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We have reported in the last years the strong effect that Be‐ and Mg‐containing Lewis acids have on the intrinsic properties of typical bases, which become acids upon complexation. In an effort to investigate these changes when the Be and Mg derivatives form clusters of increasing size, we have examined the behavior of the (MX2)n (M = Be, Mg; X = H, F; n = 1, 2, 3) clusters when they interact with ammonia, methanimine, hydrogen cyanide and pyridine, and with their corresponding deprotonated forms. The complexes obtained at the M06‐2X/aug‐cc‐pVTZ level were analyzed using the MBIE energy decomposition formalism, in parallel with QTAIM, ELF, NCIPLOT and AdNDP analyses of their electron density. For n = 1 the interaction enthalpy for the different families of monomers, Be (Mg) hydrides and Be (Mg) fluorides, follows the same trend as the intrinsic basicity of the base that interacts with them. This interaction is greatly reinforced after the deprotonation of the base, resulting in a significant enhancement of the intrinsic acidity of the corresponding MX2–Base complex. For (MX2)2 clusters a further reinforcement of the interaction with the base is observed, this reinforcement being again larger for the deprotonated complexes. However, the concomitant increase of their intrinsic acidity is one order of magnitude larger for hydrides than for fluorides. Unexpectedly, the cyclic conformers (MX2)3, which are more unstable than the linear ones, become the global minima after association with the base and the same is true for the deprotonated complex. Accordingly, a further increase of the intrinsic acidity of the (MX2)3–Base complexes with respect to the (MX2)2–Base ones is observed. This effect is maximum for (MgF2)3 clusters, to the point that the (MgF2)3–Base complexes become more acidic than nitric acid, the extreme case being the cluster (MgF2)3–NCH, whose acidity is higher than that of perchloric acid. [ABSTRACT FROM AUTHOR]

[Display omitted] The optimization of the adsorption of oxygen-containing intermediates on platinum (Pt) sites of Pt-based electrocatalysts is crucial for the oxygen reduction reaction process. Currently, a large amount of researches mainly focus on modifying the bulk structure of the electrocatalysts, however, the vital role of solvent effect on the phase interfaces is often overlooked. Here, we successfully developed an electrocatalyst in which the ordered PtCo alloy anchors on the cobalt (Co) single-atoms/clusters decorated support (Co 1,n N C) and its surface is further optimized using hydrophobic ionic liquid (IL). Experimental studies and theoretical calculations indicate that compressive stress on Pt lattice contributed by intrinsic structure and the local hydrophobicity caused by IL on the surface can suppress the stabilization of *OH on Pt. This synergistic effect affords outstanding catalytic performance, exhibiting a half-wave potential (E 1/2) of 0.916 V vs. RHE and a mass activity (MA) of 1350.3 mA mg Pt −1 in 0.1 mol/L perchloric acid (0.1 M HClO 4) electrolyte, much better than the commercial Pt/C (0.849 V vs. RHE and 145.5 mA mg Pt −1 for E 1/2 and MA, respectively). Moreover, the E 1/2 of IL-PtCo/Co 1,n N C only lost 5 mV after 10,000 cyclic voltammetry (CV) cycles due to a strong and synergistic contact of the intermetallic PtCo alloy with the Co 1,n N C support and IL. This research provides an effective method for designing efficient electrocatalysts by combining intrinsic structure and surface modification. [ABSTRACT FROM AUTHOR]

The effect of anions on the positive electrospray ionization (ESI) of proteins in different strong acids with varying pH values from 3 to 1 is studied using high-pressure ESI. Reducing the pH from ∼2 to 1 caused a drastic shift in charge state from a high-charge-state distribution (HCSD) to a narrow low-charge-state distribution (LCSD). The shift in charge state was consistent with the circular dichroism result that showed a conformational change due to the "acid-induced folding" of proteins from an unfolding state to a compact molten globule state. Acids of different anions produced noticeable differences in the average charge for HCSD and LCSD. For HCSD, the average charge was lower than the value typically observed using formic and acetic acids. As for LCSD, the average charge was lower than the "native" charge. The high abundance of acid anion that induces the protein compaction was believed to play a role in charge reduction. The effectiveness of anions to "refold" a highly unfolded protein to a compact state and the propensity to reduce the charge of HCSD for proteins appeared to follow the selectivity series of anions towards the stationary phase in ion chromatography. However, the propensity of anions to reduce the charge for LCSD follows quite an opposite trend. The presence of ammonium salt in the acidic solution was found to increase the charge of LCSD. The simple mass spectrum with a narrow distribution of charge state obtained with perchloric acid at pH 1 was demonstrated to facilitate the counting of basic sites. [ABSTRACT FROM AUTHOR]

Herein, we developed a highly diastereoselective silver-catalyzed intramolecular cyclopropanation of prochiral alkyne-tethered 1,3-dicarbonitriles using perchloric acid as an effective oxidizing agent. This method facilitates the construction of densely functionalized complex [6.6.5.3] frameworks having three all-carbon quaternary stereocenters in high yields. The significance of the reaction was demonstrated by a gram-scale reaction and post-synthetic modifications of the product. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The discharge of the zinc–perchloric acid–lead dioxide electrochemical system at temperatures from –50 to +50°C was studied. Zinc coatings, including those subjected to chromate passivation, can be used as anode materials for fast-activated reserve chemical power sources. The tests of pilot batches confirmed that the power sources met the activation time requirements (no more than 50 ms). The power sources of the given system are characterized by increased discharge voltage (the maximum voltage of one cell is 2.12–2.44 V) compared with that of the lead–perchloric acid–lead dioxide system (1.50–1.86 V). The disadvantages of the zinc–perchloric acid–lead dioxide system were revealed: instability of discharge characteristics and possible cell polarity reversal as a result of side reactions, which may have a significant negative impact on the reliability of reserve power sources. [ABSTRACT FROM AUTHOR]

A convenient synthetic strategy has been developed for the synthesis of a pentasaccharide related to the cell wall O‐polysaccharide of Acinetobacter baumannii (A. baumannii) 90 in very good yield applying a stereoselective [3+2] block glycosylation reaction. The synthesis of the target pentasaccharide was challenging due to the presence of a rare sugar, 4‐amino‐4‐deoxy‐D‐fucose and several α‐glycosidic linkages in it. The construction of 1,2‐cis glycosyl linkages were achieved using a combination of copper(II) bromide and tetra‐n‐butylammonium bromide (TBAB) or a combination of N‐iodosuccinimide (NIS) and trimethylsilyl trifluoromethanesulfonate (TMSOTf) as thiophilic glycosylation activator. Perchloric acid supported over silica (HClO4‐SiO2) mediated orthogonal glycosylation reaction has been carried out using glycosyl trichloroacetimidate derivative as donor and thioglycoside as acceptor. [ABSTRACT FROM AUTHOR]

