Optimization of Procedure for Isolation and Determination of Pyrrolizidine Alkaloids from Plant Material

rasprostranjenih u biljnom svetu. Više stotina PA i njihovih derivata N-oksidaidentifikovano je u preko 6000 biljaka, koje pripadaju različitim biljnim familijama.Mnoge biljke bogate PA koriste se u tradicionalnoj medicini u Aziji i Africi, što ih činiinteresantnim za fitohemijska istraživanja. Sa druge strane, neki PA su veoma toksičniza ljude i životinje. Akutno trovanje PA dovodi do oštećenja jetre, dok dugotrajnaizloženost subletalnim dozama dovodi do kumulativnih oštećenja, ispoljavanjaneurotoksičnih, mutagenih i karcinogenih efekata. Zbog svega ovog je naučnoistraživanje PA značajno, pa je neophodan razvoj analitičkih metoda za određivanjepojedinačnih i ukupnih pirolizidinskih alkaloida u biljnom materijalu. Uprkos brojnimpredloženim postupcima za izolovanje i prečišćavanje pirolizidinskih alkaloida, zbograznolikosti njihovih struktura i hemijskih svojstava, ni jedan od njih nije našao širokuprimenu u praksi. Stoga je cilj ove doktorske teze optimizacija svih faza postupka zaizolovanje pirolizidinskih alkaloida iz biljnog materijala, tako da se ova strukturnorazličita jedinjenja mogu izolovati sa maksimalnim prinosima. Kao model-sistemupotrebljena je biljna vrsta Rindera umbellata Bunge. Pored toga, cilj teze je iizolovanje pojedinačnih alkaloida iz pomenute biljne vrste, njihova karakterizacija,odnosno određivanje struktura.Izolovano je i strukturno okarakterisano šest PA (7-angeloilheliotridan, 7-angeloilheliotridin, lindelofin, 7-angeloilrinderin, punktanecin i heliosupin, PA1 – PA6,redom)

Analysis of the efficiency of insurance companies in Serbia using the fuzzy AHP and TOPSIS methods

The aim of this study is to propose a fuzzy multi-criteria model that will facilitate the assessment of insurance companies’ efficiency. This study includes all companies operating within the insurance sector in Serbia in the period from 2007 to 2014 and the data were used from the published financial statements of insurance companies. Five key indicators were identified for the assessment and rating of insurance companies. Fuzzy Analytic Hierarchy Process (FAHP) and Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) were used for building the proposed model. In the first stage, priority weights of criteria were defined by using the FAHP, while in the second phase the insurance companies were ranked using the TOPSIS method

Učinak amiodarona na rožnicu

The most common side-effect of the anti-arrhythmic amiodarone is keratopathy. The goal of this study was to assess the frequency of this side-effect in our population of cardiology patients treated with amiodarone. We also wanted to assess the consequences on eye sight. The study was conducted as collaboration between the divisions of ophthalmology and cardiology of Sestre milosrdnice University Hospital, Zagreb and it included patients receiving amiodarone for longer than 6 months (100-800 mg/ day). Changes on the cornea were objectively evaluated using a biomicroscope and have been classified into three stages. Clinical changes on the cornea have been observed in 92% of the patients. Changes in eye sight were not observed. Amiodarone keratopathy is related to dosage and duration of treatment. This keratopathy progresses even with reduced dosage; however, complete regression occurs once administration of medication is discontinued. Taking this study into account, as well as the available published data, we are of the opinion that amiodarone therapy should not be discontinued due to changes in the eye-sight and if the amiodarone therapy is of critical importance to the welfare of the patient.Kod primjene antiaritmika amiodarona najčešće registrirana nuspojava je keratopatija. Cilj ovog rada je ispitati koliko je ova nuspojava frekventna u populaciji naših kardioloških pacijenata na terapiji amiodaronom i od kakvog je značaja za kvalitetu vida. Ispitivanje je provedeno u suradnji klinike za oftalmologiju i kardiologiju KB "Sestre milosrdnice", Zagreb. Uključeni su pacijenti na terapiji amiodaronom duže od 6 mjeseci (100-800 mg/dan). Promjene na rožnici objektivno su registrirane biomikroskopom i svrstane u tri stupnja. One su registrirane kod 92% pacijenata. Promjene kvalitete vida nisu registrirane. Amiodaronska keratopatija u korelaciji je s dnevnom dozom i duljinom trajanja terapije. Smanjenje dnevne doze ne dovodi do regresije keratopatije, dok je kompletna regresija zabilježena nakon prestanka primjene lijeka. S obzirom na ovo istraživanje i podatke iz literature, mišljenja smo, da nije potrebno prekidati terapiju amiodaronom zbog promjena na rožnici ukoliko nema poremećaja vida i ako je terapija amiodaronom od vitalnog značenja za pacijenta

