structure-properties relationship
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- MeSH
- krysa rodu rattus MeSH
- peptidy MeSH
- receptory neurotransmiterů MeSH
- Check Tag
- krysa rodu rattus MeSH
Štúdium lokálnych anestetík: časť 153: Vzťah medzi chemickou štruktúrou, fyzikálno-chemickými vlastnosťami a biologickou aktivitou v sérii piperidínopropylesterov alko-xysubstituovaných kyselín fenylkarbámovýchBoli stanovené fyzikálno-chemické parametre (povrchové napätie, disociačná konšt anta, RF a RMhodnoty – pomocou chromatografie na tenkej vrstve, logaritmus kapacitného faktora k pomocouHPLC) 30 látok zo skupiny piperidínopropylesterov kyselín o-, m-, p-alkoxyfenylkarbámovýchs lokálne-anestetickou aktivitou. Pomocou QSAR bol študovaný vzťah chemická štruktúra – fyzi-kálno-chemické vlastnosti – lokálno-anestetická aktivita. Výsledky štúdia ukázali, že medzi log k,RM a počtom C v alkoxysubstituente je lineárna závislosť.
Physical-chemical parameters (surface tension, dissociation constant, RF and R M values determinedby means of TLC, logarithm of the capacity factor by means of HPLC) of 30 compounds from thegroup of piperidinopropylesters of o-, m-, p-alkoxyphenylcarbamic acids with local-anaestheticactivity were determined. The correlation chemical structure – physical-chemical properties –local-anaesthetic activity was studied by means of QSAR. The results of the study have d emonstra-ted a linear dependence between log k, RM, and the number of C in the alkoxysubstituent.
V rámci systematického studia derivátů kyseliny fenylkarbamové s účinkem lokálně anestetickýmbyla připravena série 1-metyl-2-piperidinoetylesterů kyselin 2-, 3- a 4-alkoxy (metoxy až decyloxy)fenylkarbamových a nesubstituovaný derivát, tedy 1-metyl-2-piperidinoetylester kyseliny fenylkar-bamové. U připravené série látek se studoval vzájemný vztah povrchové lokálně anestetické aktivitya některých fyzikálních a fyzikálně-chemických parametrů (g, pKa, pH zákalu, log P, p, RMr, log k’)a kvantifikoval se metodou analýzy QSAR. Do korelace byly vzaty i sterické konstanty L a B4,molární refrakce (MR), valenční indexy molekulové konektivity ( 1 c v ), počet uhlíků alkoxysubstitu-enta (Cx) a molekulová hmotnost (Mr). Studiem se zjistilo, že lineární vztah je mezi počtem uhlíkůalkoxysubstituenta (Cx), tabelovanými nebo vypočítanými hodnotami (Mr, L, B4, MR, 1 c v ) a experi-mentálně získanými fyzikálně-chemickými parametry (RMr, log P, p, log k’, pH zákalu, pKa).
Within the framework of a systematic study of phenylcarbamic acid derivatives with local anaes-thetic effects, a series of 1-methyl-2-piperidinoethylesters of 2-, 3- and 4-alkoxy(methoxy to decylo-xy)phenylcarbamic acids and an unsubstituted derivative, i.e. 1-methyl-2-piperidinoethylester ofphenylcarbamic acid, were prepared. In the prepared series of compounds, the mutual relationshipof the surface local anaesthetic activity and some physical and physico-chemical parameters (g, pKa,pH of turbidity, log P, p, RMr, log k’) was studied and quantified by the method of QSAR analysis.The steric constants L and B4, molar refraction (MR), valence indices of molecular connectivity ( 1 c v ),the number of carbons of the alkoxysubstituent (Cx) and molecular mass (Mr) were also correlated.The study has revealed that there exists a linear relation between the number of the carbons of thealkoxysubstituent (Cx), tabulated or calculated values (Mr, L, B4, MR, 1 c v ) and experimentallyobtained physico-chemical parameters (RMr, log P, p, log k’, pH of turbidity, pKa).
Compared to other cereal or tuber starches, wheat starch shows mainly two different types of granules, the A-starch and B-starch, which are separated in starch processing. These types differ not only in size or shape but also in chemical structure of amylopectin, arrangement in granules, and lipid and protein contents. Chemical composition and structure of starch influence on physicochemical properties (specific surface, crystallinity, gelatinization characteristics) and functionality. Processing of B-starch (filtration, drying) is problematic for its small particles. Nevertheless, the challenge for other uses of B-starch has been taken up in designing new technological processes. Hence B-starch becomes a valuable raw material in other processes. Examples of its applications in enzymatic processes producing syrups, in modifications affording tailor-made starches, for flavour carriers, baking, extrusion and, last but not least, in biodegradable polymers are given.
Enzymes have a wide range of applications in different industries owing to their high specificity and efficiency. Immobilization is often used to improve biocatalyst properties, operational stability, and reusability. However, changes in the structure of biocatalysts during immobilization and under process conditions are still largely uncertain. Here, three microscopy techniques - bright-field, confocal and electron microscopy - were applied to determine the distribution and structure of an immobilized biocatalyst. Free enzyme (haloalkane dehalogenase), cross-linked enzyme aggregates (CLEAs) and CLEAs entrapped in polyvinyl alcohol lenses (lentikats) were used as model systems. Electron microscopy revealed that sonicated CLEAs underwent morphological changes that strongly correlated with increased catalytic activity compared to less structured, non-treated CLEAs. Confocal microscopy confirmed that loading of the biocatalyst was not the only factor affecting the catalytic activity of the lentikats. Confocal microscopy also showed a significant reduction in the pore size of lentikats exposed to 25% tetrahydrofuran and 50% dioxane. Narrow pores appeared to provide protection to CLEAs from the detrimental action of cosolvents, which significantly correlated with higher activity of CLEAs compared to free enzyme. The results showed that microscopy can provide valuable information about the structure and properties of a biocatalyst during immobilization and under process conditions.
- MeSH
- biokatalýza MeSH
- dioxany farmakologie MeSH
- furany farmakologie MeSH
- hydrolasy chemie metabolismus MeSH
- mikroskopie metody MeSH
- proteiny červů chemie metabolismus MeSH
- Schistosoma japonicum enzymologie MeSH
- stabilita enzymů MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