Teneligliptin (TEN) is a novel, third-generation DPP4 inhibitor (Dipeptidyl peptidase) used for the treatment of Type 2 Diabetes Mellitus. A rapid, simple and highly sensitive stability-indicating reverse-phase high-performance liquid chromatographic technique coupled with a photodiode array detector was developed and validated for the estimation of TEN. The λ max was determined at 246 nm. The mobile phase comprised Methanol: Water (containing 1% perchloric acid):Triethylamine (80:20:1) at room temperature with a flow rate of 1 mL min−1. The chromatographic separation was achieved with Inertsil C-18 Octadecyl-silica (ODS) (250 × 4.6 mm), 5 μm column with a retention time of 2.6 min (min). The developed method is fast with a run time of 6 min and sensitive with LOD 35 ng mL−1 that was never reported earlier. The calibration curve was found to be linear in the range of 1–32 μg mL−1 with a R2 value of 0.990. The developed method is validated as per International Conference on Harmonization guidelines. TEN was evaluated under stress conditions that included hydrolytic (acid, alkali and neutral), oxidative and thermal degradation. Significant degradation was observed in basic, oxidative and thermal degradation conditions. The developed method was employed successfully to estimate the amount of TEN in bulk and pharmaceutical formulation. [ABSTRACT FROM AUTHOR]

This study examines the kinetics and mechanism of the oxygen reduction reaction (ORR) on a polycrystalline rhodium electrode (Rh(poly)) in acidic and alkaline media, using rotating disc electrode measurements. This study found that the ORR activity of the Rh(poly) electrode decreases in the order of 0.1 M NaOH > 0.1 M HClO4 > 0.05 M H2SO4 concerning the half-wave potentials. The Tafel slopes for ORR on Rh(poly) in the cathodic direction are 60 and 120 mV dec−1 at low and high overpotentials, respectively, in perchloric acid and alkaline solutions. However, strongly adsorbed sulfate anions hinder the ORR on Rh(poly) in sulfuric acid, leading to higher Tafel slopes. The highest ORR activity of Rh(poly) in an alkaline media suggests the promoting role of the specifically adsorbed OH− anions and RhOH. In all cases, ORR on Rh(poly) proceeds through the 4e-series reaction pathway. [ABSTRACT FROM AUTHOR]

Layer removal with electropolishing is a well-established method when measuring residual stress profiles with lab-XRD. This is done to measure the depth impact from processes such as shot peening, heat treatment, or machining. Electropolishing is used to minimize the influence on the inherent residual stresses of the material during layer removal, performed successively in incremental steps to specific depths followed by measurement. Great control of the material removal is critical for the measured stresses at each depth. Therefore, the selection of size of the measurement spot and electropolishing parameters is essential. The main objective in this work is to investigate how different electrolytes and electropolishing equipment affect the resulting surface roughness, geometry, microstructure, and consequently the measured residual stress. A second objective has been to establish a methodology of assessing the acquired electropolished depth. The aim has been to get a better understanding of the influence of the layer removal method on the accuracy of the acquired depth. Evaluation has been done by electropolishing one ground and one shot peened sample of a low-alloy carbon steel, grade 1.1730, with different methods. The results showed a difference in stresses depending on the electrolyte used where the perchloric acid had better ability to retain the stresses compared to the saturated salt. Electropolishing with saturated salt is fast and results in evenly distributed material removal but has high surface roughness, which is due to a difference in electropolishing of the two phases, ferrite, and pearlite. Perchloric acid electropolishing is slower but generates a smooth surface as both ferrite and pearlite have the same material removal rates but may cause an increased material removal for the center of the electropolished area. In this work, it is suggested to use perchloric acid electropolishing for the final layer removal step. [ABSTRACT FROM AUTHOR]

This article introduces a highly proficient and environmentally friendly process for producing pyranopyrazole-5-carbonitriles with outstanding yields. This involves a multicomponent synthesis using commonly available aldehydes, malononitrile, ethyl acetoacetate, and phenylhydrazine, conducted in ethanol with perchloric acid supported on silica (HClO4-SiO2) as a solid catalyst. Utilizing HClO4-SiO2 as a reusable catalyst underscores the sustainability of this approach, offering a valuable green chemical strategy for pyranopyrazole synthesis. Characterization of the synthesized compounds was achieved using FTIR, 1H NMR, 13C NMR, and Mass spectrometry. Additionally, molecular docking studies revealed significant binding energies of the compounds to receptor-active sites, further validating their potential pharmacological relevance. [ABSTRACT FROM AUTHOR]

The validity of the Asami-Kumada method (sodium hydrosulfite + EDTA extraction, AK method) for determining the potentially environmentally available trace metals (Cr, Mn, Co, Ni, Cu, Zn, Cd, Pb) in paddy field soil was evaluated. This was accomplished by comparing it with the results of the dilute HNO3 extraction method (ISO method), nitrate acid – perchloric acid degradation method, and dilute hydrochloric acid extraction method on 250 paddy field soil samples. The coefficient of determination for the AK method in metals, excluding Cr, ranged from 0.92 (Ni of non-Andisols) to 0.99 (Mn, Cu, Zn and Cd of non-Andisols) compared to the ISO method. The slope of the linear regression of the AK method's measured values against those of the ISO method for metals, excluding Cr, ranged from 0.99 (Cd of non-Andisols) to 1.52 (Cu of Andisols). However, the measurements of Fe using the AK method were significantly higher than those obtained using the ISO method. The slope was measured to be 3.6 (for non-Andisols) or 5.7 (for Andisols). The increase in trace metal measurements using the AK method was probably due to the dissolution of Fe oxides and hydroxides, which release trace metals after reduction by sodium hydrosulfite. Thus, although the measured values using the AK method of trace metals, excluding Cr, tended to be slightly higher than those obtained using the ISO method as Fe oxides and hydroxides dissolved, the measured values of those metals by both methods were closely correlated. The AK method is a viable alternative to the ISO method for measuring the potentially environmentally available trace metal contents, excluding Cr, in paddy field soils. Additionally, the AK method conveniently measures free Fe oxides simultaneously. [ABSTRACT FROM AUTHOR]

Aqueous Redox Flow Batteries (ARFB) are the most prominent technology for large-scale energy storage applications. The energy density of the ARFBs is mainly determined by the electrolyte components, which highly influence the flow battery performance. In the present work, we acutely investigated the various electrolyte compositions and optimized the best electrolyte for realizing the high performance of Zn-Br2 ARFBs. The electrode kinetics, such as rate constant, exchange current density, conductivity, and diffusion coefficient, were analyzed using electrochemical techniques, cyclic voltammetry, and electrochemical impedance analysis. It was observed that zinc bromide (ZnBr2) + perchloric acid (HClO4) + 1-Ethyl-1-methylmorpholinium bromide (MEM) + N-ethyl-N-methylpyrrolidinium bromide (MEP) and ZnBr2 + zinc chloride (ZnCl2) + MEM + MEP electrolytes showed improved performance, where the redox kinetics of 2Br-/Br2 redox couple is greatly enhanced. The presence of perchloric acid unlocks the capacity of full electro-oxidation of bromide (Br-) to bromine (Br2) as it involves 1e- per Br-, which would be highly beneficial to attain high energy density. Further, Zn-Br2 RFB adopted with optimized electrolyte formulation ZnBr2 + HClO4 + MEM+ MEP shows a better round-trip efficiency and displays a stable long cycling performance over 200 cycles with an energy (EE) and coulombic efficiency (CE) of > 68% and > 92%, respectively.

