Articoli di riviste sul tema "Azote – Solubilité"

Durum wheat needs energy to accomplish the main metabolic and physiological functions; this energy is provided mainly by nitrogen which is also a fundamental constituent of the plant. Despite its importance and because of its high solubility, nitrogen is classified as a potential pollutant for the environment. The objective of this work is to study the response of four varieties of durum wheat (Karim, Razzak, INRAT100 and Dhahbi) to nitrogen treatment. The results showed that the new variety (Dhahbi) gave highest yield and water use efficiency either with or without fertilization thanks to the impact of genetic improvement. Thus, it is recommended to plant the Dhahbi variety to limit the use of nitrogen fertilizers, protect the environment and maximize gross income, especially for small farmers.

Background:Imidazole is one of the most explored and marketed azole utilized for the treatment of fungal infections. Lanosterol 14α-demethylase (Cytochrome P450DM) is the active target site for azole antifungals.Aim and Objective:This study emphasized on evaluation of a series of halogenated imidazole analogues using molecular docking studies for anti-Candidal activity. Furthermore, the model was refined by molecular dynamic simulation.Methods:Halogenated imidazole analogues (PS1-PS30) were obtained from literature for the study. The imidazole analogues were prepared using Chem sketch and molecular docking was performed using Molergo Virtual Docker program and ADMET study was carried out by using Accelry’s Accord for Excel programme.Results:The docking study indicated that all the imidazole analogues (PS1-PS30) and standard drugs i.e., Ketoconazole, Miconazole and Clotrimazole possessed interaction with protein residue, heme cofactor and water molecule positioned above Heme cofactor of 14α-demethylase. Further, the ADMET study indicated that most of the halogenated imidazoles possessed good absorption, human intestinal absorption, aqueous solubility and blood brain penetration.Conclusion:Halogenated imidazole analogues may be used as potential lead molecules as 14α- demethylase inhibitors.

Estimates of the nitrogen solubility in model steels of various compositions based on Fe-13%Cr with additional alloying (a small amount from hundredths of a percent to 1.5%) with elements (Mn, Mo, V, Nb) that increase the solubility of nitrogen in iron-based solid solutions are calculated. 60 variants of compositions were studied. Based on previously obtained own experimental data for nitrogen-containing steels with a content of 16%Cr-5%Ni-Nb for martensitic steel, a preliminary assessment of the composition stability coefficient of nitrogen used in the calculations of its (nitrogen) solubility was carried out. The resulting value of the composition stability coefficient is lower than for austenitic steels. For steels of all composition variants with calculated nitrogen content and different content of additional alloying elements (Mn, Mo, V, Nb), the phase composition was estimated using a modified Scheffler—Delong diagram and a nonequilibrium Potak—Sagalevich diagram for steel, which processed on solid solution. It is shown, among other things, that all compositions of Fe-13%Cr-Mn, Mo, V, Nb with a low carbon content (0.03—0.05%) with the maximum calculated solubility of nitrogen in the metal are in the martensitic-ferritic region. By calculation, the temperature of the martensitic transformation beginning was obtained using the empirical Finkler—Schirra formula and a correlation was established between the temperature of the martensitic transformation beginning and the Niequivalent/Crequivalent ratio (chromium and nickel equivalents calculated using formulas for the modified Scheffler—Delong diagram).

Different metal complexes of the azole-based ligands have been synthesized and characterized based on the solubility, percentage yield, melting points and conductivity a well as the antimicrobial evaluations on the selected fungi species of plant pathogens. The studies revealed that solid metal complexes were soluble in 80% water and 20% (DMSO) dimethylsulphuroxide and the percentage yields were of appreciable high while the conductivity results showed that metal complexes were non-electrolytes. The solid complexes were also screened against the fungi species: Rhizoctonia solani,Pythium aphaindermatum,Rhizoctonia cerealis,Sclerotium rofisil ,Phyphotoria palmivora (causative agent of black pod diseases) and Benlate a commercial anti fungi agent (as control).The results of the present studies confirmed that metal complexes had good inhibitory actions on the growth of the fungi species and metal complexes appeared to be more proactive on the tested organisms than the free ligands.DOI: http://dx.doi.org/10.3126/ijasbt.v1i4.9176 Int J Appl Sci Biotechnol, Vol. 1(4): 258-265

