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Molecular self-assembly and self-replication of short amphiphilic peptides
No full textCilj ovog rada bio je sintetizirati i okarakterizirati spoj (S)-11-(2-heptanamido-3-(1H-imidazol-4-il)propanamido)-N-(piridin-4-ilmetil)undekanamid hidroklorid (7a), derivat
L-histidina (L-His), kao potencijalni gelator male molekulske mase (LMWG, eng. low molecular weight gelator) amfifilnih svojstava. Ispitan je potencijal molekulskog samoudruživanja ciljanog spoja, odnosno formiranja hidrogelova, kao i sposobnost koordinacije Zn2+. Nadalje, istražena je katalitička aktivnost novosintetiziranog spoja pri hidrolitičkoj reakciji raspada p-nitrofenil acetata (p-NPA) na p-nitrofenol (p-NP), koja modelira proces hidrolize prirodnih estera u biološkim sustavima. Prethodno sintetizirani spojevi, strukturni analozi spoja 7a s različitom aminokiselinom (7b – derivat L-fenilalanina, 7c – derivat L-fenilglicina i 7d – derivat L-triptofana) također su ispitani na mogućnost stvaranja kompleksa sa Zn2+ i katalitičko djelovanje. Mjerenja su provedena metodama UV/Vis spektroskopije. Novosintetizirani spoj 7a u svojoj strukturi sadrži dug alifatski lanac, aminokiselinu L-His i terminalni 4-pikolilamin. Njegova priprava uspješno je provedena u 7 stupnjeva: 1. zaštićivanje 11-aminoundekanske kiseline (AUDA) Boc-skupinom (1);
2. aktivacija spoja 1 pomoću N-hidroksisukcinimida (NHS) (3); 3. supstitucija sukcinimidne skupine spoja 3 za 4-pikolilamin (4); 4. uklanjanje Boc-zaštitne skupine sa spoja 4 (5);
5. sinteza spoja 2 iz L-His i heptanoil-klorida; 6. kondenzacijska reakcija spojeva 5 i 2 (6);
7. prevođenje spoja 6 u hidrokloridnu sol (7a). Ciljani spoj 7a ispitan je na mogućnost geliranja deionizirane vode i fosfatnog pufera pri čemu ne tvori hidrogel, već koloidnu otopinu, dok spojevi 7b, 7c i 7d uspješno tvore hidrogelove. Svi ispitivani spojevi pokazali su mogućnost koordinacije Zn2+, kao i katalitički učinak u hidrolitičkoj reakciji nastanka p-NP iz p-NPA, uz potrebnu dodatnu optimizaciju metode.The aim of the study was to synthesize and characterize compound (S)-11-(2-heptanamido-3-(1H-imidazol-4-yl)propanamido)-N-(pyridin-4-ylmethyl)undecanamide hydrochloride (7a), a derivative of L-histidine (L-His), as a potential low molecular weight gelator (LMWG) of amphiphilic properties. The target compound was examined for its molecular self-assembly potential, i.e. formation of hydrogels, as well as the ability to coordinate Zn2+. Furthermore, the catalytic activity of the newly synthesized compound was investigated through the reaction of hydrolytic conversion of p-nitrophenyl acetate (p-NPA) to p-nitrophenol (p-NP), which models the process of natural ester hydrolysis reaction in biological systems. Previously synthesized compounds, structural analogues of compound 7a with altered amino acids (7b – L-phenylalanine derivative, 7c – L-phenylglycine derivative and 7d – L-tryptophan derivative) were also investigated for the possibility of forming complexes with Zn2+ and catalytic action. Measurements were carried by UV/Vis spectroscopy. Newly synthesized compound 7a contains a long aliphatic chain, amino acid
L-His and terminal 4-picolylamine. Its preparation was successfully carried out in 7 steps:
1. protection of 11-aminoundecanoic acid (AUDA) with a Boc group (1); 2. activation of compound 1 by N-hydroxysuccinimide (NHS) (3); 3. substitution of the succinimide group of compound 3 for 4-picolylamine (4); 4. removal of the Boc-protective group from compound 4 (5); 5. synthesis of compound 2 from L-His and heptanoyl-chloride; 6. condensation reaction between compounds 5 and 2 (6); 7. conversion of compound 6 into a hydrochloride salt (7a). The targeted compound 7a was evaluated for the possibility of gel formation with deionized water and phosphate buffer, whereby a colloidal solution was formed, while compounds 7b, 7c and 7d successfully form hydrogels. All tested compounds showed the possibility of Zn2+ coordination, as well as catalytic activity in the hydrolytic reaction of p-NP formation from
