Iron-binding and anti-fenton properties of novel amino acid-derived cyclic imide dioximes

We present a novel route for the preparation of amino acid-derived cyclic imide dioxime derivatives. Readily accessible amino acids were conveniently converted to their corresponding cyclic imide dioximes in simple synthetic steps. The aim of this work was to describe and compare the iron-chelating and antioxidant properties of synthesized compounds in relation to their molecular structure, and in particular, which of those features are essential for iron(II)-chelating ability. The glutarimide dioxime moiety has been established as an iron(II)-binding motif and imparts potent anti-Fenton properties to the compounds. Compound 3 was shown to strongly suppress hydroxyl radical formation by preventing iron cycling via Fe-complexation. These findings provide insights into the structural requirements for achieving anti-Fenton activity and highlight the potential use of glutarimide dioximes as antioxidants

An Imposition of the VSM Model (Viable System Model) to Ensure Better Interoperability

Javna uprava in njeni procesi organiziranosti predstavljajo skupaj s posameznimi organizacijskimi strukturami področje, ki mora biti v sedanjih kriznih časih deležno še večje pozornosti, saj tudi spremembe obstoječih organizacijskih struktur omogočajo stroškovne prihranke, hkrati pa povečajo učinkovitost in odzivnost delovanja javne uprave glede na razmere v okolju. V magistrskem delu smo najprej opredelili pojma organiziranost in javna uprava, kaj ta dva pojma sploh predstavljata, nadalje smo opisali cilje organizacije, katere cilje posamezne oblike organizacije zasledujejo in na kakšen način jih dosegajo. Ob vsem tem je potrebno omeniti tudi pomembnost same organizacijske strukture kot osnove za uspešno delovanje posamezne organizacije znotraj javne uprave. Seveda se postavlja vprašanje, kakšne oblike organizacijskih struktur poznamo, katere od njih so najbolj uporabne in v katerih primerih. Pomemben dejavnik organiziranosti kot tudi organizacije same predstavljajo organizacijski procesi. Zakaj je potrebna procesna organiziranost? Na kakšen način sodobna tehnologija vpliva na spremembe organiziranosti? Kateri so tisti dejavniki, ki nam omogočajo spremembe poslovnih procesov? Katere oblike organiziranosti javne uprave so največkrat uporabljene v praksi? Vse to so vprašanja, na katera smo podali odgovore v prvem poglavju. Prav tako smo poskušali opisati sedanje stanje organiziranosti na Ministrstvu za finance Republike Slovenije in opredelili tiste poslovne procese, ki po našem mnenju predstavljajo osnovo za spremembo organiziranosti. V naslednjem poglavju smo podrobno opisali model VSM (Viable System Model), ki bo predstavljal izhodišče za spremembe v obliki organiziranosti. Podroben opis sistemov modela VSM, od sistema 1 do sistema 5, nam bo omogočal spoznati tiste njegove lastnosti, ki bodo osnova za razmišljanje o spremenjeni obliki organiziranosti. Temu sledi poglavje o interoperabilnosti v javni upravi, v katerem smo definirali pojem interoperabilnosti, opisali sedanje stanje interoperabilnosti v Sloveniji in opredelili vidike (nivoje), ki predstavljajo osnovo za uvedbo standardov interoperabilnosti v prakso. Hkrati je potrebno poudariti, da tudi sam model VSM temelji na čim večji povezanosti posameznih sistemov (organizacij) med sabo in tudi na ta način izboljšuje delovanje posameznih organizacij tako pri odnosih znotraj le-teh kot tudi v povezavah z okoljem. Poglavje o uvajanju modela VSM na Ministrstvu za finance Republike Slovenije je namenjeno podrobnemu opisu predvidenih sprememb. Postavlja se vprašanje, zakaj so spremembe nujne. Le z nenehnimi spremembami ostaja organizacija učinkovita, fleksibilna in sposobna hitrega odzivanja na zahteve trga (v našem primeru ostalih udeležencev iz okolja državne uprave in vseh ostalih). Opredelili smo spremenjeno organizacijsko strukturo skozi sisteme od 1 do 5, ki bo skupaj s tehnološkimi spremembami zagotavljala učinkovito delovanje ministrstva. Ne smemo pozabiti niti na možnosti uvedbe novih IKT (informacijsko-komunikacijskih tehnologij), s katerimi se konkurenčna prednost organizacije le še poveča. Analiza statistične raziskave je pokazala, da lahko dve hipotezi delno potrdimo, eno pa zavrnemo. Potrdimo lahko hipotezi, da sta tako odzivni čas kot tudi pretok informacij odvisna od razvitosti IT infrastrukture. Hipotezo, da obstaja povezanost med razvitostjo IT infrastrukture in stopnjo organiziranosti organizacije, zavrnemo, saj statistična analiza ne pokaže povezanosti med tema dvema dejavnikoma.Public administration and its processes of organization, together with individual organizational structures, represent a field to which a special focus should be given in the time of crisis. The changes in present organizational structures enable financial savings and increase the efficiency and response in the work of public administration, according to the conditions in the environment. In this master\u27s thesis, firstly, the terms organization and public administration are defined, secondly, a description of organizational goals is given, more precisely, which goals specific means of organizations aim for and in what ways they reach them. The importance of an organizational structure is also worth mentioning, as it presents the basis for successful work of an individual organization within public administration. A question surfaces, and that is what means of organizational structures do we know, which of them are the most useful and in which cases? An important factor of organizing as well as the organization itself are the organizational processes. Why is organization of processes important? In what way does the modern technology influence the changes in organization, which are the factors that enable the changes in business processes? Which means of public administration organization are mostly used in practice? All the above are the questions which are answered in the first chapter. Furthermore, we describe the present situation of organization at the Ministry of Finance of the Republic of Slovenia and specify those business processes which, in our opinion, represent the basis for a change in organization. In the next chapter, VSM (Viable System Model) is described in detail, and it represents the origin for changes in the ways of organization. A detailed description of VSM model from system 1 to 5 enables us to recognize those characteristics of the model that provide the basis for thinking about the changed form of organization. The next chapter on interoperability in public administration follows, where the term interoperability is defined, then the present state of interoperability in Slovenia is described and those aspects (levels) which represent the basis for the introduction of interoperability standards in practice. It is, of course, worth stressing that the VSM model itself is based on the highest possible interconnection of specific systems (organizations) and thus improves the work of individual organizations, in relationships within, as well as in connections with the environment. The chapter on introducing the VSM model at the Ministry of Finance of the Republic of Slovenia is focused on the detailed description of estimated changes. The question is why are the changes necessary? The organization remains efficient, flexible and capable of fast response to the market needs (in our case the other participants from the environment of public administration and all the others) only with continuous changes. We try to specify the changed organizational structure through systems 1 to 5, which ensures the efficient work of the ministry, together with the technological changes. We must not forget about the possibility of introducing new ICT technologies with the help of which the competitive advantage of the organization only increases. The analysis of the statistical research shows that two hypotheses can be confirmed and one refuted. The confirmed hypotheses are that the response time as well as the information flow depend on the development of IT infrastructure. The hypothesis that there is a connection between the development of IT infrastructure and the level of organization was refuted, since the statistical analysis does not show any connections between these two factors

