Journal of The Serbian Chemical Society最新文献_第6页

Assignment of NMR spectral data of diastereomeric tetrahydrofuranyl acetals directly from their mixture by spectral simulation 光谱模拟直接从四氢呋喃缩醛混合物中提取非对映异构体的核磁共振光谱数据

IF 1 4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc230614054n

Milan Nešić, M. Nesic, N. Radulović

{"title":"Assignment of NMR spectral data of diastereomeric tetrahydrofuranyl acetals directly from their mixture by spectral simulation","authors":"Milan Nešić, M. Nesic, N. Radulović","doi":"10.2298/jsc230614054n","DOIUrl":"https://doi.org/10.2298/jsc230614054n","url":null,"abstract":"In this study, an NMR spectral analysis of the mixture of diastereomeric acetals, synthesized from 2,3-dihydrofurane and a racemic mixture of citronellol, was performed. 1H NMR full spin analysis was achieved by manually adjusting ?H and J values (previously calculated using the Spartan software) to fit the experimentally available values, followed by further optimization using MestreNova software. The simulated 1H- and 13C-NMR spectra of individual diastereomers, as well as their superimposed and summed spectra, were compared with the obtained experimental spectra. Spin simulation of proton signals was particularly useful for the assignment of the diastereotopic protons of tetrahydrofuranyl moiety and diastereomer discrimination. The NMR spectral data of individual diastereomers - chemical shifts, coupling constants, HMBC, and NOESY interactions were systematized in appropriate tables and schemes. To the best of our knowledge, this is for the first time that the complete assignment of tetrahydrofuranyl moiety was performed, and the data obtained herein may be of great importance for the utilization of this protecting group in the future.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68517777","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}

引用次数: 0

High cell density cultivation of Bacillus subtilis NCIM 2063: Modeling, optimization and a scale-up procedure 枯草芽孢杆菌NCIM 2063的高密度培养:建模、优化和放大过程

IF 1 4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc230407036s

Sandra Stamenkovic-Stojanovic, Ivana T. Karabegović, B. Danilović, Stojan Mančić, M. Lazić

{"title":"High cell density cultivation of Bacillus subtilis NCIM 2063: Modeling, optimization and a scale-up procedure","authors":"Sandra Stamenkovic-Stojanovic, Ivana T. Karabegović, B. Danilović, Stojan Mančić, M. Lazić","doi":"10.2298/jsc230407036s","DOIUrl":"https://doi.org/10.2298/jsc230407036s","url":null,"abstract":"Bacillus subtilis is a non-pathogenic, sporulating, gram-positive bacteria with pronounced antimicrobial and metabolic activity and great potential for wide application in various fields. The aim of this paper was to determine the optimum B. subtilis NCIM 2063 growth conditions and to scale up biomass production from shake flasks to a bioreactor level. The critical growth parameters and their interaction effects were studied using Box-Bekhen experimental design and response surface methodology. Developed model equations were statistically significant with good prediction capability. It was found that during shake flask cultivation glucose should be added in concentration up to 5 g l-1 in DSM medium, OTR at 10 mol m-3h-1 and temperature of 33 ?C, to achieve the maximum number of viable cells and spores. To scale up the process from shake flasks to the bioreactor level kLa was used as a main criterion. Scale up effect was evaluated by comparing the growth kinetics in the shake flasks and in a laboratory bioreactor. The total number of cells obtained in the bioreactor was 4.57?109 CFU ml-1 which is 1.41 times higher than the number of cells in the shake flasks (3.24?109 CFU ml-1), proving that the scale-up procedure was conducted successfully.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68517784","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}

引用次数: 0

Antidiabetic potential of simple carbamate derivatives: Comparative experimental and computational study 简单氨基甲酸酯衍生物的抗糖尿病潜力:比较实验和计算研究