Synthesis of the pentasaccharide corresponding to the K14 capsular polysaccharide from ST25 Acinetobacter baumannii isolate, D46 and O‐polysaccharide of Acinetobacter baumannii O11 has been achieved in very good yield using a convergent stereoselective [3+2] block glycosylation strategy. The synthetic scheme includes several regio‐ and stereose lective glycosylations as well as orthogonal glycosylation with high yield. Thioglycosides have been used as glycosyl donors using a combination of copper(II) bromide and tetra‐n‐butylammonium bromide (TBAB) as thiophilic activator for 1,2‐cis glycosylation and a combination of N‐iodosuccinimide (NIS) and trimethylsilyl trifluoromethanesulfonate (TMSOTf) as thiophilic activator for 1,2‐trans glycosylation. Glycosyl trichloroacetimidate derivative was used as glycosyl donor using perchloric acid supported on silica (HClO4–SiO2) as activator. A catalytic transfer hydrogenation reaction has been carried out for the removal of benzyloxy and benzylidene functional groups using triethylsilane as hydrogen source. [ABSTRACT FROM AUTHOR]

Nanoporous gold (NPG) is a promising catalytic material for the oxidation of CO and methanol applications. However, NPGs are prone to extensive macroscopic cracking that often decrease mechanic properties of NPGs and depresses their catalytic action. To produce crack-free NPG with an ultra-finer porosity in room temperature, the anionic surfactant sodium dodecyl sulfate (SDS) was added in electrochemical dealloying process. SDS has the effect of reducing the surface diffusion of gold which hinder the initial coarsening of ligaments and prevents interior silver atoms from being exposed and dissolved. As a result, the pore and ligment size are finer, but higher residual silver of NPG samples. NPG with pore size down to 2 nm and the ligament 4.0 nm was successfully fabricated with 13.32 mM SDS in perchloric acid solution. The surface diffusion coefficient of Au atoms was 1.6 × 10−24 m2·s−1, nearly 3 orders of magnitude smaller than that of Au atoms in the absence of SDS (2.8 × 10−21 m2·s−1). Nanoindentation results demonstrated that high residual silver content made NPG samples harder and stiffer，the specific surface areas of NPG with 6.66 mM SDS was 190 m2 g−1 by BET. This work provided very important clues on how to control the crack free ultrafine nanoporous structure of other materials. [ABSTRACT FROM AUTHOR]

Lipoxygenases (LOXs) catalyze dioxygenation of polyunsaturated fatty acids (PUFAs) into fatty acid hydroperoxides (FAHPs), which can be further transformed into a number of value-added compounds. LOXs have garnered interest as biocatalysts for various industrial applications. Therefore, a high-throughput LOX activity assay is essential to evaluate their performance under different conditions. This study aimed to enhance the suitability of the ferrous-oxidized xylenol orange (FOX) assay for screening LOX activity across a wide pH range with different PUFAs. The narrow linear detection range of the standard FOX assay restricts its utility in screening LOX activity. To address this, the concentration of perchloric acid in the xylenol orange reagent was adjusted. The modified assay exhibited a fivefold expansion in the linear detection range for hydroperoxides and accommodated samples with pH values ranging from 3 to 10. The assay could quantify various hydroperoxide species, indicating its applicability in assessing LOX substrate preferences. Due to sensitivity to pH, buffer types, and hydroperoxide species, the assay required calibration using the respective standard compound diluted in the same buffer as the measured sample. The use of correction factors is suggested when financial constraints limit the use of FAHP standard compounds in routine LOX substrate preference analysis. FAHP quantification by the modified FOX assay aligned well with results obtained using the commonly used conjugated diene method, while offering a quicker and broader sample pH range assessment. Thus, the modified FOX assay can be used as a reliable high-throughput screening method for determining LOX activity. Key points: • Modifying perchloric acid level in FOX reagent expands its linear detection range • The modified FOX assay is applicable for screening LOX activity in a wide pH range • The modified FOX assay effectively assesses substrate specificity of LOX [ABSTRACT FROM AUTHOR]

The electrodeposition of polyaniline films is usually carried out in acid solutions such as hydrochloric acid, perchloric acid or sulfuric acid, and more rarely in organic acids such as camphorsulfonic acid (CSA). In this study, the impact of the presence of a surfactant in the electrolytic solution based on hydrochloric acid or CSA was evaluated by successively using anionic (sodium dodecyl sulfate, SDS), cationic (cetyltrimethylammonium bromide, CTAB), and non-ionic (Tritonx100) surfactants. Whatever the surfactant and the acid used, the electrochemical oxidation of aniline has successfully led to the formation of a thick polyaniline (PANI) film through a quasi-reversible reaction controlled by the diffusion of aniline monomers. The nature of the surfactant was shown to affect physico-chemical properties of the film, in particular its morphological features (morphology, thickness, roughness), electrochemical activity, specific capacitance, and conductivity. For example, PANI films containing SDS had a spongy morphology when PANI films containing Tritonx100 had a more fibrous and compact structure. Glow Discharge Optical Emission Spectroscopy (GDOES) experiments also highlighted differences depending on the acid used since chloride anions, fromHCl,were present only on the top surface of the PANI films when camphorsulfonate anions were present everywhere throughout the polymer film, which impacts the doping process and electrochemical activity of the films. Moreover, the specific capacitance of the PANI/CSA films is higher and more sensitive to current density variation than the one of PANI/HCl films. Finally, electrochemical impedance experiments evidenced that the conductivity of PANI films electrodeposited from CSA solutions was much higher than the one of PANI films prepared from HCl solutions, and highly dependent on the nature of the surfactant, the most conductive films being obtained in the presence of SDS and Tritonx100. Therefore, the originality of this work comes from the possibility of modulating the conductivity, capacitance and electroactivity of electrodeposited polyaniline films using surfactants of different polarity, and from the determination of the distribution of ions in the films using the GDOES technique, which is rarely used to characterise organic films. [ABSTRACT FROM AUTHOR]

