Chemical structure determination growing species

The Laboratory of Lactones, Coumarins, and Terpenoids (headed by Prof. G.P Sidyakin) studied various plants for lactone content, particularly for the lactones leucomisine and austricine, which were isolated from Artemisia leucodes. Both lactones possess pronounced anti-inflammatory action. As a compound possessing pronounced angio-protective, hypolipidemic, hypo-cholesterolemic, and anti-inflammatory actions, leucomisine has passed medical tests and has been introduced into medical practice under the preparation name Oligvon. Since 1970, systematic studies of chemical compounds found in various species of the genus Ferula, which grows in the territory of Uzbekistan and adjacent republics, have been conducted. As a result, more than 50 species of Ferula have been investigated, from which more than 250 new terpenoids, coumarins, and esters have been isolated and their chemical structures determined. Natural esters of mono- and sesquiterpene alcohols with aromatic acids were discovered for the first time in this lab (Kurmukov and Akhmedkhodzhaeva 1994). 

Two other related compounds were isolated from a different colony of the same species growing in a separate district. Endiandric acid B, ( )-4-(6 -phenyl-tetracyclo-[5,4,2,0 ]trideca-4, 6 -dien-l r-yl)but-2-enoic acid (116), was purified from the small amount of co-existing endiandric acid A (115) by esterification with diazomethane, separation, and subsequent hydrolysis (4). Chemical and spectroscopic evidence proved that endiandric acid B was a vinylog of endiandric acid A. The structure of the other compound, abbreviated as acid C, was determined by H-NMR spectroscopy and also by X-ray crystallography on a Diels-Alder adduct with A-methyl-maleimide as 4-[(E, E )-5 -phenylpenta-2, 4 -dien-r-yl]tetracyclo-[5,4,0,0 , 0 ]undec-10-ene-8-carboxylic acid (117) (6). 

The properties of some polymers are dependent on their microstructure for example isotactic polypropylene is crystalline whereas atactic polypropylene is amorphous. Microstructure effects are also exemplified by polybutadienes, where the mode of addition of the diene to the growing chain leads to 1,2-addition, 1,3-addition and 1,4-addition, which may be as or trans. The fraction of different addition species changes the mechanical properties of the polymer. Another example is provided by the chemical composition of a copolymer and its sequence distribution, which together determine its ultimate properties. It is thus of great importance to be able to characterize polymer micro structure. This is generally done using spectroscopic methods, specifically infrared spectroscopy and nuclear magnetic resonance spectroscopy. 

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