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Karakterizacija zečijeg antiseruma proizvedenog na rekombinantni protein Ara h 2 iz kikirikija biohemijskim i imunohemijskim metodama
No full textKroz rad je prikazana karakterizacija antitela koja su dobijena imunizacijom kunića Ara h 2 proteinom i njihova primena u ELISA testu sa peroksidazom i alkalnom fosfatazom, kao i u Western blot analizi
Structural patterns and cytotoxic activity of dinuclear Cu(II), Ni(II) and Cd(II) complexes with pyridine-based malonic acid dihydrazone
No full textA dinuclear Cu(II) complex, [Cu2(L)(H2L)](ClO4)2·4H2O (Cu-1), with a condensation derivative of 2-acetylpyridine and malonic acid dihydrazide (H2L), was obtained through a direct synthesis. After recrystallization, the single-crystalline product was characterized by single crystal X-ray diffraction analysis, EPR, UV/Vis and IR spectroscopy. In the resulting dimeric Cu(II) complex, one ligand molecule is coordinated in its dianionic form, while the other is coordinated in its neutral form. Both ligands adopt a bis-tridentate coordination mode through an NNO donor atom set. Perchlorate ions and water molecules are in the outer coordination sphere, consistent with the conductometric measurement. The coordination geometry around the Cu(II) ion is distorted octahedral. Comparative structural analysis using FIM (Full interaction map) methodology and Hirshfeld surface analysis, along with 2D fingerprint plots of intermolecular interactions revealed significant structural differences among Cu-1 and previously synthesized Ni(II) complexes [Ni2(HL)H2L](ClO4)3∙3DMSO (Ni-1) and [Ni2(H2L)2](ClO4)4∙4DMSO·EtOH (Ni-2), as well as Cd(II) complex [Cd2(H2O)2(H2L)2](ClO4)4·4H2O (Cd-1). Finally, the cytotoxic activities of these dinuclear complexes were evaluated with comparisons drawn based on their half-maximal inhibitory concentration values
Degradation of fluoroquinolone antibiotic levofloxacin by UV-induced ferric ion photolysis in aqueous medium: The role of pH and chelation
No full textThe increased use of fluoroquinolone antibiotic levofloxacin (LVX) contributes to its significant presence as a pollutant in water and soil environments and the consequent need for developing efficient water processing methods for its degradation and removal. The understanding of coordination and photo-chemistry of LVX in the presence of ferric ions enables potential improvements of iron-based advanced oxidation processes (AOPs) for wastewater treatment. Herein, the pH-dependence of LVX chelation with ferric ions was investigated by UV–Vis and fluorescence spectroscopy at pH 2, pH 5, and pH 7. The results obtained for examined pHs showed pH 5 as optimal for forming LVX-Fe3+ complex. The formation of LVX-Fe3+ complex makes coordinated LVX more susceptible to oxidation. Photosensitivity of LVX and LVX/Fe3+ system to UV irradiation was examined at acidic pHs, using UV–Vis spectroscopy and HPLC analysis. In acidic aqueous solutions, LVX remains unchanged after UV irradiation, while the presence of ferric ions promotes its UV-induced photodegradation. The investigated UV/Fe(III)-based AOP for degradation of LVX showed the best performance at pH 5 in the presence of Fe3+ ions in excess due to LVX-Fe3+ complex formation and sufficient amount of Fe3+–OH− species available for photolysis and production of OH• radical.Peer-reviewed manuscript: [https://cherry.chem.bg.ac.rs/handle/123456789/7059]Supplementary information: [https://cherry.chem.bg.ac.rs/handle/123456789/7060
Ispitivanje potencijala sulfat-redukujućih bakterija za biodegradaciju perfluorooktan sulfonata
No full textCilj ovog rada bio je ispitivanje potencijala sulfat-redukujućih bakterija (SRB), izolovanih iz zagađenog
rečnog sedimenta, za biodegradaciju perfluorooktan sulfonata (PFOS). Izolovane mešane SRB kulture,
M1-3 i M2-4, gajene su na modifikovanoj Baar-ovoj podlozi uz postepeno povećanje koncentracija PFOSa
(5–30 ppm). Praćenjem rasta mikroorganizama utvrđeno je da PFOS ne ispoljava inhibitorni efekat na
metabolizam SRB, što ukazuje na njihovu tolerantnost na visoke koncentracije ovog jedinjenja. Analiza
uzoraka pomoću tečne hromatografije sa tandem masenom spektrometrijom (LC-MS/MS) sprovedena je
nakon 7, 14 i 21 dana inkubacije, sa ciljem procene promene koncentracije PFOS-a. Dobijeni rezultati nisu