The monitoring of essential and toxic elements in patients with Opioid Use Disorder (OUD) undergoing methadone treatment (MT) is important, and there is limited previous research on the urinary levels of these elements in MT patients. Therefore, the present study aimed to analyze certain elements in the context of methadone treatment compared to a healthy group. In this study, patients with opioid use disorder undergoing MT (n = 67) were compared with a healthy group of companions (n = 62) in terms of urinary concentrations of some essential elements (selenium (Se), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), calcium (Ca)) and toxic elements (lead (Pb), cadmium (Cd), arsenic (As), and chromium (Cr)). Urine samples were prepared using the acid digestion method with a mixture of nitric acid and perchloric acid and assessed using the ICP-MS method. Our results showed that the two groups had no significant differences in terms of gender, education level, occupation, and smoking status. Urinary concentrations of Se, Cu, and Fe levels were significantly lower in the MT group compared to the healthy subjects. However, the concentrations of Pb, Cd, As, Mn, Cr, and Ca in the MT group were higher than in the healthy group (p < 0.05). No significant difference was established between the levels of Zn in the two groups (p = 0.232). The results of regression analysis revealed that the differences between the concentration levels of all metals (except Zn) between two groups were still remained significant after adjusting for all variables (p < 0.05). The data obtained in the current study showed lower urinary concentrations of some essential elements and higher levels of some toxic elements in the MT group compared to the healthy subjects. These findings should be incorporated into harm-reduction interventions. [ABSTRACT FROM AUTHOR]

The effect of two aminothiophene derivatives, namely (2-amino-4-phenylthiophene-3-carbonitrile) APTC and (2- amino-4-p-tolylthiophene-3-carbonitrile) ATTC, as carbon steel corrosion inhibitors in a perchloric acid medium was investigated. The study was performed by weight loss method, quantum chemical calculations (DFT) and Scanning electron microscope (SEM). The impact of the two aminothiophene derivatives as inhibitors was positively correlated with concentration, temperature, and exposure time. The value of the active energy of the inhibition corrosion reaction of carbon steel is greater than that obtained for the blank solution. All experimental data were consistent with the Langmuir adsorption isotherm, and the value and sign of the adsorption free energy obtained indicated that the inhibitor molecules were spontaneously adsorbed on the carbon surface by a mixed adsorption mechanism. The SEM surface analysis showed the formation of a protective organic film on the steel surface. The DFT supported the experimental results and showed that the inhibition effect is structure-dependent. [ABSTRACT FROM AUTHOR]

This article presents a study on the tert-butylation reaction of amino acids, carboxylic acids, and alcohols using bis(trifluoromethanesulfonyl)imide (Tf2NH) as a reagent. The study found that this method resulted in faster reactions and higher yields compared to conventional methods. The authors suggest that this information could be valuable to synthetic organic chemists as an alternative to using perchloric acid, as it offers safer conversions and improved reaction rates and yields. [Extracted from the article]

Using the method of cyclic voltammetry (CV), the electrocatalytic activity in the hydrogen evolution reaction (HER) in the presence of perchloric acid and N-methyl-2,2′-bipyridinium and N,N′-dimethyl-2,2′-bipyridinium iodides was studied. Conducting preparative electrolysis with simultaneous gas chromatography showed that in both cases the catalytic process is realized, however, in the case of N,N′-dimethyl-2,2′-bipyridinium iodide, the efficiency of the electrocatalytic process is much higher than in the case of N-methyl-2,2′-bipyridinium iodide. It has been shown for the first time the possibility to selectively engage different catalytic centers to hydrogen evolution reaction by varying the potential or the concentration of the acid. So, in case of N,N′-dimethyl-2,2′-bipyridinium iodide at low acid concentrations the catalytic process proceeds according to a homogeneous mechanism in parallel on both catalytic centers. At high acid concentrations on the CV two new waves appear which associated with the formation of additional pathways for the generating of molecular hydrogen - in the second wave it is realized according to the intramolecular mechanism, while in the third wave it is realized according to the heterogeneous mechanism. In the case of N-methyl-2,2′-bipyridinium iodide, one catalytic center can be selectively involved or both centers can "work" in parallel according to a different mechanism by varying the potential of the electrocatalytic process. It is important to note that the discovered phenomenon has not been previously described in the literature. It is shown for the first time that by varying the potential of the electrocatalytic process, it is possible to control the mechanism (switch) and the efficiency of the process. [Display omitted] • HER of new members of the family of metal-free electrocatalysts studied. • The TOF value strongly depends on potential and concentration of the acid. • It is possible to selectively engage different catalytic centers within one molecule. • HER process is realized simultaneously by three mechanisms. [ABSTRACT FROM AUTHOR]

Background: Canned fish products are widely consumed in Egypt, particularly for protein-rich meals that are quick to prepare and low in calories. Canned fish products are contaminated with toxic metals from the fish itself or from canning materials during processing. Aim: To determine the residual levels of cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), aluminum (Al), and Tin (Sn) in some canned fish products obtained from retail shops in Mansoura, Egypt. Furthermore, noncarcinogenic health risks evaluation for the Egyptian population due to hazardous metal oral intake. Methods: One hundred canned fish products (20 each of herring, mackerel, salmon, sardine, and tuna) were collected from May to September 2023, and canned fish products were obtained from Mansoura city markets in Egypt. Samples were digested in a solution composed of 60% nitric acid and 40% perchloric acid, and then an atomic absorption spectrophotometer was used for the detection of selected toxic metals. Results: It was found that the residual level of hazardous metals exceeded the acceptability level established in the European Union for Pb, Cd, and Hg by 20%, 10%, and 10%, 15%, 5%, and 20%, 35%, 30%, and 45%, 25%, 25%, and 40%, in examined herring, mackerel, sardine, and tuna, respectively. In contrast, all salmon samples were accepted for Pb and Hg, and only 5% were not accepted due to a higher Cd level than the maximum permissible limit. The average estimated daily intake of (EDI) is below the tolerable daily intakes (TDIs) for all metals. Comparatively, the EDI of Hg was 0.265 μg/kg body weight (B.W) exceeded TDIs 0.228 μg/kg B.W. The hazard index for canned tuna and sardines is more than one. Conclusion: Canned fish products are contaminated with a variety of toxic metals, especially sardine and tuna. Therefore, it is advised to decrease the consumption rate of such fish products. [ABSTRACT FROM AUTHOR]

Even though chiral recognition for crown‐ether CSPs is generally understood, on a molecular level, exact mechanisms for the resolution are still unclear. Furthermore, short peptide analytes often contain multiple amino moieties capable of binding to the crown ether selector. In order to extend the understanding in chiral recognition mechanisms, polar organic mode separation of Tyr‐Arg‐Phe‐Lys‐NH2 tetrapeptide llll/dddd enantiomers on S‐ and R‐(3,3′‐diphenyl‐1,1′‐binaphthyl)‐20‐crown‐6 stationary phases was studied with 50‐mM perchloric acid in methanol as mobile phase. Deviation from the generally acceptable 1:1 stoichiometry was supported by mass spectroscopy analysis of the formed complexes between tetrapeptide enantiomer and crown ether selectors, which revealed adducts possessing 1:1, 1:2, and 1:3 stoichiometry. Further investigation of complexation induced shifts by NMR indicated on different binding mechanisms between llll/dddd enantiomers of Tyr‐Arg‐Phe‐Lys‐NH2 and crown ether selectors. Enantioselective proton shifts were observed in studied tetrapeptide tyrosine and phenylalanine residues exclusively for llll enantiomer upon binding with S‐(3,3′‐diphenyl‐1,1′‐binaphthyl)‐20‐crown‐6 selector (and dddd enantiomer with R‐(3,3′‐diphenyl‐1,1′‐binaphthyl)‐20‐crown‐6 selector), indicating that these two amino acid residues contribute to chiral recognition. The obtained results were in agreement with the LC data. [ABSTRACT FROM AUTHOR]

