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As a kind of aminoglycoside antibiotics, kanamycin (KAN) is widely applied to animal husbandry and aquaculture. However, the abuse of KAN causes the large-scale discharge of it into rivers, lakes and groundwater, which threatens environmental safety and human health. Therefore, it is imperative to develop a method that is applicable to detect KAN in an efficient and accurate way. The colorimetric method based on enzymes provides a feasible solution for the detection of organic pollutants. However, the extensive application of natural enzymes is constrained by high cost and low stability. Herein, a polyoxometalate-based nanozyme, namely [H 7 SiW 9 V 3 O 40 (DPA) 3 ]·4H 2 O (SiW 9 V 3 /DPA) (DPA = dipyridylamine), is synthesized. As a low-cost nanozyme with high stability compared to natural enzymes, SiW 9 V 3 /DPA performs well in laccase-mimicking activity. It can be used to induce chromogenic reaction between 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP), which generates red products. With the addition of KAN, the color fades. That is to say, KAN can be detected with colorimetric assay in the concentration range 0.1 to 100 μM with high selectivity and low limit of detection (LOD) of 6.28 μM. Moreover, SiW 9 V 3 /DPA is applied to KAN detection in lake and river water and milk with satisfactory results. To sum up, polyoxometalate-based nanozyme is expected to provide a promising solution to the detection of organic pollutants in the aquatic environment., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

This study aimed to determine the pharmacokinetic profile of two active metabolites of metamizole (dipyrone), N-methyl-4-aminoanthypyrine (MAA) and 4-aminoanthypyrine (AA), after intravenous administration in cats. Eight healthy mixed-breed cats were intravenously administered metamizole (25 mg/kg). Blood samples were collected at predetermined time points for up to 48 h after administration. Information on behavioral changes in the animals and adverse effects was collected. Plasma aliquots were processed and analyzed using the ultra-performance liquid chromatography tandem mass spectrometry technique. A validated UPLC-MS/MS method was used to characterize the pharmacokinetics of MAA and AA. Salivation was identified as an adverse clinical sign. The mean maximal plasma concentrations of MAA and AA were 29.31 ± 24.57 μg/mL and 1.69 ± 0.36 μg/mL, with half-lives of around 4.98 and 14 h, respectively. The area under the plasma concentration curve values were 28.54 ± 11.33 and 49.54 ± 11.38 h*μg/mL for MAA and AA, respectively. The plasma concentration of MAA was detectable for up to 24 h and was smaller than AA. AA was detectable for >48 h. Results suggest that metamizole is converted into active metabolites in cats. Further PK/PD and safety studies should be performed before defining the dose or administration intervals for clinical use., Competing Interests: Declaration of Competing Interest The authors declare no potential conflicts of interest with respect to the research, authorship, or publication of this article., (Copyright © 2023. Published by Elsevier Ltd.)

The synthesis of four new azo-Schiff base ligands from 2-hydroxy-3-methoxy-5-(phenyldiazenyl)benzaldehyde and 4-aminoantipyrine is described in this study. The molecular structures of all the scaffolds were confirmed using NMR spectroscopies such as 1 H and 13 C, as well as FT-IR and Mass spectroscopy. After successful synthesis and characterization of all the ligands, their in vitro antibacterial, antioxidant and anti-inflammatory activities were carried out by using standard protocols. Results revealed that all the four ligands (L1-L4) possessed excellent biological potency., (© 2022 John Wiley & Sons Ltd.)

The extracellular enzyme with oxidase function was extracted from the Neonothopanus nambi luminescent fungus by using mild processing of mycelium with β-glucosidase and then isolated by gel-filtration chromatography. The extracted enzyme is found to be a FAD-containing protein, catalyzing phenol co-oxidation with 4-aminoantipyrine without addition of H 2 O 2 , which distinguishes it from peroxidases. This fact allowed us to assume that this enzyme may be a mixed-function oxidase. According to gel-filtration chromatography and SDS-PAGE, the oxidase has molecular weight of 60 kDa. The enzyme exhibits maximum activity at 55-70 °C and pH 5.0. Kinetic parameters K m and V max of the oxidase for phenol were 0.21 mM and 0.40 µM min -1 . We suggest that the extracted enzyme can be useful to develop a simplified biosensor for colorimetric detection of phenol in aqueous media, which does not require using hydrogen peroxide., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Novel α-aminophosphonates 4 were synthesized via one pot three-component reaction of 4-aminoantipyrine, aldehydes, triphenylphosphite and Lewis acid catalyst. The chemical structures of all the synthesized compounds were elucidated by IR, NMR and MS spectral analysis. The antimicrobial activity of 4 was tested in vitro against pathogenic microbes such as E.coli, S.aureus, A.niger and C.albicans. Three of them (4f-h) exhibited high antimicrobial activity and were loaded to carrageenan cryogel for drug delivery studies. With the aid of cellulose nanofibrils (CNF) as reinforcing material and glyoxal as a cross-linking agent, porous cryogels with improved mechanical properties were obtained. Among all, CAR-7 presents the optimum cryogel sample, which contained around 16% CNF and 0.2 mL/15 mL polymer blend. CAR-7 demonstrated highest mechanical compressive strength, porosity (80%), and swelling capacity (75%). Sustainable release behavior over 24 h was observed for the loaded cryogels. The antimicrobial activity of cryogels against S.aureus showed marginal differences between samples. CAR-9 (loaded with 4f) showed the highest reduction percentage in number of bacterial colonies (99.94%) followed by CAR-11 (loaded with 4h, 99.3%) and finally CAR-10 (loaded with 4g, 99.29%)., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Diabetes mellitus is one of the most common chronic diseases worldwide. Generally, the levels of fasting or postprandial blood glucose and other biomarkers, such as glycated albumin, glycated hemoglobin, and 1,5-anhydroglucitol, are used to diagnose or monitor diabetes progression. In the present study, we developed a sensor to simultaneously detect the glucose levels and glycation ratios of human serum albumin using a lateral flow assay. Based on the specific enzymatic reactions and immunoassays, a spiked glucose solution, total human serum albumin, and glycated albumin were measured simultaneously. To test the performance of the developed sensor, clinical serum samples from healthy subjects and patients with diabetes were analyzed. The glucose level and glycation ratios of the clinical samples were determined with reasonable correlation. The R -squared values of glucose level and glycation ratio measurements were 0.932 and 0.930, respectively. The average detection recoveries of the sensor were 85.80% for glucose and 98.32% for the glycation ratio. The glucose level and glycation ratio in our results were crosschecked with reference diagnostic values of diabetes. Based on the outcomes of the present study, we propose that this novel platform can be utilized for the simultaneous detection of glucose and glycation ratios to diagnose and monitor diabetes mellitus.

