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Improving the bioremediation of leachate from biowaste
No full textU današnje vrijeme svijet se suočava s problemom različitog onečišćenja okoliša. Ljudske aktivnosti povećale su pritisak na prirodne resurse i postale izvor brojnih onečišćujućih tvari. Primjena bioloških procesa za obradu otpadnih voda kategorizira se kao zelena tehnologija zbog iskorištavanja potencijala mikrobioloških konzorcija. Mikroorganizmi su ključno rješenje za prevladavanje izazova jer zbog svoje iznimne metaboličke aktivnosti opstaju na svim područjima u biosferi. Bioremedijacija je biološki mehanizam obnavljanja onečišćenog okoliša te je uključena u razgradnju različitih onečišćujućih tvari iz okoline kroz sveobuhvatno djelovanje mikroorganizma. U ovom radu istraženo je poboljšanje bioremedijacije procjedne vode dobivene iz biootpada biostimulacijom te bioaugmentacijom procjedne vode pomoću egzogenih kultura termofilnih mikroorganizama u šaržnim uvjetima. Fizikalno-kemijskim i mikroskopskim analizama dobiven je uvid u tijek procesa biorazgradnje prisutnih organskih onečišćujućih tvari. Vrijednost pH kretala se u optimalnom području za rast bakterijskih kultura te je iznosila 7,2±1,5. Svjetlosnom mikroskopijom dobiven je brzi uvid u promjene sustava tijekom procesa bioremedijacije. Učinkovitost poboljšanja bioremedijacije procjedne vode iz biootpada iznosila je 91 %.Nowadays, the world is facing the problem of various environmental pollutions. Human activities have increased the pressure on natural resources and have become the source of numerous pollutants. The application of biological processes for wastewater treatment is classified as a green technology due to the use of the potential of microbiological consortia. Microorganisms are an important solution for addressing the challenges, as they are found in all areas of the biosphere due to their exceptional metabolic activity. Bioremediation is a biological mechanism to restore the polluted environment and deals with the degradation of various pollutants from the environment through the comprehensive action of microorganisms. This work investigated the improvement of bioremediation of leachate from biowaste by biostimulation and bioaugmentation of leachate with exogenous cultures of the thermophilic microorganisms under batch conditions. Physico-chemical and microscopic analyses provided insight into the course of the biodegradation process of the organic pollutants present. The pH value of 7.2±1.5 was in the optimal range for the bacterial growth. Light microscopy allows a quicker insight into the system changes during bioremediation process. The efficiency of the bioremediation improvement of biowaste leachate was 91%
Sorption of sulfamethoxazole - sulfametoxazole imprinted polymer vs. non-imprinted polymer
No full textSulfametoksazol je sulfonamidni antibiotik koji se najčešće koristi u humanoj medicini. Neučinkovito uklanjanje sulfametoksazola iz otpadnih voda tijekom postupaka obrade otpadnih voda, dovodi do njegove povećane prisutnosti u okolišu što može izazvati štetne učinke na okoliš, zdravlje ljudi i životinja. Jedan od najvažnijih procesa za uklanjanje farmaceutika iz okoliša je sorpcija. Stoga je u ovome radu ispitana sorpcija sulfametoksazola na polimeru sa i bez otiska molekule sulfametoksazola i utjecaj pH, temperature, ionske jakosti, mase sorbensa i matrice otpadne vode. Na temelju koeficijenata determinacije