A novel heterogeneous pumice supported perchloric acid catalyzed synthesis of tetrahydrobenzo[b]pyran has developed via multi-component condensation of aromatic aldehydes, dimedone and malononitrile. The catalyst was characterized by IR, XRD, EDS, SEM, and TGA techniques which confirmed the formation novel pumice supported perchloric acid. The present protocol proved to have numerous advantages like one-pot reaction, good yield, short reaction time, inexpensive catalyst, recyclability and reusability of the catalyst, simple experimental and work up procedure, and purification of targeted molecules without column chromatography. [ABSTRACT FROM AUTHOR]

The influence of the positive electrode properties on the activation time of the reserve chemical power sources based on the lead–perchloric acid–lead dioxide system is studied. Coatings of cathodes with lead dioxide obtained under various conditions are characterized by scanning electron spectroscopy, X-ray spectral microanalysis, X-ray photoelectron spectroscopy, and standard contact porosimetry. The improvement of the performance characteristics of the power sources including the ensuring of a short time of their activation at a low temperature is shown to be possible with the use of a lead dioxide nanoporous coating. To evaluate the applicability of cathodes for the manufacturing of power sources with a minimal activation time, a diagnostic principle is used that it based on the testing of the cathodes by chronopotentiometric measurements during their galvanostatic discharge. Pilot industrial samples of small-sized reserve power sources of the above-mentioned electrochemical system with unprecedented short activation time (less than 30 ms at temperature –50°С) were manufactured and tested. [ABSTRACT FROM AUTHOR]

The relationship between the discharge characteristics of reserve chemical power sources of the lead–perchloric acid–lead dioxide system and the physicochemical properties of electroplated cathode coatings with lead dioxide, including phase composition and microstructure, has been studied. The study reveals that the discharge characteristics of power sources can be enhanced by employing a two-layer lead dioxide coating consisting of a porous outer layer and a denser inner layer. The findings have been validated through the production and testing of industrial prototypes of pilot miniature reserve power sources, which exhibit improved performance even at low temperatures (activation time, less than 30 ms; discharge capacity, ~200 mA min/cm2; discharge voltage per cell, 1.8–1.2 V at –50°C). [ABSTRACT FROM AUTHOR]

Present work elicits an account of synthesizing a new series of pyrrolo[1,2-b]pyrazole scaffolds involving multi component reaction (MCR) strategy, assisted by silica-supported perchloric acid HClO4-SiO2 as the heterogeneous catalyst. It embraces methyl 2-cyano-2-(phenyldiazenyl)acetate as the key precursor. The reusability of the catalyst up to five synthetic cycles is the value-added advantage of the protocol. Moreover, feasibility of the strategy has been endorsed on the basis of EcoScale values in the sustainable limits. Structural corroboration of all the newly synthesized compounds and catalyst have been ascertained by different spectro analytical data viz., IR, 1H NMR, mass, XRD, TG/DTA and FE-SEM. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A pentadentate Cu(II) complex, [CuII(dpaq)](ClO4) (1), featuring a redox active ligand, H-dpaq (H-dpaq = 2-[bis(pyridine-2-ylmethyl)]amino-N-quinolin-8-yl-acetamidate), catalyses four-electron reduction of dioxygen by decamethylferrocene (Fc*) in the presence of trifluoroacetic acid (CF3COOH) in acetone at 298 K. No catalytic oxygen reduction was observed in the presence of stronger Brønsted acids than CF3COOH, such as perchloric acid (HClO4) or trifluoromethanesulphonic acid (HOTf). In contrast, facile catalytic reduction of O2 occurs by Fc* with 1 and HClO4 or HOTf in dimethylformamide (DMF). The use of CF3COOH as the proton source in DMF results in the suppression of O2 reduction under otherwise identical reaction conditions. While the O2 reduction reactions in DMF are linearly dependent on the pKa of Brønsted acids, the acid dependence on catalytic O2-reduction reactivity by 1 in acetone showed complete reversal. Cyclic voltammetry studies using p-chloranil as the probe substrates in the presence of acids in the solvents reveal that the strengths of the protonic acids increase significantly in acetone compared to that in DMF. The amidate-N in [CuII(dpaq)](ClO4) (1) undergoes protonation in the presence of HClO4 or HOTf in DMF to form [CuII(H-dpaq)]2+ (1-H+), but not in the presence of CF3COOH. Enhanced acid strength of CF3COOH in acetone, however, effectively protonates 1 and triggers O2 reduction. Protonation of 1 with HClO4 or HOTf in acetone results in the change of its coordination environment, and this protonated species does not trigger O2 reduction. Detailed kinetic studies indicate that 1-H+ undergoes reduction by two-electrons and the reduced species binds O2 to form a Cu(II)-superoxo intermediate. This is followed by a rate-determining proton-coupled electron-transfer (PCET) reduction to generate the Cu(II)-hydroperoxo intermediate. While catalytic O2 reduction in acetone occurs predominantly via a 4e−/4H+ pathway, product selectivity (H2O vs. H2O2) in DMF depends upon the concentration of the reductant (Fc*). While dioxygen reduction to H2O2 is favoured at low [Fc*], mechanistic studies suggest that O2 reduction with high [Fc*] proceeds via a [2e− + 2e−] mechanism, where the released H2O2 during catalysis is further reduced to water. [ABSTRACT FROM AUTHOR]

Context: In this work, a series of heterocyclic alkenes were prepared by the reaction of 2-hydroxy-1-naphthaldehyde with various heterocyclic active methylene compounds via Knoevenagel condensation reaction using mesoporous silica, MCM 41, supported perchloric acid as an efficient green catalytic system under solvent-free conditions. A comparative study of the conventional method vs the green method was also reported with the same raw materials. 1H NMR, 13C NMR, IR, and mass spectroscopic techniques were used for the characterization of synthesized compounds. Methods: Computational study was performed for these compounds by applying density functional theory (DFT) at M06 functional and 6-311G (d,p) basis set to interpret the electronic structures and counter check the experimental findings. The frequency analysis with aforementioned levels of DFT was performed to confirm the stability associated with optimized geometries. The true minimum for the optimized geometries for 1, 2, and 3 was achieved as indicated by the absence of negative eigenvalues in all the calculated frequencies. Additionally, natural bond orbitals (NBOs) and nonlinear optical (NLO) properties were explored utilizing the aforementioned level and basis set combination via DFT, whereas the frontier molecular orbitals (FMOs) evaluation was done at time-dependent density functional theory TDDFT at M06/6-311G(d,p). The global reactivity parameters were also calculated using the FMO data. These computation-based outcomes were found in good agreement with the experimental findings. [ABSTRACT FROM AUTHOR]

