Teorijsko ispitivanje antiradikalske aktivnosti delfinidina

Delphinidin, one of the natural anthocyanin pigments was theoretically (at M05-2X/6-311+G(d,p) level of theory) investigated for its ability scavange potentially highly damaging hydroxyl and superoxide anion radicals. Theoretical calculations point to HAT and SPLET mechanisms as operative for delphinidin in all solvents under investigations.Teoretski (na M05-2X/6-311+G(d,p) nivou teorije) je ispitivana sposobnost delfinidina, prirodnog antocijaninskog pigmenta, da reaguje sa potencijalno veoma štetnim hidroksi i superoksid anjon radikalima. Proračuni su pokazali da su HAT i SPLET mogući mehanizmi u svim rastvaračima

Ispitivanje antioksidativnih mehanizama kempferola sa hidroksi radikalom i superoksid radikal anjonom

Kaempferol, one of the most bioactive plant flavonoids was theoretically (at M05-2X/6-311G(d,p) level of theory) investigated for its ability scavange potentially highly damaging hydroxyl and superoxide anion radicals. Theoretical calculations point to HAT and SPLET mechanisms as operative for kaempferol in all solvents under investigations.Teoretski (na M05-2X/6-311G(d,p) nivou teorije) je ispitivana sposobnost kempferola, važnog bioaktivnog biljnog jedinjenja flavonoida, da reaguje sa potencijalno veoma štetnim hidroksi radikalom i superoksid radikal anjonom. Proračuni su pokazali da su HAT i SPLET mogući mehanizmi u svim rastvaračima

Maldi-tof ms characterization of transition metal complexes

In this work, we have analyzed the positive ion MALDI-TOF mass spectra of cationic complexes [PdCl(dien)]Cl and [Ru(en)2Cl2]Cl acquired with different matrices: 2,5- dihydroxybenzoic acid (DHB), α-cyano hydroxycinnamic acid (CHCA) and quercetin. The necessity to test several matrix/analyte combinations for reliable identification and characterization of metallo-drugs is emphasized in this work

Theoretical study of the thermodynamics of the mechanisms underlying antiradical activity of cinnamic acid derivatives

The role of antiradical moieties (catechol, guaiacyl and carboxyl group) and molecular conformation in antioxidative potency of dihydrocaffeic acid (DHCA) and dihydroferulic acid (DHFA) was investigated by density functional theory (DFT) method. The thermodynamic preference of different reaction paths of double (2H+/2e-) free radical scavenging mechanisms was estimated. Antiradical potency of DHCA and DHFA was compared with that exerted by their unsaturated analogs - caffeic acid (CA) and ferulic acid (FA). Cis/trans and anti-isomers of studied cinnamic acid derivatives may scavenge free radicals via double processes by involvement of catechol or guaiacyl moiety. Carboxyl group of syn-isomers may also participate in the inactivation of free radicals. Gibbs free energies of reactions with various free radicals indicate that syn-DHCA and syn-DHFA, colon catabolites that could be present in systemic circulation in low μM concentrations, have a potential to contribute to health benefits by direct free radical scavenging.Publishe

Fluorometrijsko određivanje hesperidina u sokovima od pomorandže prisutnim na tržištu Srbije

The spectrofluorometric method based on fluorescence ability of aluminium - hesperidin complex for the determination of hesperidin in orange juice is proposed. The linearity range of hesperidin in methanolicaqueous solution was 0.08 - 18.0 μg/mL with LOD and LOQ values as 0.023 μg/mL and 0.070 μg/mL, respectively, and recovery values in the range 97.8 - 99.7 %. Method was simplified by omitting any of surphactant agents usually applied in similar procedures, and successfully applied for the determination of hesperidin in orange juices commercially available on the Serbian market.U radu je predložena spektrofluorimetrijska metoda za određivanje sadržaja hesperidina u sokovima od pomorandže zasnovana na sposobnosti fluorescencije kompleksa aluminijum - hesperidin. Utvrđena je oblast linearnosti za određivanje hesperidina u metanolno-vodenim rastvora od 0.08 do 18.0 μg/mL, pri čemu je LOD= 0.023 μg/mL i LOQ= 0.070 μg/mL, a recovery vrednost 97.8 - 99.7 %. Metoda je pojednostavljena izostavljanjem često korišćenih površinski aktivnih materija koje se koriste u sličnim procedurama i uspešno je primenjena za određivanje sadržaja hesperidina u sokovima od pomorandže prisutnim na tržištu Srbije

