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Optimal cell spreading and interplay of vascular smooth muscle cells (VSMC), inflammatory cells, and cell adhesion molecules (CAM) are critical for progressive atherosclerosis and cardiovascular complications. The role of vitronectin (VTN), a major cell attachment glycoprotein, in the pathogenesis of atherosclerosis remains elusive. In this study, we attempt to examine the pathological role of VTN in arterial plaque progression and inflammation. We found that, relative expression analysis of VTN from the liver of Apolipoprotein E (ApoE) Knockout mice revealed that atherosclerotic progression induced by feeding mice with high cholesterol diet (HCD) causes a significant downregulation of VTN mRNA as well as protein after 60 days. Promoter assay confirmed that cholesterol modulates the expression of VTN by influencing its promoter. Mimicking VTN reduction with siRNA in HCD fed ApoE Knockout mice, accelerated athero‐inflammation with an increase in NF‐kB, ICAM‐1, and VCAM‐1 at the site of the plaque along with upregulation of inflammatory proteins like MCP‐1 and IL‐1β in the plasma. Also, matrix metalloprotease (MMP)‐9 and MMP‐12 expression were increased and collagen content was decreased in the plaque, in VTN deficient condition. This might pose a challenge to plaque integrity. Human subjects with acute coronary syndrome or having risk factors of atherosclerosis have lower levels of VTN compared to healthy controls suggesting a clinical significance of plasma VTN in the pathophysiology of coronary artery disease. We establish that, VTN plays a pivotal role in cholesterol‐driven atherosclerosis and aortic inflammation and might be a useful indicator for atherosclerotic plaque burden and stability.

Abiotic stresses have a detrimental impact on plant growth and productivity and are a major threat to sustainable crop production in rapidly changing environments. Proline, an important amino acid, plays an important role in maintaining the metabolism and growth of plants under abiotic stress conditions. Many insights indicate a positive relationship between proline accumulation and tolerance of plants to various abiotic stresses. Because of its metal chelator properties, it acts as a molecular chaperone, an antioxidative defence molecule that scavenges reactive oxygen species (ROS), as well as having signalling behaviour to activate specific gene functions that are crucial for plant recovery from stresses. It also acts as an osmoprotectant, a potential source to acquire nitrogen as well as carbon, and plays a significant role in the flowering and development of plants. Overproduction of proline in plant cells contributes to maintaining cellular homeostasis, water uptake, osmotic adjustment and redox balance to restore the cell structures and mitigate oxidative damage. Many reports reveal that transgenic plants, particularly those overexpressing genes tailored for proline accumulation, exhibit better adaptation to abiotic stresses. Therefore, this review aims to provide a comprehensive update on proline biosynthesis and accumulation in plants and its putative regulatory roles in mediating plant defence against abiotic stresses. Additionally, the current and future directions in research concerning manipulation of proline to induce gene functions that appear promising in genetics and genomics approaches to improve plant adaptive responses under changing climate conditions are also highlighted.

Polyethylene glycol-6000 supported copper-molybdenum nanoparticles (CuO–MoO3@PEG) has been synthesized as a highly efficient, novel and recyclable heterogeneous catalyst by simple impregnation method. The catalyst was characterized by FTIR, XRD, SEM, EDX, elemental mapping, TEM, TGA, EPR, ICP-AES, UV–visible DRS and XPS analyses. The catalyst was successfully applied for the enamination of pyrimidine dione and dimedone (1,3- dicarbonyl compounds). The catalyst was found to be efficient up to five cycles with minor loss in catalytic activity. The recovered catalyst (5th run) retained its structure integrity which was confirmed by FTIR, XRD, SEM, TEM, TGA, and ICP-AES analyses. The products (β-enaminones) were obtained in excellent yield (92%) and short reaction time period (30–35 ​min).

A novel mesostructured catalyst sulphated alumina tungstic acid (SATA) has been prepared by an easy route. Various techniques such as IR, XRD, SEM, EDX, TEM, TGA and BET were used to characterize the synthesized catalyst. The catalytic activity of the meso material has been explored by synthesizing a series of new pyrazole carbonitrile derivatives from aromatic aldehydes, ethylcyanoacetate, phenylhydrazine/hydrazine hydrate in ethanol under reflux conditions. Furthermore, the "greenness" of this protocol when estimated by green metrics, displayed satisfactory results. The protocol is free from column chromatography, and toxic solvents and is more efficient as compared to reported ones.