(R^2 > 0,9999) i odličnog slaganja qe,exp s qe,calc, kinetiku sorpcije na oba sorbensa najbolje opisuje pseudokinetički model 2. reda. Za opis sorpcije pri svim navedenim uvjetima korištene su linearna, Freundlichova i Langmuirova izoterma, a rezultati pokazuju najbolje slaganje sa lineranim oblikom izoterme (R^2 > 0,99 za NIP, R^2 > 0,99 za MIP osim u tri slučaja gdje R^2 > 0,98). Vrijednost koeficijenta raspodjele (Kd) je pri svim ispitivanim utjecajima znatno veći za MIP nego za NIP što ukazuje na veći afinitet sorpcije sulfametoksazola na MIP-u. Također, dobivene vrijednosti faktora utiskivanja ukazuju na uspješno molekularno utiskivanje i veću sposobnost MIP-a za sorpciju sulfametoksazola u odnosu na NIP.Sulfamethoxazole is a sulfonamide antibiotic that is most commonly used in human medicine. The inefficient removal of sulfamethoxazole from wastewater during wastewater treatment leads to its increased presence in the environment, which can have a negative impact on the environment and human and animal health. One of the most important processes for the removal of pharmaceuticals from the environment is sorption. Therefore, the sorption of sulfamethoxazole on sulfamethoxazole-imprinted polymer and non-imprinted polymer and the influence of pH, temperature, ionic strength, sorbent mass and wastewater matrix were investigated in this work. Due to the coefficients of determination (R^2 > 0.9999) and the excellent agreement between qe,exp and qe,calc, the sorption kinetics on both sorbents are best described by the second-order pseudokinetic model. Linear, Freundlich and Langmuir isotherms were used to describe sorption under all conditions mentioned, and the results show the best compatibility with the linear form of the isotherm (R^2 > 0.99 for NIP, R^2 > 0.99 for MIP except in three cases where R^2 > 0.98). The partition coefficient (Kd) for all tested effects is significantly higher for MIP than for NIP, indicating a higher sorption affinity of sulfamethoxazole to MIP. The values obtained for the imprinting factor also indicate a successful molecular imprinting and a greater ability of MIP to sorb sulfamethoxazole compared to NIP
Using thermal methods in the optimization of drug product
No full textKorištenjem termičkih metoda poput termogravimetrijske analize (TGA) i diferencijalne pretražne kalorimetrije (DSC) istraživali smo međudjelovanja djelatne tvari, doksiciklina, i pomoćnih tvari, kao što su 2-hidroksipropil β-ciklodekstrin (kleptosa), natrijev hidrogen karbonat, polivinilpirolidon i askorbinska kiselina koje se koriste u oblikovanju farmaceutskih proizvoda. Na temelju istraživanja ustanovili smo koje pomoćne tvari reagiraju s djelatnom tvari te u kojoj mjeri ta interakcija ima stabilizacijski, odnosno destabilizacijski učinak. Strukturna analiza aktivne tvari provedena je u cilju identifikacije uzorka doksiciklin hiklata, korištenjem rendgenske difrakcije na polikristalnom uzorku. Dobiveni podaci uspoređeni su s kristalnim strukturama pohranjenima u kristalografskoj bazi podataka. Uvidom u kristalnu strukturu potvrđeno je da djelatna tvar sadrži dvije molekule doksiciklina u obliku hidrokloridne soli te jednu molekulu vode i etanola. Ustanovljeno je da formulacija koja sadrži kleptosu pokazuje veliku vjerojatnost interakcije između doksiciklina i ciklodekstrina, što bi moglo biti posljedica nastanka inkluzijskog kompleksa. U slučaju formulacije s polivinilpirolidonom nisu uočene promjene koje bi ukazivale na interakciju između doksiciklina i polimera. Dodavanje natrijevog hidrogenkarbonata u formulaciju sugerira moguću interakciju, koja se može ostvariti putem kationskih interakcija ili reakcijom hidrogenkarbonata s pozitivno nabijenim dijelovima molekula. Za smjesu doksiciklina i askorbinske kiseline, termička mjerenja pokazuju veliku vjerojatnost negativnog utjecaja askorbinske kiseline na stabilnost doksiciklina, što može dovesti do razgradnje spoja ili stvaranja nove kristalne forme. Provedeno istraživanje potvrdilo je hipotezu da termičke metode mogu poslužiti u odabiru pomoćnih tvari pogodnih za izradu formulacija, kao i pružiti ključne informacije o potencijalnim interakcijama koje mogu utjecati na stabilnost i učinkovitost konačnog farmaceutskog proizvoda.Using thermal methods such as thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), we investigated the interactions between the active substance, doxycycline, and excipients, such as kleptose, sodium hydrogen carbonate, ascorbic acid and K2S, which are used in the formulation of pharmaceutical products. Based on the research, we