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Analysis of pigments from integument of Graphosoma semipunctatum.
Krajíček, Jan ; Bosáková, Zuzana (advisor) ; Svobodová, Eva (referee)
Pterines belong to an important group of compounds, acting as pigments in many species. Some of them are probably responsible for characteristic coloration of the insect group (Hereroptera). This coloration is considered to be a visual warning signal for optically orientating predators (birds, lizards etc.). In this work, pterines in the species of Graphosoma semipunctatum have been investigated by high performance liquid chromatography. To develope an appropriate separation method, the reverse-phase separation mode with C18 stationary phase (Spherisorb ODS 2) and binary mobile phase (organic modifier/buffer or water) was used. The effect of type and content of organic modifiers (methanol, ethanol, tetrahydrofuran) and concentration of phosphate buffer pH 3.0 (10 - 30 mM) in the mobile phases on retention and separation behavior of the studied pterines (leukopterin, biopterin, xanthopterin, isoxanthopterin and erythropterin) was studied. Under the optimized separation conditions (5/95 (v/v) methanol/20 mM phosphate buffer, pH 3.0, flow rate 0.7 ml.min-1 , UV detection at 290 nm), the extract from the integument of Graphosoma semipunctatum was analyzed.
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The application of high-efficiency separation methods for chiral and achiral separations
Šubová, Martina ; Bosáková, Zuzana (advisor) ; Jelínek, Ivan (referee) ; Fischer, Jan (referee)
In the first part of the doctoral thesis, the capillary electrophoresis was used to test the potential chiral separation properties of monosubstituted cyclodextrin derivatives, namely PEMEDA- and PEMPDA-β-cyclodextrins for the group of selected analytes. Both selectors exhibited excellent enantioseparation properties for N-boc-D,L-tryptophan, where the enantiomers were completely separated even at 0.5 mmol·l-1 concentration of the cyclodextrin derivative in the background electrolyte. However, the differences between the enantiodiscrimination properties of individual derivatives were minimal. The second test group consisted of two cyclodextrin derivatives, namely 2-O- and 3-O- cinnamyl-α-cyclodextrins. These derivatives are able to form supramolecular polymers in aqueous solutions that disintegrate at elevated temperature. The formation of these polymers was tested by NMR and DLS experiments. None of the tested cyclodextrin derivatives showed enantiodiscrimination properties towards a group of selected analytes. In the frame of antipredatory study, HPLC-MS/MS method working in HILIC mode was used for separation of ten pterin derivatives and riboflavin, which can be present as pigments in insects, reptiles or amphibians as a part of their warning coloration. The developed methodology was applied for...
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The application of high-efficiency separation methods for chiral and achiral separations
Šubová, Martina
In the first part of the doctoral thesis, the capillary electrophoresis was used to test the potential chiral separation properties of monosubstituted cyclodextrin derivatives, namely PEMEDA- and PEMPDA-β-cyclodextrins for the group of selected analytes. Both selectors exhibited excellent enantioseparation properties for N-boc-D,L-tryptophan, where the enantiomers were completely separated even at 0.5 mmol·l-1 concentration of the cyclodextrin derivative in the background electrolyte. However, the differences between the enantiodiscrimination properties of individual derivatives were minimal. The second test group consisted of two cyclodextrin derivatives, namely 2-O- and 3-O- cinnamyl-α-cyclodextrins. These derivatives are able to form supramolecular polymers in aqueous solutions that disintegrate at elevated temperature. The formation of these polymers was tested by NMR and DLS experiments. None of the tested cyclodextrin derivatives showed enantiodiscrimination properties towards a group of selected analytes. In the frame of antipredatory study, HPLC-MS/MS method working in HILIC mode was used for separation of ten pterin derivatives and riboflavin, which can be present as pigments in insects, reptiles or amphibians as a part of their warning coloration. The developed methodology was applied for...