Silica modified imidazolium [smim] based halometallic ionic liquids, [smim][MCl4] (M = Fe, Cu and Zn), were synthesized for the evaluation of acidic and catalytic properties. Among these ILs, [smim][FeCl4]− was used for the preparation of heterogeneous catalyst ([smim][FeCl4]−@Nd2O3) by simple immobilization of IL on Nd2O3 nanoparticles. The structure of [smim][FeCl4]−@Nd2O3 was established by various techniques including FTIR, Raman, UV-vis DRS, powder XRD, SEM/EDX, elemental mapping, TEM, TGA, EPR and XPS analyses. The stability of nano-catalyst, [smim][ FeCl4]−@Nd2O3, was established with the help of zeta potential analysis which showed a value of −40.32 mV lying under the stability range. Potentiometric titration with n-butyl amine was used to evaluate the acidic properties of [smim][MCl4] as well as [smim][FeCl4]−@Nd2O3. The catalytic potential of the material was probed through the one pot synthesis of N-aryl indeno pyrrole derivatives. The results showed excellent performance of the material by producing a high yield (98%) of indeno pyrrole derivatives. A recyclability experiment revealed that the catalyst was efficient in up to five cycles with insignificant loss in catalytic activity. The evaluation of green metrics indicated the sustainability of the present protocol in terms of high atom economy and low E-factor.

A highly efficient and eco-friendly route for the reduction of graphene oxide (GO) to reduced graphene oxide (rGO) was developed by using polyvinylpyrrolidone coated CeO2 NPs (PVP–CeO2) as a reducing and stabilizing agent. The resulting carbonaceous material, PVP–CeO2/rGO, was well characterized with different spectroscopic techniques such as Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), elemental mapping, Transmission Electron Microscopy (TEM), Raman spectroscopy, powder X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), X-ray Photoelectron Spectroscopy (XPS), and Thermal Gravimetric (TG) analyses. The material exhibited high catalytic potential towards multicomponent reactions for the synthesis of biologically relevant benzodiazepine derivatives in aqueous media. The efficiency of the material for the desired reaction was shown in the form of an excellent product yield (96–98%) and a very short reaction time period (7–10 min). The use of water as solvent and recyclability of the catalyst made the present protocol acceptable from a green perspective.

The aim of the present protocol is to develop a facile route for the synthesis of novel ionic liquid (IL)-functionalized graphene nano sheets (IMD-Si/FeCl4−@GNS). An imidazolium IL with tetrachloroferrate as an anion (IMD-Si/FeCl4−) was used to reduce graphene oxide. IMD-Si/FeCl4−@GNS were well characterized using various techniques such as Fourier transform infrared (FTIR), Raman, ultraviolet-visible diffuse reflectance spectroscopy (UV-VIS DRS), scanning electron microscopy/energy dispersive X-ray (SEM/EDX), elemental mapping, transmission electron microscopy (TEM), powder X-ray diffraction (XRD), thermal gravimetry (TG), electron paramagnetic resonance (EPR), and X-ray photoelectron spectroscopy (XPS) analyses. The IL-functionalized material was investigated for its catalytic properties and found to be an efficient catalyst for the synthesis of (E)-selective substituted thiosemicarbazone derivatives. The (E)-selectivity was confirmed using DFT calculations which showed that the (E)-isomer was stabilized by 4.90 kcal mol−1 more than the (Z)-isomer. The catalyst maintained its catalytic activity for six successive runs.

HClO4–SiO2 catalyzed synthesis of coumarinyl chalcones (8a–j) under solvent-free conditions is reported. The catalyst is characterized by powder XRD and SEM–EDX analysis. The stability of the catalyst is evaluated by thermogravimetric (TG) and differential scanning calorimetry (DSC) techniques. The remarkable features of this green protocol are the excellent yields of the products, shorter reaction time, simple experimental procedure, easy preparation and reusability of the catalyst. Keywords: HClO4–SiO2, Coumarinyl chalcones, Heterogeneous catalyst, Thermal solvent-free conditions

Pyrazines are renowned heterocyclic compounds that have played an important role in drug design and are part of many polycyclic compounds of biological and industrial significance. In this article, a novel chitosan-immobilized ionic liquid, [DSIM][AlCl3]x–@CS, has been synthesized easily at ambient temperature and used for catalyzing the synthesis of a series of biologically relevant pyrazine derivatives. The catalyst is well characterized by various techniques such as Fourier transform infrared spectroscopy, Raman spectroscopy, solid-state 13C MAS nuclear magnetic resonance, scanning electron microscopy/energy-dispersive X-ray, elemental mapping, transmission electron microscopy, powder X-ray diffraction, and thermal gravimetric analyses. The advantageous features of the present energy-sustainable methodology include high yield of product (>99%), shorter reaction time periods, and recyclability of the catalyst.

