Investigation of interaction between atazanvir sulphate and bovine serum albumin by using fluorescence spectroscopy

The fluorescence spectroscopic technique has been capably employed to investigate the interaction between bovine serum albumin (BSA) and atazanvir sulphate (AS) under the physiological pH 7.4 condition. The binding constant, number of binding site, thermodynamic parameters such as ∆G, ∆H, ∆S and nature of binding forces between BSA-AS were obtained by measuring the steady state fluorescence quenching of BSA by AS. The static quenching was confirmed from Stern-Volmer quenching constant at different temperature. The effect of AS on the conformation of BSA was analyzed using synchronous and three-dimensional fluorescence spectroscopy

A Chalcone Based Novel Fluorescent Nanoprobe for Selective Detection of Al 3+ Ion in Aqueous Medium

Abstract A chalcone based novel fluorescent organic nanoparticles are prepared by reprecipitation method. The Dynamic Light Scattering histogram shows narrow particle size distribution and the average diameter of particle is 37.2 nm. The Scanning Electron Microphotograph shows the fibre like morphology. The blue shifted UV-visible spectra. The significant large Stokes shift of Trans-3-(9-Anthryl)-1-phenylprop-2-en-1-one nanoparticles (APPONPs) in aqueous suspension as compared with that of a dilute solution of Trans-3-(9-Anthryl)-1-phenylprop-2-en-1-one (APPO) in acetone indicates H-aggregation of molecules by π-π stacking. An intense fluorescence band peaking at 556 nm is attributed to Aggregation Induced Enhanced Emission (AIEE) by direct excitation of APPONPs. The binding of Al 3+ increased the fluorescence of APPONPs while other cations actually decreases the fluorescence. The fluorescence enhancement of APPONPs by Al 3+ was discussed on the basis of hard and soft acid and base (HSAB) theory. The enhancement of APPONPs emission is linear in the concentration range 0-80 μM of Al 3+ . The enhancement of fluorescence of APPONPs results obeys the straight line equation with RSD = 0.9879%. The present method has Limit of Detection (LOD)= 1.148 μM of Al 3+ which is lower than the LOD reported for Al 3+ by using other methods like colorimetry, potentiometry. This study was succesfully applied to develop fluorimetric method for determination of Al 3+ in environmental samples. The method affords fairly practical and economical approach

An Efficient and Modified Biginelli-Type Synthesis of 3,4-Dihydro-1H-indeno[1,2-d]pyrimidine-2,5-dione Using Phosphorous Pentoxide

<div><p></p><p>A simple, clean and convenient one-pot method has been developed for the synthesis of 4-phenyl-3,4-dihydro-1H-indeno[1,2-d]pyrimidine-2,5-dione and 4-phenyl-2-thioxo-1,2,3,4-tetrahydro-5H-indeno[1,2-d]pyrimidine-5-one by multicomponent condensation of 1,3-indanedione, aromatic aldehydes and urea/thiourea using phosphorus pentoxide in ethanol under reflux conditions. The simple workup procedure and moderate to good yields within short time are some important features of this protocol. The synthesized compounds have been interpreted on the basis of their spectroscopic data.</p> </div

Spectroscopic analysis on the binding interaction of biologically active pyrimidine derivative with bovine serum albumin

A biologically active antibacterial reagent, 2–amino-6-hydroxy–4–(4-N, N-dimethylaminophenyl)-pyrimidine-5-carbonitrile (AHDMAPPC), was synthesized. It was employed to investigate the binding interaction with the bovine serum albumin (BSA) in detail using different spectroscopic methods. It exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus which are common food poisoning bacteria. The experimental results showed that the fluorescence quenching of model carrier protein BSA by AHDMAPPC was due to static quenching. The site binding constants and number of binding sites (n≈1) were determined at three different temperatures based on fluorescence quenching results. The thermodynamic parameters, enthalpy change (ΔH), free energy (ΔG) and entropy change (ΔS) for the reaction were calculated to be 15.15 kJ/mol, –36.11 kJ/mol and 51.26 J/mol K according to van't Hoff equation, respectively. The results indicated that the reaction was an endothermic and spontaneous process, and hydrophobic interactions played a major role in the binding between drug and BSA. The distance between donor and acceptor is 2.79 nm according to Förster's theory. The alterations of the BSA secondary structure in the presence of AHDMAPPC were confirmed by UV–visible, synchronous fluorescence, circular dichroism (CD) and three-dimensional fluorescence spectra. All these results indicated that AHDMAPPC can bind to BSA and be effectively transported and eliminated in the body. It can be a useful guideline for further drug design

Evaluation of insecticidal activity of some benzofused heterocycles against different insect pests

754-762The twelve benzo-fused N,O,S-heterocyclic compounds have been investigated for biological activity against major pests of field crops, third instar larvae of Spodoptera litura (F.) and several stored product pests namely, Sitophilus zeamais (M.),<i style="mso-bidi-font-style: normal"> Tribolium castaneum (H.) and Callosobruchus chinensis (L.). Responses show variation with test compounds, insect species, doses and exposure times individually. All the reported benzothiazines and benzoxines heterocycles have been prepared by eco-friendly method and characterized by IR, 13C and 1H NMR. The bioassay has been investigated with oviposition deterrency, LC50, chi-square and randomized block design. These results suggest that most of the compounds demonstrate potent insecticidal activity by feeding method (mortality 77-97%) in comparison to the contact and larvicidal activity. </span