found out which excipients react with the active substance and to what extent this interaction has a stabilizing or destabilizing effect. The structural analysis of the active substance was carried out in order to identify the sample of doxycycline hyclate, using X-ray diffraction on a polycrystalline sample. The obtained data was compared with the crystal structures stored in the crystallographic database. An insight into the crystal structure confirmed that the active substance contains two molecules of doxycycline in the form of a chloride salt and one molecule of water and ethanol. It was found that the formulation containing kleptosa shows a high probability of interaction between doxycycline and cyclodextrin, which could be a consequence of the formation of an inclusion complex. In the case of the formulation with polyvinylpyrrolidone, no changes were observed that would indicate an interaction between doxycycline and the polymer. The addition of sodium hydrogencarbonate to the formulation suggests a possible interaction, which can be realized through cationic interactions or by the reaction of hydrogencarbonate with positively charged parts of the molecules. For the mixture of doxycycline and ascorbic acid, thermal measurements show a high probability of a negative influence of ascorbic acid on the stability of doxycycline, which may lead to the decomposition of the compound or the formation of a new crystalline form. The conducted research confirmed the hypothesis that thermal methods can serve in the selection of excipients suitable for creating formulations, as well as provide key information about potential interactions that can affect the stability and effectiveness of the final pharmaceutical product
The influence of advanced oxidation processes on ecotoxicity
No full textPraćenje ekotoksičnosti tijekom naprednih oksidacijskih procesa u obradi vode igra ključnu ulogu za očuvanje okoliša te u osiguravanju kvalitete vode za potrošnju. Napredni oksidacijski procesi, poput ozonizacije, UV/zračenja ili naprednih oksidacijskih postupaka s kisikom ili vodikovim peroksidom, sve su češće korišteni radi uklanjanja organskih onečišćenja iz vode. Međutim, ti procesi mogu generirati nusprodukte koji su toksični i mogu predstavljati potencijalnu prijetnju zdravlju ljudi. Stoga je praćenje ekotoksičnosti ključno kako bi se identificirali potencijalno štetni spojevi koji se formiraju tijekom ovih procesa. Cilj ovoga rada bio je ispitati ekotoksičnost prije i nakon uklanjanja izabranih ksenobiotika iz vode primjenomnaprednog oksidacijskog procesa fotolize uz dodatak vodikovog peroksida kao tehnologije u obradi voda. Izabrani ksenobiotici nalaze se u skupini anthelmintika (albendazol, febantel i mebendazol), te u skupini pesticida (acetamiprid, kloianidin i tiakloprid). Ispitivanja su se provodila pri pH-vrijednosti 4 i tri različite koncentracije vodikovog peroksida (20, 50 i 100 mM). Fotoliza otopina ksenobiotika koncentracije 10 mg L^-1 provodila se u Suntest CPS+ uređaju za simuliranje Sunčeve svjetlosti (UV/VIS), a pojedina se otopina fotolizirala u tri različita vremena (60, 180 i 300 min). Ekotoksičnost je ispitivana prema standardnoj metodi ISO 11348 – 3:2007 primjenom luminiscentne bakterije Vibrio fischeri. Rezultati ukazuju na sljedeći poredak ekotoksičnosti standardnih otopina ispitivanih ksenobiotika: acetamiprid>febantel>tiakloprid>klotianidin>albendazol>mebendazol. Smjese razgradnih produkata albendazola, febantela i mebendazola nisu pokazali znakove ekotoksičnosti. Oksidacijski proces UV/H2O2 pri ispitivanim koncentracijama pokazao se učinkovitim u razgradnji ovih anthelmintika bez ekotoksičnih nusprodukata. Acetamiprid, klotianidin i tiakloprid daju ekotoksične razgradne produkte, no u konačnici su se pri najvišoj koncentraciji oksidansa i najduljem vremenu izlaganja iste uklonile. Najekotoksičnije smjese produkata pokazao je klotianidin, potom acetamiprid te tiakloprid.Ecotoxicity monitoring during advanced oxidation processes in water