Glycation of biological macromolecules, due to hyperglycemia, promotes the formation of advanced glycation end products (AGEs). It is accelerated in diabetic patients and is responsible for the pathophysiology and progression of diabetes. Previous reports have shown that amount of AGEs formation and glycation-induced structural damage is higher in hemoglobin (Hb) than other proteins present in blood. In our previous study, we have shown structural changes in Hb by D-ribose which may result into the generation of immunogenic neo-epitopes. Thus, we hypothesized that D-ribose induced structural perturbations in Hb, could result in the formation of neo-epitopes which may provoke an auto-immune response and may also be involved in the immuno-pathogenesis of diabetes type-2 associated complications. Therefore, in the current study, we analyzed the prevalence of autoantibodies in diabetic patient's sera against D-ribose glycated-Hb by direct binding and competitive ELISA. Direct binding ELISA confirmed that autoantibodies in diabetic patients exhibit significantly high binding with D-ribose glycated-Hb as compared to its native form. The antigen binding specificity of these antibodies was also screened by competitive inhibition ELISA. We also used D-glucose glycated-Hb as a positive control to detect the presence of auto-antibodies by direct binding and inhibiton ELISA. We found that D-glucose glycated-Hb binds with T2DM samples but the affinity to binding is lower than D-ribose glycated-Hb. The overall findings of this study suggest the prevalence of circulating autoantibodies against D-ribose glycated-Hb in diabetic patients and thus, the level of these autoantibodies may be used as biomarker for progression of diabetes.

d -ribose, a reducing sugar, in diabetic hyperglycemia provokes non-enzymatic glycoxidation of hemoglobin (Hb), an abundant protein of red blood cells (RBCs). Different types of intermediates adduct formation occur during glycoxidation, such as advanced glycation end-products (AGEs) which lead to amyloid formation due to structural and conformational alterations in protein. Therefore, the study of these intermediate adducts plays a pivotal role to discern their relationship with diabetes mellitus and related disorders. Here, we investigated the interaction mechanism of d -ribose with Hb, and Hb prebound phytochemical thymoquinone (TQ). Our investigation reveals that the interaction of TQ with histidine residues of Hb interferes with the interaction of d -ribose with glycine residues at the glycation-site. Based on that, we had performed a time-based (21-days) in-vitro glycoxidation study at 37 °C to investigate the structural perturbation mechanism of Hb at different time-intervals in absence/presence of TQ. We found that prolonged glycoxidation induces amyloid formation in absence of TQ but in its presence, the process was prohibited. In summary, this study examined and characterized biophysically different intermediate-states of protein carrying glycoxidation-modification. Our findings suggested that TQ potentially affects interaction of d -ribose with Hb that prevents glycoxidation and protofibril formation, which establishes TQ as a potential therapeutic agent.

Cholesterol homeostasis results from a delicate interplay between influx and efflux of free cholesterol primarily mediated by ABCA1. Here we report downregulation of ABCA1 in hyper-cholesterol conditions in macrophages, which might be responsible for compromised reverse cholesterol transport and hyperlipidemia. Surprisingly, this is countered by the upregulation of a lesser known family member ABCA5 to maintain cholesterol efflux. The relative contribution of ABCA1 and ABCA5 toward cholesterol efflux was evaluated and revealed ABCA5 as the primary efflux mediator under high cholesterol load. These observations were correlated to cholesterol load in circulation in vivo, and we observed an inverse expression profile in mice models of atherosclerosis (ApoE-/-) and hyperlipidemia (PPARα-/-) in response to high cholesterol diet. Observations were further validated in human plasma samples. Simulation studies revealed a unique conformation of ABCA5 proposing a favored route for cholesterol loading onto high-density lipoproteins for reverse cholesterol transport. Thus, our study implicates a functional complementation between these two transporters, formulating an efficient strategy to maintain efflux in cholesterol excess conditions in macrophages.