Influence of cancerostatic perifosine on membrane fluidity of liposomes and different cell lines as measured by electron paramagnetic resonance

AIM: To test whether membrane fluidity and its changes are important for the sensitivity of cells to the action of perifosine (OPP), a new anticancer drug targeting cell membrane and not DNA. METHOD: Influence of OPP on the membrane structure of OPP-resistant MCF7, and OPP-sensitive MT3 breast cancer cell lines, as well as of mouse fibroblasts (L929) cell lines, and model cells (liposomes) was investigated by electron paramagnetic resonance, using spin labeled derivative of OPP (P5) and 5-doxylpalmitoyl methylester (MeFASL(10,3)) as spin probes. RESULTS: OPP increased membrane fluidity of all cell lines at concentrations higher than 50 µM (on the level of P ≤ 0.05, t test). In cells, the differences were observed only by P5 and not by MeFASL(10,3). Average order parameter S(eff) decreased for about 12% in MCF7 and L929 and only for 8% in OPP-sensitive MT3 cells, showing that there was no correlation between membrane fluidity changes and sensitivity of cells to OPP. The only correlation we found was between OPP sensitivity and the cell growth rate. In liposomes, both spin probes were sensitive to the action of OPP. S(eff) decreased with increasing concentration of OPP. For MeFASL(10,3) a significant decrease was observed at 4 mol% OPP, while for P5 it was observed at 8 mol%. CONCLUSION: Influence of OPP on plasma membrane fluidity of breast cancer cells is not the determining factor in the sensitivity of cells to OPP

Synthesis and evaluation of antioxidant properties of 2-substituted quinazolin-4(3H)-ones

