Pub Date : 2023-12-07DOI: 10.6001/chemija.2023.34.4.3
Aurimas Plaga, Birutė Sapijanskaitė-Banevič, R. Vaickelionienė
Hydrazides are very important precursors for the synthesis of a wide variety of derivatives, including heterocyclic compounds of biological interest in drug design and discovery. Acid hydrazides with a pyrrole, thiophene, furan, quinoline, isoquinoline, isoxazole and benzimidazole core in the structure were found to be used in medicine, pharmacy, agriculture and many other fields. In the search for compounds with antibacterial properties, mono- and dihydrazides were used in this study to prepare 1-(4-substituted phenyl)-5-oxopyr-rolidine-3-carbohydrazide derivatives bearing the corresponding hydrazone and azole substituents. The formation of the target compounds was performed via condensation reactions with the chosen aromatic aldehydes and isatin, which led to the construction of the appropriate hydrazone-type structures as well as with diketones which afforded compounds with pyrazole and pyrrole nuclei. In addition, a preliminary antibacterial evaluation of the synthesised compounds was performed using the gram-positive Bacillus subtilis and the gramnegative Escherichia coli bacterial strains. As it was expected, the evaluation revealed potential antibacterial candidates that can help address the global challenges of antibiotic resistance and infectious disease outbreaks.
{"title":"Synthesis and investigation of antibacterial activity of 1-(4-substituted phenyl)-5-oxopyrrolidine-3-carbohydrazide derivatives","authors":"Aurimas Plaga, Birutė Sapijanskaitė-Banevič, R. Vaickelionienė","doi":"10.6001/chemija.2023.34.4.3","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.4.3","url":null,"abstract":"\u0000 \u0000 \u0000 \u0000Hydrazides are very important precursors for the synthesis of a wide variety of derivatives, including heterocyclic compounds of biological interest in drug design and discovery. Acid hydrazides with a pyrrole, thiophene, furan, quinoline, isoquinoline, isoxazole and benzimidazole core in the structure were found to be used in medicine, pharmacy, agriculture and many other fields. \u0000In the search for compounds with antibacterial properties, mono- and dihydrazides were used in this study to prepare 1-(4-substituted phenyl)-5-oxopyr-rolidine-3-carbohydrazide derivatives bearing the corresponding hydrazone and azole substituents. \u0000The formation of the target compounds was performed via condensation reactions with the chosen aromatic aldehydes and isatin, which led to the construction of the appropriate hydrazone-type structures as well as with diketones which afforded compounds with pyrazole and pyrrole nuclei. \u0000In addition, a preliminary antibacterial evaluation of the synthesised compounds was performed using the gram-positive Bacillus subtilis and the gramnegative Escherichia coli bacterial strains. As it was expected, the evaluation revealed potential antibacterial candidates that can help address the global challenges of antibiotic resistance and infectious disease outbreaks. \u0000 \u0000 \u0000 \u0000","PeriodicalId":9720,"journal":{"name":"Chemija","volume":"134 ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138983580","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 : 2023-12-07DOI: 10.6001/chemija.2023.34.4.2
Paulina Kaziukonytė, Tomas Venslauskas, Kamilė Venskūnaitė, Ieva Žutautė, A. Brukštus
The efficient synthesis of 4-alkyl-6-(5-aryl-1,2,3-thiadiazol-4-yl)benzene-1,3-diols as potential isoform-specific Hsp90 inhibitors was developed. The synthetic pathway starts from the commercially available 1,3-benzenediol and employs well-known reactions. The Friedel–Crafts acylation and carbonyl group reduction to the methylene group gave 1-(5-alkyl-2,4-dihydroxyphenyl)-2-arylethan-1-ones. The subsequently carried out condensation with ethyl carbazate and Hurd–Mori cyclisation gave title compounds.
