Predviđanje retencije β-diketonato kompleksa u TLC sistemima na silika-gelu primenom kvantitativnog odnosa strukture i retencije

Quantitative structure retention relationships for a series of 30 mixed beta-diketonato complexes of cobalt(III), chromium(III) and ruthenium(III) were derived by multiple linear regression analyses using molecular descriptors obtained by quantum chemical calculations. The retention parameters were obtained by thin layer chromatography on silica gel using mono and two-component solvent systems. The molecular descriptors included in the multiple linear regression analysis were molecular weight, molecular volume, surface area, hydrophilic lipophilic balance, percent hydrophilic surface area, dipole moment, polarizability, refractivity, energy of the highest occupied molecular orbital and energy of the lowest unoccupied molecular orbital. High agreement between the experimental and predicted retention parameters was obtained when polarizability and the hydrophilic lipophilic balance were used as the molecular descriptors. Comparison of the models with those established on polyacrylonitrile showed that the structure of the sorbent is responsible for the chromatographic behaviour of the same compounds. The presented models can be used for the prediction of the retention of new solutes in screening chromatographic systems.U ovom radu kvantifikovan je odnos strukture i retencije 30 mešovitih β-diketonato kompleksa kobalta(III), hroma(III) i rutenijuma(III) primenom multilinearne regresione analize korišćenjem molekulskih deskriptora, koji su dobijeni pomoću kvantno-hemijskih izračunavanja. Retencioni parametri su dobijeni tankoslojnom hromatografijom na silika-gelu primenom mono-i dvokomponetnih rastvarača. Molekulski deskriptori koji su uključeni u multilinearnu regresionu analizu su molekulska težina, molekulska zapremina, površina, hidrofilni-lipofilni balans, procenat hidrofilne površine, dipolni momenat, polarizabilnost, refraktivnost, energija najviše zauzete molekulske orbitale i energija najniže prazne molekulske orbitale. Dobijena je zadovoljavajuća korelacija između eksperimentalnih retencionih parametara i retencionih parametara predviđenih postavljenim modelima, koji sadrže polarizabilnost i hidrofilni-lipofilni balans kao deskriptore. Poređenja ovih modela sa modelima dobijenim na poliakrilonitrilnom sorbentu, za ista jedinjenja, pokazuju da je struktura sorbenta odgovorna za hromatografsko ponašanje. Ovi modeli se mogu koristiti za predviđanje retencije novih jedinjenja u datim hromatografskim sistemima

Modern analytical techniques in the assessment of the authenticity of Serbian honey

Food authenticity in a broader sense means fulfilling chemical and physical criteria prescribed by the proposed legislation. In the case of honey authenticity, two aspects are of major concern: the manufacturing process and the labelling of final products in terms of their geographical and botanical origin. A reliable assessment of honey authenticity has been a long-term preoccupation of chemists-analysts and it usually involves the use of several criteria and chemical markers, as well as a combination of analytical and statistical (chemometric) methods. This paper provides an overview of different criteria and modern methods for the assessment of honey authenticity in the case of a statistically significant number of authentic honey samples of several botanical types from various regions of Serbia

Production of stilbenes in callus cultures of the Maltese indigenous grapevine variety, Ġellewża

