Pub Date : 2023-12-24DOI: 10.20450/mjcce.2023.2782
R. Gulaboski
Utilizing pulse voltammetric techniques for the electrochemical analysis of lipophilic redox systems has proven to be an effective method for studying a diverse range of redox compounds, from simple molecules to intricate proteins. To extract relevant thermodynamic and kinetic data from electrochemical analysis of redox systems exhibiting strong surface activity, there's a crucial need to decipher the underlying electrochemical mechanism in the system being examined. The "split net peak" phenomenon, a defining characteristic observed in all surface-active redox systems featuring fast electron transfer under square-wave voltammetry conditions, has been investigated in this study to establish diagnostic criteria for identifying surface electrochemical mechanisms associated with preceding, subsequent, regenerative, and reactant-inactivating chemical reactions. This understanding can be achieved by tracking the influence of the chemical reaction rate on the split square-wave voltammetric peaks in a particular electrochemical mechanism. The approach reported in the current work enables a very simple and precise differentiation between the elaborated mechanisms frequently encountered in protein-film voltammetry methodologies.
{"title":"The net peak splitting phenomenon in square-wave voltammetry – A simple diagnostic tool to distinguish between surface electrode mechanisms associated with different chemical reactions","authors":"R. Gulaboski","doi":"10.20450/mjcce.2023.2782","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2782","url":null,"abstract":"Utilizing pulse voltammetric techniques for the electrochemical analysis of lipophilic redox systems has proven to be an effective method for studying a diverse range of redox compounds, from simple molecules to intricate proteins. To extract relevant thermodynamic and kinetic data from electrochemical analysis of redox systems exhibiting strong surface activity, there's a crucial need to decipher the underlying electrochemical mechanism in the system being examined. The \"split net peak\" phenomenon, a defining characteristic observed in all surface-active redox systems featuring fast electron transfer under square-wave voltammetry conditions, has been investigated in this study to establish diagnostic criteria for identifying surface electrochemical mechanisms associated with preceding, subsequent, regenerative, and reactant-inactivating chemical reactions. This understanding can be achieved by tracking the influence of the chemical reaction rate on the split square-wave voltammetric peaks in a particular electrochemical mechanism. The approach reported in the current work enables a very simple and precise differentiation between the elaborated mechanisms frequently encountered in protein-film voltammetry methodologies.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":"405 3","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-29DOI: 10.20450/mjcce.2023.2688
A. A Al-Owais, Ibrahim S El-Hallag, E. H. El-Mossalamy
Hydroquinone (HQ) was electrochemically measured using convolutive cyclic voltammetry and differential pulse voltammetry (DPV) on a nano-architecture mesoporous platinum film electrochemically grown from a hexagonal liquid crystalline template of C16EO8 surfactant in 1.0 mol/l HClO4. The HQ cyclic voltammograms produced one oxidative peak in the forward sweep of potential and one reductive peak in the reverse sweep. The effect of HQ concentration was investigated using the different electrochemical methods mentioned above. The modified platinum electrode exhibits good sensitivity for the determination of the HQ compound in 1.0 mol/l HClO4. The best executive was found for the i-t curve method developed from cyclic voltammetry of HQ. It exhibits a linear peak current response over the concentration range of 8 to 55 µmol/l, with a detection limit of 0.5726 µmol/l and a quantification limit of 1.9088 µmol/l, confirming the accuracy and sensitivity of this quick, cheap, and easy method.
