Synthesis,spectroscopic exploration,biocidal activities,and crystal structures of 3‐(3‐fluorophenyl)‐2‐phenylpropenoic acid and trimethyltin(IV) complex

The ligand, 3‐(3‐fluorophenyl)‐2‐phenylpropenoic acid, [C₁₅H₁₁FO₂] ( I ) was prepared by reacting equimolar amount of phenyl acetic acid with 3‐fluorobenzaldehyde (1:1) using Perkin condensation method. The trimethyltin(IV) carboxylate, [Me₃SnO₂FH₁₀C₁₅] ( II ) was synthesized by refluxing an equimolar (1:1) mixture of trimethyltin chloride and silver salt of the ligand acid, [C₁₅H₁₀FO₂Ag] ( Ia ). The ligand and complex both were characterized by elemental analysis, IR, mass, ¹H NMR, and X‐ray crystallographic data. On the basis of ¹H NMR data, (²J[^117/119Sn, ¹H] and C Sn C bond angle), it is concluded that the environment around the tin atom in solution is tetrahedral. The Infrared spectroscopic results showed that trimethyltin(IV) derivative has 5‐coordinated polymeric structure with bridging carboxylate groups in the solid state, which has been confirmed by the X‐ray crystallographic data. The crystal of ligand acid ( I ) is triclinic with space group Pbar1. However, the crystal of the complex ( II ) is monoclinic with space group C_2/c. The geometry around the tin atom is distorted trigonal bipyramid with O(1) and O(2) atoms in apical positions. The ligand ( I ) and complex ( II ) were also tested for their biocidal activities. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:398–406, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20032     

Preprocessing Strategies for Sparse Infrared Spectroscopy: A Case Study on Cartilage Diagnostics

The aim of the study was to optimize preprocessing of sparse infrared spectral data. The sparse data were obtained by reducing broadband Fourier transform infrared attenuated total reflectance spectra of bovine and human cartilage, as well as of simulated spectral data, comprising several thousand spectral variables into datasets comprising only seven spectral variables. Different preprocessing approaches were compared, including simple baseline correction and normalization procedures, and model-based preprocessing, such as multiplicative signal correction (MSC). The optimal preprocessing was selected based on the quality of classification models established by partial least squares discriminant analysis for discriminating healthy and damaged cartilage samples. The best results for the sparse data were obtained by preprocessing using a baseline offset correction at 1800 cm⁻¹, followed by peak normalization at 850 cm⁻¹ and preprocessing by MSC.     

A copper diimine‐based honeycomb‐like porous network as an efficient reduction catalyst

Nitrophenols are among the widely used industrial chemicals worldwide; however, their hazardous effects on environment are a major concern nowadays. Therefore, the conversion of environmentally detrimental p‐nitrophenol (PNP) to industrially valuable p‐aminophenol (PAP), a prototype reaction, is an important organic transformation reaction. However, the traditional conversion of PNP to PAP is an expensive and environmentally unfriendly process. Here, we report a honeycomb‐like porous network with zeolite‐like channels formed by the self‐organization of copper, 1,10‐phenanthroline, 4,4′‐bipyridine, and water. This porous network effectively catalyzed the transformation of hazardous PNP to pharmaceutically valued PAP. In the presence of complex, PNP to PAP conversion occurred in a few minutes, which is otherwise a very sluggish process. To assess the kinetics, the catalytic conversion of PNP to PAP was studied at five different temperatures. The linearity of lnC_t/C_o versus temperature plot indicated pseudo‐first‐order kinetics. The copper complex with zeolite like channels may find applications as a reduction catalyst both on laboratory and industrial scales and in green chemistry for the remediation of pollutants.     

Drier Climatic Conditions Increase Withanolide Content of Withania coagulans Enhancing Its Inhibitory Potential Against Human Prostate Cancer Cells

Applied Biochemistry and Biotechnology - Prostate cancer is one of the major causes of cancer-related deaths in men and there is a growing interest in identifying natural compounds for its...     

Experimental investigation of TiO2–water nanofluid flow and heat transfer inside wavy mini-channel heat sinks

Journal of Thermal Analysis and Calorimetry - The present study comprises experimental investigation on heat transfer and hydrodynamic characteristics of TiO2 nanofluid as coolant in wavy channel...     

Thermal performance enhancement of shell and helical coil heat exchanger using MWCNTs/water nanofluid

Journal of Thermal Analysis and Calorimetry - Heat exchangers serve as pivotal components in industries. Enhancement in the performance of heat exchangers has been the focus of researchers in the...     