Rezafungin is a novel echinocandin with exceptional stability and solubility and a uniquely long half-life allowing for front-loaded drug exposure with once-weekly dosing. Rezafungin has been shown comparable to other echinocandins, with activity against Candida spp. and Aspergillus spp. including subsets of echinocandin-resistant Candida auris and azole-resistant Aspergillus isolates. Available clinical data show robust safety and promising efficacy. Phase III trials will provide data on efficacy of rezafungin for the treatment of candidemia and invasive candidiasis and for the prevention of invasive fungal disease in blood and bone marrow transplant recipients. Rezafungin is a promising new candidate in the antifungal arsenal that opens up clinical possibilities based on its impressive half-life, such as early hospital discharge for stable patients and use as prophylaxis in immunocompromised patients.

Heterocyclic compounds have an extremely important practical application, since many heterocycles are the basis of the most valuable medicinal substances, both natural (vitamins, enzymes, alkaloids, etc.) and synthetic biologically active compounds. The work mainly considers the most relevant directions for various purposes drugs search by modifying known bioactive natural, organoelement and framework compounds with 1,2-azole, oxazole, oxadiazole, thiazole, triazole, pyridine, pyrimidine heterocycles over the past 10 years. Chemical modification makes it possible to increase the water solubility of the compounds, which is important when choosing the pathways for the most rational drug introduction into the body, to reduce the toxicity of the corresponding substances, to increase the breadth of the therapeutic action, and also to give new valuable medicinal properties, thus significantly expanding their application in medicine and agriculture.

Background: Itraconazole is a triazole derivative and possesses structural similarities to the azole group (imidazoles and triazoles). It is a broad spectrum fungistatic. It belongs to BCS class II category i.e. it has poor solubility and high permeability. Objective: Dissolution enhancement of poorly soluble itraconazole using purified neem gum as a natural carrier via binary dispersions and other methods was studied. Topical gel formulations of binary dispersions were developed and evaluated for in vitro and in vivo antifungal activity. Methods: Five batches of solid dispersions (SD1-SD5) in various ratios of drug: neem gum were prepared by the solvent evaporation technique. Other mixtures were also prepared by kneading, cogrinding, physical mixing methods and evaluated further. Topical gel formulations were further developed and evaluated for antifungal activity (both in vitro and in vivo). Results: Equilibrium solubility studies of various mixtures indicated SD3 (1:3) as the optimum batch out of all solid dispersion batches. Equilibrium solubility studies of mixtures (KM, CGM, PM, SM) indicated significant solubility enhancement of kneading mixture in comparison to other mixtures. FTIR studies indicated no interaction of the drug to the polymer. DSC, SEM and XRD studies indicated a transition from crystalline to the amorphous state of the drug. SD3 batch showed remarkably improved dissolution characteristics (100% drug release in 1.5 h) in comparison to the pure drug (38% in 2h). Further, the topical gel of SD3 was evaluated for in vitro diffusion, in vitro and in vivo antifungal activity. Sustained drug release (53% in 24 h) was observed in SD3 based gel formulation which is significantly higher than that in comparison to pure drug based gel (30% in 24 h). The increased area of zone of inhibition of SD3 based gel indicated better antifungal activity of the SD3 gel formulation. Further histopathology examination of skin specimens indicated enhanced efficacy of SD3 based gel in comparison to pure drug based gel. Conclusion: Solid dispersion based topical gel formulation exhibits better antifungal activity in comparison to pure drug based gel.