{"title":"Quantitative determination of hydroquinone via electrochemical methods at nano-architecture platinum electrode","authors":"A. A Al-Owais, Ibrahim S El-Hallag, E. H. El-Mossalamy","doi":"10.20450/mjcce.2023.2688","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2688","url":null,"abstract":"Hydroquinone (HQ) was electrochemically measured using convolutive cyclic voltammetry and differential pulse voltammetry (DPV) on a nano-architecture mesoporous platinum film electrochemically grown from a hexagonal liquid crystalline template of C16EO8 surfactant in 1.0 mol/l HClO4. The HQ cyclic voltammograms produced one oxidative peak in the forward sweep of potential and one reductive peak in the reverse sweep. The effect of HQ concentration was investigated using the different electrochemical methods mentioned above. The modified platinum electrode exhibits good sensitivity for the determination of the HQ compound in 1.0 mol/l HClO4. The best executive was found for the i-t curve method developed from cyclic voltammetry of HQ. It exhibits a linear peak current response over the concentration range of 8 to 55 µmol/l, with a detection limit of 0.5726 µmol/l and a quantification limit of 1.9088 µmol/l, confirming the accuracy and sensitivity of this quick, cheap, and easy method.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42936426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-27DOI: 10.20450/mjcce.2023.2680
Coumba Gueye, P. A. Diaw, M. Mbaye, O. Mbaye, L. Cissé, Diabou Gaye Seye, J. Aaron, N. Oturan, M. Oturan
A spectrofluorimetric method was developed to determine residues of two β-blockers, atenolol (AT) and bisoprolol fumarate (BF), in Senegal's natural waters. The electronic absorption and fluorescence spectral properties of both β-blockers were investigated in several organic solvent mixtures [e.g., MeOH/H2O (60/40 v/v), cyclodextrins (β-cyclodextrin, HP-β-CD], and in the presence of surfactants (SDS, Triton X, Tween 80). After optimization, satisfactory analytical figures of merit were obtained for the determination of both β-blockers: concentration linear dynamic range of over one to two orders of magnitude, limits of detection (LODs) from 1.3 to 5.4 ng/ml for BF and from 1.2 to 3.7 ng/ml for AT, limits of quantification (LOQs) from 4.5 to 18.1 ng/ml for BF and from 4.0 to 12.5 ng/ml for AT. Relative standard deviations (RSDs) were between 2.1 and 5.3 %, according to the β-blockers. The spectrofluorimetric method was applied to the analysis of fortified river water and wastewater (effluent) collected in Senegal and France and spiked with both β-blockers. It yielded good recovery values, from 93.3 to 107.8 % for AT and from 97.4 to 108.9 % for BF. Our results demonstrated the simplicity, rapidity, and sensitivity of the spectrofluorimetric method to quantify residues of β-blockers in environmental waters.
{"title":"Spectrofluorimetric determination of beta-blockers atenolol and bisoprolol fumarate residues in Senegal natural waters","authors":"Coumba Gueye, P. A. Diaw, M. Mbaye, O. Mbaye, L. Cissé, Diabou Gaye Seye, J. Aaron, N. Oturan, M. Oturan","doi":"10.20450/mjcce.2023.2680","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2680","url":null,"abstract":"A spectrofluorimetric method was developed to determine residues of two β-blockers, atenolol (AT) and bisoprolol fumarate (BF), in Senegal's natural waters. The electronic absorption and fluorescence spectral properties of both β-blockers were investigated in several organic solvent mixtures [e.g., MeOH/H2O (60/40 v/v), cyclodextrins (β-cyclodextrin, HP-β-CD], and in the presence of surfactants (SDS, Triton X, Tween 80). After optimization, satisfactory analytical figures of merit were obtained for the determination of both β-blockers: concentration linear dynamic range of over one to two orders of magnitude, limits of detection (LODs) from 1.3 to 5.4 ng/ml for BF and from 1.2 to 3.7 ng/ml for AT, limits of quantification (LOQs) from 4.5 to 18.1 ng/ml for BF and from 4.0 to 12.5 ng/ml for AT. Relative standard deviations (RSDs) were between 2.1 and 5.3 %, according to the β-blockers. The spectrofluorimetric method was applied to the analysis of fortified river water and wastewater (effluent) collected in Senegal and France and spiked with both β-blockers. It yielded good recovery values, from 93.3 to 107.8 % for AT and from 97.4 to 108.9 % for BF. Our results demonstrated the simplicity, rapidity, and sensitivity of the spectrofluorimetric method to quantify residues of β-blockers in environmental waters.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44817012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-26DOI: 10.20450/mjcce.2023.2552
G. Dević, M. Pergal, M. Pergal
In the present study, statistical correlation analysis and multivariate statistical techniques (PCA/FA) were employed to investigate polycyclic aromatic hydrocarbons (PAHs) in sediments, such as illite-montmorillonite (IM) and calcite (Ct), from two sedimentary environments of the Tertiary Krepoljin brown coal basin in Serbia. The coal and sediment layers were formed in fresh-water bogs during the Lower Miocene period. The total amount of extractable PAHs was determined by gas chromatography with a triple quad mass detector (GC-MS-MS), and it ranged from 449 to 10585 μg l−1 in all sediments. Eight of the total 16 PAHs, which ranged from 175.17 to 658.42 μg l−1, include benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, which are regarded as potentially carcinogenic, indicating a higher possibility of adverse ecological effects. Medium molecular-weight (MMW) PAHs were found to be predominant in all sediments. PAH concentrations are affected by several factors, such as carbon content, H/C mole ratio, and (less significant) O/C mole ratio. The non-existence of a correlation between the N/C ratio and other parameters indicates unspecific changes which accompany the original organic matter. The lower-sulfur Ct sediment samples were found to have a higher PAH content than higher sulfur IM samples, leading to the conclusion that the PAH content of sediments may be related to the depositional environment.