The production of secondary metabolites in tissue culture has been considered as an alternative to the cultivation and harvesting of crops intended for this purpose. The present study was aimed at the growth of callus and production of polyphenolic compound of callus derived from a Maltese indigenous grapevine variety, Ġellewża. Callus was inoculated onto plant growth regulators-enriched Murashige Skoog media (MSm) to determine whether polyphenols are produced in vitro as well as to determine the best combination of plant growth regulators needed for the production of these metabolites. From results obtained, it was observed that the best callus production was obtained by auxin-enriched MSm. In fact, indole acetic acid and indole acetic acid /6-benzyl aminopurine enhanced biomass accumulation (3.04 g and 3.39 g) as opposed to the others (<1.97 g). On the other hand, parameters showing the presence of flavonoids (tonality, 3.80), particularly anthocyanins (24.09 mg/kg) and total polyphenols (1.42 mg/g), were optimum in the presence of cytokinins, particularly 6-benzyl aminopurine. Analysis for single polyphenols revealed a high amount a particular stilbene: polydatin (glucoside of resveratrol). Resveratrol and other typical polyphenols, found in mature berries, were also found in significant quantities, while the other polyphenolic compounds were found in minimal quantities. This is the first study to describe the production and composition of polyphenols in Ġellewża callus cultures. From the results obtained, it can be seen that this grape tissue is an excellent alternative for the production of polyphenols from the stilbene group, which can be upscaled and exploited commercially.This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Grant no.172017) and by the Malta Council for Science and Technology (Research and Innovation Special Project 2008-01-VOTIVVOM-Valorization of the indigenous vine varieties of Malta: Conservation, Assessment and Innovation [R&I-SP-2008-01]).peer-reviewe

Predviđanje retencije β-diketonato kompleksa u TLC sistemima na silika-gelu primenom kvantitativnog odnosa strukture i retencije

Quantitative structure retention relationships for a series of 30 mixed beta-diketonato complexes of cobalt(III), chromium(III) and ruthenium(III) were derived by multiple linear regression analyses using molecular descriptors obtained by quantum chemical calculations. The retention parameters were obtained by thin layer chromatography on silica gel using mono and two-component solvent systems. The molecular descriptors included in the multiple linear regression analysis were molecular weight, molecular volume, surface area, hydrophilic lipophilic balance, percent hydrophilic surface area, dipole moment, polarizability, refractivity, energy of the highest occupied molecular orbital and energy of the lowest unoccupied molecular orbital. High agreement between the experimental and predicted retention parameters was obtained when polarizability and the hydrophilic lipophilic balance were used as the molecular descriptors. Comparison of the models with those established on polyacrylonitrile showed that the structure of the sorbent is responsible for the chromatographic behaviour of the same compounds. The presented models can be used for the prediction of the retention of new solutes in screening chromatographic systems.U ovom radu kvantifikovan je odnos strukture i retencije 30 mešovitih β-diketonato kompleksa kobalta(III), hroma(III) i rutenijuma(III) primenom multilinearne regresione analize korišćenjem molekulskih deskriptora, koji su dobijeni pomoću kvantno-hemijskih izračunavanja. Retencioni parametri su dobijeni tankoslojnom hromatografijom na silika-gelu primenom mono-i dvokomponetnih rastvarača. Molekulski deskriptori koji su uključeni u multilinearnu regresionu analizu su molekulska težina, molekulska zapremina, površina, hidrofilni-lipofilni balans, procenat hidrofilne površine, dipolni momenat, polarizabilnost, refraktivnost, energija najviše zauzete molekulske orbitale i energija najniže prazne molekulske orbitale. Dobijena je zadovoljavajuća korelacija između eksperimentalnih retencionih parametara i retencionih parametara predviđenih postavljenim modelima, koji sadrže polarizabilnost i hidrofilni-lipofilni balans kao deskriptore. Poređenja ovih modela sa modelima dobijenim na poliakrilonitrilnom sorbentu, za ista jedinjenja, pokazuju da je struktura sorbenta odgovorna za hromatografsko ponašanje. Ovi modeli se mogu koristiti za predviđanje retencije novih jedinjenja u datim hromatografskim sistemima

Supplementary data for the article: Stefanović, V.; Trifković, J.; Mutić, J.; Tešić, Ž. Metal Accumulation Capacity of Parasol Mushroom (Macrolepiota Procera) from Rasina Region (Serbia). Environ. Sci. Pollut. Res. 2016, 23 (13), 13178–13190. https://doi.org/10.1007/s11356-016-6486-7