Quinazolinones represent an important scaffold in medicinal chemistry with diverse biological activities. Here, two series of 2-substituted quinazolin-4(3H)-ones were synthesized and evaluated for their antioxidant properties using three different methods, namely DPPH, ABTS and TEAC$_{CUPRAC}$, to obtain key information about the structure–antioxidant activity relationships of a diverse set of substituents at position 2 of the main quinazolinone scaffold. Regarding the antioxidant activity, ABTS and TEAC$_{CUPRAC}$ assays were more sensitive and gave more reliable results than the DPPH assay. To obtain antioxidant activity of 2-phenylquinazolin-4(3H)-one, the presence of at least one hydroxyl group in addition to the methoxy substituent or the second hydroxyl on the phenyl ring in the ortho or para positions is required. An additional ethylene linker between quinazolinone ring and phenolic substituent, present in the second series (compounds 25a and 25b), leads to increased antioxidant activity. Furthermore, in addition to antioxidant activity, the derivatives with two hydroxyl groups in the ortho position on the phenyl ring exhibited metal-chelating properties. Our study represents a successful use of three different antioxidant activity evaluation methods to define 2-(2,3-dihydroxyphenyl)quinazolin-4(3H)-one 21e as a potent antioxidant with promising metal-chelating properties

Rational design to biologics development: The polysorbates point of view

Formulation development is an essential part of any biopharmaceuticals development programme, and this will affect quality, safety and efficacy of the final drug product. The vast majority of biopharmaceuticals on the market are therapeutic proteins; however, these are less stable compared to conventional pharmaceuticals. To counter aggregation, denaturation and surface adsorption of proteins in solution, surfactants are added to the formulations; however, the choice of the best formulation is a challenge that is faced during formulation development. Polysorbates are the most widely used surfactants in the pharmaceutical industry and are presented in >80% of commercial monoclonal antibody formulations. In this review, we provide a general overview of polysorbates and their issues, and the characteristics that have to be taken into account during formulation development. Degradation of polysorbates, namely by hydrolysis and/or oxidation, is one of the main concerns associated with their use. Furthermore, degradation of polysorbates is determined by formulation composition, pH and storage conditions, therefore underlining the importance and complexity of protein formulation development using polysorbates. A need-based approach should be used for correct selection of excipients in protein formulations that contain polysorbates

Degradation of polysorbates 20 and 80 catalysed by histidine chloride buffer

Polysorbates are amphiphilic, non-ionic surfactants, and they represent one of the key components of biopharmaceuticals. They serve as stabilisers, and their degradation can cause particle formation, which has been an industry-wide issue over the past decade. To determine the influence of the buffers most frequently used in biopharmaceuticals on polysorbate degradation, an accelerated stability study was carried out using placebo formulations containing 0.02% polysorbates and 20 mM buffers (pH 5.5, 6.5). These included histidine chloride, sodium citrate, sodium succinate and sodium phosphate buffers. The rate of polysorbate degradation was highest in histidine chloride buffer, and therefore we further focused on the mechanism here. The predominant degradation pathway of polysorbates in this buffer was ester hydrolysis, catalysed by the imidazole moiety of the histidine. Interestingly, the presence of therapeutic proteins in the formulations slowed histidine-catalysed degradation of polysorbates in 50% of cases, with negligible degradation seen otherwise. This emphasises the complex nature of the interactions between the components of biopharmaceutical drug products. Nonetheless, there are disadvantages of using histidine chloride buffers in biopharmaceuticals that contain polysorbates. Careful consideration should be given to selection of excipients used in parenteral formulations, whereby compatibility between buffer and surfactant is of key importance

Protein formulations containing polysorbates

Proteins are prone to post-translational modifications at specific sites, which can affect their physicochemical properties, and consequently also their safety and efficacy. Sources of post-translational modifications include oxygen and reactive oxygen species. Additionally, catalytic amounts of Fe(II) or Cu(I) can promote increased activities of reactive oxygen species, and thus catalyse the production of particularly reactive hydroxyl radicals. When oxidative post-translational modifications are detected in the biopharmaceutical industry, it is common practice to add chelators to the formulation. However, the resultant complexes with metals can be even more damaging. Indeed, this is supported here using an ascorbate redox system assay and peptide mapping. Ethylenediaminetetraacetic acid (EDTA) addition strongly accelerated the formation of hydroxyl radicals in an iron-ascorbate system, while diethylenetriaminepentaacetic acid (DTPA) addition did not. When Fe(III) was substituted with Cu(II), EDTA addition almost stopped hydroxyl radical production, whereas DTPA addition showed continued production, but at a reduced rate. Further, EDTA accelerated metal-catalysed oxidation of proteins, and thus did not protect them from Fe-mediated oxidative damage. As every formulation is unique, justification for EDTA or DTPA addition should be based on experimental data and not common practice