{"title":"Synthesis of novel 4-alkyl-6-(5-aryl-1,2,3-thiadiazol-4-yl) benzene-1,3-diols as potential Hsp90 inhibitors","authors":"Paulina Kaziukonytė, Tomas Venslauskas, Kamilė Venskūnaitė, Ieva Žutautė, A. Brukštus","doi":"10.6001/chemija.2023.34.4.2","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.4.2","url":null,"abstract":"\u0000 \u0000 \u0000 \u0000The efficient synthesis of 4-alkyl-6-(5-aryl-1,2,3-thiadiazol-4-yl)benzene-1,3-diols as potential isoform-specific Hsp90 inhibitors was developed. The synthetic pathway starts from the commercially available 1,3-benzenediol and employs well-known reactions. The Friedel–Crafts acylation and carbonyl group reduction to the methylene group gave 1-(5-alkyl-2,4-dihydroxyphenyl)-2-arylethan-1-ones. The subsequently carried out condensation with ethyl carbazate and Hurd–Mori cyclisation gave title compounds. \u0000 \u0000 \u0000 \u0000","PeriodicalId":9720,"journal":{"name":"Chemija","volume":"37 37","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139011697","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 : 2023-12-07DOI: 10.6001/chemija.2023.34.4.1
Huma Amber, Karina Vjūnova, Z. Sukackienė, D. Šimkūnaitė, J. Vaičiūnienė, L. Tamašauskaitė-Tamašiūnaitė, E. Norkus
In this study, the catalytic hydrogen generation was evaluated on the cobalt–iron (CoFe), cobalt–iron–manganese (CoFeMn) and cobalt–ironmolybdenum (CoFeMo) coatings deposited on the Ni foam substrate using the electroless metal plating method and morpholine borane as the reducing agent. The characterisation of the surface morphology, structure and composition of resulted coatings was done using scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The catalytic activity of the prepared CoFe/Ni, CoFeMn/Ni and CoFeMo/Ni catalysts was investigated for hydrogen generation from an alkaline sodium borohydride (NaBH4) solution at different temperatures. It was found that the hydrogen generation rate of ca. 5.2, 7.8 and 11.7 L min–1 g–1 was achieved by using the CoFe/ Ni, CoFeMo/Ni and CoFeMn/Ni coatings, respectively, at 343 K. Among the investigated catalysts, CoFeMn/Ni exhibits the lowest activation energy of 62.4 kJ mol–1 and the highest HGR of 11.7 L min–1 g–1 at 343 K.
本研究采用无电解金属电镀法和吗啉硼烷作为还原剂，对沉积在泡沫镍基底上的钴铁（CoFe）、钴铁锰（CoFeMn）和钴铁钼（CoFeMo）镀层的催化制氢效果进行了评估。使用扫描电子显微镜（SEM）和电感耦合等离子体光发射光谱（ICP-OES）对所制备涂层的表面形貌、结构和成分进行了表征。研究了制备的 CoFe/Ni、CoFeMn/Ni 和 CoFeMo/Ni 催化剂在不同温度下从碱性硼氢化钠（NaBH4）溶液中制氢的催化活性。研究发现，在 343 K 下，使用 CoFe/Ni、CoFeMo/Ni 和 CoFeMn/Ni 涂层的制氢率分别达到约 5.2、7.8 和 11.7 L min-1 g-1。
{"title":"Hydrogen production on CoFe, CoFeMn and CoFeMo coatings deposited on Ni foam via electroless metal plating","authors":"Huma Amber, Karina Vjūnova, Z. Sukackienė, D. Šimkūnaitė, J. Vaičiūnienė, L. Tamašauskaitė-Tamašiūnaitė, E. Norkus","doi":"10.6001/chemija.2023.34.4.1","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.4.1","url":null,"abstract":"\u0000 \u0000 \u0000 \u0000In this study, the catalytic hydrogen generation was evaluated on the cobalt–iron (CoFe), cobalt–iron–manganese (CoFeMn) and cobalt–ironmolybdenum (CoFeMo) coatings deposited on the Ni foam substrate using the electroless metal plating method and morpholine borane as the reducing agent. The characterisation of the surface morphology, structure and composition of resulted coatings was done using scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The catalytic activity of the prepared CoFe/Ni, CoFeMn/Ni and CoFeMo/Ni catalysts was investigated for hydrogen generation from an alkaline sodium borohydride (NaBH4) solution at different temperatures. It was found that the hydrogen generation rate of ca. 5.2, 7.8 and 11.7 L min–1 g–1 was achieved by using the CoFe/ Ni, CoFeMo/Ni and CoFeMn/Ni coatings, respectively, at 343 K. Among the investigated catalysts, CoFeMn/Ni exhibits the lowest activation energy of 62.4 kJ mol–1 and the highest HGR of 11.7 L min–1 g–1 at 343 K. \u0000 \u0000 \u0000 \u0000","PeriodicalId":9720,"journal":{"name":"Chemija","volume":"44 23","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139011656","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 : 2023-09-17DOI: 10.6001/chemija.2023.34.3.1
Edita Daublytė, Marija Kalnaitytė, Aliona Klimovich, Audrius Drabavičius, Tatjana Charkova
Four polyols were used as stabilisers to synthesise silver nanospheres under reflux and microwave irradiation conditions. The nanoparticles were covered with a protective up to 10 nm silicon dioxide shell. The shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) technique was used to analyse the self-assembled monolayer of 4-mercaptobenzoic acid (4-MBA) by applying the produced silver core-silica shell nanoparticles. The article provides a detailed description of the synthesis, analysis and application of the nanoparticles based on UV/Vis, HR-TEM and SHINERS data.