treatment plays a key role in protecting the environment and in ensuring the quality of water for consumption. Advanced oxidation processes, such as ozonation, UV/irradiation, or advanced oxidation processes with oxygen or hydrogen peroxide, have increasingly been used to remove organic contaminants from water. However, these processes can generate byproducts that are toxic and can pose a potential threat to human health. Therefore, toxicity monitoring is essential to identify potentially harmful compounds that are formed during these processes. The aim of this study was to investigate the ecotoxicity before and after the removal of selected xenobiotics from water using an advanced oxidation process, photolysis with the addition of hydrogen peroxide, as a water treatment technology. The selected xenobiotics belong to the group of anthelmintics (albendazole, febantel, and mebendazole) and the group of pesticides (acetamiprid, clothianidin, and thiacloprid). The experiments were conducted at a pH value of 4 and with three different concentrations of hydrogen peroxide (20, 50, and 100 mM). The photolysis of xenobiotic solutions at a concentration of
10 mg L^-1 was carried out in the Suntest CPS+ device for simulating sunlight (UV-VIS), with each solution being photolyzed for three different durations (60, 180, and 300 min). The ecotoxicity was assessed according to the standard method ISO 11348 – 3:2007 using the luminescent bacteria Vibrio fischeri. Results indicate the following order of ecotoxicity of the tested xenobiotic standard solutions: acetamiprid>febantel>thiacloprid>clothianidin>albendazole>mebendazole. The degradation product mixtures of albendazole, febantel, and mebendazole showed no signs of ecotoxicity. The UV/ H2O2 oxidation process at the tested concentrations proved effective in degrading these anthelmintics without producing ecotoxic by-products. Acetamiprid, clothianidin, and thiacloprid produce ecotoxic degradation products, but these were ultimately removed at the highest oxidant concentration and longest exposure time. The most ecotoxic mixtures of degradation products were shown by clothianidin, followed by acetamiprid and thiacloprid
Isolation and characterization of glucose dehydrogenase from different microorganisms
No full textEnzim glukoza dehidrogenaza (GDH) pronalazi široku primjenu u različitim industrijama i znanstvenim istraživanjima. Koristi se u biokatalitičkim procesima za proizvodnju biovodika, ključna je komponenta u biosenzorima za mjerenje koncentracije glukoze u krvi, primjenjuje se u fermentacijskim procesima, gdje služi kao biokatalizator za pretvorbu glukoze u različite biokemikalije. U ovom istraživanju provedena je izolacija i karakterizacija enzima GDH porijeklom iz tri različita mikroorganizma, Saccharomyces cerevisiae, Bacillus subtilis i Pseudomonas sp.. Mikroorganizmi su kultivirani u kontroliranim laboratorijskim uvjetima, a tijekom uzgoja, praćena je promjena koncentracije biomase. Kada je biomasa ušla u stacionarnu fazu rasta, stanice su odvojene od podloge i ultrazvučno razbijene. U sirovim ekstraktima ispitana je aktivnost enzima GDH pri čemu je aktivnost zabilježena u biomasi S. cerevisiae i Pseudomonas sp. Dobiveni enzimi GDH dodatno su karakterizirani na način da im je određen pH i temperaturni optimum te skladišna stabilnost pri različitim temperaturama. Za enzim GDH porijeklom iz S. cerevisiae utvrđeno je da je optimalna temperatura, T = 35 °C, odnosno pH 8,8, dok je za enzim GDH porijeklom iz Pseudomonas sp. određena T = 40 °C, a pH 8,65. Ispitivanjem stabilnosti dobivenih enzima, utvrđeno je da je enzim GDH porijeklom iz oba izvora stabilniji pri nižim temperaturama (T = 4 °C) u odnosu na povišene temperature (T = 40 °C).Glucose dehydrogenase (GDH) is widely used in various industries and in scientific research. It is used in biocatalytic processes for biohydrogen production, serves as a key component in biosensors for measuring glucose concentration in the blood and is used in fermentation processes