Abstract Although Candida albicans remains the main cause of candidiasis, in recent years a significant number of infections has been attributed to non-albicans Candida (NAC) species, including Candida krusei. This epidemiological change can be partly explained by the increased resistance of NAC species to antifungal drugs. C. krusei is a diploid, dimorphic ascomycetous yeast that inhabits the mucosal membrane of healthy individuals. However, this yeast can cause life-threatening infections in immunocompromised patients, with hematologic malignancy patients and those using prolonged azole prophylaxis being at higher risk. Fungal infections are usually treated with five major classes of antifungal agents which include azoles, echinocandins, polyenes, allylamines, and nucleoside analogues. Fluconazole, an azole, is the most commonly used antifungal drug due to its low host toxicity, high water solubility, and high bioavailability. However, C. krusei possesses intrinsic resistance to this drug while also rapidly developing acquired resistance to other antifungal drugs. The mechanisms of antifungal resistance of this yeast involve the alteration and overexpression of drug target, reduction in intracellular drug concentration and development of a bypass pathway. Antifungal resistance menace coupled with the paucity of the antifungal arsenal as well as challenges involved in antifungal drug development, partly due to the eukaryotic nature of both fungi and humans, have left researchers to exploit alternative therapies. Here we briefly review our current knowledge of the biology, pathophysiology and epidemiology of a potential multidrug-resistant fungal pathogen, C. krusei, while also discussing the mechanisms of drug resistance of Candida species and alternative therapeutic approaches.

Redox flow batteries (RFBs) are rapidly gaining traction among large-scale storage solutions for intermittent renewable energy. Given the anticipated global scale of this technology, there is an intensive ongoing search for active electrolyte species containing all earth-abundant elements. Potential RFB actives must satisfy several criteria to maximize battery performance, namely, high solubility in the RFB solvent, optimum reduction potential, and chemical stability in all redox states. Given the near infinite possible molecular combinations of the primary atoms C, H, N, O, S, and Fe, computational chemistry is an invaluable tool to accelerate the discovery of promising new RFB active compounds. Towards that end, we performed DFT calculations on two major systems: iron(III/II) tris-2,2’-bipyridine, [Fe(bpy)3]3+/2+, as a model organometallic species, and azoles as a class of small, aromatic organic compounds. For [Fe(bpy)3]3+/2+, after extensive benchmarking of various functionals, basis sets, and other parameters, we accurately predict this complex’s one-electron reduction potential. The computational protocols employed on this system serve to open up the entire class or organometallics to predictive DFT calculations for future high-throughput screening. We also performed frequency calculations in the construction of a potential energy surface of [Fe(bpy)3]3+/2+’s degradation products, with consideration of all possible spin states, during this species’ hydrolysis-initiated dimerization to µ-O-[Fe(III)(bpy)2(H2O)]2 4+. The PES is discussed in light of literature-reported mechanisms for this system. Our study on functionalized azole compounds is motivated by recent demonstrations of azo compounds for RFBs in both aqueous and non-aqueous configurations. The azo group and its related nitro to amino group-containing monomeric species offers a plethora of potentially reversible redox transformations. Here, we investigate the redox potential and solvation energies of six azole-based compounds via DFT. Amino/nitro-functionalized azoles are small, aromatic compounds with the possibility to store up to six electrons per core, which would afford unprecedented energy densities in RFBs. The findings identify several species along the nitro-azo-amino pathway that have favorable redox potentials as anolyte or catholyte species (Fig. 1), as well as potentially high water solubility. Such coupling of anolyte-catholyte species from the same class of compounds would afford a crossover-proof RFB configuration analogous to vanadium systems that has not been demonstrated for aqueous organic flow batteries. Moreover, redox potentials between cis and trans isomers of the azo species were quantified, implicating further utility of these compounds in photo-mediated cells. These results will guide experimental investigations into the feasibility of implementing azole compounds for RFBs. Figure 1. Calculated redox potentials (Latimer diagram) for various azoles, including monomeric (nitro-nitroso-hydroxylamine-amino) and dimeric (azo-type) electron transfer events. Species falling outside the -0.5 to 0.5 V range (dotted lines) implicate their potential viability as RFB anolyte (V<-0.5) or catholyte (V>0.5) redox couples. Potentials were derived from DFT-level frequency calculations (free energies) utilizing the TPSS functional, def2-TZVPP basis set, and implicit solvation (CPCM H2O, vacuum- and solvent-optimized geometries). Figure 1