{"title":"Synthesis of silver nanoparticles with polyols under reflux and microwave irradiation conditions","authors":"Edita Daublytė, Marija Kalnaitytė, Aliona Klimovich, Audrius Drabavičius, Tatjana Charkova","doi":"10.6001/chemija.2023.34.3.1","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.3.1","url":null,"abstract":"Four polyols were used as stabilisers to synthesise silver nanospheres under reflux and microwave irradiation conditions. The nanoparticles were covered with a protective up to 10 nm silicon dioxide shell. The shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) technique was used to analyse the self-assembled monolayer of 4-mercaptobenzoic acid (4-MBA) by applying the produced silver core-silica shell nanoparticles. The article provides a detailed description of the synthesis, analysis and application of the nanoparticles based on UV/Vis, HR-TEM and SHINERS data.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135259099","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 : 2023-09-17DOI: 10.6001/chemija.2023.34.3.2
Turlybek N. Nurakhmetov, Temirulan T. Alibay, Doszhan A. Tolekov, Raushan K. Shamiyeva, Sapargali Pazylbek, Dovydas Karoblis, Rimantas Raudonis, Aleksej Zarkov, Jonas Kiuberis, Aivaras Kareiva
Vacuum ultraviolet and thermal activation spectroscopies were used to study the nature of intrinsic emission and the mechanisms of the formation of electron and hole trapping centres in irradiated Li2SO4 powders and crystals. The obtained results along with excitation spectra showed that recombination emission at 3.8–4.2 eV and 4.5–5.5 eV occurs when an electron passes from the second and third sub-bands of the valence band formed from the 2p state of oxygen to the conduction band. It has been determined that Li2SO4 electron and hole trapping centres are created when electrons are trapped in the SO42– anionic sites. The holes are localised in the form of SO4 – radicals. The spectral position and intensity of individual emission bands are dependent on the crystallographic arrangement of localised holes.
{"title":"Intrinsic emissions and formation of electron-hole trapping centres in excited Li2SO4","authors":"Turlybek N. Nurakhmetov, Temirulan T. Alibay, Doszhan A. Tolekov, Raushan K. Shamiyeva, Sapargali Pazylbek, Dovydas Karoblis, Rimantas Raudonis, Aleksej Zarkov, Jonas Kiuberis, Aivaras Kareiva","doi":"10.6001/chemija.2023.34.3.2","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.3.2","url":null,"abstract":"Vacuum ultraviolet and thermal activation spectroscopies were used to study the nature of intrinsic emission and the mechanisms of the formation of electron and hole trapping centres in irradiated Li2SO4 powders and crystals. The obtained results along with excitation spectra showed that recombination emission at 3.8–4.2 eV and 4.5–5.5 eV occurs when an electron passes from the second and third sub-bands of the valence band formed from the 2p state of oxygen to the conduction band. It has been determined that Li2SO4 electron and hole trapping centres are created when electrons are trapped in the SO42– anionic sites. The holes are localised in the form of SO4 – radicals. The spectral position and intensity of individual emission bands are dependent on the crystallographic arrangement of localised holes.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135259100","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 : 2023-09-17DOI: 10.6001/chemija.2023.34.3.3
Asta Vasiliauskaitė
The deterioration and degree of preservation of copper alloy archaeological artefacts depends on several interacting factors that began when the artefacts were buried and continue in museum storage. Ageing and deterioration processes that have begun can be slowed, but not completely stopped. The influence of the type of copper alloy and museum environment storage conditions on deterioration processes was investigated. Crossbow brooches with a triangular foot were examined using non-destructive techniques such as portable XRF and radiography, as well as the data from excavation reports. The collected data on museum storage environment was analysed using the software program Eclimatenotebook. Based on the results of this analysis, the future preservation level was calculated using the risk assessment method. Most of the brooches examined were made of brass and were in a fairly good condition. The foot and pin were the most damaged parts. Future storage conditions with a high relative humidity (up to 80%) pose a great risk to the treated and untreated brooches.
