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The derivatives of isatin have already been known to display a variety of biological activities. Therefore, the studies on their activity and its relation to structure have recently become a popular subject for investigation. The examined compounds were synthesized by the reaction of isatin and substituted primary amines and characterized by spectroscopic methods. The investigation of the antimicrobial and antioxidative activity of the synthesized compounds was performed by broth microdilution method. As for the characterization of the investigated isatin based Schiff bases, the linear solvation energy relationships (LSER) were used to analyze the solvent influence on the UV absorption maxima shifts (V-max), using the well known Kamlet-Taft model and taking geometrical isomers into consideration when possible. Linear free energy relationships (LFER) were used to analyze substituent effect on pK(a), as well as NMR chemical shifts and v max values. The antimicrobial activity and characterization were related using both experimental and theoretical methods., Derivati isatina su poznati po potencijalnoj biološkoj aktivnosti, pa su postali interesantni za proučavanje veze između navedene aktivnosti i njihovih strukturnih karakteristika. Naš tim ih je godinama istraživao sa oba aspekta i u ovom preglednom radu su prikazani svi rezultati od značaja do kojih smo došli. Ispitivani derivati isatina su sintetisani reakcijom između isatina i različitih primarnih amina, okarakterisani su spektroskopskim metodama (FTIR, NMR) kao i elementalnom analizom. Na njima su izvršena i razna teorijska proučavanja kao i određivanje antimikrobne aktivnosti, kako bi se stekla što potpunija slika o vezi između njihove strukture i aktivnosti i odredila jedinjenja za dalja ispitivanja zbog njihovog potencijala za primenu.

The derivatives of isatin have already been known to display a variety of biological activities. Therefore, the studies on their activity and its relation to structure have recently become a popular subject for investigation. The examined compounds were synthesized by the reaction of isatin and substituted primary amines and characterized by spectroscopic methods. The investigation of the antimicrobial and antioxidative activity of the synthesized compounds was performed by broth microdilution method. As for the characterization of the investigated isatin based Schiff bases, the linear solvation energy relationships (LSER) were used to analyze the solvent influence on the UV absorption maxima shifts (V-max), using the well known Kamlet-Taft model and taking geometrical isomers into consideration when possible. Linear free energy relationships (LFER) were used to analyze substituent effect on pK(a), as well as NMR chemical shifts and v max values. The antimicrobial activity and characterization were related using both experimental and theoretical methods., Derivati isatina su poznati po potencijalnoj biološkoj aktivnosti, pa su postali interesantni za proučavanje veze između navedene aktivnosti i njihovih strukturnih karakteristika. Naš tim ih je godinama istraživao sa oba aspekta i u ovom preglednom radu su prikazani svi rezultati od značaja do kojih smo došli. Ispitivani derivati isatina su sintetisani reakcijom između isatina i različitih primarnih amina, okarakterisani su spektroskopskim metodama (FTIR, NMR) kao i elementalnom analizom. Na njima su izvršena i razna teorijska proučavanja kao i određivanje antimikrobne aktivnosti, kako bi se stekla što potpunija slika o vezi između njihove strukture i aktivnosti i odredila jedinjenja za dalja ispitivanja zbog njihovog potencijala za primenu.

The ratios of E/Z isomers of sixteen synthesized 1,3-dihydro-3-(substituted phenylimino)-2H-indol-2-one were studied using experimental and theoretical methodology. Linear solvation energy relationships (LSER) rationalized solvent influence of the solvent-solute interactions on the UV-Vis absorption maxima shifts (v(max)) of both geometrical isomers using the Kamlet-Taft equation. Linear free energy relationships (LEER) in the form of single substituent parameter equation (SSP) was used to analyze substituent effect on pK(a), NMR chemical shifts and v(max) values. Electron charge density was obtained by the use of Quantum Theory of Atoms in Molecules, i.e. Bader's analysis. The substituent and solvent effect on intramolecular charge transfer (ICT) were interpreted with the aid of time-dependent density functional (TD-DFT) method. Additionally, the results of TD-DFT calculations quantified the efficiency of ICT from the calculated charge-transfer distance (D-CT) and amount of transferred charge (Q(CT)). The antimicrobial activity was evaluated using broth microdilution method. 3D QSAR modeling was used to demonstrate the influence of substituents effect as well as molecule geometry on antimicrobial activity. (C) 2018 Elsevier B.V. All rights reserved.