p-Diphenols, such as homogentisic acid, gentisic acid, etamsylate, and calcium dobesilate, interfere with diagnostic tests utilizing the Trinder reaction but the mechanisms of these effects are not fully understood. We observed substantial differences both in oxidation of p-diphenols by horseradish peroxidase and their influence on oxidation of 4-aminoantipyrine and various phenolic substrates. Homogentisic acid was rapidly oxidized by the enzyme and completely blocked chromophore formation. Enzymatic oxidation of the remaining p-diphenols was slow and they only moderately inhibited chromophore formation. However, in the presence of standard substrates all tested p-diphenols were rapidly converted to p-quinones. Hydrogen peroxide consumption was significantly accelerated by homogentisic acid but not much affected by the other p-diphenols. The magnitude and mechanisms of interference caused by p-diphenols therefore depend on their structure which determines their electrochemical properties - while for homogentisic acid with an electron-donating substituent and a lower reduction potential both enzymatic oxidation and reduction of the peroxidase-generated radicals occur, for p-diphenols with electron-withdrawing substituents and higher reduction potentials only the second mechanism is significant. Correlation of the effects on the Trinder reaction with reduction potentials of interfering compounds allows prediction of such properties for a wide range of other reducing compounds based on this parameter. It also explains why compounds with very different structures but strong reducing properties show such effects., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Quantification of polyamines, including putrescine, is generally performed using high-performance liquid chromatography (HPLC) or gas chromatography. However, these methods are time-consuming because of sample derivatization and analytical reagent preparation. In this study, we developed a simple and high-throughput putrescine quantification method on a 96-well microtiter plate using putrescine oxidase from Rhodococcus erythropolis NCIMB 11540, peroxidase, 4-aminoantipyrine, and N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium salt. The developed method (named as PuO-POD-4AA-TOPS method) was applicable to bacterial culture supernatants. Furthermore, putrescine concentrations determined by the developed method roughly corresponded to the concentrations determined by HPLC., (Copyright © 2020 Elsevier Inc. All rights reserved.)

A sensitive and selective nanoprobe for detection of hypochlorite (OCl - ) based on 4-aminoantipyrine (AAP) modified carbon dots (CDs-AAP) has been prepared. The CDs-AAP exhibit an emission peak at 484 nm when the excitation wavelength is 370 nm, accompanying 36 nm red shift compare with the pristine CDs. The addition of OCl - lead to the AAP on the surface of CDs experience a process of hydrazide hydrolysis and double bond addition, causing the singlet and triplet electrons of the excited state more closer in energy (ie, the energy difference between the two is reduced), eventually quenching the fluorescence of CDs due to heavy atomic effects. Central composite design (CCD) and response surface method (RSM) were used to optimize the detection variables of pH, incubation time and temperature. The designed model study indicated that the optimum detection conditions was pH 7.0, temperature 30 °C and incubation time 20 min, respectively. Under optimal conditions, the fluorescent intensity of the nanoprobe linearly responded to the OCl - concentration from 3 μM to 36 μM and the limit of detection was 40 nM. The proposed nanoprobe was successfully used to the detection of OCl - in tap water and pool water, and the recovery were in the range of 94% - 103%. In addition, the nanoprobe was also applied in imaging of VMSCs cells and labeling E.coli., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We developed an enzymatic assay system enabling easy quantification of 4-aminobutyric acid (GABA). The reaction of GABA aminotransferase obtained from Streptomyces decoyicus NBRC 13977 was combined to those of the previously developed glutamate assay system using glutamate oxidase and peroxidase. The three-enzyme system allowing GABA-dependent dye formation due to the oxidative coupling between 4-aminoantipyrine and Trinder's reagent enabled accurate quantification of 0.2 - 150 mg/L GABA. A pretreatment mixture consisting of glutamate oxidase, ascorbate oxidase and catalase eliminating glutamate, ascorbate, and hydrogen peroxide, respectively, was also prepared to remove those inhibitory substances from samples. Thus, constructed assay kit was used to measure the GABA content in tomato samples. The results were almost the same as that obtained by the conventional method using liquid chromatography-tandem mass spectrometry. The kit will become a promising tool especially for the on-site measurement of GABA content in agricultural products.

Using the original technique of treating biomass with β-glucosidase, a pool of extracellular fungal enzymes was obtained for the first time from the mycelium of basidiomycete Neonothopanus nambi. Two protein fractions containing enzymes with oxidase activity were isolated from the extract by gel-filtration chromatography and conventionally called F1 and F2. Enzyme F1 has a native molecular weight of 80-85 kDa and does not contain chromophore components; however, it catalyzes the oxidation of veratryl alcohol with K m = 0.52 mM. Probably, this enzyme is an alcohol oxidase. Enzyme F2 with a native molecular weight of approximately 60 kDa is a FAD-containing protein. It catalyzes the cooxidation of phenol with 4-aminoantipyrine without the addition of exogenous hydrogen peroxide, which distinguishes it from the known peroxidases. It was assumed that this enzyme may be a mixed-function oxidase. F2 oxidase has K m value 0.27 mM for phenol. The temperature optimums for oxidases F1 and F2 are 22-35 and 55-70°C, and pH optimums are 6 and 5, respectively.

In this work, a fluorometric and colorimetric analysis of alkaline phosphatase (ALP) activity was developed based on nanozymes. The nanozymes were composed of nucleotides (ATP, ADP and AMP) coordinated with copper ions. All three kinds of nanozymes (ATP-Cu, ADP-Cu and AMP-Cu) exhibited polyphenol oxidase (PPO)-mimic activity by catalyzing a chromogenic reaction of 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP). However, there were obvious differences in the PPO-like activity and the fluorescence of the three nanozymes produced from the same concentration of nucleotides (keeping the concentration of Cu 2+ unchanged at 5 mM). The catalytic activities of produced ADP-Cu and AMP-Cu were obviously higher than that of ATP-Cu at a certain nucleotide concentration of 3 mM. In addition, when ATP was hydrolyzed into ADP and AMP by ALP, more nanozymes were produced and the catalytic activity of the system was enhanced, which resulted in an obvious increase of the colorimetric signal. The signal intensity was proportional to ALP concentration in the range of 0-30 U L -1 , and the detection limit for ALP was 0.3 U L -1 from the colorimetric detection. Moreover, the fluorescence intensity of the produced nanozymes was also proportional to the ALP concentration in the range of 1-30 U L -1 and the detection limit was 0.45 U L -1 from the fluorescence detection. A fluorometric and colorimetric sensing ALP method was thus established. The method showed a high selectivity for ALP activity compared with proteins, amino acids and other interference components. Furthermore, the proposed method was also used to detect ALP activity in human serum samples, which showed great potential for diagnostic and practical purposes.

