|
|
Analytical chemistry unravels the diversity and function of chemicals used for communication and defence in termite societies
Krasulová, Jana ; Bosáková, Zuzana (advisor) ; Pacáková, Věra (referee) ; Lapčík, Oldřich (referee)
Analytical chemistry plays a crucial role in studies on chemical ecology and only the development of sophisticated methods enables the detection of biologically active compounds that are usually present in minute quantities and often in very complex mixtures. My thesis is dedicated to the application of modern analytical techniques and instrumentation to unravel the identity, chemical diversity and function of semiochemicals and defensive compounds used by various species of termites. The first section of this thesis aims at the identity of chemicals used in communication, the pheromones. I studied the chemistry of the trail-following communication in three selected species of termites. Besides the identification of (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol, the most frequent termite trail-following pheromone, as the trail-following pheromone in Psammotermes hybostoma (Rhinotermitidae), I participated in the description of two new structures, (10Z,13Z)-nonadeca-10,13-dien-2-one in Glossotermes oculatus (Serritermitidae) and syn-4,6-dimethylundecan-1-ol in Hodotermopsis sjoestedti (Archotermopsidae). We identified (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol to be the female sex pheromone in Psammotermes hybostoma, and syn-4,6-dimethylundecanal to be the male sex pheromone in Hodotermopsis sjoestedti. I also...
|
|
|
The Impact of Selected Endocrine Disruptors on Human Spermatogenesis
Vítků, Jana ; Hill, Martin (advisor) ; Pohanka, Michal (referee) ; Lapčík, Oldřich (referee)
Steroid hormones in testis play an important role in spermatogenesis, maintenance of the male reproductive tract, production of semen and the maintenance of secondary sex characteristics and libido. They are also discussed as a target for substances called endocrine disruptors (EDs). No complex study was conducted on evaluation of relationships between EDs and steroid spectrum in 2 biological fluids; seminal plasma and plasma. The aim of the PhD. thesis was to develop and validate a method for determination of bisphenol A (BPA) and steroid spectrum in plasma and seminal plasma and to shed more light into mechanisms of ED action and effects of BPA and polychlorinated biphenyls (PCBs) on human spermatogenesis and steroidogenesis. Two new liquid-chromatography mass spectrometry methods for determination of BPA and 11 steroids in plasma and seminal plasma were developed and validated. The methods were used for estimation of analyte concentrations in 191 men with a different degree of fertility. Concurrently, the levels of six congeners of PCBs, gonadotropins, selenium and zinc in plasma were estimated. Partial correlations adjusted for age and BMI were calculated to evaluate relationships between these analytes. Seminal BPA, but not plasma BPA, was negatively associated with sperm concentration...
|
guest ::