A convenient, eco-friendly electrophilic reaction of indole with substituted aromatic aldehydes to yield bis(indolyl)methane (BIM) derivatives. BIM derivatives are synthesized in one pot by employing a biopolymer-derived novel heterogeneous catalyst, Xanthan Perchloric Acid (XPA). The Catalyst XPA is prepared from biopolymer xanthan and treated with perchloric acid. XPA is thermally stable with sufficient acidic sites, mild, nontoxic, and reusable. The reaction proceeds smoothly at room temperature in the green context, shorter reaction time, and excellent yield under solvent-free conditions. [ABSTRACT FROM AUTHOR]

Currently, many prostate cancer patients, detected through the prostate specific antigen test, harbor organ‐confined indolent disease that cannot be differentiated from aggressive cancer according to clinically and pathologically known measures. Spermine has been considered as an endogenous inhibitor for prostate‐confined cancer growth and its expression has shown correlation with prostate cancer growth rates. If established clinically, measurements of spermine bio‐synthesis rates in prostates may predict prostate cancer growth and patient outcomes. Using rat models, we tested the feasibility of quantifying spermine bio‐synthesis rates with 13C NMR. Male Copenhagen rats (10 weeks, n = 6) were injected with uniformly 13C‐labeled L‐ornithine HCl, and were sacrificed in pairs at 10, 30, and 60 min after injection. Another two rats were injected with saline and sacrificed at 30 min as controls. Prostates were harvested and extracted with perchloric acid and the neutralized solutions were examined by 13C NMR at 600 MHz. 13C NMR revealed measurable ornithine, as well as putrescine‐spermidine‐spermine syntheses in rat prostates, allowing polyamine bio‐synthetic and ornithine bio‐catabolic rates to be calculated. Our study demonstrated the feasibility of 13C NMR for measuring bio‐synthesis rates of ornithine to spermine enzymatic reactions in rat prostates. The current study established a foundation upon which future investigations of protocols that differentiate prostate cancer growth rates according to the measure of ornithine to spermine bio‐synthetic rates may be developed. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The adsorption of hexylamine at the solution–gold interface in 1 M HClO4 in the presence of 0.1 M Fe2+ and 0.1 Fe3+ was studied by potentiodynamic, chronoamperometric and EIS methods. The main kinetic characteristics of the oxidation-reduction reaction iron ions (exchange current density, transfer coefficient, diffusion coefficients of iron ions) were determined. It was shown that the physical adsorption of hexylamine on gold can be described by the Dhar–Flory–Huggins isotherm. The values of the adsorption constant and the Gibbs free adsorption energy were obtained. A comparison of the free adsorption energy at these interfaces with the interaction energies of hexylamine and water molecules, and hexylamine molecules with each other was carried out. It was shown that hexylamine adsorption at all of these interfaces is due mainly to the hydrophobic effect of the interaction of hexylamine and water molecules. [ABSTRACT FROM AUTHOR]

Among the modern oncological therapies, one of the most promising is based on tumor hyperthermia with magnetic nanoparticles resulting from the crystallization of iron and cobalt oxides. We synthesized core–shell magnetic nanoparticles of perchlorate-CoxFe3−xO4 (x = 0; 0.5; 1.0) via the co-precipitation method and stabilized them in aqueous suspensions. Fine granulation of the dispersed ferrophase was revealed by Transmission Electron Microscopy and Dynamical Light Scattering, with FTIR data detailing the surface-interaction phenomena. X-ray diffractometry revealed specific crystallization features of inverse spinel lattice, providing crystallite size and lattice parameters dependent on the cobalt content. The results of the Vibrating Sample Magnetometry investigations indicated that cobalt doping has reduced the magnetic core size and increased the nanoparticle dimension, which could be the result of crystallization defects at the nanoparticle surface related to the presence of cobalt ions. A mathematical model was applied with a focus on the quantitative description of the temperature distribution around magnetic nanoparticles. Further development of our research will consider new cobalt ferrite nanoparticles with new cobalt contents and different organic coatings to contribute to their biocompatibility and stability in aqueous suspensions, as required by administration in living organisms. [ABSTRACT FROM AUTHOR]

Introduction: Aluminium is a predominant heavy metal found in everyday products like perfumes, antiperspirants, medication, milk, vaccinations, etc. Biologically available Aluminum is non-essential and toxic to the body. Excessive intake of Aluminum can lead to various negative consequences such as neurodegeneration of the brain, age-related changes, etc. Most of the aluminium exposure is through food and its products. Hence, this study aims to determine the Aluminium levels in milk. Materials and Methods: Twenty samples were collected and stored in the Tiruvallur district area, Chennai. They were broken down into nitric and perchloric acid (4:1 v/v) until a transparent solution was obtained. This was then filtered using Whatman filter paper and diluted. Aluminum content was estimated using a flame absorption spectrophotometer. Results: This study shows that the mean aluminum levels in the milk supply in Tiruvallur district are 116.25 ± 28.316. The current study also showed that the values are significant (p=0.000). Conclusion: Hence, the Aluminium levels of milk are within permissible levels, and care should be taken not to intake excessive amounts. [ABSTRACT FROM AUTHOR]

Background: The incidence of goitre has increased world-wide, with African countries responsible for over 28 % of the cases. The danger of perchloric acid among males working in the factories has been on the increase. Hence mitigating effects of piroxicam on perchloric acid-induced thyroid hormones disruption was studied in male Wister albino rats. Methods: A total of 19 rats (17 males; 2 females) that weighed 145.0 ± 20.5 g were used for the.study. Four rats were used for determination of median lethal dose (LD50) of perchloric acid, whereas 15 rats divided into three groups of five each, were used for induction of thyroid hormones disruption, using 100 mg/kg of perchloric acid for a period of two weeks. Thereafter group II and III rats were treated with 2.5 and 5.0 mg/kg of piroxicam, respectively. Three millilitres of blood were collected from all the rats for determination of thyroid hormones, haematological and biochemical parameters. Brain, liver, spleen, lung, kidney and heart were harvested for allometry and histopathology. Results: Findings have shown that LD50 of perchloric acid was 4207.5 ± 457.6 mg/kg body weight. Piroxicam significantly decreased (p

