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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Phenotypical and genotypical eversporting varieties

Roelofs, Eltjo Tjarks. January 1937 (has links)
Thesis (doctoral)--Rijks-Universiteit te Groningen, 1937. / From: "Genetica", deel 19, alf. 6. Includes bibliographical references (p. 535-536).
2

Extractives from eucomis montana and agapanthus inapertus.

Pillay, Bavani. January 2003 (has links)
Two species belonging to different families were investigated, Eucomis montana from the Hyacinthaceae and Agapanthus inapertus from the Agapanthaceae. To date no previous chemical investigation on Eucomis montana has been reported. Eucomis species are routinely harvested, processed and sold for the treatment of various ailments ranging from toothache, gastro-intestinal ailments, pain-producing ailments and venereal and urinary diseases. Members of the genus have shown to contain steroidal compounds and homoisoflavonoids. In this work one nortriterpenoid, a eucosterol type derivative and eleven homoisoflavonoids belonging to four classes, the 3-benzyl-4-chromanone, the 3-benzyl-3-hydroxy-4-chromanone, the 3-benzylidenyl-4-chromanone and the scillascillin type were found in the bulbs of Eucomis montana. Agapanthus species are also used by a number of African tribes medicinally. The bulbs and rhizomes of this family have been reported to contain steroidal saponins and sapogenins. In this work the roots of Agapanthus inapertus have been investigated and a tignan precursor and a lignan have been found. Structures of the compounds isolated were determined using spectroscopic techniques. / Thesis (M.Sc.)-University of Natal, Durban 2003.
3

Investigations into the analytical applications and fundamental chemistry of the chemiluminescent reactions of Tris(22-bipyridyl)ruthenium(III) with certain Papaver Somniferum alkaloids and other related compounds.

Gerardi, Richard David, mikewood@deakin.edu.au January 1999 (has links)
The reaction of tris(2,2’-bipyridyl)ruthenium(III) (Ru(bipy) <sub>3</sub><sup>3+</sup>) with various analytes to generate chemiluminescence has been well documented. This investigation sought to undertake a chemiluminometic study of the reactions of Ru(bipy) <sub>3</sub><sup>3+</sup> with selected Papaver Somniferum alkaloids and specifically synthesised phenethylamines. The investigation, based on a kinetic study, primarily addressed the effect of varying reaction conditions (pH) on Ru(bipy) <sub>3</sub><sup>3+</sup> chemiluminescence production. To monitor these reactions, a batch chemiluminometer was specifically designed, fabricated and automated to conduct an extensive study on the selected compounds of interest. The instrumentation incorporated a custom built reaction cell and comprised an ‘on-line’ sample preparation system with which calibration standards could be automatically prepared. The instrumentation provided both time-independent (peak area) and time-dependent (kinetic profile) information. A novel approach to the stabilisation of Ru(bipy) <sub>3</sub><sup>3+</sup> as a chemiluminescencent reagent was also investigated and a recirculating system was employed with the batch chemiluminometer to provide a stable supply of Ru(bipy) <sub>3</sub><sup>3+</sup>. Codeine, thebaine and 6-methoxy-codeine were the Papaver Somniferum alkaloids selected for this study and several N-methylated and N,N-dimethylated phenethylamines and methoxy-substituted phenetheylamines were also synthesised to investigate the affect of pH on the chemiluminescence emission efficiency. The versatility of the batch chemiluminometer facilitated the kinetic study of numerous analytes over a broad pH range. The exemplary performance of the chemiluminometer as an analytical instrument, was demonstrated by the calibration functions, based on peak area data, which exhibited excellent linearity and sensitivity. The estimated detection limits (3σ) for the selected alkaloids were in the range 2 x 10&<sup>-9<&/sup;> M to 7 x 10&<sup>-9<&/sup;> at pH 5.0 and above, which compared favourably to detection limits for the same compounds determined using FIA. Relative standard deviations (n=5) for peak areas ranged between 1% to 5% with a mean of 3.1% for all calibration standards above 2.5 x 10&<sup>-8<&/sup;> M. Correlation between concentration and peak area, irrespective of pH and analyte was excellent, with all but two calibration functions having r-squared values greater than 0.990. The analytical figures of merit exemplified the precision and robustness of the reagent delivery and ‘on-line’ sample preparation, as well as the sensitivity of the system. The employment of the chemiluminometer for the measurement of total chemiluminescence emission (peak area) was in itself a feasible analytical technique, which generated highly reproducible and consistent data. Excellent analytical figures of merit, based on peak area, were similarly achieved for the phenethylamines. The effects of analyte structure on chemiluminescence activity was also investigated for the alkaloids and the phenethylamines. Subtle structural variations between the three alkaloids resulted in either a moderately reduced or enhanced total emission that was two or three fold difference only. A significant difference in reaction kinetics was observed between thebaine and codeine/6-methoxy-codeine, which was dependent upon pH. The time-dependent data, namely the observed rate constants for the initial rise in intensity and for the subsequent decay rate, were obtained by fitting a mathematical function (based on the postulated reaction mechanism) to the raw data. The determination of these rate constants for chemiluminescence reactions highlighted the feasibility for utilising such measurements for quantitative analytical applications. The kinetic data were used to discriminate between analyte responses in order to determine the concentrations of individual analytes in a binary mixture. A preliminary, multi-component investigation performed on a binary mixture of codeine and 6-methoxy-codeine (1:1) successfully determined the concentrations of these individual components using such rate constant measurements. Consequently, variations in kinetics resulted in a significant difference between the relative chemiluminescence response based on peak area measurements and the relative response base on peak height measurements obtained using FIA. With regards to the observed reactivity of secondary amines and tertiary amines, chemiluminescence peak area determinations confirmed the vital role of pH on reaction efficiency, which was governed by structural features and kinetics. The tertiary amines investigated generally produced a greater emission under acidic conditions than the corresponding secondary amines. However, the measured chemiluminescence responses were highly dependent upon pH, with similar peak areas obtained for both amine groups under slightly alkaline conditions.
4

Optimalizace detekce klíčových genů biosyntetických drah alkaloidů u máku / Optimization of PCR detection of biosynthetic alkaloid pathway genes in opium poppy

SOUČKOVÁ, Sára January 2019 (has links)
The thesis deals with the creation of the biosynthetic pathways of selected alkaloids of opium poppy. Then is following the design primers for selected genes and optimization of PCR reaction of these genes for amplification and sequencing of the longest fragments. The PCR reaction was optimized for the 7OMT, TNMT and CODM genes. These genes are involved in biosynthetic pathways of morphine, codeine, papaverine, noscapine and sanguinarine. Each gene was split in half. The primers were designed separately for each half of the gene. Altogether were designed 13 pairs primers. 5 pairs primers were optimized by gradient PCR and gel electrophoresis. These primers were used for sequencing analysis.

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