{"title":"Assessment of the deterioration process of copper alloys: a case study of Central Lithuanian crossbow brooches with a triangular foot","authors":"Asta Vasiliauskaitė","doi":"10.6001/chemija.2023.34.3.3","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.3.3","url":null,"abstract":"The deterioration and degree of preservation of copper alloy archaeological artefacts depends on several interacting factors that began when the artefacts were buried and continue in museum storage. Ageing and deterioration processes that have begun can be slowed, but not completely stopped. The influence of the type of copper alloy and museum environment storage conditions on deterioration processes was investigated. Crossbow brooches with a triangular foot were examined using non-destructive techniques such as portable XRF and radiography, as well as the data from excavation reports. The collected data on museum storage environment was analysed using the software program Eclimatenotebook. Based on the results of this analysis, the future preservation level was calculated using the risk assessment method. Most of the brooches examined were made of brass and were in a fairly good condition. The foot and pin were the most damaged parts. Future storage conditions with a high relative humidity (up to 80%) pose a great risk to the treated and untreated brooches.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135259101","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 : 2023-09-17DOI: 10.6001/chemija.2023.34.3.4
Mindaugas Dailidė, Sigitas Tumkevičius
The present work deals with synthesis and biological evaluation of novel compounds as potential inhibitors of dihydrofolate reductase (DHFR) from opportunistic microorganisms – Pneumocystis carinii (pc), Toxoplasma gondii (tg) and Mycobacterium avium (ma). A set of 6 lipophilic and 1 classical antifolates of thieno[2,3-d]pyrimidine series were designed and synthesised with key pharmacophoric features of DHFR inhibitors and aminomethylene bridge joining the aromatic part and 2-amino-4-oxothieno[2,3-d]pyrimidine nucleus. Investigation of the DHFR inhibitory activity of the synthesised compounds revealed that 2-amino-6-[(4-methoxyphenylamino)-, 6--[(4-chlorophenylamino)- and 6-[(2,5 ichlorophenylamino)methyl]thieno[2,3-d]pyrimidin-4(3H)- ones had a moderate activity (IC50 56.5, 49.9 and 23 μM, respectively) against pcDHFR. Activity of those compounds against tgDHFR (IC50 6.0, 2.8 and 2.3 μM, respectively) was comparable to that of trimethoprim (IC50 2.7 μM). No synthesised lipophilic antifolates showed activity towards maDHFR. The classical antifolate 2-{4-[(2-amino-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidin-6-yl)methylamino]benzamido}-L-glutamic acid inhibited DHFRs from all microorganisms (IC50 6.6 μM for pcDHFR, 1.06 μM for tgDHFR and 16.9 μM for maDHFR).