The condensation reaction of 5-amino-3-methyl-1-phenylpyrazole-4-carboxaldehyde with enol lactone was carried out to get the expected compound involving translactonization type rearrangement. However, the reaction did not proceed as visualized and afforded rather unexpected compound 3,6-dimethyl-1,8-diphenyl-diazocino [3,4-c:7,8-c’]bispyrazole as a result of Friedlander condensation. The structure was confirmed by spectroscopic determination and further studied using density functional theory (DFT) calculations. The FT-IR and 1H NMR values were calculated and compared with those experimentally obtained in spectra. The frontier molecular orbitals (HOMO and LUMO) and molecular electrostatic potential were computed to determine the distribution of charge density and possible site for electrophilic and nucleophilic reactions. The newly synthesized compound was screened for their anti-inflammatory and antibacterial activities using formalin-induced paw edema and agar diffusion methods respectively. It was found to possess significant activities on animals models and against Gram-positive and Gram-negative bacteria.

Strontium doped MCM-41 (Sr-MCM-41) has been synthesized as an efficient, heterogeneous and recyclable catalyst. The catalyst, Sr-MCM-41 is characterized by various techniques such as FTIR, SEM, EDX, elemental Mapping, TEM, TGA, BET, XRD, XPS and ICP-AES analyses. The catalytic activity of the catalyst (Sr-MCM-41) has been explored by synthesizing a library of phenoxy pyrazolyl pyrazoline derivatives in excellent yield (96–98%) under microwave irradiation (3–5 min) using ethanol as solvent. The catalyst could be recycled upto five cycles.

The novel Nd-Salen Schiff base complex Immobilized Mesoporous Silica was synthesized by adsorption of NdCl3 on mesoporous-SiO2 and characterized soundly with various spectroscopic techniques such as FT-IR, Powder XRD, BET, TGA, SEM/EDX, TEM and ICP-AES analysis. The properties of mesoporous silica surface facilitate and accelerate the synthesis of desired products in high yields. All reactions progressed with high efficacy under solvent-free conditions and gave excellent yields avoiding slow workup and further purification of products.

Glycation of biological macromolecule leads to the establishment of advanced glycation end products (AGES) having implications in metabolic disorders. D ribose appears to be the most reactive among the naturally occurring sugars and contribute significantly to the glycation reactions in vivo, however, no report have been published yet to discuss D ribose induced glycation of hemoglobin (Hb). Therefore, the present study was designed to investigate D ribose induced glycoxidative damage to Hb protein. Briefly, the commercially available Hb was glycated with D ribose for varying time intervals. The structural perturbation induced in glycated Hb (GHb) was confirmed by biophysical techniques viz., UV-visible, fluorescence spectroscopy, circular dichroism, Fourier transform infrared spectroscopy, dynamic light scattering, MALDIthermal denaturation by UV-visible spectrophotometer and DSC. Biophysical techniques confirm the secondary and tertiary structural perturbation in GHb as compared to native Hb. The values of carbonyl content, hydroxy methyl furfural, thiobarbituric acid reactive substance and nitro blue tetrazolium were found to be increased and free lysine and free arginine content were decreased in the GHb due to structural change. Thus, results of this study have established that glycation with D ribose lead to the structural changes in the native Hb which might play an important role in pathophysiology metabolic diseases. (C) 2018 Elsevier B.V. All rights reserved.

A simple method was developed for the synthesis of sulfated bismuth oxide nanorods decorated with niobia (S-Bi2O3@Nb2O5). The material was well characterized with the help of several techniques such as FTIR, Raman, UV-vis DRS, PXRD, SEM/EDX, Elemental mapping, TEM, TGA, and BET analyses. Bronsted and Lewis acidic sites of the catalyst were measured using Hammett indicator method and pyridine FTIR spectroscopy respectively. The value of Hammett acidity function (H0 = 1.38) indicated the presence of significant number of Bronsted acidic sites while intense peak at 1452 cm−1 in the pyridine FTIR revealed the existence of a large number of Lewis acidic sites on the surface of material. Catalytic potential of the material was explored by synthesizing a library of pyrazolylmethanes via multicomponent reaction and results were excellent in terms of high product yield (90–98%) and reduced reaction time period (4–12 min). Solvent free reaction, ambient temperature, recyclability of the catalyst (up to five cycles), low E-factor (3.32–4.26), high atom economy (95.87–96.61%) and overall efficiency (92.04%–98.36%) confirmed the greenness of the present protocol.

An efficient, novel, and recyclable silica-supported copper-doped phosphotungstic acid (CuPTA/SiO2) has been synthesized by an impregnation method. The catalyst has been characterized by FTIR, XRD, SEM/EDX, ICP–AES, EPR, XPS, and NH3-TPD analyses. The catalytic application of the catalyst has been explored for Claisen–Schmidt condensation. The catalyst could be recycled for six runs without any appreciable loss in catalytic activity. The catalytic activity of the recovered catalyst after six runs was confirmed by FTIR, XRD, SEM/EDX, ICP–AES, and EPR analyses. The Claisen–Schmidt products were obtained in excellent yield in a shorter time period.