A simple imine based receptor NA-1 has been synthesized for detection of Zinc ions. Probe NA-1 showed the selective colorimetric changes with Zinc (II) ions whereas other metal ions didn't showed any observable colorimetric changes. The probe showed the very selective turn-on fluorescence response with Zn(II) ions among other rival metal ions like Cd(II) and Hg(II). The mode of binding was studied by 1 H-nmr titrations and fluorescence spectroscopy. Jobs plot analysis confirming that the probe NA-1 forms 1:1 complex with Zn(II). The observed fluorescence and absorption change further supported by theoretical calculations. The turn-on fluorescence of the probe NA-1 is probably attributable to the interruption of intramolecular charge transfer as well as ESIPT. The limit of detection of the probe for Zn(II) sensing is in the range of 14 nano molar. Cytotoxicity (MTT) assay of the probe in live HeLa cells is showing that the probe is least toxic to cells. The probe NA-1 is effectively applied to detect Zn(II) ions in HeLa cells and suggesting the probe is NA-l permeable to cell wall and viable for Zinc(II) ions imaging in live cells., (Copyright © 2019. Published by Elsevier B.V.)

Our main interest is the characterization of compounds to support the development of alternatives to currently marketed drugs that are losing effectiveness due to the development of resistance. Schiff bases are promising biologically interesting compounds having a wide range of pharmaceutical properties, including anti-inflammatory, antipyretic, and antimicrobial activities, among others. In this work, we have synthesized 12 Schiff base derivatives of 4-aminoantipyrine. In vitro antimicrobial, antioxidant, and cytotoxicity properties are analyzed, as well as in silico predictive adsorption, distribution, metabolism, and excretion (ADME) and bioactivity scores. Results identify two potential Schiff bases: one effective against E. faecalis and the other with antioxidant activity. Both have reasonable ADME scores and provides a scaffold for developing more effective compounds in the future. Initial studies are usually limited to laboratory in vitro approaches, and following these initial studies, much research is needed before a drug can reach the clinic. Nevertheless, these laboratory approaches are mandatory and constitute a first filter to discriminate among potential drug candidates and chemical compounds that should be discarded., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

Sulfation is an important way for detoxifying xenobiotics and endobiotics including catechols. Enzymatic sulfation occurs usually with high chemo- and/or regioselectivity under mild reaction conditions. In this study, a two-step p-NPS-4-AAP screening system for laboratory evolution of aryl sulfotransferase B (ASTB) was developed in 96-well microtiter plates to improve the sulfate transfer efficiency toward catechols. Increased transfer efficiency and improved sulfation stoichiometry are achieved through the two-step screening procedure in a one-pot reaction. In the first step, the p-NPS assay is used (detection of the colorimetric by-product, p-nitrophenol) to determine the apparent ASTB activity. The sulfated product, 3-chlorocatechol-1-monosulfate, is quantified by the 4-aminoantipyrine (4-AAP) assay in the second step. Comparison of product formation to p-NPS consumption ensures successful directed evolution campaigns of ASTB. Optimization yielded a coefficient of variation below 15% for the two-step screening system (p-NPS-4-AAP). In total, 1760 clones from an ASTB-SeSaM library were screened toward the improved sulfation activity of 3-chlorocatechol. The turnover number (k cat = 41 ± 2 s -1 ) and catalytic efficiency (k cat /K M = 0.41 μM -1 s -1 ) of the final variant ASTB-M5 were improved 2.4- and 2.3-fold compared with ASTB-WT. HPLC analysis confirmed the improved sulfate stoichiometry of ASTB-M5 with a conversion of 58% (ASTB-WT 29%; two-fold improvement). Mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) confirmed the chemo- and regioselectivity, which yielded exclusively 3-chlorocatechol-1-monosulfate. For all five additionally investigated catechols, the variant ASTB-M5 achieved an improved k cat value of up to 4.5-fold and sulfate transfer efficiency was also increased (up to 2.3-fold).

Metamizole (MT), an analgesic and antipyretic drug, is rapidly hydrolyzed to the active primary metabolite 4-methylaminoantipyrine (MAA) and relatively active secondary metabolite 4-aminoantipyrine (AA). The aim of this study was to assess the pharmacokinetic profiles of MAA and AA after dose of 25 mg/kg MT by intravenous (i.v.), intramuscular (i.m.), oral (p.o.), and rectal (RC) routes in dogs. Six dogs were randomly allocated to an open, single-dose, four-treatment, four-phase, unpaired, crossover study design. Blood was collected at predetermined times within 24 hr, and plasma was analyzed by a validated HPLC-UV method. Plasma concentrations of MAA and AA after i.v., i.m., p.o., and RC administrations of MT were detectable from 5 (i.v. and i.m.) or 30 (p.o. and RC) min to 24 hr in all dogs. The highest concentrations of MAA were found in the i.v., then i.m., p.o., and RC groups. Plasma concentrations of AA were similar for i.v., i.m., and RC, and the concentrations were approximately double those in the PO groups. The AUC EV/IV ratio for MAA was 0.75 ± 0.11, 0.59 ± 0.08, and 0.32 ± 0.05, for i.m., p.o., and RC, respectively. The AUC EV / IV ratio for AA was 1.21 ± 0.33, 2.17 ± 0.62, and 1.08 ± 0.19, for i.m., p.o., and RC, respectively. Although further studies are needed, rectal administration seems to be the least suitable route of administration for MT in the dog., (© 2018 John Wiley & Sons Ltd.)

Hydrogen peroxide (H 2 O 2 ) plays a critical role in generating oxygen radicals as fungi attack and deconstruct plant cell walls. Its concentrations in planta, however, are often low during decomposition and evade detection by traditional methods. Here, we compared relevant methods and selected the best based on detection limits and selectivity., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Diazocoupling reaction of curcumin with different diazonium salts of p -toluidine, 2-aminopyridine, and 4-aminoantipyrine in pyridine yielded the arylhydrazones 2a - c . Arylhydrazone of p -toluidine reacted with urea, thiourea, and guanidine nitrate to produce 5,6-dihydropyrimidines. Further reaction of 2a with 2,3-diaminopyrdine in sodium ethoxide solution yielded 1 H -pyrido[2,3- b ][1,4]diazepine derivative. Bis (2,5-dihydroisoxazole) is obtained from the reaction of 2a with hydroxylamine hydrochloride, while its reactions with hydrazines afforded the respective 4,5-dihydro-1 H -pyrazoles. The target compounds were evaluated as antioxidant and antibacterial agents. The tested compounds showed good to moderate activities compared to ascorbic acid and chloramphenicol, respectively., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.