In addition to its pure form, three accurate, rapid, and simple methods have been established for determining perindopril (PRD) in its tablet form. At pH 9.0 using a borate buffer, developing the three designated methods was successful according to the reaction between PRD and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and the formation of a chromogen (with a yellow color) measurable at 460 nm using the spectrophotometric method (Method I). In addition, the produced chromogen was assessed using the spectrofluorimetric method (Method II) at 535 nm following excitation at 461 nm. Afterward, the same reaction product was separated and determined using the HPLC method with fluorescence detection (Method III). A Promosil C18 stainless steel column (Q7 5 mm particle size, 250–4.6 mm) has proven suitable for separation. The mobile phase adjustment was made at pH 3.0, with a 1.0 mL min −1 flow rate; its composition was methanol-sodium dihydrogen phosphate, 0.02 M (60: 40, v/v). Through concentration ranges of 5.0–60.0, 0.5–6.0, and 1.0–10.0 μg mL−1, the calibration curves were rectilinear for Methods I, II, and III, respectively, with limits of quantification (LOQ) of 1.08, 0.16 and 0.19 μg mL−1 as well as limits of detection (LOD) of 0.36, 0.05 and 0.06 μg mL−1. The developed methods were implemented to estimate PRD in tablets, and a comparison between the obtained outcomes utilizing the developed methods as well as obtained from the official method revealed that they were comparable. The official BP method was based on dissolving PRD in anhydrous acetic acid and titrating with 0.1 M perchloric acid, then the potentiometric determination of the end-point. The designated methods were also implemented in content uniformity testing with satisfying results. The reaction pathway proposal was speculated, and according to ICH Guidelines, the statistical evaluation of the data was performed. The three proposed methods were confirmed to be green, eco-friendly and safe to environment using Green Analytical procedure index (GAPI) method. [ABSTRACT FROM AUTHOR]

PtCuCo nanoframes with internal structural support exhibit superior activity and durability for both of ORR and MOR. [Display omitted] • PtCuCo nanoframes with internal structural support were prepared via a facile approach. • The inner-positioned structural support can boost the structural robustness. • PtCuCo nanoframes showed outstanding activity and durability in both ORR and MOR. Developing highly durable and active catalysts with the morphology of structurally robust nanoframes toward oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) in acidic environment is crucial but still a great challenge to completely achieve in a single material. Herein, PtCuCo nanoframes (PtCuCo NFs) with internal support structures as enhanced bifunctional electrocatalysts were prepared by a facile one-pot approach. PtCuCo NFs exhibited remarkable activity and durability for ORR and MOR owing to the ternary compositions and the structure-fortifying frame structures. Impressively, the specific/mass activity of PtCuCo NFs were 12.8/7.5 times as large as that of commercial Pt/C for ORR in perchloric acid solution. For MOR in sulfuric acid solution, the mass/specific activity of PtCuCo NFs was 1.66 A mg Pt -1/4.24 mA cm−2, which was 5.4/9.4 times as large as that of Pt/C. This work may provide a promising nanoframe material to develop dual catalysts for fuel cells. [ABSTRACT FROM AUTHOR]

The report presents the first method for simultaneous determination of plasma 2-(3-hydroxy-5-phosphonooxymethyl-2-methyl-4-pyridyl)-1,3-thiazolidine-4-carboxylic acid (HPPTCA), an adduct of cysteine (Cys) and active form of vitamin B6 pyridoxal 5′-phosphate (PLP), as well as total low molecular-weight thiols content, including Cys, homocysteine (Hcy), cysteinyl-glycine (Cys-Gly), and glutathione (GSH). The assay is based on high performance liquid chromatography coupled with ultraviolet detection (HPLC–UV) and involves disulfides reduction with tris(2-carboxyethyl)phosphine (TCEP), derivatization with 2-chloro-1-methylquinolinium tetrafluoroborate (CMQT) followed by sample deproteinization with perchloric acid (PCA). The chromatographic separation of obtained stable UV-absorbing derivatives is achieved on ZORBAX SB-C18 (150 × 4.6 mm, 5.0 µm) column using gradient elution with eluent consisted of 0.1 mol/L trichloroacetic acid (TCA), pH 1.7 and acetonitrile (ACN), delivered at a flow rate 1 mL/min. Under these conditions, the analytes are separated within 14 min at room temperature, and quantified by monitoring at 355 nm. Regarding HPPTCA, the assay linearity was demonstrated within a 1–100 µmol/L in plasma and the lowest concentration on the calibration curve was recognized as the limit of quantification (LOQ). The accuracy ranged from 92.74 to 105.57% and 95.43 to 115.73%, while precision varied from 2.48 to 6.99% and 0.84 to 6.98% for intra- and inter-day measurements, respectively. The utility of the assay was proved by application to plasma samples delivered by apparently healthy donors (n = 18) in which the HPPTCA concentration ranged from 19.2 to 65.6 µmol/L. The HPLC–UV assay provides complementary tool for routine clinical analysis, facilitating further studies on the role of aminothiols and HPPTCA in living systems. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The conventional Klason lignin (KL) method has some shortcomings in the determination of lignin content, such as large sample consumption, long analysis time, and a large number of errors. Therefore, a rapid and accurate method for lignin content determination was studied. In this paper, flax fibers in three forms, namely, flax raw, flax noil and flax rove, were selected for the study, and the acetyl bromide-ultraviolet spectrophotometric lignin (ABUL) method was optimized for quantitative testing of the lignin content in flax fibers. The effect of acetyl bromide concentration, perchloric acid dosage, reaction temperature, and reaction time on the absorbance value was tested systematically. The test results indicated that the maximum characteristic absorption peak of lignin in flax fiber was determined at 276 nm. The optimized reaction conditions were as follows: acetyl bromide concentration of 35%, perchloric acid dosage of 0.3 mL, reaction temperature of 70°C, and reaction time of 80 min. The standard curve of the ABUL method was y = 23.75714 x – 0.00636, R 2 = 0.99913. By comparing the lignin content of flax fiber tested by the KL method and the ABUL method, it was found that the lignin content of flax raw, flax noil, and flax rove tested by the ABUL method was higher than that of the KL method. In addition, the ABUL method has the advantages of simplicity, rapidity, accuracy, and small sample consumption compared with the KL method. [ABSTRACT FROM AUTHOR]

A convergent [4+2] stereoselective block glycosylation strategy has been developed for the synthesis of the hexasaccharide repeating unit of the capsular polysaccharide of Klebsiella K19 strain in very good yield. The p -methoxybenzyl (PMB) group was used as a temporary alkyl protecting group, which was removed by tuning the glycosylation conditions. A thioglycoside was used as a glycosyl acceptor in an orthogonal glycosylation reaction. A late-stage TEMPO-mediated selective oxidation of a primary hydroxyl group into carboxylic acid allowed incorporation of the d -glucuronic acid moiety in the hexasaccharide. A combination of N -iodosuccinimide (NIS) and perchloric acid supported over silica (HClO4 –SiO2) was used as a thiophilic promoter for the activation of thioglycosides. HClO4 –SiO2 was also used as a solid acid activator for a glycosyl trichloroacetimidate derivative. [ABSTRACT FROM AUTHOR]