Photocatalytic Reductive Radical-Polar Crossover for a Base-Free Corey–Seebach Reaction

A metal-free generation of carbanion nucleophiles is of prime importance in organic synthesis. Herein we report a photocatalytic approach to the Corey–Seebach reaction. The presented method operates under mild redox-neutral and base-free conditions giving the desired product with high functional group tolerance. The reaction is enabled by the combination of photo- and hydrogen atom transfer (HAT) catalysis. This catalytic merger allows a C−H to carbanion activation by the abstraction of a hydrogen atom followed by radical reduction. The generated nucleophilic intermediate is then capable of adding to carbonyl electrophiles. The obtained dithiane can be easily converted to the valuable α-hydroxy carbonyl in a subsequent step. The proposed reaction mechanism is supported by emission quenching, radical–radical homocoupling and deuterium labeling studies as well as by calculated redox-potentials and bond strengths.     

Synthesis of isoniazid-1,2,3-triazole conjugates: Antitubercular,antimicrobial evaluation and molecular docking study

In the present study, a series of new isoniazid-1,2,3-triazole conjugates ( 5a-k ) was synthesized via click chemistry approach. The newly synthesized compounds were assessed for their in vitro antitubercular and antimicrobial activities. The compound 5g has displayed potent antitubercular activity against Mycobacterium tuberculosis H37Rv (Mtb) with MIC value 1.56 μg/mL. The active compounds were screened for their cytotoxicity profile by MTT assay against RAW 264.7 cell line. The four compounds have shown good in vitro antimicrobial activities against both antibacterial and antifungal pathogens. A molecular docking study was accomplished to identify the probable mode of action of synthesized derivatives. These compounds have shown excellent binding affinity toward Enoyl-acp reductase (INHA) and DNA gyrase.     

Effects of Essential Oils of Elettaria cardamomum Grown in India and Guatemala on Gram-Negative Bacteria and Gastrointestinal Disorders

The present study examined the chemical composition and antimicrobial and gastrointestinal activity of the essential oils of Elettaria cardamomum (L.) Maton harvested in India (EC-I) and Guatemala (EC-G). Monoterpenes were present in higher concentration in EC-I (83.24%) than in EC-G (73.03%), whereas sesquiterpenes were present in a higher concentration in EC-G (18.35%) than in EC-I (9.27%). Minimum inhibitory concentrations (MICs) of 0.5 and 0.25 mg/mL were demonstrated against Pseudomonas aeruginosa in EC-G and EC-I, respectively, whereas MICs of 1 and 0.5 mg/mL were demonstrated against Escherichia coli in EC-G and EC-I, respectively. The treatment with control had the highest kill-time potential, whereas the treatment with oils had shorter kill-time. EC-I was observed to be more potent in the castor oil-induced diarrhea model than EC-G. At 100 and 200 mg/kg, P.O., EC-I exhibited 40% and 80% protection, respectively, and EC-G exhibited 20% and 60% protection, respectively, in mice, whereas loperamide (10 mg/kg, i.p., positive control) exhibited 100% protection. In the in vitro experiments, EC-I inhibited both carbachol (CCh, 1 µM) and high K⁺ (80 mM)-induced contractions at significantly lower concentrations than EC-G. Thus, EC-I significantly inhibited P. aeruginosa and E. coli and exhibited more potent antidiarrheal and antispasmodic effects than EC-G.     

Catalytic Conversion of Xylose to Furfural by p-Toluenesulfonic Acid (pTSA) and Chlorides: Process Optimization and Kinetic Modeling

Furfural is one of the most promising precursor chemicals with an extended range of downstream derivatives. In this work, conversion of xylose to produce furfural was performed by employing p-toluenesulfonic acid (pTSA) as a catalyst in DMSO medium at moderate temperature and atmospheric pressure. The production process was optimized based on kinetic modeling of xylose conversion to furfural alongwith simultaneous formation of humin from xylose and furfural. The synergetic effects of organic acids and Lewis acids were investigated. Results showed that the catalyst pTSA-CrCl₃·6H₂O was a promising combined catalyst due to the high furfural yield (53.10%) at a moderate temperature of 120 °C. Observed kinetic modeling illustrated that the condensation of furfural in the DMSO solvent medium actually could be neglected. The established model was found to be satisfactory and could be well applied for process simulation and optimization with adequate accuracy. The estimated values of activation energies for xylose dehydration, condensation of xylose, and furfural to humin were 81.80, 66.50, and 93.02 kJ/mol, respectively.