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Comprehensive analysis of warning and defense compounds of true bugs by high-performance separation methods
Krajíček, Jan
Insects have developed many strategies of defence against predators in the course of evolution. The evolutionarily oldest and most widely used type of defence is chemical defence, followed by acoustic or optical defence. However, many species of insects use simultaneously multiple types of warning signals, which affect different sensory receptors of the given predator. Such a complex method of warning signals is called multimodal method. It may consist of a combination of simultaneous chemical and optical signals, or a combination of acoustic and optical signalling. The combination of chemical and optical signalling used against a predator is probably the most common form of multimodal signalling. The presented work deals with the analysis of biologically active substances, which participate in the defence mechanisms of a widespread species of insects - true bugs (Heteroptera). Pterin derivatives represent a large group of natural compounds derived from pteridin, bicyclic heterocycle, and they are found in virtually all living organisms from bacteria to vertebrates. In insects, they primarily serve as pigments, resulting for example in striking coloration of cuticles of Heteroptera. The first part of the dissertation was focused on identification and quantification of pterin derivatives in cuticles...
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The application of high-efficiency separation methods for chiral and achiral separations
Šubová, Martina
In the first part of the doctoral thesis, the capillary electrophoresis was used to test the potential chiral separation properties of monosubstituted cyclodextrin derivatives, namely PEMEDA- and PEMPDA-β-cyclodextrins for the group of selected analytes. Both selectors exhibited excellent enantioseparation properties for N-boc-D,L-tryptophan, where the enantiomers were completely separated even at 0.5 mmol·l-1 concentration of the cyclodextrin derivative in the background electrolyte. However, the differences between the enantiodiscrimination properties of individual derivatives were minimal. The second test group consisted of two cyclodextrin derivatives, namely 2-O- and 3-O- cinnamyl-α-cyclodextrins. These derivatives are able to form supramolecular polymers in aqueous solutions that disintegrate at elevated temperature. The formation of these polymers was tested by NMR and DLS experiments. None of the tested cyclodextrin derivatives showed enantiodiscrimination properties towards a group of selected analytes. In the frame of antipredatory study, HPLC-MS/MS method working in HILIC mode was used for separation of ten pterin derivatives and riboflavin, which can be present as pigments in insects, reptiles or amphibians as a part of their warning coloration. The developed methodology was applied for...
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The application of high-efficiency separation methods for chiral and achiral separations
Šubová, Martina ; Bosáková, Zuzana (advisor) ; Jelínek, Ivan (referee) ; Fischer, Jan (referee)
In the first part of the doctoral thesis, the capillary electrophoresis was used to test the potential chiral separation properties of monosubstituted cyclodextrin derivatives, namely PEMEDA- and PEMPDA-β-cyclodextrins for the group of selected analytes. Both selectors exhibited excellent enantioseparation properties for N-boc-D,L-tryptophan, where the enantiomers were completely separated even at 0.5 mmol·l-1 concentration of the cyclodextrin derivative in the background electrolyte. However, the differences between the enantiodiscrimination properties of individual derivatives were minimal. The second test group consisted of two cyclodextrin derivatives, namely 2-O- and 3-O- cinnamyl-α-cyclodextrins. These derivatives are able to form supramolecular polymers in aqueous solutions that disintegrate at elevated temperature. The formation of these polymers was tested by NMR and DLS experiments. None of the tested cyclodextrin derivatives showed enantiodiscrimination properties towards a group of selected analytes. In the frame of antipredatory study, HPLC-MS/MS method working in HILIC mode was used for separation of ten pterin derivatives and riboflavin, which can be present as pigments in insects, reptiles or amphibians as a part of their warning coloration. The developed methodology was applied for...