本研究主要从卡氏肺囊虫(pc)、刚地弓形虫(tg)和鸟分枝杆菌(ma)等条件微生物中合成和评价作为二氢叶酸还原酶(DHFR)潜在抑制剂的新化合物。设计并合成了一组6亲脂性和1经典的硫代[2,3-d]嘧啶系列抗叶酸药，其具有DHFR抑制剂的关键药效特征，并具有连接芳香部分和2-氨基-4-氧硫代[2,3-d]嘧啶核的氨基甲基桥。结果表明，2-氨基-6-[(4-甲氧基苯基氨基)-、6-[(4-氯苯氨基)-和6-[(2,5氯苯氨基)甲基]噻吩[2,3-d]嘧啶-4(3H)-对pcDHFR具有中等抑制活性(IC50分别为56.5、49.9和23 μM)。这些化合物对tgDHFR的IC50分别为6.0、2.8和2.3 μM，与甲氧苄啶的IC50为2.7 μM相当。合成的亲脂性抗叶酸剂未显示对maDHFR的活性。经典的抗叶酸剂2-{4-[(2-氨基-4-氧-3,4-二氢噻吩[2,3-d]嘧啶-6-基)甲胺]苄胺}- l -谷氨酸对所有微生物的DHFRs均有抑制作用(IC50对pcDHFR为6.6 μM，对tgDHFR为1.06 μM，对maDHFR为16.9 μM)。
{"title":"Synthesis and dihydrofolate reductase inhibitory activity of 2-amino-6-(arylaminomethyl) thieno[2,3-d]pyrimidin-4(3H)-ones","authors":"Mindaugas Dailidė, Sigitas Tumkevičius","doi":"10.6001/chemija.2023.34.3.4","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.3.4","url":null,"abstract":"The present work deals with synthesis and biological evaluation of novel compounds as potential inhibitors of dihydrofolate reductase (DHFR) from opportunistic microorganisms – Pneumocystis carinii (pc), Toxoplasma gondii (tg) and Mycobacterium avium (ma). A set of 6 lipophilic and 1 classical antifolates of thieno[2,3-d]pyrimidine series were designed and synthesised with key pharmacophoric features of DHFR inhibitors and aminomethylene bridge joining the aromatic part and 2-amino-4-oxothieno[2,3-d]pyrimidine nucleus. Investigation of the DHFR inhibitory activity of the synthesised compounds revealed that 2-amino-6-[(4-methoxyphenylamino)-, 6--[(4-chlorophenylamino)- and 6-[(2,5 ichlorophenylamino)methyl]thieno[2,3-d]pyrimidin-4(3H)- ones had a moderate activity (IC50 56.5, 49.9 and 23 μM, respectively) against pcDHFR. Activity of those compounds against tgDHFR (IC50 6.0, 2.8 and 2.3 μM, respectively) was comparable to that of trimethoprim (IC50 2.7 μM). No synthesised lipophilic antifolates showed activity towards maDHFR. The classical antifolate 2-{4-[(2-amino-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidin-6-yl)methylamino]benzamido}-L-glutamic acid inhibited DHFRs from all microorganisms (IC50 6.6 μM for pcDHFR, 1.06 μM for tgDHFR and 16.9 μM for maDHFR).","PeriodicalId":9720,"journal":{"name":"Chemija","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135259096","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 : 2023-07-05DOI: 10.6001/chemija.2023.34.2.4
T. Petrulionienė, T. Murauskas, Mantas Norkus, E. Naujalis
Migration is a known phenomenon defined as the partitioning of certain chemical compounds from plastic food packaging into food and has been intensely investigated in recent years. Due to outstanding chemical and physical properties plastics are used in many fields. Polypropylene and polyethylene are extensively used polymers because of their chemical resistance, high tensile strength and low density. To improve the properties of the plastics, additives such as plasticizers, stabilizers, antioxidants, lubricants, pigments and others are required to be added. However, they can migrate from the plastics into the food and contaminate it during production or storage. Therefore, the aim of this study was to investigate commercial polypropylene and polyethylene packages to determine what most often used additives and degradation products of the food packages can migrate to food. After the initial identification of plastics by Fourier-transform infrared spectrometry, the determination of cadmium, chromium, lead and mercury was carried out by atomic absorption spectrophotometry. To evaluate possible volatile and semi-volatile organic compounds thermal desorption gas chromatography coupled with mass spectrometry was used. The results revealing the presence of different potential organic compounds and metals emitted during the degradation process of different types of food contact materials are discussed.