Introduction/Background Neoadjuvant chemotherapy (NACT) is increasingly used in locally advanced or selected stage 4B endometrial cancer that is considered unsuitable for primary surgery, despite the lack of randomised evidence. In the West of Scotland Cancer Network (WoSCAN), NACT is offered to women with inoperable locally advanced disease or limited stage 4B disease (omental/peritoneal involvement and/or small volume lung metastases/pleural effusion). This study aimed to identify the proportion of patients proceeding to delayed primary surgery or interval debulking surgery following NACT for endometrial cancer and evaluate survival outcomes. Methodology Data were collected retrospectively from electronic clinical records of WoSCAN patients who commenced NACT between January 2012 and December 2016. Statistical analysis was performed using R®. OS was estimated using Kaplan-Meier method and Cox9s proportional-hazards models used to calculate unadjusted hazard ratios (HR). Results 54 patients were identified; median age was 67 years (range 36–85). All women had Stage III (57.4%) or IV (42.6%) disease. Pathological subtype consisted of serous (42.6%), endometrioid (31.5%), or other (25.9%). NACT regimen was almost exclusively Carboplatin/ Paclitaxel (92.6%); a median of 4 cycles were administered (range 1-6). 66.7% proceeded to surgery, 7.4% received primary (chemo)radiotherapy, and 25.9% received no definitive therapy. Of the 36 patients who underwent surgery, 83.3% received adjuvant radiotherapy. Data were censored in February 2018 at which time 33.3% were alive. Median OS was 31.12 months (95% CI 24.93–58.49); 40.8 months (95% CI 25.6 - Not reached) in the surgical cohort versus 18.6 months (95% CI 8.1–60.6) in patients who received NACT alone (HR 2.28 (95% CI 1.14–4.56)). Conclusion 66.7% of women proceeded to surgery following NACT. Median OS is significantly improved with surgery compared to NACT alone. NACT is a valid option in patients with advanced endometrial cancer who are not suitable for primary surgery. Disclosure Nothing to disclose.

A sulfonic acid functionalized metal–organic framework (S-IRMOF-3) has been synthesized by dropwise addition of chlorosulfonic acid (0.5 mL) in IRMOF-3 (1 g) containing 20 mL of CHCl3 at 0 °C under simple stirring. The catalyst was applied in Knoevenagel condensation of various aromatic and hetero-aromatic aldehydes forming acrylonitrile derivatives. The catalyst was characterized thoroughly by using FT-IR, XRD, 13C MAS NMR, SEM, EDX, elemental mapping, TEM, BET, NH3-TPD and TGA/DTA techniques. The presence of characteristic bands at 1694 cm−1, 1254–769 cm−1 and 1033 cm−1 in the FT-IR spectrum, 2θ ≃ 6.7° and 9.8° in the XRD pattern and δ = 31.79, 39.55, 129.61, 131.46 (4C, CH), 133.54, 140.07 (2C), 167.71, 171.47 ppm (2C, 2CO) in the solid state 13C MAS NMR spectrum confirmed the successful formation of catalyst. This new eco-friendly approach resulted in a significant improvement in the synthetic efficiency (90–96% yield), high product purity, and minimizing the production of chemical wastes without using highly toxic reagents for the synthesis of acrylonitriles with selectivity for (Z)-isomer. Steric interactions seem to have an influence on the control of the Z-configurational isomers. By performing DFT calculations, it was found that the (Z)-isomer 3a is stabilized by 1.64 kcal mol−1 more than the (E)-isomer. The catalyst could be reused for five consecutive cycles without substantial loss in catalytic activity.

A heterogeneous nanosilica-bonded N-propylsulfamic acid catalyst was successfully prepared and characterized by FT-IR, powder XRD, SEM–EDX, TEM, 13C CP–MAS, and TG analyses. The promoting ability of this nanocomposite was probed through highly efficient synthesis of 1,5-benzodiazepines by a three component reaction of o-phenylenediamines, 3-acetyl-4-hydroxycoumarin, and different aldehydes. The catalyst was recycled for eight cycles with almost unaltered catalytic activity. The advantages of present protocol are energy efficiency, excellent yield of products in shorter reaction time (5–10 min), and use of non-toxic catalyst/solvent.