Among different Candida species triggering vaginal candidiasis, Candida albicans is the most predominant yeast. It is commonly treated using azole drugs such as Tioconazole (TIO) and Econazole (ECO). However, their low water solubility may affect their therapeutic efficiency. Therefore, the aim of this research was to produce a novel chitosan nanocapsule based delivery system comprising of TIO or ECO and to study their suitability in vaginal application. These systems were characterized by their physicochemical properties, encapsulation efficiency, in vitro release, storage stability, cytotoxicity, and in vitro biological activity. Both nanocapsules loaded with TIO (average hydrodynamic size of 146.8 ± 0.8 nm, zeta potential of +24.7 ± 1.1 mV) or ECO (average hydrodynamic size of 127.1 ± 1.5 nm, zeta potential of +33.0 ± 1.0 mV) showed excellent association efficiency (99% for TIO and 87% for ECO). The analysis of size, polydispersity index, and zeta potential of the systems at 4, 25, and 37 °C (over a period of two months) showed the stability of the systems. Finally, the developed nanosystems presented fungicidal activity against C. albicans at non-toxic concentrations (studied on model human skin cells). The results obtained from this study are the first step in the development of a pharmaceutical dosage form suitable for the treatment of vaginal candidiasis.

Abstract Composites consisting of polyvinyl alcohol, nitrogen- and phosphorus-containing waste materials were prepared and studied as materials for encapsulation of mineral fertilizers By-products of biodiesel production (rapeseed cake, crude glycerol), horn meal (waste product of haberdashery) and phosphogypsum (by-product of the production of phosphorus fertilizers) were used as the fillers of the composites. The films of the composites with the different amounts of nitrogen and phosphorus were prepared using different fillers or their mixtures. Mechanical, properties of the films, hygroscopicity, solubility in water were studied. The composites developed were used for the encapsulation of mineral fertilizers. It was established that encapsulation resulted in the increase of the time of release of the fertilizers. The developed slow-release fertilizers represent a combination of inorganic and organic compounds. The organic part consists of nitrogen- and phosphorus containing horn meal and rapeseed cake. Since assimilation of organic substances is considerably longer, nitrogen and phosphorus of these components will be available for plants much later than inorganic nitrogen and phosphorus. Thus the composite film will not only decrease the rate of desorption of the components from the granules of the fertilizers but will also prolong the impact of the fertilizers on the plants.

The need for new antifungal agents has never been greater. Over the last 10 years the incidence of life-threatening fungal infections has increased dramatically as the population of immunocompromised individuals induding cancer, organ transplant, and AIDS patients has increased. Present therapeutic options for· the treatment of these infections are limited to compounds in two classes, the polyenes and the azoles. Some polyene research still continues with analogs of amphotericin B in the hopes of decreasing toxicity. Much work continues in the azole area with follow-up compounds to fluconazole and itraconazole in order to expand the spectrum and provide oral and iv formulation potential. A newer class of cell wall active agents that has been developed to the point of seeing clinical candidates is the cyclic lipopeptide echinocandin family. This group has the potential of providing broad spectrum fungicidal activity with a much lower toxicity level than .the current agents. Another newer class of natural products known as the aureobasidins has potent, oral fungicidal activity against Candida spp. Research has continued with the pradimicins to produce several new semisynthetic derivatives with comparable activity and spectrum to the parent compound but with improved water-solubility. Work with the nikkomycin class has delineated points of the SAR but has not produced compounds of sufficient potency for clinical use. The allylamines have been examined further to provide analogs of terbinafine with increased Candida activity but are still most highly potent versus dermatophytes. Several other newer classes with unique mechanisms of action have also been identified.

