Master Degree / Yüksek Lisans Tezleri

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Access Right: Open AccessSubject: search.filters.subject.Alkaloids

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  • Master Thesis
    Characterization of Glycoalkaloid Content and Molecular Mapping in Eggplant
    (Izmir Institute of Technology, 2006) Kırsoy, Öyküm; Frary, Anne
    In this thesis, solamargine which is a known eggplant glycoalkaloid and has an important place for human health was characterized in eggplant. For characterization, two eggplant lines S.melongena MM738 and S.linnaeanum MM195 were used. Although, for identification and detection of glycoalkaloid concentration, many different methods have been utilized, for this thesis, high-performance liquid chromatography (HPLC) was used to analyze glycoalkaloid concentration in eggplant. In HPLC, spiking of samples was done using a solamargine standard and it was found that S. melongena had an undetectable level of solamargine while S. linnaeanum had between 17.6 and 33.4 mg (average 25.5 ± 11) solamargine per gram of freeze dried powder. In addition to characterization of glycoalkaloids in S.melongena MM738 and S.linnaeanum MM195, different types of molecular markers were surveyed for polymorphism in S.melongena MM738 and S.linnaeanum MM195 for mapping. A total of 47 polymorphic markers were then tested on the F2 population and located on the eggplant molecular genetic map.
  • Master Thesis
    Genetic Mapping and Characterization of Eggplant for Glycoalkaloid Content
    (Izmir Institute of Technology, 2010) Gürbüz, Nergiz; Doğanlar, Sami
    Most plants including eggplant, produce toxins against insects, pathogens and animals. The biggest class of these toxins is alkaloids. Generally plants produce alkaloids in a glycosidic form which are called glycoalkaloids. Glycoalkaloids have toxic effects on human health. For example, as a result of disrupting the cell membrane, the gastrointestinal track and other organs are damaged. Glycoalkaloids are not only toxic to human health but also they have beneficial effects. For example, they decrease cholesterol level, and have anticancer activity. And also they are used as a precursor for steroidal drugs. Therefore, isolation and determination of glycoalkaloids content is important. For this aim, column chromatography was performed and solamargine and solasonine were obtained. Totally 122,8 mg solamargine, solasonine and solamargine and solasonine mix from Solanum linnaeanum were obtained. Their identities were confirmed via 1H NMR and mass spectroscopy. For determination of glycoalkaloid content HPLC method was developed via changing different parameters such as mobile phase, pH, temperature, flow rate and column type. It was found that separation of glycoalkaloids by using RP column without phosphate buffer was not sufficient. On the other hand, separation of glycoalkaloids by using carbohydrate column was better but this type of column is not stable. Furthermore, linkage mapping was performed by using CAPs and SSR methods; and 385 COSII markers and 221 SSR markers were tested. Of the tested markers, 38 of the COS II markers and 28 of the SSR markers were found to be polymorphic. A total of 52 of these markers were mapped.
  • Master Thesis
    Inhibition of Catechol-0 (comt) Enzyme Activity by Some Plant-Derived Alkaloids and Phenols
    (Izmir Institute of Technology, 2009) Yalçın, Dilek; Bayraktar, Oğuz
    In this study, inhibition potentials of harmal seed alkaloids and olive leaf polyphenols were investigated on COMT catalyzed methylation reaction. Inhibition performances of natural alkaloids and polyphenolics whose purities were attempted to be increased by extraction and fractionation were compared with standards of these compounds and the best known COMT inhibitor, 3,5-dinitrocatechol. COMT enzyme inhibition experiments were performed with sentitive fluorometric method. In this method, Km values for SAM and aesculetin substrates were found as 3.5 + 0.3 uM and 6.4 + 0.4 uM, respectively. As a result of the inhibition study, the highest inhibitory effect is observed for harmine and harmaline rich fractions among harmal seed alkaloids. Inhibition constants indicating degree of competitiveness and noncompetitiveness (Ki and aKi) of the harmine fraction which has the highest inhibition performance were calculated as 0.15±0.07 ug/ml and 1.28±0.06 ug/ml, respectively.In the studies performed with standards of olive leaf polyphenols, while it was observed that rutin has inhibitory effect, oleuropein was found less effective. However, oleuropein rich fraction of olive leaf extract showed higher inhibitory effect than crude extract and rutin. It was also observed that polyphenolic extracts obtained from vitex, terebinth and mastic leaves showed high inhibition capacities, it was thought that fractionation should be performed for these plants. As a more general conclusion, it was revealed that harmal seed alkaloids and olive leaf fractions with high purity are promising natural COMT inhibitors. By performing this study, the kinetic inhibition constants of extracts, their fractions and standards could be determined and they could be reported into literature.