The ratios of E/Z isomers of sixteen synthesized 1,3-dihydro-3-(substituted phenylimino)-2H-indol-2-one were studied using experimental and theoretical methodology. Linear solvation energy relationships (LSER) rationalized solvent influence of the solvent-solute interactions on the UV-Vis absorption maxima shifts (v(max)) of both geometrical isomers using the Kamlet-Taft equation. Linear free energy relationships (LEER) in the form of single substituent parameter equation (SSP) was used to analyze substituent effect on pK(a), NMR chemical shifts and v(max) values. Electron charge density was obtained by the use of Quantum Theory of Atoms in Molecules, i.e. Bader's analysis. The substituent and solvent effect on intramolecular charge transfer (ICT) were interpreted with the aid of time-dependent density functional (TD-DFT) method. Additionally, the results of TD-DFT calculations quantified the efficiency of ICT from the calculated charge-transfer distance (D-CT) and amount of transferred charge (Q(CT)). The antimicrobial activity was evaluated using broth microdilution method. 3D QSAR modeling was used to demonstrate the influence of substituents effect as well as molecule geometry on antimicrobial activity. (C) 2018 Elsevier B.V. All rights reserved.

The ratios of E/Z isomers of sixteen synthesized 1,3-dihydro-3-(substituted phenylimino)-2H-indol-2-one were studied using experimental and theoretical methodology. Linear solvation energy relationships (LSER) rationalized solvent influence of the solvent-solute interactions on the UV-Vis absorption maxima shifts (v(max)) of both geometrical isomers using the Kamlet-Taft equation. Linear free energy relationships (LEER) in the form of single substituent parameter equation (SSP) was used to analyze substituent effect on pK(a), NMR chemical shifts and v(max) values. Electron charge density was obtained by the use of Quantum Theory of Atoms in Molecules, i.e. Bader's analysis. The substituent and solvent effect on intramolecular charge transfer (ICT) were interpreted with the aid of time-dependent density functional (TD-DFT) method. Additionally, the results of TD-DFT calculations quantified the efficiency of ICT from the calculated charge-transfer distance (D-CT) and amount of transferred charge (Q(CT)). The antimicrobial activity was evaluated using broth microdilution method. 3D QSAR modeling was used to demonstrate the influence of substituents effect as well as molecule geometry on antimicrobial activity. (C) 2018 Elsevier B.V. All rights reserved.

The ratios of E/Z isomers of sixteen synthesized 1,3-dihydro-3-(substituted phenylimino)-2H-indol-2-one were studied using experimental and theoretical methodology. Linear solvation energy relationships (LSER) rationalized solvent influence of the solvent-solute interactions on the UV-Vis absorption maxima shifts (v(max)) of both geometrical isomers using the Kamlet-Taft equation. Linear free energy relationships (LEER) in the form of single substituent parameter equation (SSP) was used to analyze substituent effect on pK(a), NMR chemical shifts and v(max) values. Electron charge density was obtained by the use of Quantum Theory of Atoms in Molecules, i.e. Bader's analysis. The substituent and solvent effect on intramolecular charge transfer (ICT) were interpreted with the aid of time-dependent density functional (TD-DFT) method. Additionally, the results of TD-DFT calculations quantified the efficiency of ICT from the calculated charge-transfer distance (D-CT) and amount of transferred charge (Q(CT)). The antimicrobial activity was evaluated using broth microdilution method. 3D QSAR modeling was used to demonstrate the influence of substituents effect as well as molecule geometry on antimicrobial activity. (C) 2018 Elsevier B.V. All rights reserved.