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Comprehensive analysis of warning and defense compounds of true bugs by high-performance separation methods
Krajíček, Jan ; Bosáková, Zuzana (advisor) ; Feltl, Ladislav (referee) ; Ventura, Karel (referee)
Insects have developed many strategies of defence against predators in the course of evolution. The evolutionarily oldest and most widely used type of defence is chemical defence, followed by acoustic or optical defence. However, many species of insects use simultaneously multiple types of warning signals, which affect different sensory receptors of the given predator. Such a complex method of warning signals is called multimodal method. It may consist of a combination of simultaneous chemical and optical signals, or a combination of acoustic and optical signalling. The combination of chemical and optical signalling used against a predator is probably the most common form of multimodal signalling. The presented work deals with the analysis of biologically active substances, which participate in the defence mechanisms of a widespread species of insects - true bugs (Heteroptera). Pterin derivatives represent a large group of natural compounds derived from pteridin, bicyclic heterocycle, and they are found in virtually all living organisms from bacteria to vertebrates. In insects, they primarily serve as pigments, resulting for example in striking coloration of cuticles of Heteroptera. The first part of the dissertation was focused on identification and quantification of pterin derivatives in cuticles...
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Comprehensive analysis of warning and defense compounds of true bugs by high-performance separation methods
Krajíček, Jan
Insects have developed many strategies of defence against predators in the course of evolution. The evolutionarily oldest and most widely used type of defence is chemical defence, followed by acoustic or optical defence. However, many species of insects use simultaneously multiple types of warning signals, which affect different sensory receptors of the given predator. Such a complex method of warning signals is called multimodal method. It may consist of a combination of simultaneous chemical and optical signals, or a combination of acoustic and optical signalling. The combination of chemical and optical signalling used against a predator is probably the most common form of multimodal signalling. The presented work deals with the analysis of biologically active substances, which participate in the defence mechanisms of a widespread species of insects - true bugs (Heteroptera). Pterin derivatives represent a large group of natural compounds derived from pteridin, bicyclic heterocycle, and they are found in virtually all living organisms from bacteria to vertebrates. In insects, they primarily serve as pigments, resulting for example in striking coloration of cuticles of Heteroptera. The first part of the dissertation was focused on identification and quantification of pterin derivatives in cuticles...
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Analysis of pterine derivatives by capillary zone electrophoresis
Krajíček, Jan ; Bosáková, Zuzana (advisor) ; Čabala, Radomír (referee)
Pterins belong to an important group of compounds, acting as inhibitors, sensiziters, enzymes, coenzymes, pigments etc. and together with carotenoids and anthraquinones are responsible for characteristic coloration of bugs. This work was focused on the development of a capillary electrophoretic separation method for the analysis of six pterine derivatives, namely biopterine, neopterine, isoxanthopterine, leukopterine, xanthopterine and erythropterine and on their identification in the real samples. Separation was conducted in an uncoated fused-silica capillary termostated at 30 řC. Separation electrolyte contained boric acid, tris(hydroxymethyl)aminomethane and disodium salt of ethylenediaminetetraacetic acid. The effects of buffer pH, concentration of electrolyte components, separation voltage and wavelength of UV detection on electromigration behavior and detection sensitivity were studied. Under the optimized separation conditions, organic extracts of the three forms of Graphosoma semipunctatum bugs were analyzed.
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Analysis of pigments from integument of Graphosoma semipunctatum.
Krajíček, Jan ; Svobodová, Eva (referee) ; Bosáková, Zuzana (advisor)
Pterines belong to an important group of compounds, acting as pigments in many species. Some of them are probably responsible for characteristic coloration of the insect group (Hereroptera). This coloration is considered to be a visual warning signal for optically orientating predators (birds, lizards etc.). In this work, pterines in the species of Graphosoma semipunctatum have been investigated by high performance liquid chromatography. To develope an appropriate separation method, the reverse-phase separation mode with C18 stationary phase (Spherisorb ODS 2) and binary mobile phase (organic modifier/buffer or water) was used. The effect of type and content of organic modifiers (methanol, ethanol, tetrahydrofuran) and concentration of phosphate buffer pH 3.0 (10 - 30 mM) in the mobile phases on retention and separation behavior of the studied pterines (leukopterin, biopterin, xanthopterin, isoxanthopterin and erythropterin) was studied. Under the optimized separation conditions (5/95 (v/v) methanol/20 mM phosphate buffer, pH 3.0, flow rate 0.7 ml.min-1 , UV detection at 290 nm), the extract from the integument of Graphosoma semipunctatum was analyzed.
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