p-NPA, with necessary additional method optimization
Synthesis and spectroscopic characterization of novel acrylonitrile benzoxazole derivatives as potential sensors for pH in solutions
No full textU ovom radu provedena je sinteza novih akrilonitrilnih derivata benzoksazola. Nadalje, sintetizirani derivati 10-13 spektroskopski su okarakterizirani kako bi se utvrdila mogućnost njihove primjene kao potencijalnih optičkih pH senzora u otopinama. Sinteza spojeva 10-13 provedena je uobičajenim reakcijama organske kemije temeljenih na načelima zelene kemije, te reakcijom potpomognutom mikrovalovima. Aktivacijom malonitrila 1 uz TMSCl
(trimetilsilil-klorid) 2 i etanol, priređen je etil-2-cijano-acetamidat-hidroklorid 3. Glavni prekursor, tj. 2-cijanometilbenzoksazol 5 sintetiziran je reakcijom 2-aminofenola 4 i spoja 3 korištenjem dviju različitih metoda, u talini i reakcijom potpomognutom mikrovalovima. Ciljani akrilonitrilni derivati benzoksazola 10-13 dobiveni su Knoevenagelovom reakcijom, između
2-cijanometilbenzoksazola 5 i odgovarajućih benzaldehida 6-9 u vodi kao otapalu i uz korištenje K2CO3 u reaktoru za paralelnu sintezu. Sintetizirani spojevi 10-13 okarakterizirani su UV/Vis spektroskopijom u sedam organskih otapala različitih polarnosti, te UV/Vis pH titracijama u otopinama pufera različitih pH vrijednosti. Strukture spojeva 10-13 potvrđene su 1H i 13C NMR spektroskopijom. Provedena ispitivanja pokazala su bitne promjene spektroskopskih svojstava spojeva 10-13 ovisno o polarnosti otapala te promjeni pH vrijednosti, što ukazuje na moguću potencijalnu primjenu sintetiziranih spojeva kao optičkih pH senzora u otopinama.This work represents the synthesis of novel acrylonitrile derived benzoxazoles. Onwards, synthesized derivatives 10-13 were spectroscopically characterized in order to determine their possibility for the application as potential optical pH sensors in solutions. The synthesis of compounds 10-13 was carried out by common reactions of organic chemistry based on the principles of green chemistry and by microwave assisted reaction. By activating malonitrile 1 with TMSCl (trimethylsilyl chloride) 2 and ethanol, ethyl-2-cyano-acetamidate-hydrochloride 3 was prepared. The main precursor, i.e. 2-cyanomethylbenzoxazole 5 was synthesized by the reaction of 2-aminophenol 4 and compound 3 using two different methods, reaction in melt and microwave assisted reaction. Targeted acrylonitrile derived benzoxazole 10-13 were obtained by the Knoevenagel reaction, from
2-cyanomethylbenzoxazole 5 and the corresponding benzaldehydes 6-9 in water as a solvent and using K2CO3 in a reactor for parallel synthesis. The synthesized compounds 10-13 were characterized by UV/Vis spectroscopy in seven organic solvents with different polarity, and UV/Vis pH titrations with buffered solutions of different pH values. The structures of compounds 10-13 were confirmed by 1H and 13C NMR spectroscopy. Conducted experiments showed significant changes in the spectroscopic properties of compounds 10-13 with a change of the polarity and pH values, which indicates the possible potential use of the synthesized compounds as optical pH sensors in solutions
Chemical influence of the production of cosmetics on the environment
No full textKozmetička sredstva su proizvodi koji se koriste svaki dan. Oni mogu sadržavati prirodne ili sintetičke sastojke, a neki od njih negativno utječu na okoliš. Kozmetička industrija ima značaj utjecaj na okoliš kroz cijeli proizvodni ciklus, od proizvodnje, pakiranja pa sve do upotrebe proizvoda. Tijekom proizvodnje dolazi do ispuštanja stakleničkih plinova, a preko otpadnih voda spojevi kao što su: parabeini, ftalati, triklosan, aluminij i fotoreproduktivna sredstva dospijevaju u okoliš i onečišćuju ga. Velik problem stvara i otpad koji se unatoč regulacijama i zakonima i dalje nepravilno odlaže. U budućnosti je potrebno raditi na novim tehnološkim inovacijama koje će omogućiti ponovno upotrebu različitih sirovina u proizvodnim