4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc220923058s

Relja Surucic, Ivana Jevtic, Tatjana Stanojkovic, Jelena Popovic-Djordjevic

{"title":"Antidiabetic potential of simple carbamate derivatives: Comparative experimental and computational study","authors":"Relja Surucic, Ivana Jevtic, Tatjana Stanojkovic, Jelena Popovic-Djordjevic","doi":"10.2298/jsc220923058s","DOIUrl":"https://doi.org/10.2298/jsc220923058s","url":null,"abstract":"With the increasing global burden of diabetes mellitus type 2, the search for the new drugs, with better pharmacological profile is continued. As a part of this surge, the synthesis, pharmacological in vitro and computational evaluation of five, simple carbamate derivatives, against carbohydrate digestive enzyme ?-glucosidase, is disclosed herein. Results of the experimental and computational assessment indicated that examined carbamates deterred the activity of ?-glucosidase with acceptable IC50 values ranging from 65.34 to 79.89 ?M compared to a standard drug acarbose (109.71 ?M). Similarly, studied compounds displayed in silico binding affinity for ?-glucosidase enzyme with significant binding energies. Preliminary toxicity profiles of studied carbamates against three cancerous cell lines indicated their poor activity, suggesting that significant structural modifications have to be made to improve their anticancer efficiency. Results of the present study indicate that examined carbamates were able to virtually or experimentally interact with an important target of diabetes mellitus type 2. Additionally, a new pharmacophore model is proposed featuring hydrogen bond donating carbamate -NH group, hydrogen bond accepting carbamate -OCH3 group and hydrophobic stabilization of aromatic moieties.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135360531","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}

引用次数: 0

Pictorial based learning: Promoting conceptual change in chemical kinetics 基于图像的学习:促进化学动力学概念的改变

IF 1 4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc220403070h

Habiddin Habiddin, Herunata Herunata, Oktavia Sulistina, Aceng Haetami, Maysara Maysara, Dušica D. Rodić

{"title":"Pictorial based learning: Promoting conceptual change in chemical kinetics","authors":"Habiddin Habiddin, Herunata Herunata, Oktavia Sulistina, Aceng Haetami, Maysara Maysara, Dušica D. Rodić","doi":"10.2298/jsc220403070h","DOIUrl":"https://doi.org/10.2298/jsc220403070h","url":null,"abstract":"This study aimed to examine the effect of pictorial based learning (PcBL) on conceptual change in the topic of chemical kinetics. The four-tier instrument (FTDICK) previously developed was deployed to map conceptual change within chemical kinetics concepts. First-year chemistry students at an Indonesian university formed an experimental and a control group. The experimental group experienced the PcBL approach while the control one experienced direct instruction (DI). The conceptual changes demonstrated by the two groups are classified into four categories, namely complete, partial, false and random. Complete conceptual change (CCC) had the highest occurrence rate among the four categories. However, generalising that PcBL and DI are influential in promoting conceptual change in the field of chemical kinetics may be too ambitious. Therefore, further research is needed to reach that conclusion. The effectiveness of PcBL and DI in promoting conceptual change in this study was almost equal. However, in answering the FTDICK questions, the PcBL students showed a better performance reflecting more sound scientific understanding than DI students did.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68514090","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}

引用次数: 0

Analysis of the initial education of chemistry teachers and their attitudes towards teaching in the Republic of Serbia 塞尔维亚共和国化学教师初教状况及教学态度分析

IF 1 4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc220822039h

Saša A. Horvat, V. Popovic, Dušica D. Rodić, Tamara N. Rončević

{"title":"Analysis of the initial education of chemistry teachers and their attitudes towards teaching in the Republic of Serbia","authors":"Saša A. Horvat, V. Popovic, Dušica D. Rodić, Tamara N. Rončević","doi":"10.2298/jsc220822039h","DOIUrl":"https://doi.org/10.2298/jsc220822039h","url":null,"abstract":"This research was aimed to analyse the current state in primary and secondary schools in the Republic of Serbia regarding chemistry teachers? initial education and self-perceived competencies. As an instrument, a questionnaire of 20 questions was used, which was prepared in the form of a Google questionnaire. The questions were divided into five groups to examine data on the structure of chemistry teachers (gender, age, place and school where they teach), the level of education obtained and the method of acquisition and acquired competencies, and finally the personal opinion of chemistry teachers about the teaching profession, advantages, disadvantages and possible recommendations to his/her students in terms of choosing this profession as a possible career. The questionnaire was sent to 1537 schools and 497 chemistry teachers took part in the questionnaire. The results showed that chemistry teachers are predominantly women, mostly aged 36- 55, full-time employed and with an average working experience of over 11 years. Most teachers have appropriate education and acquired competencies. They cite working with children as the biggest advantage of the teaching profession while as the biggest disadvantage, they report a constant increase in the volume of administration from year to year.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68515360","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}