Here, we developed functional nucleic acid (FNA)-encapsulated electrospun fibermats. To facilitate stable FNA encapsulation in the γ-PGA/GPTMS fibermats, we used the FNA as an FNA/streptavidin complex, and as a representative FNA, we selected a DNAzyme, the DNA/hemin complex, which is composed of G-quadraplex-forming single-stranded DNA and hemin and exhibits oxidation activity with the aid of a cocatalyst, H 2 O 2 . Scanning electron microscopy and Fourier-transform infrared spectroscopy measurements revealed that encapsulation of the DNA/hemin complex (∼1 wt % against the γ-PGA/GPTMS hybrid) in the nanofibers of the γ-PGA/GPTMS fibermats did not affect the structure of the original nanofibers. However, because a unique MW-dependent molecular permeability originated from the 3D network structure of the γ-PGA/GPTMS hybrid, low-MW substrates such as 4-aminoantipyrine, N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline, and luminol were able to reach the encapsulated DNA/hemin complex by permeating to the inside of the nanofibers from an immersion buffer and then underwent catalytic oxidation. Conversely, nucleases, which are proteins featuring high MWs (>5 kDa), could not penetrate the γ-PGA/GPTMS nanofibers, and the encapsulated DNA/hemin complex was therefore effectively protected against nuclease digestion. Thus, encapsulating FNAs on the inside of the nanofibers of fibermats offers clear advantages for the practical application of FNAs in sensors and drugs, particularly for use in the in vivo circumstances.

Dendrite-like cobalt selenide nanostructures were synthesized from cobalt and selenium powder precursors by a solvothermal method in anhydrous ethylenediamine. The as-prepared nanocrystalline cobalt selenide was found to possess peroxidase-like activity that could catalyze the reaction of peroxidase substrates in the presence of H 2 O 2 . A spectrophotometric method for uric acid (UA) determination was developed based on the nanocrystalline cobalt selenide-catalyzed coupling reaction between N -ethyl- N -(3-sulfopropyl)-3-methylaniline sodium salt and 4-aminoantipyrine (4-AAP) in the presence of H 2 O 2 . Under optimum conditions, the absorbance was proportional to the concentration of UA over the range of 2.0-40 μM with a detection limit of 0.5 μM. The applicability of the proposed method has been validated by determination of UA in human serum samples with satisfactory results., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

The commenced work deals with the synthesis, characterization and evaluation of biological activities of 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one. The synthesis was done by the condensation of aromatic acid chlorides with 4-aminoantipyrine. The structures of synthesized derivatives were elucidated using IR, Mass, 1 H NMR and 13 C NMR spectroscopy, and their UV-Visible and fluorescence properties were studied. The compounds showed significant dual fluorescence. Molecular docking was used to understand the small molecule-receptor protein interaction. The derivatives were screened for their in vitro cytotoxic activity against the reference drug pazopanib on human cervical cancer cell line (SiHa) using MTT assay.

Silica based materials find applications as excipients and particularly as drug delivery agents for pharmaceutical drugs. Their performance can be crucially affected by surface treatments, as it can modify the adsorption (and release) of these formulations. The role of surface modification on the features of 4-formaminoantipyrine (FAA) adsorbed on β-cristobalite (001) surface is studied by means of simulations based on the Density Functional Theory (DFT). Starting from the results of FAA in interaction with a dehydroxylated surface; a fully hydroxylated surface and a functionalized surface with benzalkonium chloride (BC) surfactant have been added to study the configurational landscape. Calculations suggest that the trend for FAA preferential adsorption on silica surfaces is: dehydroxylated>hydroxylated>BC-functionalized. The potential for hydrogen bonding causes the main contribution to the bonding while dispersion forces present an additional contribution independently of whether the drug is hydrogen-bonded or BC-bonded to the surface. Adsorption takes mainly place through nitrogen atoms in the heterocyclic ring, the carbonyl and amine functional groups. Associated mode's shifts and concurrent changes in bond length are also observed showing accordance between electronic and geometrical structure results. BC surfactant reduces the number of formed H-bonds and lowers the attractive molecule-surface interaction being it useful to prevent particle agglomeration and could favor drug release in therapies that requires faster but controlled delivery., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Metamizole (MT) is a pyrazolone nonsteroidal anti-inflammatory drug labelled for humans and animals. The aim of this study was to assess the pharmacokinetics of its active metabolites 4-methylamino-antipyrine (MAA) and 4-amino-antipyrine (AA) in male piglets after a single intramuscular injection of MT. Eight healthy male piglets were administered MT (100 mg/kg) intramuscularly. Blood was sampled at scheduled time intervals, and drug plasma concentrations evaluated by a validated HPLC method. MAA and AA plasma concentrations were quantitatively detectable from 0.25 to 48 h and 0.50 to 72 h, respectively, in 6 of 8 and 7 of 8 animals. The average maximum concentrations of MAA and AA were of 47.59 and 4.94 mg/mL, respectively. The average half-lives were 8.57 and 13.3 h for MAA and AA, respectively. This study showed that the amount of MAA and AA produced in piglets is different to that in the animal species previously investigated. Further studies are necessary to understand whether these differences in MAA and AA plasma concentrations between animal species necessitate diverse therapeutic drug dosing., (© 2016 John Wiley & Sons Ltd.)

In this work, for the first time, we demonstrate a supercapacitive microbial fuel cell which integrates the energy harvesting function of a microbial fuel cell (MFC) with the high-power operation of an internal supercapacitor. The pursued strategies are: (i) the increase of the cell voltage by the use of high potential cathodes like bilirubin oxidase (BOx) or iron-aminoantipyrine (Fe-AAPyr); (ii) the use of an additional capacitive electrode (additional electrode, AdE) which is short-circuited with the MFC cathode and coupled with the MFC anode (MFC-AdE). The high working potential of BOx cathode and the low impedances of the additional capacitive electrode and the MFC anode permitted to achieve up to 19 mW (84.4 Wm(-2), 152 Wm(-3)), the highest power value ever reported for MFCs. Exploiting the supercapacitive properties of the MFC electrodes allows the system to be simpler, cheaper and more efficient without additional electronics management added with respect to an MFC/external supercapacitor coupling. The use of the AdE makes it possible to decouple energy and power and to achieve recharge times in the order of few seconds making the system appealing for practical applications., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Two substituted aromatic carbonyl compounds (compounds 1 and 2) of 4-aminoantipyrine were synthesized by condensation of fluorine substituted benzoyl chlorides and 4-aminoantipyrine. The structures of synthesized derivatives were established on the basis of UV-Vis, IR, and Mass, (1)H, (13)C NMR and Fluorescence spectroscopy. Both compounds showed significant fluorescence emission and two broad emission bands were observed in the region at 340 nm and 450 nm on excitation at 280 nm. Theoretically to prove that the molecule has anticancer activity against cervical cancer cells, the compounds were analyzed for molecular docking interactions with HPV16-E7 target protein by Glide protocol. Furthermore, 4-aminoantipyrine derivatives were evaluated for their in vitro cytotoxic activity against human cervical cancer cells (SiHa) by MTT assay. Compound 1 showed two fold higher activity (IC50=0.912 μM) over compound 2, and its activity was similar to that of Pazopanib, suggesting that although the two compounds were chemically very similar the difference in substituent on the phenyl moiety caused changes in properties., (Copyright © 2015 Elsevier B.V. All rights reserved.)