Removal of organically bound sulfur from oil shale by iron(III)-ion generated-regenerated from pyrite by the action of Acidithiobacillus ferrooxidans

Oil shales are one of the alternative sources of hydrocarbon fuels ("synthetic petroleum"), characterized by the increased sulfur and nitrogen content which represent even greater ecological problem in use, compared to classical fuels. Acidithiobacillus ferrooxidans is capable of oxidizing pyrite to iron (III)-ion, providing a strong oxidation agent at low pH. We have used this oxidizing agent for oxidation of sulfur present in DBT as a substrate model to demonstrate its potential to oxidize organically bound sulfur in oil shales. An HCl-concentrate was used as the hydrocarbon matrix. Acidithiobacillus ferrooxidans is already recognized to oxidize the pyritic sulfur component, thereby potentially providing a complete sulfur removal system. By applying GC-MS we established that DBT transformation occurred by oxidation or elimination of sulfur. The products obtained are more soluble in water than parent compounds and this reduces concentration of organic sulfur.BIOHYDROMETALLURY: FROM THE SINGLE CELL TO THE ENVIRONMEN

Composition, Antioxidant Potential, and Antimicrobial Activity of Helichrysum plicatum DC. Various Extracts

Helichrysum plicatum DC. is widely used in folk medicine in treating a variety of health disorders. The aim of this study was to examine the influence of different extraction solvents on the chemical composition, antioxidant potential, and antimicrobial activities of H. plicatum. Aerial parts were separately extracted with ethanol, dichloromethane, and sunflower oil. The oil extract (OE) was re-extracted with acetonitrile. A total of 142 compounds were tentatively identified in ethanolic (EE), dichloromethane (DCME), and acetonitrile (ACNE) extracts using HPLC-DAD/ESI-ToF-MS. The dominant compound class in all extracts were α-pyrones, alongside flavonoids in EE, terpenoids in DCME and ACNE, and phloroglucinols in DCME. The antioxidant potential of the extracts was assessed by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. EE and DCME possessed the most potent radical scavenging capacity. Antimicrobial activity was investigated on eight bacterial, two yeast, and one fungal species. All extracts exhibited high antifungal and notable antibacterial activities compared to control substances, with DCME being the most potent. DCME exhibited stronger antimicrobial activity against P. aeruginosa than the standard chloramphenicol