引用次数: 0

A novel PGA/TiO2 nanocomposite prepared with poly(γ-glutamic acid) from the newly isolated Bacillus subtilis 17B strain 从新分离的枯草芽孢杆菌17B菌株中制备聚γ-谷氨酸PGA/TiO2纳米复合材料

IF 1 4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc221116011s

Marinela Sokarda-Slavic, Vanja Ralic, B. Nastasijević, Milica Matijević, Z. Vujčić, Aleksandra Margetić

{"title":"A novel PGA/TiO2 nanocomposite prepared with poly(γ-glutamic acid) from the newly isolated Bacillus subtilis 17B strain","authors":"Marinela Sokarda-Slavic, Vanja Ralic, B. Nastasijević, Milica Matijević, Z. Vujčić, Aleksandra Margetić","doi":"10.2298/jsc221116011s","DOIUrl":"https://doi.org/10.2298/jsc221116011s","url":null,"abstract":"Poly(?-glutamic acid) (PGA), naturally produced by Bacillus species, is a biodegradable, non-toxic, biocompatible, and non-immunogenic negatively charged polymer. Due to its properties, it has found various applications in the food, cosmetic and pharmaceutical industries. In this work, Bacillus subtilis 17B was selected as the best PGA producer among fifty wild-types Bacillus strains tested and characterized as a glutamate-independent producer. The production of PGA by the newly identified strain was optimized and increased tenfold using the Box-Behnken experimental design. The purity of PGA after recovery and purification from the fermentation broth was confirmed by SDS-PAGE followed by Methylene Blue staining. PGA was characterized by ESI MS and used for the preparation of a new nanocomposite with TiO2. The synthesis of PGA/TiO2 nanocomposite, its structural analysis, and cytotoxic effect on the cervical cancer cell line (HeLa cell) was investigated to determine the potential anti-cancer usage of this newly prepared material. Encouraging, PGA/TiO2 nanocomposite showed an increased cytotoxic effect compared to TiO2 alone.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68515750","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}

引用次数: 1

On the importance of π-π interactions in the structural stability of phycocyanins 论π-π相互作用在藻蓝蛋白结构稳定性中的重要性

IF 1 4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc221201008b

Luka M. Breberina, M. Nikolic, S. Stojanovic, M. Zlatovic

{"title":"On the importance of π-π interactions in the structural stability of phycocyanins","authors":"Luka M. Breberina, M. Nikolic, S. Stojanovic, M. Zlatovic","doi":"10.2298/jsc221201008b","DOIUrl":"https://doi.org/10.2298/jsc221201008b","url":null,"abstract":"The influences of ?-? interactions in phycocyanin proteins and their environmental preferences were analyzed. The observations indicate that the majority of the aromatic residues in phycocyanin proteins are involved in ?-? interactions. Phe and Tyr residues were found to be involved in ?-? interactions much more frequently than Trp or His. Similarly, the Phe-Phe and Tyr-Tyr ?-? interacting pair had the highest frequency of occurrence. In addition to ?-? interactions, the aromatic residues also form ?-networks in phycocyanins. The ?-? interactions are most favorable at the pair distance range of 5.5-7 ?, with a clear preference for T-shaped ring arrangements. Using ab initio calculations, we observed that most of the ?-? interactions have energy from 0 to -10 kJ mol-1. Stabilization centers for these proteins showed that all residues found in ?-? interactions are important in locating one or more such centers. ?-? interacting residues are evolutionary conserved. The results obtained from this study will be beneficial in further understanding the structural stability and eventual development of protein engineering of phycocyanins.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68516279","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}