{"title":"Polycyclic aromatic hydrocarbons in two sedimentary environments of the Tertiary Krepoljin coal basin","authors":"G. Dević, M. Pergal, M. Pergal","doi":"10.20450/mjcce.2023.2552","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2552","url":null,"abstract":"In the present study, statistical correlation analysis and multivariate statistical techniques (PCA/FA) were employed to investigate polycyclic aromatic hydrocarbons (PAHs) in sediments, such as illite-montmorillonite (IM) and calcite (Ct), from two sedimentary environments of the Tertiary Krepoljin brown coal basin in Serbia. The coal and sediment layers were formed in fresh-water bogs during the Lower Miocene period. The total amount of extractable PAHs was determined by gas chromatography with a triple quad mass detector (GC-MS-MS), and it ranged from 449 to 10585 μg l−1 in all sediments. Eight of the total 16 PAHs, which ranged from 175.17 to 658.42 μg l−1, include benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, which are regarded as potentially carcinogenic, indicating a higher possibility of adverse ecological effects. Medium molecular-weight (MMW) PAHs were found to be predominant in all sediments. PAH concentrations are affected by several factors, such as carbon content, H/C mole ratio, and (less significant) O/C mole ratio. The non-existence of a correlation between the N/C ratio and other parameters indicates unspecific changes which accompany the original organic matter. The lower-sulfur Ct sediment samples were found to have a higher PAH content than higher sulfur IM samples, leading to the conclusion that the PAH content of sediments may be related to the depositional environment.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42124140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-26DOI: 10.20450/mjcce.2023.2702
J. Lović, N. Nikolić, P. Živković, S. Dimitrijević, M. Stevanović
A series of bimetallic Sn-Pd catalysts were prepared by a template-free two step electrodeposition method. According to this method, Sn was electrodeposited firstly in potentiostatic or galvanostatic regime on Cu electrodes in the form of dendrites, then Pd was galvanostatically electrodeposited in the second step on the electrode with the electrodeposited Sn dendrites. The produced Sn-Pd electrocatalysts were compared with an electrocatalyst obtained by Pd electrodeposition on a bare Cu electrode. The morphological and elemental analysis of Sn-Pd and Pd electrocatalysts was performed by means of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. The dendrites of various shapes and degree of branching were obtained by Sn deposition depending on electrodeposition regime, while Pd was electrodeposited in a form of compact Pd islands on both Sn dendrites and the Cu electrode. Cyclic voltammetry (CV) was applied for the electrochemical examination of Sn-Pd and Pd catalysts towards the ethanol oxidation reaction (EOR) in the alkaline solution. The electrocatalyst Sn0.6-Pd0.4 with an atomic ratio of 60 at.% Sn-40 at.% Pd showed higher oxidation efficiency and better tolerance towards intermediate species in EOR than the other examined electrocatalysts . It was shown that the lower fraction of Pd, relative to Sn, was crucial to achieving optimal synergy of Sn with Pd thus contributing to enhanced electrochemical behavior regarding EOR.