procesima. Danas sve više tvrtki pokušava voditi društveno odgovorno poslovanje unutar svoje kompanije, a predvodnici u tome su kompanije Henkel i Procter&Gamble.Cosmetic products are used every day. They can contain natural or synthetic ingredients, and some of them have a negative impact on the environment. The cosmetics industry has a significant impact on the environment throughout the entire production cycle, from production, packaging to product use. During production, greenhouse gases are released, and compounds such as parabens, phthalates, triclosan, aluminium and UV filters enter the environment through wastewater and pollute it. A major problem is also caused by waste that, despite regulations and laws, continues to be improperly disposed. In the future, it is necessary to work on new technological innovations that will enable the reuse of various materials in production processes. Today, more and more companies are trying to conduct socially responsible business within their company, and the leaders in this area are companies: Henkel and Procter&Gamble
Overview and perspective of AEM electrolysis process control
No full textZeleni vodik, koji je potpuno čisti energent, ističe se kao učinkovita zamjena fosilnih goriva te se smatra jednim od najperspektivnijih održivih izvora energije u borbi protiv klimatskih promjena. Prednost vodikove energije, u usporedbi s drugim oblicima obnovljivih izvora energije, je mogućnost njenog dugotrajnog skladištenja i akumulacije te trošenja na zahtjev. Najčešća metoda dobivanja zelenog vodika je elektroliza vode uz korištenje električne energije iz obnovljivih izvora. Među raznim istraženim tehnologijama elektrolize, kao što su alkalna elektroliza (engl. alkaline electrolysis – AE), elektroliza s protonsko propusnom membranom (engl. proton exchange membrane – PEM) te elektroliza s čvrstim oksidom (engl. solid oxide electrolysis – SOE), prisutni su problemi, kao što su neučinkovitost, niska ekonomičnost i konstrukcijski problemi. Posljednjih nekoliko godina sve veću pozornost privlači nova metoda elektrolize s anionsko propusnom membranom (engl. anion exchange membrane – AEM). U ovoj tehnologiji upotrebljavaju se jeftinije komponente za izradu katalizatora i polimernih membrana što omogućuje ekonomičniju proizvodnju vodika. Iako je razvoj takve tehnologije napredovao, potrebna su daljnja istraživanja s ciljem poboljšanja stabilnosti i energetske učinkovitosti. U radu je dan pregled i analiza dosadašnjih postignuća temeljenih na procesu proizvodnje zelenog vodika AEM elektrolizom. Opisano je vođenje procesa i prikazana je mjerno regulacijska tehnika.Green hydrogen, a completely clean energy source, stands out as an efficient alternative to fossil fuels and is considered one of the most promising sustainable energy sources in the fight against climate change. Compared to other renewable energy sources, hydrogen has the advantage that can be stored for the long term and used on demand. The most common method of obtaining hydrogen is water electrolysis using electricity from renewable sources. Among the various electrolysis technologies that have been researched, such as alkaline electrolysis – AE, proton exchange membrane – PEM and solid oxide electrolysis – SOE, there are problems such as inefficiency, low cost effectiveness and design problems. Over the last years, increasing attention has been given to a new electrolysis method using an anion exchange membrane – AEM. This technology utilizes cheaper components for the production of catalysts and polimer membranes, making hydrogen production more costeffective. Although the development of AEM technology has made progress in recent years, further research is needed to improve its stability and energy efficiency. This thesis analyzes the progress made in hydrogen production by AEM water electrolysis. It explains the control of this process, with particular attention to measurement and control techniques
New carbamate derivatives of resveratrol - synthesis, spectroscopic characterization, physico-chemical properties and cholinesterase inhibition