引用次数: 0

Impaired local hydrophobicity, structural stability and conformational flexibility due to point mutations in sult1 family of enzymes sult1家族酶的点突变导致局部疏水性、结构稳定性和构象灵活性受损

IF 1 4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc230210022c

Silvana Ceauranu, V. Ostafe, A. Isvoran

引用次数: 1

Impedance response of aluminum alloys with varying Mg content in Al-Mg systems during exposure to chloride corrosion environment Al-Mg体系中不同Mg含量铝合金在氯化物腐蚀环境下的阻抗响应

IF 1 4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc230505031s

J. Scepanovic, Pavlovic Pantovic, Darko Vuksanovic, G. Šekularac, M. Pavlovic

{"title":"Impedance response of aluminum alloys with varying Mg content in Al-Mg systems during exposure to chloride corrosion environment","authors":"J. Scepanovic, Pavlovic Pantovic, Darko Vuksanovic, G. Šekularac, M. Pavlovic","doi":"10.2298/jsc230505031s","DOIUrl":"https://doi.org/10.2298/jsc230505031s","url":null,"abstract":"This research discusses the corrosion behavior of as-cast Al alloys with different Mg content by potentiostatic electrochemical impedance spectroscopy (PEIS). The complex plane spectra of all samples feature a high-frequency loop, followed by semi-infinite diffusion impedance characteristics at low frequencies, with the corrosion-induced formation of a defined porous structure of a layer making finite diffusion through the pores dominant upon prolonged exposure. The most compact layer causes the most pronounced and well-resolved finite diffusion features in the impedance spectra of the sample with the highest Mg content, while the sample with the lowest Mg content has a highly porous layer unable to slow down the corrosion rate at the layer/sample surface interface. The highest layer capacitance and diffusion admittance are found in the sample with the highest Mg content, with a more adherent protective film expected to form. However, the growth rate of the layer was not adequate for the remarkable closing of the pits, indicating the weakness of this sample towards pit activity. The results show that increasing Mg content improves corrosion resistance and clearly separates bulky corrosion from localized pitting corrosion, but it also increases the thickness of a more compact, poorly adhesive layer.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68517607","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}

引用次数: 0

The effects of online learning about the Brønsted-Lowry theory of acids and bases in the first grade of grammar school during the COVID-19 pandemic 新冠肺炎疫情期间，小学一年级学生在线学习Brønsted-Lowry酸碱理论的效果

4区化学

Journal of The Serbian Chemical Society Pub Date : 2023-01-01 DOI: 10.2298/jsc230330059h

Ana-Andrea Holik, Dragica Trivic

{"title":"The effects of online learning about the Brønsted-Lowry theory of acids and bases in the first grade of grammar school during the COVID-19 pandemic","authors":"Ana-Andrea Holik, Dragica Trivic","doi":"10.2298/jsc230330059h","DOIUrl":"https://doi.org/10.2298/jsc230330059h","url":null,"abstract":"The aim of this paper was to examine the effects of the application of online material on the Br?nsted-Lowry theory of acids and bases on the active construction of knowledge in first-grade grammar school students during the COVID-19 pandemic. The online material was designed to enable students: (a) to learn the teaching material in smaller parts; (b) to assess the acquired knowledge after each part of the teaching material; (c) to progress through the lesson at their own pace; (d) to visualise and interrelate the macroscopic, submicroscopic and symbolic representations of the contents about acids and bases by using a video recording and illustrations; (e) to re-examine the accuracy of the given answers. The research sample consisted of 122 first-grade grammar school students, who learnt about the Br?nsted-Lowry theory for the first time. The instruments used in this research study were two tests (a pre-test and a post-test), the validity of which was examined by two university professors and two grammar school chemistry teachers. The applied approach enabled the active construction of knowledge in the majority of students, while it provided the teachers with an insight into the progress and outcomes of the process.","PeriodicalId":17489,"journal":{"name":"Journal of The Serbian Chemical Society","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135400055","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}

引用次数: 0