{"title":"Influence of electrodeposition regime and Sn:Pd ratios in Sn-Pd electrocatalysts on ethanol oxidation reaction","authors":"J. Lović, N. Nikolić, P. Živković, S. Dimitrijević, M. Stevanović","doi":"10.20450/mjcce.2023.2702","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2702","url":null,"abstract":"A series of bimetallic Sn-Pd catalysts were prepared by a template-free two step electrodeposition method. According to this method, Sn was electrodeposited firstly in potentiostatic or galvanostatic regime on Cu electrodes in the form of dendrites, then Pd was galvanostatically electrodeposited in the second step on the electrode with the electrodeposited Sn dendrites. The produced Sn-Pd electrocatalysts were compared with an electrocatalyst obtained by Pd electrodeposition on a bare Cu electrode. The morphological and elemental analysis of Sn-Pd and Pd electrocatalysts was performed by means of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. The dendrites of various shapes and degree of branching were obtained by Sn deposition depending on electrodeposition regime, while Pd was electrodeposited in a form of compact Pd islands on both Sn dendrites and the Cu electrode. Cyclic voltammetry (CV) was applied for the electrochemical examination of Sn-Pd and Pd catalysts towards the ethanol oxidation reaction (EOR) in the alkaline solution. The electrocatalyst Sn0.6-Pd0.4 with an atomic ratio of 60 at.% Sn-40 at.% Pd showed higher oxidation efficiency and better tolerance towards intermediate species in EOR than the other examined electrocatalysts . It was shown that the lower fraction of Pd, relative to Sn, was crucial to achieving optimal synergy of Sn with Pd thus contributing to enhanced electrochemical behavior regarding EOR.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":"185 ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41274008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-12DOI: 10.20450/mjcce.2023.2638
Zlatko Lozanovski, J. Petreska Stanoeva, J. Bogdanov
In order to improve the bioavailability of curcumin, studies have been undertaken to prepare the so-called monocarbonyl analogs of curcumin (MACs) and assess their biological activity. These analogs contain an electrophilic α,β-unsaturated carbonyl moiety (Michael acceptor). Several key biological processes are connected/controlled with thiol alkylation (glutathione, cysteine, cysteine peptide residues). The most likely reaction is the Michael addition between the α,β-unsaturated acceptor and a corresponding thiol. 2,6-Bisarylidenecyclohexanone and 3,5-bisarylidenepiperidin-4-one scaffolds offer convenient tunability of electrophilicity and redox properties of the Michael acceptor by the introduction of various substituents. In this study, several MACs were prepared by Claisen-Schmidt condensation reaction, and their reactivity with 2-(dimethylamino)ethanethiol was evaluated. For this purpose, based on the UV-Vis spectra of the analogs and thiol(s), a proper method for spectrophotometric evaluation of their reactivity with 2-(dimethylamino)ethanethiol was optimized. The relative reactivity of the analogs was 7 > 2 > 5 > 4 > 1 ≈ 6. The developed method is simple, and it can be extended to assess the reactivity of other MACs.
{"title":"Development of a spectrophotometric method for assessment of the relative reactivity of monocarbonyl analogs of curcumin with 2-(dimethylamino)ethanethiol","authors":"Zlatko Lozanovski, J. Petreska Stanoeva, J. Bogdanov","doi":"10.20450/mjcce.2023.2638","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2638","url":null,"abstract":"In order to improve the bioavailability of curcumin, studies have been undertaken to prepare the so-called monocarbonyl analogs of curcumin (MACs) and assess their biological activity. These analogs contain an electrophilic α,β-unsaturated carbonyl moiety (Michael acceptor). Several key biological processes are connected/controlled with thiol alkylation (glutathione, cysteine, cysteine peptide residues). The most likely reaction is the Michael addition between the α,β-unsaturated acceptor and a corresponding thiol. 2,6-Bisarylidenecyclohexanone and 3,5-bisarylidenepiperidin-4-one scaffolds offer convenient tunability of electrophilicity and redox properties of the Michael acceptor by the introduction of various substituents. In this study, several MACs were prepared by Claisen-Schmidt condensation reaction, and their reactivity with 2-(dimethylamino)ethanethiol was evaluated. For this purpose, based on the UV-Vis spectra of the analogs and thiol(s), a proper method for spectrophotometric evaluation of their reactivity with 2-(dimethylamino)ethanethiol was optimized. The relative reactivity of the analogs was 7 > 2 > 5 > 4 > 1 ≈ 6. The developed method is simple, and it can be extended to assess the reactivity of other MACs.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46566713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-12DOI: 10.20450/mjcce.2023.2675
V. Petruševski, Sašo Kalajdžievski
Photographic slides of an aperiodic heptagonal tiling were used as two-dimensional diffraction gratings (as a standard approach) to describe and demonstrate the basic properties of dodecagonal quasicrystals. The paper completes our earlier two publications dealing with (1) Penrose (decagonal) and Ammann (octagonal) quasicrystals and (2) dodecagonal quasicrystals, the diffraction gratings of which were constructed and presented in an analogous manner.