{"title":"Emission of additives and degradation products from commercial polypropylene, polyethylene and their composite packages","authors":"T. Petrulionienė, T. Murauskas, Mantas Norkus, E. Naujalis","doi":"10.6001/chemija.2023.34.2.4","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.2.4","url":null,"abstract":"Migration is a known phenomenon defined as the partitioning of certain chemical compounds from plastic food packaging into food and has been intensely investigated in recent years. Due to outstanding chemical and physical properties plastics are used in many fields. Polypropylene and polyethylene are extensively used polymers because of their chemical resistance, high tensile strength and low density. To improve the properties of the plastics, additives such as plasticizers, stabilizers, antioxidants, lubricants, pigments and others are required to be added. However, they can migrate from the plastics into the food and contaminate it during production or storage. Therefore, the aim of this study was to investigate commercial polypropylene and polyethylene packages to determine what most often used additives and degradation products of the food packages can migrate to food. After the initial identification of plastics by Fourier-transform infrared spectrometry, the determination of cadmium, chromium, lead and mercury was carried out by atomic absorption spectrophotometry. To evaluate possible volatile and semi-volatile organic compounds thermal desorption gas chromatography coupled with mass spectrometry was used. The results revealing the presence of different potential organic compounds and metals emitted during the degradation process of different types of food contact materials are discussed.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41511182","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 : 2023-07-05DOI: 10.6001/chemija.2023.34.2.2
Daiva Kazlauskienė, Palma Nenortienė, Deividas Kvedaravičius, J. Daukšienė, S. Velžienė
Amino acids are important for the human body as initial metabolites of polypeptides and proteins. The grass small-flowered galinsoga (Galinsoga parviflora L.) accumulates a large amount of various amino acids, this grass is not poisonous and edible in some countries. The aim of this research is to analyze the qualitative and quantitative composition of amino acids in the herb of small-flowered galinsoga (Galinsoga parviflora L.): to select the most suitable extraction conditions of amino acids from the Galinsoga parviflora herb; to apply the gas chromatography method for the determination of amino acids.
{"title":"Investigation of the qualitative and quantitative composition of amino acids in the herb of smallflowered galinsoga (Galinsoga parviflora L.) using gas chromatography","authors":"Daiva Kazlauskienė, Palma Nenortienė, Deividas Kvedaravičius, J. Daukšienė, S. Velžienė","doi":"10.6001/chemija.2023.34.2.2","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.2.2","url":null,"abstract":"Amino acids are important for the human body as initial metabolites of polypeptides and proteins. The grass small-flowered galinsoga (Galinsoga parviflora L.) accumulates a large amount of various amino acids, this grass is not poisonous and edible in some countries. The aim of this research is to analyze the qualitative and quantitative composition of amino acids in the herb of small-flowered galinsoga (Galinsoga parviflora L.): to select the most suitable extraction conditions of amino acids from the Galinsoga parviflora herb; to apply the gas chromatography method for the determination of amino acids.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44466740","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 : 2023-07-05DOI: 10.6001/chemija.2023.34.2.1
A. Kozma, A. Malinina, E. Golub, V. Rusyn, N. Golub, Vitalii Dziamko, Viktoriia Dziamko, O. Malinin, A. Solomon
For mercury dibromide HgBr2, a promising component of the working mixture of gas-discharge exciplex sources of coherent (lasers) and spontaneous (exciplex lamps) radiation, as well as a promising nonlinear optical crystal for the infrared radiation process, thermodynamic and thermochemical properties in the temperature range 173–512 K were investigated. The established basic thermodynamic (isobaric heat capacity Ср, total entropy S, enthalpy H and Gibbs energy G) and thermochemical (enthalpy ΔHf and Gibbs energy ΔGf of formation) functions of HgBr2 were compared with the known literature data at 298–514 K. The obtained results differed from the literature within 1–2% (for Ср), 0.1–0.2% (for S, H and G) and 0.1–0.6% (for ΔHf and ΔGf). The experimental data, combined with semi-empirical approaches and ab initio calculations taken from the literature, were used to estimate the previously unknown additional thermodynamic and thermophysical properties of HgBr2: isochoric heat capacity CV, Debye temperature θD, volume thermal expansion αV, isothermal compressibility βT (isothermal bulk modulus BT = 1/βT), Grüneisen constant γG, phonon longitudinal vl, transverse vs, average –v velocities and phonon thermal conductivity κ. In the present work, it was found that crystalline mercury dibromide expands strongly upon heating and has a low phonon thermal conductivity.
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