as a biocatalyst for converting glucose into various biochemicals. In this study, GDH enzymes were isolated and characterised from three different microorganisms, Saccharomyces cerevisiae, Bacillus subtilis and Pseudomonas sp.. The microorganisms were cultivated under controlled laboratory conditions and the biomass concentration was monitored during the cultivation process. When the biomass reached the stationary growth phase, the cells were separated from the medium and disrupted by ultrasonication. GDH activity was analysed in the crude extracts, and the activity was detected in the biomass of S. cerevisiae and Pseudomonas sp. The GDH obtained were further characterised by determining their pH and temperature optima as well as their storage stability at different temperatures. An optimum temperature of T = 35 °C and an optimum pH of 8.8 were determined for the GDH from S. cerevisiae. For the GDH from Pseudomonas sp. the optimal temperature was T = 40 °C and the optimal pH was 8.65. Stability tests showed that the GDH enzymes from both sources were more stable at lower temperatures (T = 4 °C) than at higher temperatures (T = 40 °C)
Electrochemical characterization of Methylene blue
No full textOvim radom ispitana su elektrokemijska svojstva metilenskog modrila na različitim elektrodama koristeći voltametriju linearne promjene potencijala i pravokutnovalnu voltametriju. Korištene su elektroda od staklastog ugljika i zlatna štapićasta elektroda te ugljikova i zlatna sitotiskana elektroda. Radne otopine potrebnih pH vrijednosti pripremljene su razrjeđenjem matične otopine na traženu koncentraciju te je provedeno mjerenje u optimalnim uvjetima. Mjerenjima su utvrđeni reakcijski mehanizmi metilenskog modrila na pojedinim elektrodama. Određena je i kontrola reakcije te je snimljen apsorpcijski spektar usporediv sa literaturnim vrijednostima.The study of this work was examining the electrochemical properties of methylene blue on different electrodes by using linear sweep voltammetry and square wave voltammetry. Electrodes of interest were glassy carbon and gold disk electrodes and carbon and gold screen printed electrodes. The working solutions were prepared by diluting the stock solution to a desired concentration using acid, buffer or base solutions, and measurements were conducted in optimal conditions. The reaction mechanisms of methylene blue on given electrodes were determined in accordance with measurement results. The established reaction control and the recorded absorption spectrum both give literature comparable values
Synthesis, spectroscopic characterization and biological activity of new thienobenzo-1,2,3-triazolium salts
No full textCilj ovog rada bio je sintetizirati nove derivate tienobenzo-triazolnih soli kako bi se ispitala njihova inhibicija na enzime kolinesteraza. Sintetski put sastojao se od četiri koraka. Prvi korak uključivao je sintezu triazolnih aldehida koji zatim sudjeluju u Wittigovoj reakciji. U toj reakciji, aldehidi reagiraju s fosforovim ilidom tvoreći alekene. U ovom slučaju, triazolni aldehidi reagiraju s 2-tienilnom soli pri čemu nastaju triazolni tienostilbeni. Tako dobiveni konjugirani sustav podložan je fotokemijskoj ciklizaciji. Pri osvjetljavanju triazolnih tienostilbena dolazi do zatvaranja šesteročlanog prstena, odnosno do nastanka tienobenzo-triazola. Produkti navedenih reakcija izolirani su i pročišćeni kolonskom kromatografijom na silika-gelu uporabom određenog sustava otapala. Na kraju, fotoprodukti se prevode u nabijene soli alkiliranjem triazolnog prstena pomoću bromida. Triazolne soli okarakterizirane su pomoću NMR i HRMS analize. Rezultati ispitivanja biološke aktivnosti pokazali su da spojevi 9 i 14 imaju najbolju inhibiciju enzima butirilkolinesteraze, s IC50 vrijednostima od 0,31 i 1,06 μM, što je za desetke puta bolja vrijednost od standardnog reverzibilnog inhibitora galantamina.The aim of this study was to synthesize new derivatives of thienobenzo-triazolium salts in order to evaluate their inhibitory