pokazali značajno smanjenje koncentracije PFOS-a u odnosu na kontrolu, što ukazuje da u okviru
eksperimentalnih uslova i perioda ispitivanja nije došlo do biodegradacije. Dodatno, izvršeno je brojanje
mikroorganizama u anaerobnim uslovima na Baar-ovoj podlozi sa 2% agra, gde su izbrojane samo crne
kolonije koje su formirale talog gvožđe-sulfida, produkt metabolizma SRB. Prisustvo značajnog broja
kolonija ukazuje na uspešan rast SRB i potvrđuje da su izolovane kulture vitalne u uslovima izlaganja
PFOS-u
Kompleksi folne kiseline i aminomodifikovanih β-ciklodekstrina: ispitivanje stabilnosti, rastvorljivosti i fotostabilnosti
No full textCilj ovog rada je ispitivanje povećanja rastvorljivosti i hemijske, odnosno fotostabilnosti
inkluzionih kompleksa folne kiseline sa amino-modifikovanim β-ciklodekstrinima. Polazeći od
činjenice da je folna kiselina izuzetno važan vitamin B kompleksa, neophodan za odvijanje
metabolizma jednougljeničnih fragmenata, odnosno sintezu nukleinskih kiselina, epigenetsku
kontrolu gena i prevenciju defekata neuralne cevi; istovremeno i jedinjenje male rastvorljivosti i
izrazite fotoosetljivosti; teorijski okvir rada zasnovan je na dobro poznatoj sposobnosti ciklodekstrina
da povećavaju rastvorljivost i stabilnost inače osetljivih i slaborastvorljivih biološki aktivnih
molekula.
U okviru ovog rada, konstruisani su dijagrami fazne rastvorljivosti folne kiseline, u prisustvu
β-CD, propilendiamin-β-CD (PDA-β-CD) i piperazin-β-CD (PIP-β-CD), na osnovu kojih su
izračunate konstante stabilnosti inkluzionih kompleksa. Ispitan je stabilišući efekat PIP-β-CD prema
folnoj kiselini, u uslovima konstantnog ozračivanja UV-zracima, ali i uslovima različitih pH vrednosti
rastvora. Dobijeni rezultati pokazuju da amino-modifikovani derivati β-ciklodekstrina značajno utiču
na povećanje rastvorljivosti folne kiseline (3,33 puta), pri čemu je najizraženiji efekat postignut
primenom PIP-β-CD. PIP-β-CD se takođe pokazao superiorinijim, u odnosu na β-CD, ostvarivanjem
većeg stepena zaštite od fotodegradacije, te produžavanjem vremena poluraspada folne kiseline od
29,2 minuta u puferu, i 34,0 minuta u prisustvu β-CD, na 50,4 minuta
Development of novel analogs of the TRi-1 and TRi-2 selenoprotein thioredoxin reductase inhibitors with initial assessment of their cytotoxicity profiles
No full textThe human selenoprotein thioredoxin reductases are encoded and expressed as separate cytosolic (TXNRD1) and mitochondrial (TXNRD2) isoforms, with both having been suggested as potential anticancer drug targets. The TRi-1 compound was recently shown to preferentially inhibit TXNRD1 in cells, while the TRi-2 compound seems to target both isoforms in a cellular context, albeit to different extent. Attempting to evaluate whether TXNRD1 or TXNRD2 inhibition most closely correlates with cytotoxicity, we here synthesized several analogs of both TRi-1 and TRi-2, including triphenyl phosphonium derivatives designed to accumulate in mitochondria. We evaluated 11 compounds in comparison with TRi-1 and TRi-2 with regards to inhibition of TXNRD1 and TXNRD2 in pure enzyme assays, and their cytotoxicity profiles towards human lung adenocarcinoma A549 cells, with constitutively high NRF2 activity and thus potent antioxidant defense. Human squamous cell carcinoma FaDu cells with lower NRF2 and lower TXNRD1 activity were much more sensitive to the compounds. The results strengthen the notion that compound-derived inhibition of either TXNRD1 or TXNRD2 can yield cytotoxicity in human cancer cells. Comparing two pairs of matched inhibitor scaffolds for the effects of adding a triphenyl phosphonium group, we found that this moiety conferred minimal inhibition of cellular cytosolic TXNRD1 activity, as assessed using the specific RX1 activity probe, while maintaining cytotoxicity, which was thus likely involving targeting of TXNRD2 in the mitochondria. Our results represent a blueprint for initial evaluations of novel small molecule inhibitors of TXNRD1 and TXNRD2, correlating such inhibition of pure enzymes as well as in cells in relation to their cytotoxicity
Efekat suplementacije polinezasićenim masnim kiselinama na parametre oksidativnog stresa kod pacijentkinja sa karcinomom dojke
