novel family of ether derivatives was synthesized using podocarpic acid (a natural tricyclic diterpene derived from podocarpus species) as a template. Novel ether derivatives of podocarpic acid were synthesized from podocarpic acid in three steps. The first step involved methylation of podocarpic acid with dimethyl sulfate to form methyl-o-methyl podocarpate. The second step was iodination of methyl-o-methyl podocarpate with iodine in presence of a mercury catalyst to form 13-iodo methyl-o-methyl podocarpate. This was followed by formation of novel aliphatic ethers using a copper catalyst. Thus this research had led to the discovery of new methodology for synthesis of three novel aliphatic ether derivatives of podocarpic acid. These ethers will be tested for their biological activity against various types of cancer, tuberculosis by National Institutes of Health.

Plants can interact with many different organisms on many trophic levels in their life. In this thesis I investigated how three biotic inertactions, powdery mildew infection, caused by Podosphaera ferruginea, predispersal seed predation by Dusky Large Blue (Phengaris nausithous) and Scarce Large Blue (P. teleius) and deer grazing affect life cycle and population biology of the Great Burnet (Sanguisorba officinalis L.). I also analysed their preferences of environmental conditions. Most of studied plant populations growth rates (λ) were lower than 1 and population decreased, but quite surprisingly for more populations vegetative reproduction was more important than reproduction by seeds. All intraction mentioned above affects more generative reproduction, and thus their influence on Great Burnet population dynamics is low, even with modelled maximal possible effect. Environment conditions analysis showed that powdery mildew occurs on sites with more flowering individuals, where spreading is very easy, butterflies preferred high, well noticeable flower heads grown high above other vegetation and host ant presence. For host ants' presence model locality was only significant variable.