{"title":"Heptagonal quasicrystals: Construction of 2D lattices and demonstrations using laser pointers – Concluding part","authors":"V. Petruševski, Sašo Kalajdžievski","doi":"10.20450/mjcce.2023.2675","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2675","url":null,"abstract":"Photographic slides of an aperiodic heptagonal tiling were used as two-dimensional diffraction gratings (as a standard approach) to describe and demonstrate the basic properties of dodecagonal quasicrystals. The paper completes our earlier two publications dealing with (1) Penrose (decagonal) and Ammann (octagonal) quasicrystals and (2) dodecagonal quasicrystals, the diffraction gratings of which were constructed and presented in an analogous manner.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49389204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-30DOI: 10.20450/mjcce.2023.2563
H. İlkimen, Yasemin Tunca, Ekrem Tunca, M. Bülbül, C. Yeni̇kaya
In this study, two new proton transfer salts of sulfonamide derivatives of maleic acid, namely (ClHabt)+(mabsmal)– (1) and (ClHabt)+(pabsmal)– (2), were obtained from 2-amino-6-chlorobenzothiazole (Clabt) and N-(3-sulfamoylphenyl)maleamide acid (Hmabsmal) and N-(4-sulfamoylphenyl)maleamide acid (Hpabsmal), respectively. Also, the Cu(II) complexes (3 and 4) of salts (1 and 2) and of Hmabsmal (5) were prepared. Compounds 1‒5 were characterized by elemental, NMR (1H and 13C), FTIR, and thermal analyses, as well as UV-Vis, magnetic moment, and molar conductivity measurements. Carbonic anhydrase isoenzymes (hCA I and II) were purified from human erythrocyte cells by affinity chromatography. The effects of the synthesized compounds on the hydratase and esterase activities of CA isoenzymes were studied in vitro. The results reveal that the synthesized compounds inhibit both esterase and hydratase activities of hCA I and hCA II. The inhibition constants of the compounds (Ki) were determined according to the esterase activity measurements. Ki values of 1‒5 are in the range of 0.06 ± 0.003 µM and 4.25 ± 0.100 µM for hCA I, and of 0.02 ± 0.001 µM and 3.21 ± 0.200 µM for hCA II.
{"title":"Carbonic anhydrase inhibitory activities of novel proton transfer salts and their Cu(II) complexes","authors":"H. İlkimen, Yasemin Tunca, Ekrem Tunca, M. Bülbül, C. Yeni̇kaya","doi":"10.20450/mjcce.2023.2563","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2563","url":null,"abstract":"In this study, two new proton transfer salts of sulfonamide derivatives of maleic acid, namely (ClHabt)+(mabsmal)– (1) and (ClHabt)+(pabsmal)– (2), were obtained from 2-amino-6-chlorobenzothiazole (Clabt) and N-(3-sulfamoylphenyl)maleamide acid (Hmabsmal) and N-(4-sulfamoylphenyl)maleamide acid (Hpabsmal), respectively. Also, the Cu(II) complexes (3 and 4) of salts (1 and 2) and of Hmabsmal (5) were prepared. Compounds 1‒5 were characterized by elemental, NMR (1H and 13C), FTIR, and thermal analyses, as well as UV-Vis, magnetic moment, and molar conductivity measurements. Carbonic anhydrase isoenzymes (hCA I and II) were purified from human erythrocyte cells by affinity chromatography. The effects of the synthesized compounds on the hydratase and esterase activities of CA isoenzymes were studied in vitro. The results reveal that the synthesized compounds inhibit both esterase and hydratase activities of hCA I and hCA II. The inhibition constants of the compounds (Ki) were determined according to the esterase activity measurements. Ki values of 1‒5 are in the range of 0.06 ± 0.003 µM and 4.25 ± 0.100 µM for hCA I, and of 0.02 ± 0.001 µM and 3.21 ± 0.200 µM for hCA II.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48756614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-29DOI: 10.20450/mjcce.2023.2677
A. Al-Owais, I. El-Hallag, Elsayed El-Mossalamy
