Glutamic acid-derived hydrazine reagent for derivatization of carbonyl compounds

U okviru provedenih istraživanja osmišljen je i pripravljen novi reagens za derivatizaciju karbonilnih spojeva, hidrazino-derivat glutaminske kiseline, koji je upotrebljen za određivanje karbonilnih spojeva LC-MS/MS metodom. Istraživanje je obuhvatilo i njegovu karakterizaciju spektroskopskim i spektrometrijskim metodama. Reakcijom hidrazino-derivata glutaminske kiseline i odabranih karbonilnih spojeva dobiveni su Glu-hidrazoni, koji su prema potrebi reducirani u Glu-hidrazide. Nastali produkti su izolirani te okarakterizirani spektroskopskim i spektrometrijskim metodama. U doktorskom radu istražene su fragmentacijske reakcije nastalih hidrazona i hidrazida u MS/MS eksperimentima kako bi se identificirali specifični ioni produkti koji su upotrijebljeni za razvoj LC-MS/MS metode. Istraženi su i optimirani reakcijski uvjeti koji su osigurali kvantitativnost derivatizacijske reakcije. Za usporedbu, sintetizirani su i okarakterizirani produkti odabranih karbonilnih spojeva s najčešće korištenim reagensom za derivatizaciju karbonilnih spojeva, 2,4 dinitrofenilhidrazinom.The scope of the study included the design and preparation of a glutamic acid-related hydrazine reagent as new reagent for the derivatization of carbonyl compounds for LC-MS/MS analysis and its characterization by spectroscopic and spectrometric methods. Reaction of the glutamic acid-related hydrazine reagent and the selected carbonyls resulted in the corresponding Glu-hydrazones which were optionally reduced to Glu-hydrazides. The formed products were isolated and characterized by spectroscopic and spectrometric methods. Fragmentation patterns of prepared hydrazones and hydrazides in MS/MS experiments were also investigated for the identification of “marker ions”, used for the development of LC-MS/MS method. The optimization of reaction conditions was performed to provide a quantitative derivatization. For comparison purposes, products of selected carbonyls with the most exploited derivatization reagent 2,4-dinitrophenylhydrazine, were also synthesized and characterized

Glutamic acid-derived hydrazine reagent for derivatization of carbonyl compounds

U okviru provedenih istraživanja osmišljen je i pripravljen novi reagens za derivatizaciju karbonilnih spojeva, hidrazino-derivat glutaminske kiseline, koji je upotrebljen za određivanje karbonilnih spojeva LC-MS/MS metodom. Istraživanje je obuhvatilo i njegovu karakterizaciju spektroskopskim i spektrometrijskim metodama. Reakcijom hidrazino-derivata glutaminske kiseline i odabranih karbonilnih spojeva dobiveni su Glu-hidrazoni, koji su prema potrebi reducirani u Glu-hidrazide. Nastali produkti su izolirani te okarakterizirani spektroskopskim i spektrometrijskim metodama. U doktorskom radu istražene su fragmentacijske reakcije nastalih hidrazona i hidrazida u MS/MS eksperimentima kako bi se identificirali specifični ioni produkti koji su upotrijebljeni za razvoj LC-MS/MS metode. Istraženi su i optimirani reakcijski uvjeti koji su osigurali kvantitativnost derivatizacijske reakcije. Za usporedbu, sintetizirani su i okarakterizirani produkti odabranih karbonilnih spojeva s najčešće korištenim reagensom za derivatizaciju karbonilnih spojeva, 2,4 dinitrofenilhidrazinom.The scope of the study included the design and preparation of a glutamic acid-related hydrazine reagent as new reagent for the derivatization of carbonyl compounds for LC-MS/MS analysis and its characterization by spectroscopic and spectrometric methods. Reaction of the glutamic acid-related hydrazine reagent and the selected carbonyls resulted in the corresponding Glu-hydrazones which were optionally reduced to Glu-hydrazides. The formed products were isolated and characterized by spectroscopic and spectrometric methods. Fragmentation patterns of prepared hydrazones and hydrazides in MS/MS experiments were also investigated for the identification of “marker ions”, used for the development of LC-MS/MS method. The optimization of reaction conditions was performed to provide a quantitative derivatization. For comparison purposes, products of selected carbonyls with the most exploited derivatization reagent 2,4-dinitrophenylhydrazine, were also synthesized and characterized