activity on cholinesterase enzymes. The synthetic pathway consisted of four steps. The first step involved the synthesis of triazole aldehydes which then participate in the Wittig reaction. In this reaction, the aldehydes react with a phosphorus ylide to form alkenes. In this case, the triazole aldehydes react with 2-thienyl salts to yield triazole thienostilbenes. The resulting conjugated system is susceptible to photochemical cyclization. Upon irradiation of triazole thienostilbenes, a six-membered ring is formed, resulting in the formation of thienobenzo-triazoles. The products of the previously mentioned reactions were isolated and purified by column chromatography on silica-gel using a specific solvent system. Finally, the photoproducts were converted into charged salts by alkylation of the triazole ring using bromides. The triazolium salts were characterized by NMR and HRMS analysis. The results of the biological activity tests showed that compounds 9 and 14 exhibit the most potent inhibition of butyrylcholinesterase, with IC50 values of 0,31 and 1,06 μM, which is several dozen times better value than the standard reversible inhibitor galantamine
Novel 2-substituted benzimidazole derivatives as potential antitumor agents: synthesis and structural characterization
No full textU ovom radu opisana je sinteza novih derivata benzimidazola i strukturna karakterizacija 1H i 13C-NMR spektroskopijom s ciljem ispitivanja njihovog antitumorskog i antibakterijskog djelovanja. Ključni prekursori 4-O-alkilirani benzaldehidi (1-6) pripravljeni su reakcijom O-alkiliranja 4-hidroksibenzaldehida a odgovarajućim haloalkilirajućim reagensima u acetonitrilu, uz K2CO3 kao bazu. Reakcijom N-klormorfolina s natrijevim azidom priređen je N-azidoetilmorfolin (7). O-alkiliranjem 4-hidroksibenzaldehida s propargil-bromidom u suhom etanolu uz K2CO3 kao bazu sintetizirani su 4-O-propargilbenzaldehidi (8 i 9). Huisgenovom 1,3-dipolarnom ciloadicijom 4-O-propargilbenzaldehida (8 i 9) s N-azidoetilmorfolinom (7) uz Cu(OAc)2 kao katalizator pripavljeni su 1,2,3-triazolni derivati benzaldehida (10 i 11). Reakcijom ciklizacije potpomognutom ultrazvukom O-alkiliranih benzaldehida (1-6) uz K2CO3 kao bazu i Na2S2O5 priređeni su derivati benzimidazola s odgovarajućim arilnim supstituentima u položaju 2 benzimidazolnog prstena (12-14, 16-27, 29-35). Strukture svih pripravljenih spojeva potvrđene su 1H i 13C-NMR spektroskopijom. Farmakološki učinci i moguće biološke mete novopripravljenih spojeva predviđene su in silico analizom (PASS).This paper describe the synthesis of novel benzaldehyde derivatives and structural characterization by 1H and 13C-NMR spectroscopy in order to examine their antitumor and antibacterial activities. Key precursors 4-O-alkylbenzaldehydes (1-6) were prepared by reaction of O-alkylation 4-hydroxybenzaldehyde with corresponding haloalkylating reagents in the presence K2CO3 as base. In reaction of N-chloromorpholine with sodium azide N-azidoethylmorpholine (7) was obtained. O-alkylation reaction of 4-hydroxybenzaldehyde with propargyl bromide in dry ethanol with K2CO3 as a base gave 4-O-alkylbenzaldehydes (8-9). 1,2,3-triazole benzaldehyde derivatives (10 i 11) were synthesized by Huisgen 1,3-dipolar cycloaddition of O-alkylbenzaldehydes (8 i 9) and N-azidoethylmorpholine (7) in the presence of Cu(OAc)2 as catalyst. Benzimidazole derivatives substituted with appropriate aril substituents in position 2 of benzimidaze ring (12-14, 16-27, 29-35) were prepared by cyclization reaction of O-alkylbenzaldehydes (1-6) with K2CO3 as base and Na2S2O5 supported with ultrasound of The structures of all newly prepared compounds were confirmed by 1H and 13C-NMR spectroscopy. Pharmacological effects and possible biological targets of novel compounds are predicted by in silico analysis (PASS)
Green synthesis of quinoline and ferrocene conjugates using mechanochemistry