Abstract An approach to modeling leaching and leaching impacts of preservative components from treated wood is presented based on three simple laboratory determinations: the amount of preservative component available for leaching (Le), equilibrium dissociation of preservative into free water in wood (Di) and diffusion coefficients for component leaching in different wood directions (D). In this study, the following inorganic wood preservative systems were investigated: chromated copper arsenate (CCA), the copper component of copper azole (CA) and alkaline copper quaternary (ACQ), and boron in disodium octaborate tetrahydrate (DOT). Aggressive leaching of finely ground wood showed that amounts of preservative compounds available for leaching were highest for borates, followed by copper in copper amine systems and arsenic in CCA, copper in CCA and chromium in CCA. The equilibrium dissociation or solubility of components in free water in the wood was much higher for borates and copper amine, followed by copper and arsenic in CCA and chromium in CCA. Use of the applicable diffusion coefficient (D) and Di or Le values in a diffusion model allows the prediction of total amount leached and emission or flux rate at different times of exposure for products with different dimensions and geometries. The approach was tested and generally validated through application of the model to results of laboratory water spray leaching of full-size lumber samples. The approach explains the rapid leaching of boron compounds (large diffusion coefficient and high initial dissociated concentration) compared to other preservative components and predicts that ACQ will have higher initial leaching rates compared to CCA and CA, but the latter preservatives will continue to leach copper at a measurable rate for a much longer time. The practical implications and limitations of the approach are discussed.

The analysis of the current state of pharmacotherapy for vulvovaginal candidiasis reveals that there is a contemporary need for the development of soft dosage forms for the local treatment of infectious diseases affecting the vulva and vagina. This should be based on azole derivatives that, despite possessing a well-established wide spectrum of antifungal and antibacterial effects, have not been utilized for vaginal administration in domestic formulations. The successful realization of this project would enable the field of domestic dermatology to provide effective, compliant, and affordable drugs for gynecological practice to the general population of Ukraine. Additionally, it would establish a viable alternative to imported pharmacotherapeutic agents. Aim. The purpose of this work is the scientific substantiation of the concentration of bifonazole in suppository compositions for vaginal use. Materials and methods. Research was conducted to investigate the influence of bifonazole concentration ranging from 1 % to 15 % in soft dosage forms for vaginal use. Model compositions were formulated on a polyethylene oxide carrier, considering its solubility. The antifungal activity of the experimental suppository compositions was chosen as the optimization parameter and assessed using the diffusion method in agar against Candida albicans ATCC 885-653. Variance analysis of the results revealed a significant impact of bifonazole concentration on the antimycotic activity of the suppository compositions based on the model polyethylene oxide. Results. The research results show that increasing the concentration of the active pharmaceutical ingredient in suppository masses above 10 % does not lead to a statistically significant increase in their antimycotic activity. Conclusions. As a result of the conducted study on the antifungal effect of suppository masses with bifonazole on a model polyethylene oxide basis, it was found that the concentration of the active pharmaceutical ingredient has a statistically significant effect on the effectiveness of the soft dosage form. It was established that a ten percent concentration of bifonazole, equivalent to 0.3 g of the biologically active substance in vaginal suppositories, provides the optimal level of their antifungal effect.

