|
|
Synthesis of modified and labeled acylceramides
Havrišák, Tomáš ; Opálka, Lukáš (advisor) ; Pour, Milan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Candidate: Tomáš Havrišák Supervisor: PharmDr. Lukáš Opálka, Ph.D Title of diploma thesis: Synthesis of modified and labeled acylceramides Upper most layer of skin, stratum corneum is providing effective barrier which protects us from impact of environment. Extracellular lipids of stratum corneum are mostly composed of ceramides, free atty acids and cholesterol. Earlier it was suggested that these lipids are highly rigid, which enables sufficient barrier function. But presently, it is known that some structural parts of these lipids are more fluid. So far, ultralong ceramides (also known as acylceramides), lipids which are necessary for correct barrier function still remain partly unexplored. Mobility of sphingosine part and linoleic ester have already been studied, but mobility of the ultralong chain is speculative. Obtaining information about mobility of particular parts of acylceramides is difficult because of their unavailability with required labelling. Our aim was to prepare acylceramides with deuterium-labelled half of their ultralong chain between carbons C17 - C32 from commercially available perdeuterated compounds. From available options we chose 1,12-dibromodocecane and...
|
|
|
Synthesis and study of 1-O-acylceramides
Jon, Vojtěch ; Vávrová, Kateřina (advisor) ; Opálka, Lukáš (referee)
The extracellular matrix of the uppermost layer of the skin, the stratum corneum (SC), consists of ceramides (Cer), cholesterol (Chol), free fatty acids (FFA) and cholesteryl sulfate (CholS). Cer play an important role in the correct barrier function of mammalian epidermis. A new type of sphingolipids, i.e., 1-O-acyl-Cer, have been found in human SC very recently; however, their role in the SC is unknown. These Cer species contain sphingosine (S) that is N- acylated with non-hydroxylated or α- hydroxylated fatty acid, and moreover, hydroxyl group at C1 in sphingosine is esterified by an additional fatty acid (lignoceric acid, C24 or palmitic acid, C16). Because 1-O-acyl-Cer are not commercially available, we aimed to synthesize physiological 1-O-acyl Cer, i.e., Cer-24NS16, Cer-16NS16 and Cer-24AS16. Moreover, we aimed to study their behaviour on permeability and microstructure of model skin lipid membranes. The 1-O-acyl-Cer were synthesized by an acylation of Cer-NS16 or Cer-AS16 with palmitic or lignoceric acid using N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide and 4- dimethylaminopyridine. Cer-AS16 was prepared by α-bromination of palmitic acid, substitution of bromine by hydroxyl and N-acylation of sphingosine by the prepared acid in the presence N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide...
|
|
|
Synthesis and study of 1-O-acylceramides
Jon, Vojtěch ; Vávrová, Kateřina (advisor) ; Opálka, Lukáš (referee)
The extracellular matrix of the uppermost layer of the skin, the stratum corneum (SC), consists of ceramides (Cer), cholesterol (Chol), free fatty acids (FFA) and cholesteryl sulfate (CholS). Cer play an important role in the correct barrier function of mammalian epidermis. A new type of sphingolipids, i.e., 1-O-acyl-Cer, have been found in human SC very recently; however, their role in the SC is unknown. These Cer species contain sphingosine (S) that is N- acylated with non-hydroxylated or α- hydroxylated fatty acid, and moreover, hydroxyl group at C1 in sphingosine is esterified by an additional fatty acid (lignoceric acid, C24 or palmitic acid, C16). Because 1-O-acyl-Cer are not commercially available, we aimed to synthesize physiological 1-O-acyl Cer, i.e., Cer-24NS16, Cer-16NS16 and Cer-24AS16. Moreover, we aimed to study their behaviour on permeability and microstructure of model skin lipid membranes. The 1-O-acyl-Cer were synthesized by an acylation of Cer-NS16 or Cer-AS16 with palmitic or lignoceric acid using N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide and 4- dimethylaminopyridine. Cer-AS16 was prepared by α-bromination of palmitic acid, substitution of bromine by hydroxyl and N-acylation of sphingosine by the prepared acid in the presence N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide...