No full textGlavni cilj ovog master rada je odredjivanje parametara oksidativnog stresa kod pacijentkinja sa KD koje su na adjuvantnoj hormonskoj terapiji inhibitorima aromataze (IA) pre i nakon 4 meseca suplementacije ribljim uljem i uljem žutog noćurka, izvorima antiinflamatornih polinezasćenih masnih kiselina (engl. polyunsaturated fatty acids, PUFA). Zbog povezanosti inflamacije i oksidativnog stresa, cilj ovog istraživanja bio da se proceni da li suplementacija ribljim uljem, bogatim eikozapentaenskom kiselinom (engl. eicosapentaenoic acid, EPA) i dokozaheksaenskom kiselinom (engl. docosahexaenoic acid, DHA) i uljem žutog noćurka bogatim γ-linolenskom kiselinom (engl. gamma-linolenic acid, GLA) utiče na nivo/koncentraciju parametera oksidativnog stresa kod ispitanica koje se leče od KD
Differential Processing of Sucrose and Invert Syrup in Honey Bees
No full textFeeding bees carbohydrates, as a substitute for nectar, has become essential in modern beekeeping. We compared the effects of 65% sucrose (SS) and 65% invert sugar (IS) syrups on the survival and enzyme activity of caged honey bees. Specifically, we analyzed glycosidase activity in the head and midgut of the bees and compared the composition of sucrose-based (SH) and invert sugar-based (IH) ?honey? stored by the bees and collected from the comb. Glycosidase activity was similar in head in contrast to midgut where it was higher in IS fed bees, which appeared to be residual yeast ?-fructofuranosidase activity. Fructose to glucose ratio in SH were 60.84/39.16 and a presence of some other sugars were detected, while ratio in IH were 48.49/51.51, almost exactly the same as in start fed (IS) (48.57/51.43). It has been demonstrated that glycosidase activity in IH was residual yeast ?-fructofuranosidase activity. Zymogram detected α-amylase band in SH, in contrast to IH, which suggest that honey bees do not add amylase into IS. In contrast to SH, no crystallization occurred in IH. SS and IS densities were 1.23 and 1.24?g/mL, respectively, increasing to 1.35?g/mL in SH and 1.28?g/mL in IH after processing. This suggests that higher humidity and restricted cleansing flight make it harder for bees to remove excess water from IH, leading to increased midgut and hindgut weight, which correlates with higher mortality in the third week for the IS-fed group and fourth week for the SS-fed group
Sinteza i karakterizacija Ru(II) kompleksa sa Šifovom bazom 3,5-di(2-piridil)-4-amino-1,2,4-triazola i 9-antracenkarbaldehida
No full textU savremenoj medicinskoj hemiji, prelazni metali zauzimaju značajno mesto u istraživanjima novih terapeutika. Njihova sposobnost da formiraju različita koordinaciona jedinjenja, stabilna u biološkim uslovima, otvara mogućnost za razvoj potpuno novih lekova. Jedan od elemenata koji je privukao posebnu pažnju jeste rutenijum (Ru) - redak, ali izuzetno zanimljiv metal iz grupe platinskih metala, poznat po svojoj hemijskoj raznovrsnosti i potencijalnoj biološkoj aktivnosti.
Interesovanje za rutenijumske komplekse naglo je poraslo nakon otkrića da neki od njih pokazuju izrazitu antitumorsku aktivnost, uz manju toksičnost u poređenju sa tradicionalnim platinskim lekovima, poput cisplatine. Istraživanja su pokazala da određeni kompleksi rutenijuma mogu da se aktiviraju unutar tumorskih ćelija putem redoks reakcija, ciljano delujući na mitohondrije, nukleinske kiseline i proteine koji učestvuju u regulaciji ćelijskog ciklusa.
Pored rutenijuma, značajnu pažnju u oblasti bioaktivnih jedinjenja privlače i heterociklična jedinjenja, naročito koja sadrže triazolni prsten. Derivati 1,2,4-triazola pokazuju širok spektar bioloških aktivnosti - od antimikrobnih, preko antitumorskih, do antivirusnih efekata. Triazolski fragmenti često se ugrađuju u strukture lekova, čime se poboljšava njihova stabilnost i interakcija sa biološkim metama.
Cilj ovog rada jeste sinteza kompleksa rutenijuma(II) sa ligandom na bazi 1,2,4-triazola koji bi u nekim budućim istraživanjima mogli biti ispitani kao potencijalni antitumorski agensi
Sinteza i karakterizacija Ru(II) kompleksa sa 3,5-di(2-piridil)-4-amino-1,2,4-triazolom i njegovim derivatom
No full textCilj ovog rada je sinteza i hemijska karakterizacija kompleksa rutenijuma(II) sa ligandima na bazi 1,2,4-triazola koji bi u nekom budućem istraživanju bili ispitivani kao potencijalni antikancerogeni agensi