Derivatives in Advanced Oxidation Processes: Experimental and Kinetic DFT Stud

Coumarins represent a broad class of compounds with pronounced pharmacological properties and therapeutic potential. The pursuit of the commercialization of these compounds requires the establishment of controlled and highly efficient degradation processes, such as advanced oxidation processes (AOPs). Application of this methodology necessitates a comprehensive understanding of the degradation mechanisms of these compounds. For this reason, possible reaction routes between HO• and recently synthesized aminophenol 4,7-dihydroxycoumarin derivatives, as model systems, were examined using electron paramagnetic resonance (EPR) spectroscopy and a quantum mechanical approach (a QM-ORSA methodology) based on density functional theory (DFT). The EPR results indicated that all compounds had significantly reduced amounts of HO• radicals present in the reaction system under physiological conditions. The kinetic DFT study showed that all investigated compounds reacted with HO• via HAT/PCET and SPLET mechanisms. The estimated overall rate constants (koverall) correlated with the EPR results satisfactorily. Unlike HO• radicals, the newly formed radicals did not show (or showed negligible) activity towards biomolecule models representing biological targets. Inactivation of the formed radical species through the synergistic action of O2/NOx or the subsequent reaction with HO• was thermodynamically favored. The ecotoxicity assessment of the starting compounds and oxidation products, formed in multistage reactions with O2/NOx and HO•, indicated that the formed products showed lower acute and chronic toxicity effects on aquatic organisms than the starting compounds, which is a prerequisite for the application of AOPs procedures in the degradation of compounds

Synthesis, structural characterization, biological activity and molecular docking study of 4,7-dihydroxycoumarin modified by aminophenol derivatives

In the present manuscript, three different 4,7-dihydroxycoumarin derivatives were prepared and structurally characterized by crystallographic and spectroscopic techniques in combination with the B3LYP-D3BJ theoretical method. Cytotoxic and antimicrobial activities of investigated compounds were screened against different cell lines and microorganisms. HCT-116 cells were most sensitive to the 3-(1-(2-hydroxyphenyl)amino) ethylidene)-2,4-dioxochroman-7-yl acetate derivative, while the best antimicrobial activity against Bacillus subtilis ATCC 6633 was shown by 3-(1-(2- hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate. The molecular docking study for all compounds with important epidermal growth factor receptors (EGFR) was performed. The results indicate that the largest contribution to the binding energy is through conventional hydrogen bonds

Teorijsko ispitivanje antiradikalske aktivnosti delfinidina

Delphinidin, one of the natural anthocyanin pigments was theoretically (at M05-2X/6-311+G(d,p) level of theory) investigated for its ability scavange potentially highly damaging hydroxyl and superoxide anion radicals. Theoretical calculations point to HAT and SPLET mechanisms as operative for delphinidin in all solvents under investigations.Teoretski (na M05-2X/6-311+G(d,p) nivou teorije) je ispitivana sposobnost delfinidina, prirodnog antocijaninskog pigmenta, da reaguje sa potencijalno veoma štetnim hidroksi i superoksid anjon radikalima. Proračuni su pokazali da su HAT i SPLET mogući mehanizmi u svim rastvaračima

Examination of Electron Transfer Mechanism of Cyanidin

Cyanidin, as one important plant pigment, was theoretically (at M05-2X/6-311+G(d,p) level of theory) investigated for its ability to scavenge potentially, highly damaging hydroxyl radical. Free radical scavenging of cyanidin was studied through electron transfer mechanism – ET (the second step in SPLET mechanism) in water and ethanol, as solvents. Examination was performed using density functional theory (DFT) and Marcus theory. Based on the thermochemical and kinetic data, it is clear that O‒H group of cyanidin in position 3` is the most suitable for reaction with hydroxyl radical through mentioned antioxidant mechanism