|
|
|
Synthesis and evaluation of human 6-hydroxyceramides
Majcher, Adam ; Opálka, Lukáš (advisor) ; Krátký, Martin (referee)
Title of the Master thesis: Synthesis and evaluation of human 6-hydroxyceramides Candidate: Adam Majcher Supervisor: PharmDr. Lukáš Opálka, Ph.D. Consultant: PharmDr. Andrej Kováčik, Ph.D. Charles University, Faculty of Pharmacy in Hradec Králové Skin Barrier Research Group, Department of Organic and Bioorganic Chemistry Ceramides (Cer), the members of sphingolipid family, occur in all human cells and play an important role in cell signaling. In high concentrations, Cer can also be found in the uppermost layer of epidermis called stratum corneum, along with free fatty acids and cholesterol (in equimolar ratio), where they form the intercellular multi-lamellar lipid matrix. The key function of stratum corneum is to ensure a permeability barrier, thus, to provide water and electrolyte homeostasis, and to prevent entry of harmful substances into the organism. Cer are composed of a sphingoid base and an acyl part derived from a long-chain fatty acid. Cer based on 6-hydroxysphingosine (H) are amongst the most unusual sphingolipids. In contrast to sphingosine-based Cer, 6-hydroxysphingosine-based Cer (H-Cer) are unique for the epidermis and, in addition, H-Cer are not typical for all mammals. Moreover, the function and biosynthesis of H-Cer in the skin is still not completely understood. Several...
|
|
|
Synthesis of new types of succinimides as a potential adjuvant
Božiková, Slavomíra ; Roh, Jaroslav (advisor) ; Opálka, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Student: Slavomíra Božiková Supervisor: doc. PharmDr. Jaroslav Roh, Ph.D. Consultant: RNDr. Dávid Maliňák, PhD Title of Diploma Thesis: Synthesis of new types of succinimides as a potential adjuvant Adjuvants represent a big group of the compounds used for the increased immune response to vaccines. This whole concept of these helper substances is more than 80 years old. The first finding that started the research of more substances was the alternative system of the aluminium salt. Important group of adjuvants are substances, which activate the immunity system to increased reaction after stimulation of toll-like receptors (TLRs) that are present in the human body. These receptors are considered as one of the most important immunity molecules. The best examined receptors of this group is the TLR4 receptor that binds various ligands. The most important ligands are the lipopolysaccharide of Gram-negative bacteria. Mechanisms of the interaction of these ligands with TLR4 are being examined recently. In my thesis I focused on the TLR4 receptors and on the synthesis of new molecules of the succinimide type, which eventually can stimulate these receptors and be potential adjuvants.
|
|
|
Substituted benzoxazoles - synthesis and biological activity
Opálka, Lukáš ; Vinšová, Jarmila (advisor) ; Vávrová, Kateřina (referee)
There were 14 compounds prepaired, including 7 Schiff bases and 7 substitued benzoxazoles. The compounds were characterised by 1 H NMR, 13 C NMR, IR, TLC and by melting point. All the new compounds aren't described in Reaxys or in Chemical Abstracts, so they can be considered as original compounds. The reaction was done in two steps. First, the Schiff base was made by the condensation of proper aminophenol and benzaldehyde and in second step, the Schiff base was cyclized by lead (IV) acetate.
|
|
|
Use of lactones in acylceramide synthesis
Moravčík, Štefan ; Opálka, Lukáš (advisor) ; Roh, Jaroslav (referee)
6 Abstract Acylceramides, subgroup of ceramides with ultralong chains, are essential component of extracellular lipid matrix in the uppermost skin layer, stratum corneum. They have crucial role in mammalian survival on dry land. Deeper understanding of their function in physiology of pathophysiology of the skin and their therapeutic potential are hampered by their limited availability. Analysis of the skin surface lipids of the ass (E. asinus) has shown, that these lipids contain up to 56% of unbranched ω-lactones (equolides), from which 51.2% is mono- unsaturated dotriacontanolide and 41.3% is mono-unsaturated triacontanolide. Carbon chain length of these lactones match the most common length of carbon chain in acylceramides (30 and 32 carbon atoms) therefore they could be used in their total synthesis. Aim of this thesis was to isolate mono-unsaturated ω-lactone with 32 carbon chain (dotriacontanolide) from the mixture of donkey skin surface lipids, followed by hydrogenation and transformation to the suitable precursor (succinmidyl ester) in order to find the easiest synthetic path in its conversion to acylceramides. We have tried many synthetic pathways. From direct aminolysis of lactone, through reaction with N-hydroxysuccinimide in various reaction conditions to opening of the lactone to the potassium...