No full textU ovom radu opisana je sinteza novih konjugata 1,1'-disupstituiranih ferocena i kinolina povezanih 1,2,3-triazolilnom poveznicom (4a–d, 5a–d, 6a, 6b, 7a i 7b). 6-supstituirani derivati kinolona 1a–1d priređeni su Conrad-Limpachovom sintezom te su nadalje prevedeni u O- i N-propargilirane derivate kinolina, odnosno kinolona 2a–2d. Ciljani konjugati 1,1'-disupstituiranih ferocena i kinolina, odnosno kinolona 4a–d, 5a–d, 6a, 6b, 7a i 7b priređeni su bakrom(I) kataliziranom azid-alkin cikloadicijom propargiliranih derivata 2a–2d, 3a i 3b i bis-azidnih derivata ferocena u mehanokemijiskim uvjetima. Strukture novosintetiziranih spojeva potvrđene su 1H NMR i 13C NMR spektroskopijom, a naknadno će se provesti i antiproliferativna ispitivanja novosintetiziranih spojeva.In this work the syntesis of novel 1,1’-disubstituted ferrocene quinoline derivatives bridged via 1,2,3-triazole linker (4a–d, 5a–d, 6a, 6b, 7a and 7b) is described. 6-Substituted quinolone derivatives 1a–1d were prepared by the Conrad-Limpach method and further transformed to O- and N-propargylated derivatives 2a–2d. The target 1,1'-disubstituted ferrocene and quinoline or quinolone conjugates 4a–d, 5a–d, 6a, 6b, 7a and 7b were prepared by copper(I) catalysed azide-alkyne cycloaddition of propargylated derivatives 2a–2d, 3a and 3b with corresponding bis-azidoferrocene derivatives. The structures of all compounds were determined by 1H NMR and 13C NMR spectroscopy. Antiproliferative evaluations of these compounds will be performed
Synthesis of new benzoxazole derivatives using the concept of molecular hybridization
No full textU ovom radu opisana je sinteza novih derivata benzoksazola konceptom molekulske hibridizacije bakrom kataliziranom klik reakcijom u niskotemperaturnom eutektičkom otapalu (DES) te njihova strukturna karakterizacija 1H- i 13C-NMR spektroskopijom. Kondenzacijom odgovarajuće supstituiranih 4-hidroksibenzaldehida i 2-aminofenola sintetizirani su derivati Schiffovih baza 1-6 koji su nadalje ciklizacijom prevedeni u 2-arilbenzoksazole. Mikrovalovima potpomognutom reakcijom propargiliranja 2-arilbenzoksazola 7-12 s propargil-bromidom uz kalijev karbonat kao bazu sintetizirani su O-propargilirani derivati benzoksazola 13-18. Odgovarajući azidi 19-21 za klik reakciju pripravljeni su reakcijom 1-(2-kloretil)pirolidin-,
1-(2-kloretil)piperidin- i 1-(2-kloretil)morfolin-hidroklorida s natrijevim azidom. Reakcijom O-propargiliranih derivata benzoksazola 13-18 s odgovarajućim azidima 19-21
1,3-dipolarnom cikloadicijom kataliziranom bakrovim (I) jodidom u niskotemperaturnom eutektičkom otapalu (DES) kolin klorid (ChCl)/glicerol (1:2) dobiveni su ciljani 1,2,3-triazolni derivati benzoksazola 22-36 u iskorištenjima 21 - 83 %. Klik reakcijama derivata benzoksazola 13 s aromatskim azidima u eutektičkom otapalu ChCl/glicerol (1:2) dobiveni su 1,2,3-triazolni derivati benzoksazola 39 i 40 u dobrim iskorištenjima.This paper describes the synthesis of new benzoxazole derivatives by molecular hybridization via copper catalyzed click reactions in a deep eutectic solvent (DES) and their structural characterization by 1H- and 13C-NMR spectroscopy. Condensation of substituted 4-hydroxybenzaldehydes and 2-aminophenols yielded the corresponding Schiff bases 1-6 which were further converted to the corresponding 2-arylbenzoxazoles 7-12 by cyclization. O-propargylated benzoxazole derivatives 13-18 were synthesized by propargylation of the obtained 2-arylbenzoxazoles with propargyl bromide and potassium carbonate as the base. In a reaction of N-chloroethylpyrrolidine, N-chloroethylpiperidine and N-chloroethylmorpholine hydrochloride with sodium azide, the corresponding azides 19-21 were prepared. Reaction of O-propargylated benzoxazole derivatives with the corresponding azides by
1,3-dipolar copper-catalyzed cycloaddition in ChCl/glycerol (1:2) based DES yielded the target 1,2,3-triazole benzoxazole derivatives 22-36 in yields 21 - 83 %. Click reactions of benzoxazole derivative 13 with aromatic azides carried out in the ChCl/glycerol (1:2) DES yielded 1,2,3-triazole benzoxazole derivatives 39 i 40 in good yields