A new heterogeneous catalyst, lanthanum immobilized on chitosan, was synthesized and used for the aza-Michael reaction of β-enaminone under microwave irradiation. The characteristic structural features of the catalyst were determined using Fourier transform infrared spectroscopy, powder X-ray diffraction, energy-dispersive X-ray spectroscopy, transmission and scanning electron microscopies and inductively coupled plasma atomic emission spectroscopy. The stability of the catalyst was evaluated using thermogravimetric analysis. The use of recyclable catalyst and glycerol as solvent makes this procedure environmentally benign and economically viable. Copyright © 2016 John Wiley & Sons, Ltd.

CMCase production by immobilized Aspergillus niger in submerged fermentation was studied .The isolated culture of Aspergillus niger was immob ilized in calcium alginate beads. Studies were carried out on different parameters li ke alginate concentration, incubation time, bead inoculum, CaCl2 concentration and curing time, which affect the pr oductivity and stability of the immobilized system. The maximum CM Case activity of 0.37 IU/ml was achieved with 4% alginate concentration, 48h of inc ubation time, 40 beads/flask of inoculum, 0.2M CaCl2 concentration and 60 min of curing time.

La/Ce mixed oxide nanoparticles dispersed on multiwalled carbon nanotubes have been synthesized by an easy route. This robust and efficient heterogeneous catalytic system was thoroughly characterized by IR, XRD, Raman, SEM, EDX, TEM, TGA and TPD-NH3 techniques. The synthesized material was screened for its catalytic activity by synthesizing various chromeno pyran derivatives employing eco-friendly parameters. The catalyst showed insignificant loss in catalytic activity on recyclability. Furthermore, the “greenness” of the methodology was supported within the realms of the well-defined green metrics like the atom economy, carbon efficiency; E-factor, reaction mass efficiency, overall efficiency, process mass intensity and the method exhibited a fine score.

A new Ce/chitosan catalyst has been prepared and used for the highly efficient synthesis of diverse range of spiropiperidine derivatives via multicomponent reaction of substituted anilines, formaldehyde and different cyclic active methylene compounds at room temperature in PEG-200. The catalyst could be reused for five consecutive cycles without appreciable loss in catalytic activity. The structure of the catalyst was determined by IR, XRD, EDX, TEM and ICP-AES techniques. The present green protocol has advantages such as novel products, energy sustainability, short reaction times, high yield of products, economic viability and recyclability of the catalyst.

An environmentally benign, highly efficient one-pot four-component synthesis of highly functionalized imidazole derivatives using different aldehydes, substituted amines, benzil, and ammonium acetate in the presence of biodegradable and highly efficient catalyst chitosan–SO3H were described. Chitosan–SO3H was found to be a heterogeneous acidic catalyst which allowed easy recovery of the catalyst. Use of microwave irradiation along with chitosan–SO3H for the synthesis of imidazole derivatives makes this protocol green. Moreover, excellent yields, shorter reaction time, chromatography-free purification, and elimination of environmentally hazardous solvents are other advantages of this protocol which leads to sustainability.

The novel LaCl3/nano-SiO2 catalyst was synthesized by adsorption of LaCl3 on nano-SiO2 and characterized by powder XRD, FE-SEM, TEM, EDX, FT-IR spectra, BET surface area, TPD of ammonia and ICP-AES analyses. It was found as an efficient catalyst for the one-pot synthesis of 2,3-dihydroquinazolinones. All reactions proceeded with high efficacy under solvent-free conditions and gave excellent yields avoiding tedious workup and purification of products.

Mesoporous silica (MCM-41) supported perchloric acid has been synthesized efficiently via wet impregnation method. The new catalyst is characterized well with small angle X-ray scattering, FT-IR, BET, TGA, EDX, SEM analyses, and chemical mapping technique. The catalytic activity of the catalyst has been tested for Biginelli reaction via multicomponent route. Good to excellent yields of products were obtained in shorter time period.

An efficient, one pot synthesis of novel uracil based pyridine derivatives under solvent-free conditions in the presence of chitosan has been described. The reaction proceeds easily and furnishes pyridine derivatives in excellent yield. The catalyst is biodegradable and is recyclable without a significant loss of catalytic activity.

The catalytic multicomponent reaction between different aldehydes, malononitrile and sodium azide, for the synthesis of functionalised tetrazoles in pure water was performed using silica molybdic acid as an acidic catalyst under microwave irradiation at ambient temperature. The catalyst showed remarkable activity by decreasing the time period of the reaction from 24 h (without catalyst) to 15 min under microwave irradiation. The catalyst successfully tolerated different aromatic and heterocyclic aldehydes furnishing the desired products in excellent yields. The major advantages of this protocol are recyclable catalyst, water as a green solvent, excellent yields, very short reaction times, use of microwaves and high TOF of the catalyst.