|
|
|
Synthesis of human ω-O-acylceramides and evaluation of their effects on barrier properties of skin lipid membranes
Opálka, Lukáš ; Vávrová, Kateřina (advisor) ; Hampl, František (referee) ; Kučerka, Norbert (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Inorganic and Organic chemistry Candidate: Mgr. Lukáš Opálka Supervisor: doc. PharmDr. Kateřina Vávrová, Ph.D. Title of doctoral thesis: Synthesis of human ω-O-acylceramides and evaluation of their effects on barrier properties of skin lipid membranes The main objective of this work was to synthesize and study human acylceramides (acylCer, ceramides of the EO type) with the focus on the relationships between the acylCer concentration , structure of their polar head, their ability to form lamellar phases and permeability of model lipid membranes. Another objective was to synthesize ceramide-1-phosphates for the study of their signaling role in skin barrier and an analogue of ganglioside GM1 with shorter acyl chain as a standard for analysis of these lipids. Ceramides (Cer) belong to the family of sphingolipids. They are the central molecules in sphingolipid metabolism, they participate on cell regulatory processes and the formation of human skin lipid barrier. The main skin barrier is situated in the stratum corneum (SC), which is the uppermost layer of skin. The purpose of SC is to maintain homeostasis of the inner environment and to prevent the penetration of exogenous substances, allergens and bacteria to the...
|
|
|
Synthesis and evaluation of human 6-hydroxyceramides
Majcher, Adam ; Opálka, Lukáš (advisor) ; Krátký, Martin (referee)
Title of the Master thesis: Synthesis and evaluation of human 6-hydroxyceramides Candidate: Adam Majcher Supervisor: PharmDr. Lukáš Opálka, Ph.D. Consultant: PharmDr. Andrej Kováčik, Ph.D. Charles University, Faculty of Pharmacy in Hradec Králové Skin Barrier Research Group, Department of Organic and Bioorganic Chemistry Ceramides (Cer), the members of sphingolipid family, occur in all human cells and play an important role in cell signaling. In high concentrations, Cer can also be found in the uppermost layer of epidermis called stratum corneum, along with free fatty acids and cholesterol (in equimolar ratio), where they form the intercellular multi-lamellar lipid matrix. The key function of stratum corneum is to ensure a permeability barrier, thus, to provide water and electrolyte homeostasis, and to prevent entry of harmful substances into the organism. Cer are composed of a sphingoid base and an acyl part derived from a long-chain fatty acid. Cer based on 6-hydroxysphingosine (H) are amongst the most unusual sphingolipids. In contrast to sphingosine-based Cer, 6-hydroxysphingosine-based Cer (H-Cer) are unique for the epidermis and, in addition, H-Cer are not typical for all mammals. Moreover, the function and biosynthesis of H-Cer in the skin is still not completely understood. Several...
|
|
|
Synthesis of phosphoramidate prodrugs "ProTides" as novel potential therapeutic agents for the treatment of congenital disorders of glycosylation and mitochondrial DNA depletion syndrome
Sedláková, Jana ; Roh, Jaroslav (advisor) ; Opálka, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Organic And Bioorganic Chemistry Candidate: Jana Sedláková Supervisors: Dr. Fabrizio Pertusati doc. PharmDr. Jaroslav Roh, Ph.D. Title of diploma thesis: Synthesis of phosphoramidate prodrugs "ProTides" as novel potential therapeutic agents for the treatment of congenital disorders of glycosylation and mitochondrial DNA depletion syndrome At the present time, no effective treatment is available neither for the most of the congenital disorders of glycosylation (CDGs) nor the mitochondrial DNA depletion syndrome (MDS). Regarding the CDG therapy, D-mannose-1-phosphate (Man-1-P) offers considerable pharmacological potential to improve the pathological patterns in patients affected by phosphomannomutase 2 deficiency (PMM2-CDG), similarly as N-acetyl-D-mannosamine-6-phosphate (ManNAc-6-P) in case of GNE myopathy (GNEM). Administration of selected deoxyribonucleotides was proposed as a potential pharmacological strategy for the treatment of MDS. Unfortunately, the problematic membrane penetration of such polar molecules reduces their effect and limits their clinical application. Hydrophobic, membrane permeable derivatives of the sugar monophosphates and nucleotides, might represent more efficient potential therapeutics for CDGs and...
|
guest ::