No full textCilj ovog rada je sinteza novih karbamatnih derivata rezveratrola koji bi se potencijalno mogli koristiti u liječenju neurodegenerativnih poremećaja zbog sposobnosti inhibiranja enzima kolinesteraza. Poznato je da rezveratrol ima iznimna biološka djelovanja, stoga se njegova struktura modificira i nadograđuje uvođenjem karbamatne skupine u svrhu poboljšavanja biološke aktivnosti, inhibicije kolinesteraza te same apsorpcije molekule u organizam. Karbamatni spojevi se sve više koriste kao strukturni elementi lijekova i prolijekova, upravo zbog svojih kemijskih, bioloških i farmakokinetičkih svojstava te iznimne stabilnosti. Novi karbamatni derivati su sintetizirani iz analoga rezveratrola (prethodno pripremljenih u našem laboratoriju), preko čije hidroksilne skupine je uvedena karbamatna skupina reakcijom s karbamoil-kloridom. Stoga, temeljna struktura sintetiziranih molekula je stilbenski skelet, odnosno tiofenski prsten povezan trans-dvostrukom vezom s fenilnim prstenom, gdje se u ortho- ili meta-položaju nalazi karbamatna skupina. Dobiveni spojevi su se pročistili ekstrakcijom i kolonskom kromatografijom. Većinom su nastali stabilniji trans-izomeri, a tamo gdje to nije slučaj je došlo do potpune ili djelomične izomerizacije. U sklopu ovog završnog rada ispitan je i drugi pristup u sintezi karbamata koji uključuje karbonilaciju imidazola u vodi. Strukture dobivenih molekula potvrdile su se spektroskopskim metodama (NMR) te su uzorci poslani na HRMS analizu. Na temelju rezultata bioloških ispitivanja najbolju inhibicijsku aktivnost prema enzimu butirilkolinesterazi je pokazao spoj 4 čija IC50 vrijednost iznosi 0,54 μM. Za navedeni spoj su dobiveni negativni rezultati genotoksičnosti.The aim of this work was the synthesis of new carbamate derivatives of resveratrol that could potentially be used in the treatment of neurodegenerative disorders due to their ability to inhibit cholinesterase enzymes. It is well known that resveratrol exhibits remarkable biological activities; therefore, its structure is modified and further developed by introducing a carbamate group to enhance its biological activity, cholinesterase inhibition, and the overall absorption of the molecule in the body. Carbamate compounds are increasingly used as structural elements in drugs and prodrugs, precisely due to their chemical, biological, and pharmacokinetic properties as well as their exceptional stability. The new carbamate derivatives were synthesized from resveratrol analogues (previously prepared in our laboratory), in which the carbamate group was introduced via the hydroxyl group through reaction with carbamoyl chloride. Accordingly, the fundamental structure of the synthesized molecules is a stilbene scaffold, i.e., a thiophene ring connected via a trans double bond to a phenyl ring, where the carbamate group is in either the ortho- or meta-position. The obtained compounds were purified by extraction and column chromatography. In most cases, the more stable trans-isomers were formed, while in other instances complete or partial isomerization occurred. As part of this study, an alternative approach to the synthesis of carbamtes was also investigated. It involves the carbonylation of imidazole in water. The structures of the synthesized molecules were confirmed by spectroscopic methods (NMR) and the samples were sent for HRMS analysis. Based on the results of the biological assays, compound 4 exhibited the best inhibitory activity against butyrylcholinesterase, with an IC50 value of 0.54 μM. Negative results for genotoxicity were obtained for this compound
Mechanochemical synthesis of double inorganic salts