We report a versatile approach for the synthesis of porous gold nanocups, porous gold nanospheres and solid gold nanoparticles. Gold nanocups are formed by the slow reduction of gold salt (HAuCl4⋅3H2O) using aminoantipyrene (AAP) as a reducing agent. Adding polyvinylpyrrolidone (PVP) to the gold salt followed by reduction with AAP resulted in the formation of porous gold nanospheres. Microwave irradiation of both of these porous gold particles resulted in the formation of slightly smaller but solid gold particles. All these nanoparticles are thoroughly characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and bright-field tomography. Due to the larger size, porous nature, low density and higher surface area, these nanomaterials may have interesting applications in catalysis, drug delivery, phototherapy and sensing., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Six derivatives of 4-amino-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one (4-aminoantipyrine), C11H13N3O, (I), have been synthesized and structurally characterized to investigate the changes in the observed hydrogen-bonding motifs compared to the original 4-aminoantipyrine. The derivatives were synthesized from the reactions of 4-aminoantipyrine with various aldehyde-, ketone- and ester-containing molecules, producing (Z)-methyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]but-2-enoate, C16H19N3O3, (II), (Z)-ethyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]but-2-enoate, C17H21N3O3, (III), ethyl 2-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]cyclohex-1-enecarboxylate, C20H25N3O3, (IV), (Z)-ethyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]-3-phenylacrylate, C22H23N3O3, (V), 2-cyano-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, C14H14N4O2, (VI), and (E)-methyl 4-{[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]methyl}benzoate, C20H19N3O3, (VII). The asymmetric units of all these compounds have one molecule on a general position. The hydrogen bonding in (I) forms chains of molecules via intermolecular N-H...O hydrogen bonds around a crystallographic sixfold screw axis. In contrast, the formation of enamines for all derived compounds except (VII) favours the formation of a six-membered intramolecular N-H...O hydrogen-bonded ring in (II)-(V) and an intermolecular N-H...O hydrogen bond in (VI), whereas there is an intramolecular C-H...O hydrogen bond in the structure of imine (VII). All the reported compounds, except for (II), feature π-π interactions, while C-H...π interactions are observed in (II), C-H...O interactions are observed in (I), (III), (V) and (VI), and a C-O...π interaction is observed in (II).

A new formulation of the bireagent kit for serum uric acid assay was developed based on the effects of pH on enzyme stability. At 4 °C, half-lives of uricases from Bacillus fastidious and Arthrobacter globiforms were longer than 15 months at pH 9.2, but became shorter at pH below 8.0; half-lives of ascorbate oxidase and peroxidase were comparable at pH 6.5 and 7.0, but became much shorter at pH higher than 7.4. In the new formulation of the bireagent kit, Reagent A contained peroxidase, 4-aminoantipyrine, and ascorbate oxidase in 50 mM phosphate buffer at pH 6.5; Reagent B contained B. fastidious or A. globiforms uricase in 50 mM sodium borate buffer at pH 9.2; Reagents A and B were mixed at 4:1 to produce a final pH from 7.2 to 7.6 for developing a stable color. The new bireagent kit consumed smaller quantities of three enzymes for the same shelf life. With the new bireagent kit, there were linear responses of absorbance at 546 nm to uric acid up to 34 mM in reaction mixtures and a good correlation of uric acid levels in clinical sera with those by a commercial kit, but stronger resistance to ascorbate. Therefore, the new formulation was advantageous., (© 2014 International Union of Biochemistry and Molecular Biology, Inc.)

A new Cu(2+)-selective chromogenic probe system based on the oxidative coupling of phenols with 4-aminoantipyrine was developed. Cu(2+) ions promoted facile coupling of phenols with 4-aminoantipyrine to yield quinoneimine dyes. Signaling with a number of phenols having no para-substituent, such as o-cresol and m-cresol, as well as p-chlorophenol having para substituent that could be expelled during the oxidation process was possible. The signaling of Cu(2+) ions was not interfered by the presence of representative metal ions except for Al(3+) ions. The possible interference from Al(3+) ions was successfully removed by using fluoride ions as a masking agent. The phenol-4-aminoantipyrine probe system showed chromogenic Cu(2+) signaling by prominent color change from colorless to pink with a detection limit of 8.5×10(-7) M. The signaling of Cu(2+) ions in practical samples using tap water and simulated semiconductor wastewater was also tested., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The Co(II), Ni(II), Cu(II) and Zn(II) complexes of the Schiff base derived from imidazole-2-carboxaldehyde and 4-aminoantipyrine were synthesized. These compounds were characterized by elemental analysis, IR, mass, (1)H NMR, electronic spectra, magnetic moment, molar conductance, thermal analysis, powder XRD and SEM. The analytical data show that the metal to ligand ratio is 1:1. The IR results show that the ligand acts as a bidentate donor coordinating through the azomethine nitrogen and imidazole nitrogen atoms. From the electronic spectra and magnetic moment value predicts the geometry of the complexes. The surface morphology of the compounds was studied by SEM. The compounds were screened for their antibacterial activity and antifungal activity using Kirby Bayer disc diffusion method. The DNA cleavage and superoxide dismutase activities of the compounds were investigated. The anticancer activities of the complexes have been carried out towards HeLa and HCT116 cancer cells., (Copyright © 2014 Elsevier B.V. All rights reserved.)