The electrochemical behavior of hydroquinone was examined experimentally using cyclic voltammetry, convolution transform, and deconvolution transform at clean ordinary and nanostructured mesoporous platinum electrodes in 1 mol/l HClO4. The cyclic voltammogram of hydroquinone (HQ) at an ordinary Pt electrode displays an anodic peak at 0.610 V and a cathodic peak at 0.117 V, with a scan rate of 50 mV·s–1. Excellent linearity was recorded between the anodic or cathodic peak currents of hydroquinone and the square root of the scan rate (υ1/2). The anodic and cathodic peak potential separation (∆Ep) was found to be 463 ± 3 mV vs. the saturated calomel electrode (SCE). It was noted that the value of peak potential separation increased with increasing the scan rate. The type of electrode reaction at both platinum electrodes in 1 mol/l HClO4 was examined and discussed. The electrochemical parameters and the nature of the mechanistic pathway of the investigated HQ were determined experimentally and ascertained via a numerical simulation method.
{"title":"Voltammetric examination of hydroquinone at ordinary and nano-architecture platinum electrodes","authors":"A. Al-Owais, I. El-Hallag, Elsayed El-Mossalamy","doi":"10.20450/mjcce.2023.2677","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2677","url":null,"abstract":"The electrochemical behavior of hydroquinone was examined experimentally using cyclic voltammetry, convolution transform, and deconvolution transform at clean ordinary and nanostructured mesoporous platinum electrodes in 1 mol/l HClO4. The cyclic voltammogram of hydroquinone (HQ) at an ordinary Pt electrode displays an anodic peak at 0.610 V and a cathodic peak at 0.117 V, with a scan rate of 50 mV·s–1. Excellent linearity was recorded between the anodic or cathodic peak currents of hydroquinone and the square root of the scan rate (υ1/2). The anodic and cathodic peak potential separation (∆Ep) was found to be 463 ± 3 mV vs. the saturated calomel electrode (SCE). It was noted that the value of peak potential separation increased with increasing the scan rate. The type of electrode reaction at both platinum electrodes in 1 mol/l HClO4 was examined and discussed. The electrochemical parameters and the nature of the mechanistic pathway of the investigated HQ were determined experimentally and ascertained via a numerical simulation method. ","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45914543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-15DOI: 10.20450/mjcce.2023.2584
Gürkan Alkan, S. Ulusoy, M. Akgün, A. Oral
Nanofibers loaded with pharmaceutical agents for various medical purposes have become more important in recent years because of their advantages, such as control on release, gas permeability, high surface area, and lightweight matrices. In the present study, polylactic acid (PLA)-gelatin (Gel) nanofibers were successfully loaded with Ibuprofen-Na/Paracetamol (henceforth Ibu-Na and Par, respectively) by electrospinning. The nanofibers were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The Ibu-Na/Par content of the nanofibers was determined by using high-performance liquid chromatography (HPLC). Their antibacterial activities were tested against Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa PA01, opportunistic pathogenic bacteria which are frequently associated with infections. Moreover, their antibiofilm activities against P. aeruginosa and E. faecalis were also investigated. The Ibu-Na-containing nanofibers exhibited antibacterial activity against S. aureus, E. coli, and E. faecalis. The inhibition zone diameters of PLA-Gel-Ibu-Na 300 against E. faecalis, S. aureus, and E. coli were calculated to be 23.0 ± 2.1 mm, 18.0 ± 1.5 mm, and 12.0 ± 1.2 mm, respectively. It was found that PLA-Gel-Ibu-Na 300 and PLA-Gel-Par 300 nanofibers’ capacity to show biofilm formation inhibition originated remarkable effects on P. aeruginosa, which were found to be 48 % and 50.4 %, respectively. This study indicated that Ibu-Na/Par-loaded nanofibers are promising materials for wound healing applications.
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