No full textMehanokemijska sinteza je sinteza inducirana vanjskom mehaničkom energijom, primjerice mljevenjem dviju ili više tvari u čvrstom stanju. Mehanička energija koja je primijenjena na krutinu uzrokuje kidanje jakih veza, što omogućuje tvorbu novih veza. Mehanokemijska sinteza omogućava sintezu bez otapala ili uz znatno smanjenu količinu otapala, čineći ju ekološki prihvatljivijom alternativom naspram klasičnih metoda sinteze. U ovom radu provedene su preliminarne sinteze kalijevih bakrovih(I) halidnih dvostrukih soli. Kalijeve bakrove(I) halidne dvostruke soli imaju raširenu primjenu u optoelektronici. Sinteze su provedene u vibracijskom kugličnom mlinu IST500. Dobiveni spojevi identificirani su difrakcijom na prahu te im je ispitana ionska provodnost.Mechanochemical synthesis is synthesis induced by external mechanical energy, for example by grinding two or more substances in a solid state. Mechanical energy applied to a solid causes strong bonds to break, allowing new bonds to form. Mechanochemical synthesis enables synthesis without solvents or with a significantly reduced amount of solvents, making it a more environmentally friendly alternative to classical synthesis methods. In this paper, preliminary syntheses of potassium copper(I) halide double salts were carried out. Potassium copper(I) halide double salts are widely used in optoelectronics. The syntheses were carried out in a vibrating ball mill IST500. The obtained compounds were identified by powder diffraction and their ionic conductivity was tested
The novel benzazole derivatives: synthesis and structural characterization
No full textU ovom radu opisana je sinteza novih derivata benzimidazola (4-6) i benzotiazola (7-10) supstituiranih s 1,2,3-triazolom te njihova strukturna karakterizacija 1H i 13C-NMR spektroskopijom. 4-O-propargilbenzaldehid (1) pripravljen je reakcijom O-alkiliranja
4-hidroksibenzaldehida potpomognutom mikrovalnim zračenjem s propargil-bromidom u suhom etanolu uz K2CO3 kao bazu. Derivati benzimidazola (2) i benzotiazola (3) s terminalnom alkinilnom skupinom sintetizirani su reakcijom kondenzacije
4-klorbenzen-1,2-diamina ili 2-aminotiofenola s 4-O-propargilbenzaldehidom (1) u DMF-u uz oksidans Na2S2O5. Bakrom kataliziranom klik reakcijom O-propargiliranog derivata benzimidazola (2) s odgovarajućim azidobenzenom u kugličnom mlinu pripremljeni su
1,4-disupstituirani derivati benzimidazola (4- 6). Derivati benzotiazola supstituirani s
1,2,3-triazolom (7-10) sintetizirani su mehanokemijskom klik reakcijom O-propragiliranog derivata benzotiazola (3) i različito supstituiranih aromatskih azida. Strukture svih novopripravljenih spojeva potvrđene su 1H i 13C-NMR spektroskopijom.This work presents synthesis of novel benzimidazole (4-6) and benzothiazole (7-10) derivatives substituted with 1,2,3-triazole and their structural characterization by 1H and
13C-NMR spectroscopy. 4-O-propargylbenzaldehide (1) was prepared by O-alkylation reaction 4-hydroxybenzaldehyde under microwave irradiation with propargyl bromide in dry ethanol with K2CO3 as a base. Benzimidazole (2) and benzothiazole (3) derivatives with terminal alknyl group were synthesized by condensation reaction of
4-chlorobenzene-1,2-diamine or 2-aminothiophenol with 4-O-propargylbenzaldehyde (1) in DMF with Na2S2O5 as oxidant. Copper-catalyzed click reaction of O-propargylated benzimidazole derivative (2) with the corresponding azidobenzene in a ball mill were prepared 1,4-disubstituted benzimidazole derivatives (4-6). Benzothiazole derivatives substituted with 1,2,3-triazole (7-10) were synthesized by mechanochemical click reaction of O-propragylated benzothiazole derivative (3) and variously substituted aromatic azides. Structures of all newly prepared compounds were confirmed by 1H and 13C-NMR spectroscopy
Analysis and simulation of industrial process control