We have optimized dispersive liquid-liquid microextraction to preconcentrate trace phenolic compounds after derivatization with 4-aminoantipyrine in artificial sea water for spectrophotometric determination. Factors such as reaction time (7.5 min), pH (9.5), solvent (chloroform), dispersing solvent (ethanol), and volume ratio of dispersing to organic phase (11:1) were optimized. Under optimum conditions, the limit of detection was 0.18 μg/L and the linearity range 1-900 μg/L. The relative standard deviation and enrichment factor were 6% (n=7) and 920, respectively. The results demonstrate the efficiency of coupling the 5530 APHA standard for derivation and dispersive liquid-liquid microextraction of phenolic compounds from seawater samples. Using this method, total phenol content in seawater from several locations in Chabahar Bay (southeast Iran) was estimated at 27.8-74.8 μg/L., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

4-Aminophenazone (Ap-1) Schiff bases i.e., 4-{(3,4,5-trimethoxybenzylidine) amino}phenazone (Ap-2), 4-{(2-chlorobenzylidine) amino}phenazone (Ap-3) and 4-{(4-chlorobenzylidine)amino} phenazone (Ap-4) were synthesized and characterized by different spectroscopic techniques. Interaction of these compounds with ds.DNA was investigated through UV-Visible spectroscopy, fluorescence spectroscopy and cyclic voltammetry at stomach (4.7) and blood (7.4) pH under 37 °C (human body temperature). Instrumental findings were further quantified both kinetically and thermodynamically. Results obtained through these techniques inferred intercalative mode of binding of all the compounds with DNA. The binding constant data, "Kb", and free energy change, ΔG, indicated comparatively greater binding affinity and more spontaneity of binding of compounds with DNA at stomach pH (4.7), respectively. However, among these compounds, Ap-4 showed comparatively greater binding at both the pH. Formation of compound-DNA complex was further confirmed through the decrease in diffusion rates after the addition of DNA. The in vivo anti-inflammatory activity of the compounds was evaluated using the carrageenan-induced hind paw edema method. The results revealed that among all the compounds, Ap-4 showed greater percentage of edema inhibition compared to standard drug., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A series of transition metal complexes of Co(II), Ni(II), Zn(II), Fe(III) and VO(IV) have been synthesized involving the Schiff base, 2,3-dimethyl-1-phenyl-4-(2-hydroxy-3-methoxy benzylideneamino)-pyrazol-5-one(L), obtained by condensation of 4-aminoantipyrine with 3-methoxy salicylaldehyde. Structural features were obtained from their FT-IR, UV-vis, NMR, ESI Mass, elemental analysis, magnetic moments, molar conductivity and thermal analysis studies. The Schiff base acts as a monovalent bidentate ligand, coordinating through the azomethine nitrogen and phenolic oxygen atom. Based on elemental and spectral studies six coordinated geometry is assigned to Co(II), Ni(II), Fe(III) and VO(IV) complexes and four coordinated geometry is assigned to Zn(II) complex. The interaction of metal complexes with Calf thymus DNA were carried out by UV-VIS titrations, fluorescence spectroscopy and viscosity measurements. The binding constants (K(b)) of the complexes were determined as 5 × 10(5) M(-1) for Co(II) complex, 1.33 × 10(4) M(-1) for Ni(II) complex, 3.33 × 10(5) M(-1) for Zn(II) complex, 1.25 × 10(5) M(-1) for Fe(III) complex and 8 × 10(5) M(-1) for VO(IV) complex. Quenching studies of the complexes indicate that these complexes strongly bind to DNA. Viscosity measurements indicate the binding mode of complexes with CT DNA by intercalation through groove. The ligand and it's metal complexes were screened for their antimicrobial activity against bacteria. The results showed the metal complexes to be biologically active, while the ligand to be inactive.

The 4-aminoantipyrine derivatives (NO2, OCH3) and their mixed-ligand complexes with amino acids have been synthesized and investigated for their binding with CT DNA using UV-visible spectroscopy, cyclic voltammetry, and viscosity measurements under physiological conditions of pH (stomach 4.7; blood 7.4). The results from all techniques i.e. binding constant (Kb), and free energy change (ΔG) were in good agreement and inferred spontaneous compound-DNA complexes formation via intercalation. Among all the compounds 1 and 4 showed comparatively greater binding at pH 7.4 as evident from its greater Kb values. All the complexes exhibit oxidative cleavage of supercoiled (SC) pBR322 plasmid DNA in the presence of H2O2 as an activator. It is remarkable that at 25μM concentration 1 and 4 completely degrade SC DNA into undetectable minor fragments and thus they act as efficient chemical nucleases. Among the new complexes, complexes 1 and 4 have highest potential against all the microorganisms tested. The results of the above biological experiments also reveal that the choice of different metal ions has little influence on the DNA binding, DNA cleavage and antimicrobial assay., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A series of novel Co(II), Cu(II), Ni(II) and Zn(II) complexes were synthesized from Schiff base(s), obtained by the condensation of 4-aminoantipyrine with furfural and amino acid (glycine(L1)/alanine(L2)/valine(L3)) and respective metal(II) chloride. Their structural features and other properties were explored from the analytical and spectral methods. The binding behaviors of the complexes to calf thymus DNA were investigated by absorption spectra, viscosity measurements and cyclic voltammetry. The intrinsic binding constants for the above synthesized complexes are found to be in the order of 10(2) to 10(5) indicating that most of the synthesized complexes are good intercalators. The binding constant values (Kb) clearly indicate that valine Schiff-base complexes have more intercalating ability than alanine and glycine Schiff-base complexes. The results indicate that the complexes bind to DNA through intercalation and act as efficient cleaving agents. The in vitro antibacterial and antifungal assay indicates that these complexes are good antimicrobial agents against various pathogens. The IC50 values of [Ni(L1)2] and [Zn(L1)2] complexes imply that these complexes have preferable ability to scavenge hydroxyl radical., (Copyright © 2014 Elsevier B.V. All rights reserved.)

4-Aminoantipyrine was utilized as key intermediate for the synthesis of pyrazolone derivatives bearing biologically active moieties. The newly synthesized compounds were characterized by IR, 1H- and 13C-NMR spectral and microanalytical studies. The compounds were screened as anticancer agents against a human tumor breast cancer cell line MCF7, and the results showed that (Z)-4-((3-amino-5-imino-1-phenyl-1H-pyrazol-4(5H)-ylidene)methylamino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 5, 3-(4-bromophenyl) -1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 13, 1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-3-(4-iodophenyl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 14, 3,3'-(4,4'-sulfonylbis(4,1-phenylene))bis(1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile) 16, (Z)-1- (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-hydrazono-4-oxo-3-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 17, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl- 2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-3-phenyl-2-(2-phenylhydrazono)-1,2,3,4-tetrahydro pyrimidine-5-carbonitrile 18, and (Z)-4-(3-amino-6-hydrazono-7-phenyl-6,7-dihydro pyrazolo[3,4-d]pyrimidin-5-yl)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 19 were the most active compounds with IC50 values ranging from 30.68 to 60.72 µM compared with Doxorubicin as positive control with the IC50 value 71.8 µM.