Glutamic acid-derived hydrazine reagent for derivatization of carbonyl compounds

U okviru provedenih istraživanja osmišljen je i pripravljen novi reagens za derivatizaciju karbonilnih spojeva, hidrazino-derivat glutaminske kiseline, koji je upotrebljen za određivanje karbonilnih spojeva LC-MS/MS metodom. Istraživanje je obuhvatilo i njegovu karakterizaciju spektroskopskim i spektrometrijskim metodama. Reakcijom hidrazino-derivata glutaminske kiseline i odabranih karbonilnih spojeva dobiveni su Glu-hidrazoni, koji su prema potrebi reducirani u Glu-hidrazide. Nastali produkti su izolirani te okarakterizirani spektroskopskim i spektrometrijskim metodama. U doktorskom radu istražene su fragmentacijske reakcije nastalih hidrazona i hidrazida u MS/MS eksperimentima kako bi se identificirali specifični ioni produkti koji su upotrijebljeni za razvoj LC-MS/MS metode. Istraženi su i optimirani reakcijski uvjeti koji su osigurali kvantitativnost derivatizacijske reakcije. Za usporedbu, sintetizirani su i okarakterizirani produkti odabranih karbonilnih spojeva s najčešće korištenim reagensom za derivatizaciju karbonilnih spojeva, 2,4 dinitrofenilhidrazinom.The scope of the study included the design and preparation of a glutamic acid-related hydrazine reagent as new reagent for the derivatization of carbonyl compounds for LC-MS/MS analysis and its characterization by spectroscopic and spectrometric methods. Reaction of the glutamic acid-related hydrazine reagent and the selected carbonyls resulted in the corresponding Glu-hydrazones which were optionally reduced to Glu-hydrazides. The formed products were isolated and characterized by spectroscopic and spectrometric methods. Fragmentation patterns of prepared hydrazones and hydrazides in MS/MS experiments were also investigated for the identification of “marker ions”, used for the development of LC-MS/MS method. The optimization of reaction conditions was performed to provide a quantitative derivatization. For comparison purposes, products of selected carbonyls with the most exploited derivatization reagent 2,4-dinitrophenylhydrazine, were also synthesized and characterized

Morfo-fiziološki i hormonski odgovor različitih sorti ozime pšenice na sušni stres u fazi klijanja i klijanaca

Drought stress can have a significant influence on the reduction of wheat (Triticum aestivum L.) growth and development. This study investigated morpho-physiological, abscisic (ABA) and salicylic (SA) acids\u27 responses of six winter wheat varieties (Rujana, Silvija, Fifi, Bubnjar, Anđelka and Pepeljuga) during the germination and seedling stage. Plants were exposed to 10 and 20% polyethylene glycol (PEG) solution for seven days. Certain morphophysiological changes were observed under stress condition in comparison to controls, such as a reduction of germination energy (GE), shoot length, relative water content (RWC), increase of root growth, depending on varieties and stress intensity. ABA was increased in all cultivars confirming stress status of the plants. SA showed a tendency to decrease depending on the concentration of PEG and was positively correlated with shoot length and shoot dry weight. In the varieties Rujana, Anđelka, Fifi and Bubnjar a less significant decrease in germination energy was recorded, compared to Pepeljuga and Silvija.Sušni stres može značajno utjecati na smanjenje rasta i razvoja pšenice. U ovom radu istraživan je morfo-fiziološki odgovor, te odgovor abscizinske (ABA) i salicilne (SA) kiseline šest sorti ozime pšenice (Rujana, Silvija, Fifi, Bubnjar, Anđelka i Pepeljuga) tijekom klijanja i faze klijanaca. Biljke su izložene 10 i 20% otopini polietilen glikola (PEG) tijekom sedam dana. Od morfo-fizioloških parametara zabilježeno je značajno smanjenje energije klijanja, smanjenje duljine izdanka, smanjenje relativnog sadržaja vode, pojačani rast korijena ovisno o stupnju stresa u odnosu na kontrolne uvjete i sorti pšenice. Koncentracija ABA je povećana u svim sortama što potvrđuje prisutnost stresa u biljkama. SA je pokazala tendenciju smanjenja ovisno o koncentraciji PEG-a i bila je u pozitivnoj korelaciji s duljinom izdanka i suhom masom izdanka. Kod sorti Pepeljuga i Silvija zabilježeno je značajno smanjenje energije klijanja u odnosu na sorte Rujana, Anđelka, Fifi i Bubnjar