A chitosan supported Dy(III) nanocatalyst was synthesised by a simple procedure. It was used as a catalyst for one pot, three component synthesis of hexahydropyrimidine derivatives. All the reactions were completed in a short time period at room temperature and the products were obtained in high to excellent yields. The catalyst was characterized by FT-IR, XRD, SEM-EDX, TEM and ICP-AES analyses. The stability of the catalyst was evaluated by TG analysis. Use of water, ambient conditions, recyclability and high TOF of the catalyst make this protocol a sustainable alternative to existing protocols.

Numerous phenolic compounds have been reported in the last decade that have a good antioxidant property and interaction affinity towards mammalian serum albumins. In the present study, we have utilized mammalian serum albumins as a model protein to examine their comparative interaction property with polyphenolic compound tannic acid (TA) by using various spectroscopic and calorimetric methods We have also monitored the esterase and antioxidant activity of mammalian serum albumins in the absence and presence of TA. The obtain results recommended that the TA have a good binding affinity (∼104 to 106M-1) towards mammalian serum albumins and shows double sequential binding sites, which depends on the concentration of TA that induced the conformational alteration which responsible for the thermal stability of proteins. Binding affinity, structural transition and thermodynamic parameters were calculated from spectroscopic and calorimetric method reveals that non-covalent interaction causes partial conformational alteration in the secondary structure of protein ie.; increase in α-helical content with decrease in β-sheet, random coil and other structure. Meanwhile, we have found that esterase activities of serum albumins were also stabilized against hydrolysis and shows higher antioxidant activity in the presence of TA because albumins its self have an immense antioxidant activity beside TA.

In the present study, we report the cooperative refolding/renaturation behaviour of guanidinium hydrochloride (GdnHCl) denatured bovine serum albumin (BSA) in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB), anionic surfactant sodium dodecyl sulphate (SDS) and their catanionic mixture in the solution of 60 mM sodium phosphate buffer of physiological pH 7.4, using artificial chaperone-assisted two-step method. Here, we have employed biophysical techniques to characterize the refolding mechanism of denatured BSA after 200 times of dilution in the presence of cationic, anionic surfactants and their catanionic mixture, separately. We have found that minimum refolding of diluted BSA in the presence of 1:1 rational mixture of CTAB and SDS (CTAB/SDS = 50/50), it may be due to the micelles formation which is responsible for the unordered microstructure aggregate formation. Other mixtures (CTAB/SDS = 20/80 and 80/20) slightly played an effective role during refolding process in the presence of methyl-β-cyclodextrin. On other hand, CTAB and SDS are more effective and reflect a good renaturation tendency of denatured BSA solution separately and in existence of methyl-β-cyclodextrin as compare to their mixture compositions. But overall, CTAB has the better renaturation tendency as compare to SDS in the existence of methyl-β-cyclodextrin. These results ascribed the presence of charge head group and length of hydrophobic tail of CTAB surfactant that plays an important task during electrostatic and hydrophobic interactions at pH 7.4 at which BSA carries negative charge on their surface. These biophysical parameters suggest that, CTAB surfactant assisted artificial chaperone protocol may be utilized in the protein renaturation/refolding studies, which may address the associated problems of biotechnological industries for the development of efficient and inexpensive folding aides, which may also be used to produced genetically engineered cells related diseases, resulting from protein misfolding/aggregation.

BiCl3-ZrO2 as an efficient heterogeneous catalyst is prepared by a simple process and characterized by FT-IR, powder XRD, SEM-EDX, XRF and BET surface area analyses. Thermal stability of the catalyst has been examined by DSC-TG analyses. The catalyst is recyclable for several runs preserving its high activity. The catalytic activity of BiCl3-ZrO2 is explained by synthesizing a series of novel pyrazolyl chalcones in excellent yields.

A simple, efficient and environmentally benign on-water protocol for the synthesis of novel 1,4-dihydropyridine derivatives via pseudo four component addition and cyclization sequence using mesoporous alumina sulphuric acid as a recyclable and heterogeneous catalyst, has been described. The catalyst showed excellent catalytic activity giving products in high yields and could be reused for seven successive catalytic cycles. The catalyst was characterized by FT-IR, XRD, FE-SEM, EDX and TG analyses. The mesoporosity of alumina was determined by BET and TEM analyses.