Isolation and Characterization of Microorganisms for Use with Manure and Chemical Fertilizers Levent Değirmenci1, Özge Kaygusuz İzgördü2, Cihan Darcan3 ORCID: 0000-0001-6608-0398; 0000-0002-3652-4266; 0000-0003-0205-3774 1 Corresponding author: Department of Chemical Engineering, Bilecik Şeyh Edebali University, 11210, Bilecik/Turkey Tel: +90 228 2141548, e-mail: levent.degirmenci@bilecik.edu.tr 2 Biotechnology Application and Research Center, Bilecik Şeyh Edebali University, 11210, Bilecik, Turkey 3 3Department of Molecular Biology and Genetics, Bilecik Şeyh Edebali University, 11210, Bilecik, Turkey Abstract A microbial consortium with the ability to utilize nitrogen of certain chemical fertilizers were established via a series of tests. Results indicated four strains, 3 of which were identified as Bacillus cereus sp and an Alcaligenes faecalis sp. which was the only non-Bacillus member of the consortium. The members of the consortium showed no antagonistic activity against each other implying their successful utilization as components of a commercial fertilizer. Keywords: IAA, siderophore, Bacillus spp., nitrogen fixation, ammonia/nitrite oxidation, MALDI-TOF MS Organik ve Kimyasal Gübre ,le Kullanılmak Üzere Mikroorganizma İzolasyon ve Karakterizasyonu Özet Farklı kimyasal gübrelerin içeriğinde yer alan azotu bitkinin kullanımına sunabilen mikroorganizma karışımı bir dizi testler sonucunda elde edilmiştir. Sonuçların değerlendirilmesiyle mikroorganizma karışımına üç Bacillus Cereus sp. suşu ile karışımın Bacillus sp. olmayan tek üyesi Alcaligenes faecalis sp. seçilmiştir. Mikroorganizma karışımında yer alan suşların birbirlerine karşı antagonistik etki göstermediği dolayısıyla karışımın mikrobiyal gübre olarak ticarileştirilmesinin mümkün olduğu da elde edilen sonuçlar arasındadır. Anahtar Kelimeler: IAA, siderophore, Bacillus spp. azot fiksasyonu, amonyum/nitrit oksidasyonu, MALDI-TOF MS 1. Introduction Chemical fertilizer is gaining an increasing attention and its harmful effects on environment possesses a serious threat [2]. Heavy metal accumulation is another problem during utilization of chemical fertilizers [2].The variation of soil pH, another problem encountered due to excessive fertilizer utilization, has negative impact on phosphorus uptake [3]. Plant growth promoting bacteria when added to soil, operate via certain mechanisms facilitating acquisition of already existing resources in soil [4]. Siderophore producing bacteria also acts as biocontrol agent capable of decreasing phytopathogen population in the flora [4–7]. Certain procedures were developed and/or modified in the present study to obtain a microbial consortium which would act as an enhancer during plant growth. 2. Materials and Method 2.1. Semi-selective isolation procedure as starting-point Semi-selective isolation procedures were conducted according to [12]. 2.2. Standard tests applied to determine the potential of isolates as PGPB. Nitrogen fixation ability, IAA production, phosphate solubility siderophore production were conducted according to [13-18]. 2.3. Specified tests to determine nitrogen evaluation potential of PGP isolates Nitrogen evaluation potential was determined according to [19]. 2.4. Biochemical tests conducted to determine Bacillus sp. in accordance with MALDI-TOF MS analyses evaluated for validation. Biochemical tests were evaluated based on positive results for both caseinase activity and starch hydrolysis [20-22]. MALDI-TOF MS analyses applied for selected strains and an isolate with positive activity towards siderophore production. 3. Results IAA production, Nitrogen fixation performance, Ammonifier selection, phosphate solubility, siderophore production ability, urea degradation, ammonium oxidation and nitrite oxidation abilities of strains were evaluated to establish a microbial consortium. 4. Conclusion and discussion • Media selection could serve as a selection criterion to assemble a certain group of microorganisms. • Tests conducted for isolates could be diversified to establish a consortium with modified properties. • Test procedures could be modified to facilitate establishment of microbial consortium. • Strains with different properties could serve as members of consortium which was the case in our study. • Identification in species level was possible to a certain extent. MALDI-TOF MS analysis presented a brief idea on strains and similar results would have been obtained in the case of applying its costlier alternatives. Hence a relatively simpler procedure is concluded to be better for initial investigation. • Evaluation of results led to investigation of certain prospects including determination of physicotolerant activity of strains and management of Fusarium wilt disease as the topics of future investigations.