Synthesis of 2,6-diazabicyclo[2.2.2]octane derivatives

2,6-Diazabiciklo[2.2.2]oktāna atvasinājumu sintēze. Pelšs J., zinātniskie vadītāji Dr. chem., vadošais pētnieks Žalubovskis R., Dr. chem., doc. Kļimenkovs I. Maģistra darbs, 51 lappuses, 7 attēli, 17 tabulas, 29 literatūras avoti, 1 pielikums. Latviešu valodā. Darbā ir veikta 2,6-diazabiciklo[2.2.2]oktān-3,5-ditionu sintēze reakcijā starp 2,6 diazabiciklo[2.2.2]oktān-3,5-dioniem un Lavesona reaģentu, kā arī iegūto biciklisko ditioamīdu alkilēšana, kuras rezultātā iegūti 3,5-bis(metiltio)-2,6-diazabiciklo[2.2.2]okta-2,5-diēni. Ir veikta arī 5-selēnokso-2,6-diazabiciklo[2.2.2]oktān-3-onu sintēze reakcijā ar Vūlinsa reaģentu. Literatūras apskatā ir apkopota informācija no pēdējo gadu publikācijām par tioimidātu un tioimīnija sāļu reducēšanas, alkilēšanas un aminēšanas reakcijām.Synthesis of 2,6-diazabicyclo[2.2.2]octane derivatives. Pelšs J., scientific supervisors Dr. chem., principal scientist Žalubovskis R., Dr. chem., doc. Kļimenkovs I. Master’s thesis, 51 pages, 7 figures, 17 tables, 29 literature references, 1 appendix. In Latvian. In this work, 2,6-diazabicyclo[2.2.2]octane-3,5-dithiones were synthesized in a reaction between 2,6-diazabicyclo[2.2.2]octane-3,5-diones and Lawesson’s reagent. The resulting bicyclic dithioamides were alkylated to yield 3,5-bis(methylthio)-2,6-diazabicyclo[2.2.2]octa-2,5-dienes. 5-Selenoxo-2,6-diazabicyclo[2.2.2]octane-3-ones were synthesized in a reaction between 2,6-diazabicyclo[2.2.2]octane-3,5-diones and Woolins’ reagent. The latest information on the reduction, alkylation and amination of thioimidates and thioiminium salts was collected in the literature review

Synthesis of 2,6-diazabicyclo[2.2.2]octan-3,5-diones

2,6-Diazabiciklo[2.2.2]oktān-3,5-dionu sintēze. Pelšs J., zinātniskie vadītāji Dr. chem., vadošais pētnieks Žalubovskis R., Grandāne A., Dr. habil. chem. prof. Zicmanis A. Bakalaura darbs, 46 lappuses, 3 attēli, 18 tabulas, 28 literatūras avoti. Latviešu valodā. Darbā ir veikta 2,6-diazabiciklo[2.2.2]oktān-3,5-dionu sintēze trīskomponentu viena reaktora reakcijā. Tika sintezēta virkne 2,6-diazabiciklo[2.2.2]oktān-3,5-dionu ar dažādiem alkil- un arilaizvietotājiem pie bicikla C-1 un C-8 atomiem. Iegūto savienojumu struktūra tika pierādīta ar KMR spektroskopiju. 2,6-Diazabiciklo[2.2.2]oktān-3,5-diona reģioizomēra bicikliskā struktūra tika apstiprināta ar rentgenstruktūranalīzi. 2,6-DIAZABICIKLO[2.2.2]OKTĀN-3,5-DIONS, TRĪSKOMPONENTU REAKCIJA, AMĪDU IEKŠMOLEKULĀRĀ CIKLIZĀCIJA.Synthesis of 2,6-diazabicyclo[2.2.2]octane-3,5-diones. Pelšs J., scientific supervisors Dr. chem., principal scientist Žalubovskis R., Grandāne A., Dr. habil. chem. prof. Zicmanis A. Bachelor’s thesis, 46 pages, 3 figures, 18 tables, 28 literature references. In this work, 2,6-diazabicyclo[2.2.2]octane-3,5-diones were synthesized by a way of a three-component one-pot reaction. A series of 2,6-diazabicyclo[2.2.2]octane-3,5-diones with a variety of subtituents at the C-1 and C-8 atoms of the bicyclic structure. The structure of the synthesized compunds was confirmed by NMR spectra. The bicyclic structure of the regioisomer of 2,6-diazabicyclo[2.2.2]octane-3,5-dione was also confimed by X-ray structure analysis. 2,6-DIAZABICYCLO[2.2.2]OCTANE-3,5-DIONE, THREE-COMPONENT REACTION, INTRA-MOLECULAR CYCLIZATION OF AMIDES

Release of Anticancer Drug Doxorubicin from Biodegradable Polymer Coated Porous Hydroxyapatite Scaffolds

In the current research slow release anticancer drug delivery system was prepared and drug release kinetics in vitro evaluated. Porous hydroxyapatite (HAp) as carrier material and doxorubicin hydrochloride (DOX) as anticancer agent was used. DOX is an anthracycline drug commonly used in cancer chemotherapy. Unfortunately, its therapeutic potential is restricted cardiotoxicity and resistance developed by the tumor cells to the molecule after treatment. To prepare HAp-DOC composites, the porous bioceramic scaffolds were impregnated with doxorubicin in low vacuum conditions. 10% (HAp-10%PLA) and 20% (HAp-20%PLA) poly lactic acid and 20% (HAp-20%PCL) poly(e-caprolactone) solutions in dichloromethane were used to form the polymer coatings on the drug/bioceramic composites. In general there was a burst release observed from all the samples during the first 2 hours followed by a much reduced release profile. In the next 5 days the drug release from all the samples decreased in the following order: 20% PLA (from 56 ng/ml to 3 ng/ml), 20% PCL (from 196 ng/ml to 6 ng/ml), 10% PLA (from 497 ng/ml to 18 ng/ml). HAp-DOX composite without the polymer coating demonstrated the drug release reduction from 230 ng/ml to 13 ng/ml. The cumulative drug release was observed over 19 days

Bioceramic Hydroxyapatite Granules for Purification of Biotechnological Products

Sorption experiments of bovine serum albumin (BSA) on hydroxyapatite (HAp) ceramic granules, prepared at three temperatures 900°C, 1000°C and 1150°C were performed at room temperature 18,6 °C and phosphate buffer, pH 5,83; 6.38 and 7,39. Thermal treatment contributed to the decrease of bovine serum albumin immobilization indicating that sorption process depended on HAp ceramics specific surface area and pH values of phosphate buffer solution. However, it was confirmed that granule size was also an important parameter for bovine serum albumin adsorption. As a result of these experiments, the most appropriate adsorption conditions and phosphate buffer pH values influence on to BSA sorption were analyzed