Piperidine-functionalized silica as a basic heterogeneous catalyst was synthesized via a simple protocol by condensing silica chloride with piperidine. The catalyst was characterized with various techniques (FT-IR, solid state NMR, scanning electron microscopy, energy-dispersive X-ray, thermogravimetric, elemental, and NH3 and CO2 temperature-programmed desorption analyses). Surface area was also evaluated through Brunauer–Emmett–Teller analysis. Its catalytic activity was evaluated for Claisen–Schmidt condensation under solvent-free conditions. The catalyst was easily recovered and reused up to five cycles without considerable loss of activity and was not deactivated due to amide formation. Also, this method has attractive advantages such as short reaction time, mild reaction conditions, good to excellent yield of products, easy handling of the catalyst and simple operational procedure. Copyright © 2014 John Wiley & Sons, Ltd.

A solvent-free and highly efficient protocol has been developed for the synthesis of novel bis-Michael addition products (3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k, 3l, 3m, 3n, 3o) using aminopropylated PEG-6000 (NH2-PEG) as a biodegradable and recyclable catalyst in excellent yields under solvent-free conditions. Other remarkable features of this environmentally benign protocol are shorter reaction time, tolerance of a wide range of C―H-activated acids, high yield of products, and simple experimental and work-up procedure as compared to conventional methods. The NH2-PEG catalyst is characterized by using FT-IR, powder XRD and scanning electron microscopy–energy dispersion X-ray spectrometric analyses. The catalyst can be recycled several times without significant loss of its catalytic activity. Copyright © 2014 John Wiley & Sons, Ltd.

For the first time sulphated silica tungstic acid (SSTA) has been synthesized and used as an acidic catalyst in organic synthesis. The catalyst was prepared by a simple method based on the reaction of silica with SOCl 2 followed by addition of sodium tungstate and then functionalization with chlorosulfonic acid. The three-component Biginelli-like condensation of different heteroaldehydes, urea and ethyl cyanoacetate or phenyl acetic acid catalyzed by SSTA under solvent-free conditions afforded novel tetrahydropyrimidines in high yields. The catalyst tolerated different heteroaldehydes and also catalyzed the synthesis of Biginelli compounds efficiently giving excellent yield of products. The catalyst was characterized by FT-IR, XRD and SEM-EDX analyses. The stability of the catalyst was evaluated by DSC and TG analyses. The major advantages of the present method are high yields, short reaction times, and solvent-free reaction conditions. The activity and simple recyclability without losing catalytic activity make this catalyst a good replacement to literature methods.

Tosic acid on silica gel (TsOH-SiO2) was synthesized and characterized using microscopic and spectroscopic techniques such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and FT-IR spectroscopy. Thermal behaviour of the catalyst was investigated by differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis. TsOH-SiO2 showed excellent catalytic activity for the Knoevenagel condensation and was recyclable for six cycles.

An efficient, eco-friendly, and sustainable protocol was described for the synthesis of new quinolinyl alkenes via Knoevenagel condensation of 2-chloro-3-formylquinoline with different active methylene compounds using [Et3NH][HSO4] as a catalyst and an environmentally benign solvent eliminating the need for a volatile organic solvent and additional catalyst. This ionic liquid is air and water stable and easy to prepare from amine and acid. Structures of the newly synthesized compounds had been elucidated on the basis of elemental analysis and spectral data (IR, 1H NMR, 13C NMR, and mass spectrometry).The ionic liquid was also characterized by 1H NMR and 13C NMR. The present methodology is a green protocol as it eliminates the need for a volatile organic solvent and additional catalyst and offers several advantages such as shorter reaction time, excellent yield of products, mild reaction conditions, simple operational procedure, and recyclablility up to seven cycles without any appreciable loss in catalyti...

Synthesis of KCC-1 silica sulphuric acid as a new catalyst has been reported. The catalyst was characterized using XRD, SEM, TEM, BET, FT-IR, TGA-DTA, and EDX analysis. The catalytic activity was evaluated for the synthesis of enaminones under solvent-free conditions. The catalyst was easily recovered and reused up to seven cycles with slight loss of activity. The attractive features of this protocol are low amount of catalyst loading, short reaction time, mild reaction conditions, good to excellent yield of the products, easy handling of the catalyst and simple operational procedure. A highly efficient Sulphated nanosilica sulphuric acid has been synthesized and applied for the synthesis of enaminones. This catalytic protocol is better for the synthesis of enaminone than previously reported procedures in terms of catalyst loading, reaction condition, reaction time and yields of the products.