Objectives: A precise, accurate and selective stability-indicating reverse phase high performance liquid chromatographic assay method has been developed for the quantitative estimation of Enzalutamide in Enzalutamide capsules dosage form. Materials and Methods: The separation was achieved by using a stationary phase Waters X-Bridge Shield RP18 (150 x 4.6 mm, 3.5µ) and the mobile phase consisted of perchloric acid buffer and acetonitrile in the proportion of (20:80 volume/volume). The run velocity was 1.2 mL/min. Enzalutamide was identified using UV detector at the wavelength of 210 nm. Column oven temperature 25°C and sample cooler temperature 25°C and infused quantity 20 µL, run time was 15 min. Results: As there is no meddling flanked by blank and placebo at the retention time of Enzalutamide. Degradation study results were shown significant degradation was observed in acid and oxidation (peroxide) stress condition. Hence it can be concluded that Enzalutamide is sensitive to acid and oxidation. To obtain system precision, a study was conducted with six replicate injections. %RSD was estimated from the peak areas of Enzalutamide establish to be 0.55% correspondingly. The relative standard deviation for method exactitude was establish to be 0.55%. The suggested HPLC technique was linear over the range of 100.6-301.8 µg/mL, the correlation coefficient was establish to be 0.9999. The accuracy studies were shown as % recovery for Enzalutamide 50% to150% level. The limit of % recovered revealed is in the assortment of 98 and 102% and the consequences obtained were establish to be within the limits. Hence the technique was establish to be accurate. The solution steadiness of the standard and samples are stable upto 48 hr on a bench top and refrigerator (2-8°C). The method is robust for changes like flow rate and column oven temperature. Performed the filter validation for sample solution 0.45 µm PVDF and 0.45 µm Nylon filterers are suitable for filtration. The method has validated as per ICH guidelines and all the validation parameters are satisfy the ICH Q2 specification acceptance limits. Conclusion: The developed method was validated for an assortment of parameters as per ICH guidelines like accuracy, precision, linearity, specificity, system suitability, solution stability and robustness. The consequences obtained were within the acceptance criteria. So, it can be concluded that the urbanized technique is simple, precise, cost-effective, eco-friendly, and safe and can be successfully employed for the routine analysis of Enzalutamide in bulk and pharmaceutical dosage forms [ABSTRACT FROM AUTHOR]

Plants are the major source of energy for humans. Leafy vegetables are rich sources of nutrients, fibers, minerals and trace elements which help in treatment of diseases and maintaining good health. However heavy metal contamination due to environmental pollution results in poisonous and hazardous effects. This study is based on the concentration of heavy metals in leafy vegetables in a village named Kundra located in district Koraput, 42 kilometers from Koraput of Odisha, India, which has a population of about 5326.About 130 samples were examined and studied from the local market of Kundra. These leafy vegetables commonly called Lal bhaji sago (Red Spinach), Muniga Sago (Drumstick Leaves) and Methi sago (Fenugeek leaves) were used for this study. The samples were cut air dried for four days. Next it was washed in 20% v/v solution of nitric acid, dried sample was then grounded into powder, it was sieved through nylon sieve of size 2mm. The digestion of the sample involves 20 ml of concentrated nitric acid, perchloric acid, and hydrochloric acid in the ratio of 10:1:3, followed by drying at 105 degree Celsius on a hot plate. The obtained solution was than filtered, the residue was than analyzed using digital spectrophotometer by continuous dilution method. The concentration of Iron, copper and zinc was determined, which constituted below permissible limit according to World Health Organization. Monitoring heavy metals in vegetables is essential; as these are considered to be a major indicator of environmental pollution. [ABSTRACT FROM AUTHOR]

The aim of the study was to study the gastroprotective properties of the dry extract of garden cabbage in the model of chronic acetic ulcer in rats. Materials and methods. Chronic ulcerative lesions of the gastric mucosa of rats were modeled by introducing 0.05 ml of a 30 % solution of acetic acid into the subserous layer of the stomach wall. The dry extract of garden cabbage in a conditionally therapeutic dose of 50 mg/kg and reference drugs omeprazole and altan were administered intragastrically for 10 days, starting from the second day of the experiment. When choosing the duration of the course of treatment, we proceeded from the data that the effectiveness of the antiulcer action in the clinic is assessed after 10-12 days of treatment. The percentage of animals with ulcers in the group, the state of the gastric mucosa were evaluated, the ulcer index and antiulcer activity were calculated. To elucidate the possible mechanism of action of the extract, we studied its effect on synthetic processes in terms of the content of RNA and DNA in homogenates of the gastric mucosa by the spectrophotometric method by reaction with perchloric acid. Results. On the model of stomach damage, caused by acetic acid, a pronounced antiulcer activity of the extract (54.26) was established at the level of omeprazole (54.62). The maximum antiulcer activity (72.75) was revealed when using the combination of the extract with omeprazole, which, in terms of ulcerative effect, is superior to monotherapy with the extract, omeprazole and altan (35.08). Reparative regeneration is a component of an adaptive tissue reaction; under conditions of violation of the reparative potencies of the mucosa, chronic diseases of the gastrointestinal tract develop. Since the final goal of antiulcer therapy is the healing of the ulcer, and the basis of this process is reparative regeneration, the reparative properties of the extract have been studied. Under the influence of cabbage extract, the content of RNA and DNA in the mucosa probably increased by 2.8 and 2.4 times, respectively, at the same level with omeprazole. If possible, to activate the synthetic processes of DEGC and omeprazole, altan significantly prevailed. The most pronounced effect of enhancing reparative processes was established with the combined use of the extract and omeprazole, which turned out to be a significant increase in the content of RNA and DNA in the gastric mucosa by 3.2 and 2.9 times compared with the control. Conclusions. On the model of chronic damage to the stomach of rats, cabbage extract showed an antiulcer effect, the severity of which was not inferior to the comparison drug, the proton pump inhibitor omeprazole, and significantly exceeded the phytopreparation - altan. The combined use of the extract and omeprazole showed the highest preventive effect of preventing the negative effects of acetic acid on the gastric mucosa. One of the mechanisms of the gastroprotective action of the extract is its ability to enhance reparative processes in the gastric mucosa. The results obtained indicate the prospects for further research on the antiulcer properties of cabbage extract with a view to its use in the complex therapy of peptic ulcer [ABSTRACT FROM AUTHOR]

The pentasaccharide repeating unit rich in 2-acetamido sugars corresponding to the O -antigenic polysaccharide from enteropathogenic Escherichia coli (E. coli) has been synthesized as the p -methoxyphenyl glycoside in excellent yield using a sequential glycosylation strategy. Regioselective glycosylation, use of a single monosaccharide intermediate in multiple glycosylations, and use of thioglycosides as glycosyl donors in the presence of a combination of N -iodosuccinimide (NIS) and perchloric acid supported over silica (HClO4 –SiO2) are key components of the synthetic strategy. All glycosylation reactions were high-yielding with excellent stereochemical outcome. [ABSTRACT FROM AUTHOR]