The interactions of 4-aminoantipyrine (AAP) with human serum albumin (HSA) have been studied by UV-visible spectroscopy, fluorescence spectroscopy and cyclic voltammetry. The binding of 4-aminoantipyrine quenches the HSA fluorescence, revealing a 1:1 interaction with a binding constant of about 10(5) M(-1). The experimental results showed that AAP effectively quenched the intrinsic fluorescence of HSA via dynamic type of quenching. In addition, according to the synchronous fluorescence spectra of HSA in presence of 4-aminoantipyrine, the tryptophan residue of the proteins are most perturbed by the binding process. The number of binding sites, the binding constant, site probe study, some common metal ions effect and the thermodynamic parameters were calculated., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Novel metal(II) complexes derived from furfurylidene-4-aminoantipyrine and 2-aminobenzothiazole were synthesized and characterized by spectroscopic (IR, (1)H NMR, UV-Vis., ESR and DART-MS) and other analytical methods. IR spectral studies indicate the binding sites of the ligand with the metal ion. Molar conductance data and magnetic susceptibility measurements provide evidence for monomeric and neutral nature of the complexes. The X band ESR spectrum of the Cu(II) complex at 300 and 77K was recorded. The electrochemical behaviour of the complexes in MeCN at 298 K was studied. Thermal studies of the ligand and its complexes show the presence of coordinated water in the complexes. The grain size of the complex was calculated by Scherrer formula using powder XRD. The surface morphology of the complexes was studied using SEM. The in vitro biological screening of the ligand and its complexes were tested against bacterial species S. aureus, E. coli, K. pneumoniae, P. vulgaris and P. aeruginosa and fungal species A. niger, R. stolonifer, A. flavus, R. bataicola and C. albicans. The DNA binding and cleavage activity of the ligand and its complexes were studied. Super oxide dismutase (SOD) activities of the ligand and its complexes have also been measured., (Copyright © 2013 Elsevier B.V. All rights reserved.)

1,5-Dimethyl-4-((2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-one (DMPO) was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively) and dipole moment (μ) were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.

Aim: To design new hydrazones with pyrazolone structure with improved biological properties., Material and Methods: New hydrazones of antipyrine have been prepared by reaction of 4-aminophenazone (4-aminoantipyrine) with chloracetylchoride and hydrazine hydrate and then condensation with various aromatic aldehydes., Results: The synthesized compounds were screened for their antibacterial activity against Gram positive (Staphylococcus aureus ATCC 25923, Sarcinalutea ATCC 9341, Bacillus cereus ATCC 14579, Bacillus subtilis) and Gram negative bacterial strains (Escherichia coli ATCC 25922) and pathogenic yeasts (Candida albicans ATCC 10231, Candida sake, Candidaglabrata). Some of them were found to have good antibacterial and antifungal activity. The antioxidant activity of these compounds was also evaluated using the total antioxidant capacity test., Conclusions: The chemical modulations performed on antipyrine structure have a good influence on the biological activity of the synthesized compounds.

A novel and simple Schiff base based on 2-pyridine formaldehyde and 4-aminoantipyrine was synthesized and characterized as a fluorescent probe. In the presence of Al(3+), the fluorescent intensity has a dramatic enhancement over other examined metal ions in aqueous solution. The method of Job's plot indicated the formation of 1:1 complex between probe and Al(3+), and the possible binding mode of the system was also proposed. Moreover, other examined metal ions had no effect on the detection of Al(3+)., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A novel series of copper(II) and palladium(II) with 4-derivatives benzaldehyde pyrazolone (L(n)) were synthesized. The mixed ligand complexes were prepared by using 1,10-phenanthroline (Phen) as second ligand. The structure of these complexes was identified and confirm by elemental analysis, molar conductivity, UV-Vis, IR and (1)H NMR spectroscopy and magnetic moment measurements as well as thermal analysis. The ligand behaves as a neutral bidentate ligand through ON donor sites. ESR spectra show the simultaneous presence of a planar trans and a nearly planar cis isomers in the 1:2 ratio for all N,O complexes [Cu(L(n))(2)]Cl(2)⋅2H(2)O. Schiff bases (L(n)) were tested against bacterial species; namely two Gram positive bacteria (Staphylococcus aureus and Bacillus cereus) and two Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae) and fungal species (Aspergillus niger, Fusarium oxysporium, Penicillium italicum and Alternaria alternata). The tested compounds have antibacterial activity against S. aureus, B. cereus and K. pneumoniae., (Copyright © 2012 Elsevier B.V. All rights reserved.)

4-Aminoantipyrine (4AAP) is widely used in the pharmaceutical industry, biochemical experiments and environmental monitoring. However, residual amounts of 4AAP in the environment may pose a threat to human health. To provide basic data that can be used to extract or eliminate 4AAP from the environment, the proton-transfer complexes of 4AAP with quinol (QL) and picric acid (PA) were synthesized and spectroscopically investigated. The interactions afforded two new proton-transfer salts named 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-aminium-4-hydroxyphenolate and 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-aminium-2,4,6-trinitrophenolate for QL and PA, respectively, via a 1:1 stoichiometry. Elemental analysis (CHN), electronic absorption, spectrophotometric titration, IR, Raman, (1)H NMR and X-ray diffraction were used to characterize the new products. The thermal stability of the synthesized CT complexes was investigated using thermogravimetric (TG) analyses, and the morphology and particle size of these complexes were obtained from scanning electron microscopy (SEM). It was found that PA and 4AAP immediately formed a yellow precipitate with a remarkable sponge-like morphology and good thermal stability up to 180°C. Finally, the biological activities of the newly synthesized CT complexes were tested for their antibacterial and antifungal activities. The results indicated that the [(4AAP)(QL)] complex exhibited strong antimicrobial activities against various bacterial and fungal strains compared with standard drugs., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: We developed a practical method for analysis of PON-1 enzymatic activity in HDL subclasses., Methods: The assay uses 4-12% polyacrylamide gradient gels, phenylacetate as substrate coupled with densitometric phenol detection using 4-aminoantipyrine. The measurement PON-1 activity in situ across the HDL subclasses has a strong correlation with the kinetic microplate assay for total PON-1 activity, r=0.91, p<0.001., Results: The same HDL-C level, healthy subjects (n=33) display a large difference in the ratio of PON-1 activity in small vs. large HDL. Since PON-1 activity is larger in HDL(3) we propose that this difference has a potent predictive value for clinical risk assessment and therapeutic choice. Our method also offers the advantage of assessing the distribution of up to six different HDL apolipoproteins in the same gel after transfer., Conclusions: We seek to further dissect the cause of a different distribution of PON-1 activity in HDL subclasses by employing this method that permits practical, inexpensive analysis of antioxidant function of HDL subclasses and has the potential for application in clinical chemistry and to shed some light on the importance of PON-1 distribution., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Three compounds derived from 4-aminoantipyrine (AA) were synthesized and their structures confirmed by melting point, elemental analysis, FT-IR, and 1H-NMR. The molecular structures of the four compounds were characterized by single-crystal X-ray diffraction and calculated by using the density functional theory (DFT) method with 6-31G (d) basis set. The calculated molecular geometries and the vibration frequencies of the AA derivatives in the ground state have been compared with the experimental data. The results show that the optimized geometries can reproduce well the crystal structural parameters, and the theoretical vibration frequencies show good agreement with the experimental data, although the experimental data are different from the theoretical ones due to the intermolecular forces. Besides, the molecular electrostatic potential (MEP) and the frontier molecular orbital (FMO) analysis of the compounds were investigated by theoretical calculations.