The ratios of E/Z isomers of sixteen synthesized 1,3-dihydro-3-(substituted phenylimino)-2H-indol-2-one were studied using experimental and theoretical methodology. Linear solvation energy relationships (LSER) rationalized solvent influence of the solvent-solute interactions on the UV-Vis absorption maxima shifts (v(max)) of both geometrical isomers using the Kamlet-Taft equation. Linear free energy relationships (LEER) in the form of single substituent parameter equation (SSP) was used to analyze substituent effect on pK(a), NMR chemical shifts and v(max) values. Electron charge density was obtained by the use of Quantum Theory of Atoms in Molecules, i.e. Bader's analysis. The substituent and solvent effect on intramolecular charge transfer (ICT) were interpreted with the aid of time-dependent density functional (TD-DFT) method. Additionally, the results of TD-DFT calculations quantified the efficiency of ICT from the calculated charge-transfer distance (D-CT) and amount of transferred charge (Q(CT)). The antimicrobial activity was evaluated using broth microdilution method. 3D QSAR modeling was used to demonstrate the influence of substituents effect as well as molecule geometry on antimicrobial activity. (C) 2018 Elsevier B.V. All rights reserved.

The ratios of E/Z isomers of sixteen synthesized 1,3-dihydro-3-(substituted phenylimino)-2H-indol-2-one were studied using experimental and theoretical methodology. Linear solvation energy relationships (LSER) rationalized solvent influence of the solvent-solute interactions on the UV-Vis absorption maxima shifts (v(max)) of both geometrical isomers using the Kamlet-Taft equation. Linear free energy relationships (LEER) in the form of single substituent parameter equation (SSP) was used to analyze substituent effect on pK(a), NMR chemical shifts and v(max) values. Electron charge density was obtained by the use of Quantum Theory of Atoms in Molecules, i.e. Bader's analysis. The substituent and solvent effect on intramolecular charge transfer (ICT) were interpreted with the aid of time-dependent density functional (TD-DFT) method. Additionally, the results of TD-DFT calculations quantified the efficiency of ICT from the calculated charge-transfer distance (D-CT) and amount of transferred charge (Q(CT)). The antimicrobial activity was evaluated using broth microdilution method. 3D QSAR modeling was used to demonstrate the influence of substituents effect as well as molecule geometry on antimicrobial activity. (C) 2018 Elsevier B.V. All rights reserved.

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide-water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone.

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide-water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone.

The multistage synthesis of the multi-wall carbon nanotubes (MWCNT) modified with polyamidoamine dendrimers, A1/and A2/MWCNT, capable of cation removal, is presented in this work, as well as novel adsorbents based on these precursor materials and modified with goethite nano-deposit, alpha-FeOOH, A1/ and A2/MWCNT-alpha-FeO(OH) adsorbents used for As(V) removal. In a batch test, the influence of pH, contact time, initial ion concentration and temperature on adsorption efficiency were studied. Adsorption data modelling by the Langmuir isotherm, revealed good adsorption capacities (in mg g(-1)) of 18.8 for As(V) and 60.1 and 44.2 for Pb2+ and Cd2+ on A2/MWCNT, respectively. Also, 27.6 and 29.8 mg g(-1) of As(V) on A1/ and A2/MWCNT-alpha-FeO(OH), respectively, were removed. Thermodynamic parameters showed that the adsorption is spontaneous and endothermic processes. Results of the study of influences of competitive ions: bicarbonate, sulfate, phosphate, silicate, chromate, fluoride and natural organic matter (NOM), i.e., humic acid (HA), showed the highest effect of phosphate on the decrease of arsenate adsorption. Time-dependent adsorption was best described by pseudo-second-order kinetic model and Weber-Morris model which predicted intra-particle diffusion as a rate-controlling step. Also, activation energy (E-a/kJ mol(-1)): 8.85 for Cd2+, 9.25 for Pb2+ and 7.98 for As(V), were obtained from kinetic data.

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide-water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone.