No full textU kemijskim procesima od laboratorija do složenih procesnih postrojenja većina procesnih veličina kontinuirano se mijenja. Posljedica je to dinamičkog vladanja procesa na koji često utječu poremećaji. Vođenje procesa je potrebno kako bi se proces održao na željenom radnom području te kako bi se kompenzirali poremećaji koji utječu na proces, a time i na kvalitetu proizvoda i procesnu opremu koja se zbog velikih oscilacija može oštetiti. Ovim završnim radom analiziraju se industrijski primjeri vođenja procesa. Pri tome se provelo ugađanje regulatora na primjeru kaskadne regulacije. Također se analiziralo kako sljepljivanje regulacijskog ventila i vanjski poremećaji utječu na stabilnost regulacijskog kruga. Primjenom proporcionalnog i integracijskog djelovanja regulatora analizirani su procesi s velikim i malim zadrškama, procesi s kaskadnim vođenjem, kao i procesi s poremećajima i mehaničkim problemima sljepljivanja izvršnih elemenata kakvi se susreću u industriji.In chemical processes from laboratories to complex process plants, most process variables are continuously changing. This is due to complex process dynamics often affected by disturbances. Process control is necessary in order to maintain the process in the desired working conditions, and to compensate the disturbances affecting the process, product quality and process equipment. In this baccalaureus thesis industrial examples of process control were analysed. Cascade control loops tuning, the effect of valve stiction and other disturbances on the control loops were examined. Using controller proportional and integral action, processes with large and small delays, cascade control, as well as processes with disturbances and mechanical issues were analysed
Supporting information: Coumarin-modified Ruthenium Complexes: Synthesis, Characterization and Antiproliferaive Activity against Gastrointestinal Malignancies
No full textSupporting information for the scientific paper entitled:
Coumarin-modified ruthenium complexes: synthesis, characterization and antiproliferative activity against malignant diseases of the digestive syste
Polymerization of flavonoids catalysed by T. versicolor laccase
No full textFlavonoidi su prirodni fitokemijski spojevi koji se nalaze u biljkama. Ključni su za brojne biološke funkcije te igraju važnu ulogu u biljnom metabolizmu. Antioksidativna i antimikrobna svojstva flavonoida usko su povezana s njihovom kemijskom strukturom, a poseban utjecaj na njihovu aktivnost ima stupanj polimerizacije. Polimerni oblici flavonoida pokazuju jača antioksidativna i antimikrobna svojstva, te bolju toplinsku stabilnost. U okviru provedenih istraživanja flavonoidi su polimerizirani pomoću enzima lakaza porijeklom iz gljive T. versicolor poznate pod nazivom puranov rep. Polimerizacija je provedena u dvije vrste reaktora: šaržnom reaktoru i protočnom mikroreaktoru. Tijekom provedbe reakcije polimerizacije praćen je utjecaj reakcijskog vremena odnosno vremena zadržavanja na karakteristične veličine procesa, konverziju, učinkovitost procesa polimerizacije i procesnu stabilnost lakaze. Oligomerna struktura dobivenih polimera, odnosno broj monomera koji čine strukturu produkta, potvrđena je infracrvenom spektroskopijom s Fourierovom transformacijom (FTIR), UV-Vis spektroskopijom (UV-Vis) te kapljevinskom kromatografijom visoke djelotvornosti (HPLC).Flavonoids are natural phytochemical compounds found in plants. They are important for numerous biological functions and play a significant role in plant metabolism. The antioxidant and antimicrobial properties of flavonoids are closely linked to their chemical structure, with the degree of polymerization having a particular influence on their activity. Polymerized forms of flavonoids exhibit stronger antioxidant and antimicrobial properties, as well as better thermal stability. In this study, flavonoids were polymerized using the enzyme laccase produced by the fungus Trametes versicolor, commonly known as turkey tail. The polymerization was carried out in two types of reactors: a batch reactor and a flow microreactor. While performing the polymerization reaction, the effects of reaction time or residence time on key process parameters such as conversion, polymerization efficiency, and enzyme process stability were monitored. The oligomeric structure, i.e., the number of monomers forming the structure, was confirmed by Fourier Transform Infrared Spectroscopy (FTIR), UV-Vis Spectroscopy (UV-Vis), and High Performance Liquid Chromatography (HPLC)