A novel series of platinum(II) and palladium(II) complexes have been synthesized by template condensation of 4-methoxybenzaldehyde, benzaldehyde, 4-chlorobenzaldehyde and 4-nitrobenzaldehyde, with appropriate 4-aminoantipyrine (4-AAP) in the presence of K(2)PtCl(4)/PdCl(2) to form complexes of the type [M(L(n))Cl(2)](where M=Pt(II) or Pd(II)). The corresponding Schiff base complexes mixed ligand were prepared by condensation of [M(L(n))Cl(2)] with ethanolamine (LH). The complexes have been characterized with the help of elemental analysis, IR, (1)H and (13)C NMR, electronic spectra, conductance measurements, magnetic susceptibilities and thermal analysis. On the basis of these studies, it is clear that ligands coordinated to metal atom in a mononuclear (NO) in (1-6), Schiff base complexes (NN(*)) in (7-9) and monobasic tridentate Schiff base complexes (NN(*)O) in (10-12). Thus, suitable square planar geometry for tetradentated state has been suggested for the metal complexes. Various ligand and nephelouxetic parameter have been calculated for the complexes. The thermal decomposition for complexes was studied., (Copyright © 2012 Elsevier B.V. All rights reserved.)

In order to evaluate the pharmacokinetics of metamizol in the presence of morphine in arthritic rats, after subcutaneous administration of the drugs, an easy, rapid, sensitive and selective analytical method was proposed and validated. The four main metamizol metabolites (4-methylaminoantipyrine, 4-aminoantipyrine, 4-acetylaminoantipyrine and 4-formylaminoantipyrine) were extracted from plasma samples (50-100μl) by a single solid-phase extraction method prior to reverse-phase high performance liquid chromatography with diode-array detection. Standard calibration graphs for all metabolites were linear within a range of 1-100μg/ml (r(2)≥0.99). The intra-day coefficients of variation (CV) were in the range of 1.3-8.4% and the inter-day CV ranged from 1.5 to 8.4%. The intra-day assay accuracy was in the range of 0.6-9.6% and the inter-day assay accuracy ranged from 0.9 to 7.5% of relative error. The lower limit of quantification was 1μg/ml for all metabolites using a plasma sample of 100μl. Plasma samples were stable at least for 4 weeks at -20°C. This method was found to be suitable for studying metamizol metabolites pharmacokinetics in arthritic rats, after simultaneous administration of metamizol and morphine, in single dose., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Few transition metal complexes of tetradentate N(2)O(2) donor Schiff base ligands containing 2-hydroxybenzylidene-4-aminoantipyrine and amino acids (alanine/valine) abbreviated to KHL(1)/KHL(2) have been synthesized. All the metal complexes have been fully characterized with the help of elemental analyses, molecular weights, molar conductance values, magnetic moments and spectroscopic data. The Schiff bases KHL(1)/KHL(2) are found to act as tetradentate ligands using N(2)O(2) donor set of atoms leading to a square-planar geometry for the complexes around the metal ions. The binding behaviors of the complexes to calf thymus DNA have been investigated by absorption spectra, viscosity measurements and cyclic voltammetry. The DNA binding constants reveal that all these complexes interact with DNA through minor groove binding mode. The studies on mechanism of photocleavage reveal that singlet oxygen ((1)O(2)) and superoxide anion radical (O(2)(-)) may play an important role in the photocleavage. The Schiff bases and their metal complexes have been screened for their in vitro antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, Klebsiella pneumoniae and antifungal activities against Aspergillus niger, Fusarium solani, Culvularia lunata, Rhizoctonia bataicola and Candida albicans by MIC method., (Copyright © 2012 Elsevier B.V. All rights reserved.)

In this work, a new method based on the combination of dispersive liquid-liquid microextraction (DLLME) with microvolume spectrophotometry has been developed as a greener and miniaturized alternative to the 5530 APHA standard method for determining phenols in water and wastewater. The method relies on the oxidative coupling of phenols with 4-aminoantipyrine (4-AAP). In order to preconcentrate the dye formed, the classical liquid-liquid extraction used in the 5530 APHA method (involving 500 mL of sample and 50 mL of trichloromethane) has been replaced by DLLME (with 5 mL of sample, 50 μL of trichloromethane and 200 μL of acetonitrile). After optimization, the method yielded limits of detection and quantification (0.8 and 2.5 μg L(-1), respectively) that were comparable with those obtained by the 5530 APHA standard method. Repeatability, expressed as relative standard deviation, was 5.2% (N=6), and the enrichment factor (EF) was 700. The proposed method was applied to the determination of phenols in different water samples and a wastewater with recoveries in the range 90-99%. The greenness profile was established in accordance with the suggestions made by the NEMI (National Environmental Methods Index). The absence of PBT (persistent bioaccumulative and toxic chemicals) and corrosive reagents and a drastic reduction of generated wastes can be emphasized., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Few novel 4-aminoantipyrine derived Schiff bases and their metal complexes were synthesized and characterized. Their structural features and other properties were deduced from the elemental analysis, magnetic susceptibility and molar conductivity as well as from mass, IR, UV-vis, (1)H NMR and EPR spectral studies. The binding of the complexes with CT-DNA was analyzed by electronic absorption spectroscopy, viscosity measurement, and cyclic voltammetry. The interaction of the metal complexes with DNA was also studied by molecular modeling with special reference to docking. The experimental and docking results revealed that the complexes have the ability of interaction with DNA of minor groove binding mode. The intrinsic binding constants (K(b)) of the complexes with CT-DNA were found out which show that they are minor groove binders. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pUC19 DNA in the presence of AH(2) (ascorbic acid). Moreover, the oxidative cleavage studies using distamycin revealed the minor groove binding for the newly synthesized 4-aminoantipyrine derived Schiff bases and their metal complexes. Evaluation of antibacterial activity of the complexes against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and Klebsiella pneumoniae exhibited that the complexes have potent biocidal activity than the free ligands., (Copyright © 2011 Elsevier B.V. All rights reserved.)