Supplementary material for: [https://doi.org/10.1007/s11356-016-6486-7]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2271

Normal-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their metabolites

The separation and chromatographic behaviour of five ACE (angiotensin converting enzyme) inhibitors and their four active metabolites were investigated by normal-phase thin-layer chromatography on silica using several mono- and binary non-aqueous solvent systems. The linear relationship between the RM values and the composition of employed mobile phase was obtained. The hydrophobicity parameters RM0 and C0 were determined from the regression data of the plots, analogous to reversed-phase chromatography. The chromatographically obtained hydrophobicity parameters were correlated with the calculated log P values. The current results were correlated with the lipophilicity of the studied ACE inhibitors and their metabolites, previously estimated by reversed-phase chromatography

Hydrogen Evolution on Zeolite Supported Platinum Clusters

NaX type zeolite was loaded with platinum, by the thermal decomposition of Pt(II) acetylacetonate, up to the Pt/NaX mass ratio 0.174. The sample, dispersed on a glassy carbon rotating disc, was used in slightly acidic solution to observe the kinetics of the hydrogen evolution reaction. A comparison was made with the rate of hydrogen evolution on smooth polycrystalline platinum, and both slower and faster evolution rates were observed, depending on the percentage of carbon black added to the zeolite sample

Sinteza i karakterizacija kompleksa cink(II), kadmijum(II), platina(II),i paladijum(II) sa kalijum-3-ditiokarboksi-3-aza-5-aminopentanoatom

Complexes of zinc(lI), cadmium(II). platinum(lI) and palladium(II) with a new poly-dentate dithiocarbamate ligand, 3-dithiocarboxy-3-aza-5-aminopentanoate (daap(-)), of the type M(daap)(2).nH(2)O (M = Zn(II), Cd(II), n = 2, or M = Pt(II) Pd(II) n = 0). have been prepared and characterized by elemental analysis. IR and UV/VIS spectroscopy, as well as magnetic measurements. The spectra of the complexes suggest a bidentate coordination of the daap- ligand to the metal ions via the sulfur atoms of the deprotonated dithiocarbamato group. The fact that under the same experimental conditions its S-methyl ester does not form complexes could be taken as proof of the suggested coordination mode.Reakcijom između cink(II), kadmijum(II), platina(II) i paladijum(II)-soli i kalijum- 3-ditiokarboksi-3-aza-5-aminopentanoata dobijeni su dogovarajući kompleksi tipa M(daap)2.nH2O. Izolovani kompleksi su okarakterisani elementarnom analizom, IR i UV/VIS spektroskopijom kao i merenjem magnetnih susceptibiliteta. Spektri kompleksa sugerišu bidentatnu koordinaciju daap liganda sa navedenim metalnim jonima preko atoma sumpora deprotonovane ditiokarbamato grupe. Kao dokaz navedenog načina koordinacije može poslužiti činjenica da pri istim eksperimentalnim uslovima S-metil estar liganda ne daje komplekse

Supplementary material for the article: Stefanović, V.; Trifković, J.; Djurdjić, S.; Vukojević, V.; Tešić, Ž.; Mutić, J. Study of Silver, Selenium and Arsenic Concentration in Wild Edible Mushroom Macrolepiota Procera, Health Benefit and Risk. Environmental Science and Pollution Research 2016, 23 (21), 22084–22098. https://doi.org/10.1007/s11356-016-7450-2

Supplementary material for: [https://doi.org/10.1007/s11356-016-7450-2]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2348

Supplementary data for the article: Stefanović, V.; Trifković, J.; Mutić, J.; Tešić, Ž. Metal Accumulation Capacity of Parasol Mushroom (Macrolepiota Procera) from Rasina Region (Serbia). Environ. Sci. Pollut. Res. 2016, 23 (13), 13178–13190. https://doi.org/10.1007/s11356-016-6486-7

Supplementary material for: [https://doi.org/10.1007/s11356-016-6486-7]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2271