Ferulic Acid and Salicylic Acid Foliar Treatments Reduce Short-Term Salt Stress in Chinese Cabbage by Increasing Phenolic Compounds Accumulation and Photosynthetic Performance

Salinity stress is one of the most damaging abiotic stresses to plants, causing disturbances in physiological, biochemical, and metabolic processes. The exogenous application of natural metabolites is a useful strategy to reduce the adverse effects of stress on crops. We investigated the effect of foliar application of salicylic acid (SA) and ferulic acid (FA) (10–100 μM) on short-term saltstressed (150 mM NaCl, 72 h) Chinese cabbage plants. Subsequently, proline level, photosynthetic performance, phenolic metabolites with special focus on selected phenolic acids (sinapic acid (SiA), FA, SA), flavonoids (quercetin (QUE), kaempferol (KAE)), and antioxidant activity were investigated in salt-stressed and phenolic acid-treated plants compared with the corresponding controls. Salt stress caused a significant increase in SA and proline contents, a decrease in phenolic compounds, antioxidant activity, and photosynthetic performance, especially due to the impairment of PSI function. SA and FA treatments, with a concentration of 10 μM, had attenuated effects on salt-stressed plants, causing a decrease in proline and SA level, and indicating that the plants suffered less metabolic disturbance. Polyphenolic compounds, especially FA, SiA, KAE, and QUE, were increased in FA and SA treatments in salt-stressed plants. Consequently, antioxidant activities were increased, and photosynthetic performances were improved. FA resulted in a better ameliorative effect on salt stress compared to SA

Hydrothermal Synthesis of FeOOH and Fe2O3 Modified Self-Organizing Immobilized TiO2 Nanotubes for Photocatalytic Degradation of 1H-Benzotriazole

In this study, titanium dioxide nanotubes were prepared by electrochemical anodization technique and modified with an aqueous solution of FeCl3 using hydrothermal synthesis method to control the amount and distribution of iron compounds on the anatase TiO2 nanotubes. The objective was to synthesize immobilized FeOOH@TiO2 or Fe2O3@TiO2 photocatalysts designed for the flow-through reactor systems ; to investigate thermal treatment effect on the photocatalytic efficiency ; to determine appropriate Fe-compounds concentration for the maximum photocatalytic activity improvement, and to explain the mechanism responsible for the enhancement. The photocatalysts were tested for the degradation of 1H-benzotriazole in water under UV/solar light irradiation. Up to two times increase in the photocatalytic activity was obtained when TiO2 nanotubes were modified with 0.8 mM Fe. At higher Fe concentrations (8 mM and 80 mM), the photocatalytic activity of the given photocatalysts decreased. To confirm the formation of FeOOH or Fe2O3 species, and to clarify the mechanism of photoactivity, X-ray diffraction (XRD), Raman spectroscopy (RS), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDS) and UV-Vis spectroscopy were used