Waste packaging polymeric foam for oil-water separation: An environmental remediation

Nowadays, its urgent need to develop and fabricate efficient, low cost, eco-friendly, oil-water separation methodologies especially for variety of polluted water in the environments. To deals with serious oil spills and industrial organic pollutants, here in we have developed a highly efficient oil-water separation methodology by using waste material such as expanded polyethylene (EPE) polymeric foam which is most commonly used for packaging as a shock absorber and most abundantly available in the surroundings as waste. Oil-water separation setup was fabricated by using waste EPE polymeric foam without any pre-treatment. By simply scratching, special properties (wettability performance) such as hydrophobicity, leophilicity, and low water adhesion was imparted to the EPE polymeric foam. The different types of oil-water mixture used for the study and separation were achieved almost up to 78%. The oil absorption efficiency of the EPE polymeric foam was within range of 0.491–0.788 g/g. In addition to efficient oil-water separation, the modified EPE polymeric foam exhibited fast and continuous oil-water separation solely by gravity. The easy operation, chemical durability, and efficiency of the waste EPE polymeric foam give it high potential for use in industrial and consumer applications for large scale oil-water separation. Keywords: Waste, Packaging foam, Oil-water separation, Removal, Wastewater, Environmental remediatio

A simple and green synthesis of highly functionalized quinoline derivatives using zinc oxide nanoparticles

1548-1554A simple and one pot method has been designed for the synthesis of highly substituted quinoline derivatives using ZnO nanoparticles in aqueous medium by means of three component condensation reaction of aromatic aldehydes, malononitrile and substituted anilines via Knoevenagel condensation followed by Michael addition in water. This new method has many advantages over reported methods like easy work-up, operational simplicity and excellent yields with short reaction time

Trouble-Free Multicomponent Method for Combinatorial Synthesis of 2‑Amino-4-phenyl-5‑<i>H</i>‑indeno[1,2‑<i>d</i>]pyrimidine-5-one and Their Screening against Cancer Cell Lines

The present study describes an alkaline water–ethanol mediated series of combinatorial synthesis of 2-amino-4-phenyl-5-<i>H</i>-indeno­[1,2<i>d</i>]­pyrimidine-5-one derivatives through sequential multicomponent reaction of 1,3indandione, aromatic aldehydes, and guanidine hydrochloride along with their anticancer evaluation. The effect of sequential addition of the components in the configuration of the desired product has been studied by UV–visible absorption spectroscopy. The synthetic method obeys most of the green chemistry principles in regard to high atom economy and greener, nontoxic, and noncarcinogenic solvent system (water–ethanol). The selected synthesized compounds have been screened against the human breast cancer cell line MCF7, human colon cancer cell line HT29, and normal viro monkey cell line, out of which 2-amino-4-(4-meth­oxy­phenyl)-5<i>H</i>-indeno­[1,2-<i>d</i>]­pyrimidin-5-one showed significant potency toward human breast cancer cell line (MCF7)

Ecofriendly synthesis and biological evaluation of 4-(4-nitro-phenyl)-2-phenyl-1,4-dihydro-benzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxylic acid ethyl ester derivatives as an antitubercular agents

<p>An ecofriendly route has been investigated for the synthesis of 4-(4-nitro-phenyl)-2-phenyl-1,4-dihydro-benzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxylic acid ethyl ester derivatives by one-pot, three-component condensation of ethyl benzoylacetate, aromatic aldehydes, and 2-amino benzimidazole using 260 mol% of citric acid as reaction mediator. Citric acid is an inexpensive, nontoxic, and green medium with smoothly activates the rate of reaction. The synthesized compounds were assessed for in vitro antimycobacterial activity against <i>Mycobacterium tuberculosis</i> H₃₇RV strain using the microplate alamar blue assay (MABA). The results indicate that among all the synthesized compound series, P-4 and P-9 compounds illustrate effective activity with a minimum inhibitory concentration of 25 µg/ml.</p

Surface plasmon resonance based colorimetric probe for vitamin B1 detection: Applications to bio-fluid analysis

This study reports simple analytical approach for thiamine (Vitamin B1) detection based on induced aggregation and alternation in colorimetric properties of gold nanoparticles (AuNPs), which was synthesized through citrate reduction approach. Furthermore, the citrate capped AuNPs are characterized by various analysing tools. The addition of thiamine persuades the aggregation of citrate-AuNPs and further leading to red to blue colour transition with decrease in absorbance intensity. The proposed method achieves good linearity with a correlation coefficient of 0.9843. By using our proposed strategy, thiamine was detected by unassisted vision as well as absorption spectroscopy. Under the most favorable condition method achieves good linear relationship between concentration range 0.01–0.8 μg mL−1 with limit of detection of 0.0067 μg mL−1. Under the premium condition, the method offers excellent selectivity towards thiamine detection in presence of different interfering species. Further practical applicability of the method was checked by using blood serum and urine sample via standard addition method. The obtained recoveries were acceptable in the range of 98.70–102.97% for added thiamine concentration. Thus, the proposed method may emerge as a target specific and highly sensitive tool towards thiamine detection