Serum biomarkers of schizophrenia

Schizophrenia is a widespread mental disorder that leads to significant functional impairments and premature death. The state of the art indicates gaps in the understanding and diagnosis of this disease, but also the need for personalized and precise approaches to patients through customized medical treatment and reliable monitoring of treatment response. In order to fulfill existing gaps, the establishment of a universal set of disorder biomarkers is a necessary step. The investigation of serum samples of Serbian patients with schizophrenia (51) and healthy controls (39), based on NMR analyses based on detection and of low molecular weight components in samples can be difficult due to overlapping signal caused by line broadening characteristics of macromolecules. A way of overcoming this problem could be the exploitation of the difference in relaxation between small molecules and macromolecular species, such as the application of a T2 filter by using the Carr–Purcell–Meiboom–Gill (CPMG) spin-echo pulse sequence, which led to the identification of 26 metabolites/biomarkers for this disorder. The established biomarker set includes aspartate/aspartic acid, lysine, 2-hydroxybutyric acid, and acylglycerols, which are identified for the first time in schizophrenia serum samples by NMR experiments. The other 22 identified metabolites in the Serbian samples are in accordance with the previously established NMR-based serum biomarker sets of Brazilian and/or Chinese patient samples. Thirteen metabolites (lactate/lactic acid, threonine, leucine, isoleucine, valine, glutamine, asparagine, alanine, gamma-aminobutyric acid, choline, glucose, glycine and tyrosine) that are common for three different ethnic and geographic origins (Serbia, Brazil and China) could be a good start point for the setup of a universal NMR serum biomarker set for schizophrenia

Evaluation of innovative and environmentally safe growing practice suitable for sustainable management of plum orchards

Intensive agricultural development based on the long-term and excessive use of chemical nitrogen fertilizers significantly contributes to a series of undesirable effects and results in environmental pollution. In line with the above, there is a pressing need for major changes in agricultural production management. Bearing in mind that fertilization strategy, among other practices, plays an important role in improving the growing technology of different fruit crops, we considered that the above mentioned problems could be overcome by introducing an environmentally safe and innovative practice inplum growing technology as well. Accordingly, a comparative study was conducted to evaluate the effects of biofertilizer (a combination of nitrogen-fixing and phosphorus-mineralizing bacteria including Azotobacter chroococcum, Bacillus megatherium and Bacillus subtilis) and chemical fertilizer (a water-soluble chemical fertilizer supplemented with the microelements B, Cu, Fe, Mn and Zn)on ʻČačanska Lepotica' and 'Stanley' plum cultivars. Morphometric characteristics (fruit weight, length and width), internal quality traits (soluble solids content and firmness) and chemical properties (total phenolic content and total antioxidant activity) of the fruit of the tested plum cultivars were assessed. The obtained results indicate that the substitution of chemical fertilization with biofertilization in 'Čačanska Lepotica' and 'Stanley' is a justified practice. Furthermore, this approach seems to havepotential as an appropriate technique in commercial plum production, which may improve yield-attributing characteristics and the phytochemical content of plum fruits.Publishe

Inhibition potency of disulphides and trisulphides on various tumor cell lines growth

Tumor is one of the leading diseases of today. Chemotherapy and radiation therapy healing chances are limited, so some alternative methods are resorted to. Many papers indicated that garlic and organosulphur compounds diallyldisulphide (DADS) and diallyltrisulphide, which are main components of garlic decrease the cancer risk and inhibit the cell proliferation. In this paper inhibition potency of disulphides (DADS and its synthetic analogues) and trisulphides with different alkyl and phenyl substituents on growth of various tumor (Non-Small cell Lung Cancer, Colon cancer, CNS Cancer, Melanoma, Ovarian Cancer, Renal Cancer, Prostate Cancer, Breast Cancer, Leukemia) cell lines was investigated. Concentration of each compound (DADS, diethyl disulphide, dipropyl disulphide, diphenyl disulphide, tetraethylthiuram disulphide (TETUDS), dimetil trisulphide, dipropyl trisulphide and metilpropyl trisulphide (MPTS) was 10 μmol/L. It was found that DADS has an inhibitory effect on the growth of several cancer cell lines, but synthetic analogues TETUDS and MPTS exhibit stronger effect on certain cells lines. MPTS inhibits the growth of even 12 cell lines for more than 10%, especially leukemia cell line SR and NCI-H522 cell line of Non-Small cell Lung Cancer (reduction of growth for 24% and 47%, resp.). Trisulphide analogues exhibit little higher inhibitory effects in comparison to disulphide ones