The multistage synthesis of the multi-wall carbon nanotubes (MWCNT) modified with polyamidoamine dendrimers, A1/and A2/MWCNT, capable of cation removal, is presented in this work, as well as novel adsorbents based on these precursor materials and modified with goethite nano-deposit, alpha-FeOOH, A1/ and A2/MWCNT-alpha-FeO(OH) adsorbents used for As(V) removal. In a batch test, the influence of pH, contact time, initial ion concentration and temperature on adsorption efficiency were studied. Adsorption data modelling by the Langmuir isotherm, revealed good adsorption capacities (in mg g(-1)) of 18.8 for As(V) and 60.1 and 44.2 for Pb2+ and Cd2+ on A2/MWCNT, respectively. Also, 27.6 and 29.8 mg g(-1) of As(V) on A1/ and A2/MWCNT-alpha-FeO(OH), respectively, were removed. Thermodynamic parameters showed that the adsorption is spontaneous and endothermic processes. Results of the study of influences of competitive ions: bicarbonate, sulfate, phosphate, silicate, chromate, fluoride and natural organic matter (NOM), i.e., humic acid (HA), showed the highest effect of phosphate on the decrease of arsenate adsorption. Time-dependent adsorption was best described by pseudo-second-order kinetic model and Weber-Morris model which predicted intra-particle diffusion as a rate-controlling step. Also, activation energy (E-a/kJ mol(-1)): 8.85 for Cd2+, 9.25 for Pb2+ and 7.98 for As(V), were obtained from kinetic data.

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide-water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone.

The isatin derivatives, Schiff bases, were synthesized by the reaction of isatin and various substituted primary amines and characterized by several spectroscopic methods. Investigation of the antimicrobial activity of the synthesized compounds was performed by the agar dilution method, against different strains of bacteria and one fungus. The antioxidative activity of the synthesized compounds was also determined. Some of the compounds showed significant activity against the selected strains of microorganisms and antioxidative activity.

The isatin derivatives, Schiff bases, were synthesized by the reaction of isatin and various substituted primary amines and characterized by several spectroscopic methods. Investigation of the antimicrobial activity of the synthesized compounds was performed by the agar dilution method, against different strains of bacteria and one fungus. The antioxidative activity of the synthesized compounds was also determined. Some of the compounds showed significant activity against the selected strains of microorganisms and antioxidative activity.

The ultraviolet absorption spectra of the carboxyl group of three isomeric pyridine carboxylic acids N-oxides (picolinic acid N-oxide, nicotinic acid N-oxide and isonicotinic acid N-oxide) were determined in fourteen solvents in the wavelength range from 200 to 400 nm. The position of the absorption maxima (λmax) of the examined acids showed that the ultraviolet absorption maximum wavelengths of picolinic acid N-oxide are the shortest, and those of isonicotinic acid N-oxide acid are the longest. In order to analyze the solvent effect on the obtained absorption spectra, the ultraviolet absorption frequen­cies of the electronic transitions in the carboxylic group of the examined acids were correlated using a total solvatochromic equation of the form Vmax = V0 + + Sπ*+ aα+ bβ, where Vmax is the absorption frequency (1/λmax), π*is a measure of the solvent polarity, β represents the scale of solvent hydrogen bond acceptor basicities and α represents the scale of solvent hydrogen bond donor acidities. The correlation of the spectroscopic data was carried out by means of multiple linear regression analysis. The solvent effects on the ultra­violet absorption maximums of the examined acids were discussed., UV apsorpcioni spektri pikolinske kiseline N-oksida, nikotinske kiseline N-oksida i izonikotinske kiseline N-oksida određeni su u 14 protičnih i aprotičnih rastvarača u opsegu od 200-400 nm. Položaji maksimuma apsorpcije bili su najniži za pikolinsku kiseline N-oksid, a najviši za izonikotinsku kiseline N-oksid. Da bi se analizirao uticaj ratvarača, apsorpcione frekvence su korelisane Kamlet-Taftovom jednačinom, kojom se uticaj polarnosti/polarizabilnosti, proton-donorskog i proton-akceptorskog dejstva rastvarača može kvantitativno izraziti.