Synthesis and characterization of long-chain tartaric acid diamides as novel ceramide-like compounds

molecule

New synthetic strategies for xanthene-dye-appended cyclodextrins

Xanthene dyes can be appended to cyclodextrins via an ester or amide bridge in order to switch the fluorescence on or off. This is made possible through the formation of nonfluorescent lactones or lactams as the fluorophore can reversibly cyclize. In this context we report a green approach for the synthesis of switchable xanthene-dye-appended cyclodextrins based on the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM). By using 6-monoamino-β-cyclodextrin and commercially available inexpensive dyes, we prepared rhodamine- and fluorescein-appended cyclodextrins. The compounds were characterized by NMR and IR spectroscopy and MS spectrometry, their UV–vis spectra were recorded at various pH, and their purity was determined by capillary electrophoresis. Two potential models for the supramolecular assembly of the xanthene-dye-appended cyclodextrins were developed based on the set of data collected by the extensive NMR characterization

Identification of Triterpenes and β-sitosterol in the Bark of Plane Tree Extracts

Plane tree is planted as ornamental tree in urban areas. This tree naturally sheds its bark during the spring; however, the shed bark is commonly regarded as a waste material without any significant application.On the other hand, the bark of plane tree may be an important source of industrially relevant compounds, most notably betulinic acid. In our study a Supercritical Fluid Ultra Performance Convergence Chromatography (UPC2) system coupled with Evaporative Light Scattering Detector (ELSD), along with conventional HPLC, GC-MS and NMR were successfully utilized to analyze triterpenes in the extracts from the bark of plane tree. We show that not only betulinic acid, but other important triterpenes: betulin, betulinic aldehyde and β-sitosterol are also present in the extract of the plane tree bark. Among these the main compound is betulinic acid, with up to an order of magnitude larger concentration than the other constituents. The applied extraction method has a significant role on the concentration of the different compounds in the extracts. Most notably, neat scCO2 is not suitable to extract the polar betulinic acid, however betulin and betulinic aldehyde can be extracted selectively

Bio- és gyógyszermolekulák mikrospeciációja = Microspeciation of bio- and drug molecules

A kutatás csoportosított eredményei az alábbiak: 1) Új elvek és módszerek bio- és gyógyszermolekulák mikrospeciációjában 1)a) A mikroszkópikus lipofilitás meghatározása, különös tekintettel az ikerionos és töltésmentes protonáltsági izomerekre A hatóanyagok felszívódásában kulcsfontosságú mikroszkópikus lipofilitás jellemzéséhez levezettük a szükséges összefüggéseket és meghatároztuk konkrét értéküket több jelentős molekulára (morfin, tiroxin, nifluminsav, vinpocetin) 1)b) Torzításmentes, erősen lúgos oldatokban is használható, NMR alapú pH-meghatározási módszerkidolgozása és alkalmazása 2) Bio-, gyógyszer- és gyógyszerjelölt molekulák részecskéinek receptor-kötési vizsgálata in silico módszerekkel 3) Biomolekulák metabonomikai analízise 4) Biológiai alapmolekulák (szerotonin, tiroxin, arginin) mikrospeciációja 5) Néhány hatóanyag (cetirizin, famotidin, tolperizon, fluorokinolonok) mikrospeciációja 6) Bio- és gyógyszermolekulák ciklodextrin komplexeinek részecske-specifikus egyensúlyi és szerkezeti jellemzése 7) Új gyógyszerjelölt vegyületek szintézise és jellemzése 8) Összefoglaló közlemények megjelentetése a témakörben Ezen eredmények 31 közlemény és egy könyvrészlet formájában jelentek meg jelentős nemzetközi folyóiratokban ( J. Med. Chem, J. Proteom. Res, Anal. Bioanal. Chem, J. Pharm. Biomed. Anal., Eur, J. Pharm. Sci., Electrophoresis, Tetrahedron Letters, stb.) | Results of the funded research can be sorted as follows: 1) New principles and methods in the microspeciation of bio and drug molecules 1)a) Determination of microscopic lipophilicity, with special regard to the noncharged and zwitterionic protonation isomers. Physicochemical relationships of microscopic lipophilicity, the key parameter in pharmacokinetics have been deduced, and real microscopic lipophilicities have been determined for such important molecules as morphine, thyroxin, niflumic acid, vinpocetine. 1)b) Elaboration and application of an undistorted, NMR-based pH determination method that can be used in highly basic solutions too. 2) Receptor-binding studies on bio-, drug and drug candidate molecules, by in silico techniques. 3) Metabonomic analysis of biomolecules 4) Microspeciation of some fundamental biomolecules (serotonin, thyroxin, arginin) 5) Microspeciation of some therapeutic agents (cetirizin, famotidin, tolperizon, fluorokinolons9 6) Species-specific equilibrium and structural characterization of cyclodextrin complexation of bio- and drug molecules 7) Synthesis and characterization of new drug candidates 8) Publishing related review papers These results have been published as 31 papers and one book chapter in prestigious international journals, including J. Med. Chem., J. Proteome. Res, Anal. Bioanal. Chem, J. Pharm. Biomed. Anal., Eur, J. Pharm. Sci., Electrophoresis, Tetrahedron Letters