Proton induced X-ray emission (PIXE) technique for determining multi-element composition of transformed hairy root cultures of Boerhaavia diffusa L.: an important medicinal herb

Therapeutically important inorganic elements in Agrobacterium rhizogenes-mediated genetically transformed hairy root cultures (HRCs) of a pharmaceutically significant herb Boerhaavia diffusa were quantified using proton induced X-ray emission technique. This was compared with that of roots from the naturally grown donor plant. Two macro-elements (Ca & K) and eight different trace elements namely V, Cr, Mn, Fe, Co, Cu Zn, and Ni were detected and their content was determined. In HRCs of a transformed rhizoclone, calcium and potassium had values which were significantly higher than that of in vivo roots. The concentrations of several trace elements, which are known to have a positive implication in human healthcare, were found to be either comparable (Fe) to that in the natural root samples or higher (Mn, Zn, Cr, Cu, Co) in the transformed rhizoclone. The genetically transformed HRCs can thus serve as a fast-proliferating renewable resource of medicinally useful minerals targeting specific diseases.     

Synthesis of Bicyclic N‐Methylpyrazoline and Pyrazole Derivatives from α,β‐Unsaturated Ketones and N,N‐Dimethylhydrazine: An Illustration of Reductive Cyclization

The reaction of N,N‐dimethylhydrazine with α,β‐unsaturated keto precursors such as 2‐benzylidenecyclohexanone, 2,6‐bis(benzylidene)cyclohexanone, and 3,5‐bis(benzylidene)‐1‐methyl‐4‐piperidone hydrochloride provided bicyclic N‐methylpyrazoles instead of hydrazones or any Michael addition products. The crystal structure of a representative pyrazole is reported. The proposed mechanism for the formation of the bicyclic N‐methylpyrazole 1 is outlined.     

TFA-catalysed tandem double cyclisation: A one-pot,metal-free routes for novel indolo-imidazo[1,2-a]pyridine derivatives

A transition-metal free, one-pot tandem synthetic routes for novel indole and imidazo[1,2-a]pyridine derivative hybrids have been established. An efficient three-component reaction was designed with incorporation of two sequential Groebke–Blackburn–Bienayme (GBB) and cyclization reaction in one-pot under mild acidic condition. The salient feature of this protocol is atom economy, good yield and operational simplicity. A molecular prospective library of 32 compounds was synthesized by utilizing the various substituted aryl aldehydes and 2-aminopyridine.     

Polymerization of Acrylonitrile: Kinetics of the Reaction Initiated by the Redox System Mn3/Mannitol

Polymerization of acrylonitrile initiated by the redox system Mn³⁺/mannitol has been investigated in aqueous sulfuric acid in the temperature range 35–50°C. The rate of polymerization R_p and the rate of disappearance of Mn⁺³ (?R_M) were measured. The effect of certain water-miscible organic solvents, inorganic salts and complexing agents on the rate of polymerization have been investigated. Based on the experimental results, a suitable reaction mechanism is suggested involving the formation of complex between Mn³⁺ and the hydroxyl group of the substrate molecule, whose decomposition yields the initiating free radical; the polymer chain is terminated by the mutual combination of growing chains.     

Catalytic Deactivation and Regeneration of Nickel Microparticles in a Home-Built Microchannel-Coupled Millireactor: Substrate Specificity and Multiphase Flow Dependency

Substrate-assisted product desorption often proposed in heterogeneous catalysis (nanozymes) denounces the catalytic deactivation of these catalysts. On the contrary, the catalytic deactivation of rigid heterogeneous catalyst becomes noticeable in a continuous flow reactor. Surprisingly, it has been addressed inadequately and in an isolated manner. In this study, we have developed a cost-effective non-lithographic method for the fabrication of a PDMS-based microchannel-coupled-millreactor. Immobilized nickel particles are resistant to leaching in the flow process. During continuous operation, millireactors show a strong catalytic activity for reduction of resazurin and p-nitrophenol with a conversion rate of almost 100 %. Catalytic poisoning is ubiquitous and gets gradually prominent whereas complete catalytic deactivation of magnetic Ni-microparticles is found to be an instantaneous process. Relatively large-sized resorufin binds predominantly to the surface and thereby blocks the access of the substrate to the Ni-particles. The dissociations of product molecules - resorufin and p-aminophenol are the rate-limiting steps that caused the abrupt deactivation of Ni-microparticle. The kinetic mechanism of heterogeneous derived from the Langmuir-Hinshelwood mechanism satisfactorily explains the catalytic poisoning and deactivation of nickel microparticles. This study sheds light on the intricacies of catalytic activity and poisoning of magnetic nickel microparticles.     

Convenient phosphorus tribromide induced syntheses of substituted 1-arylmethylnaphthalenes from 1-tetralone derivatives

A series of 1-arylmethylnaphthalenes 7a-g and 11 have been synthesized conveniently in good yields at room temperature through phosphorus tribromide induced aromatization of 1-aryl-[3,4]-dihydronaphthyl-methanols 6a-g and 10, which were obtained from 1-tetralone derivatives.     

Dioxygen Activation by Redox-Active Bis(aldimine) Ligand Bridged Diruthenium Complex Possessing Singlet Ground State

The unexplored ‘actor’ behavior of redox-active bis(aldimine) congener, p-phenylene-bis(picoline)aldimine (L1), towards dioxygen activation and subsequent functionalization of its backbone was demonstrated on coordination with {Ru(acac)₂} (acac= acetylacetonate). Reaction under aerobic condition led to the one-pot generation of dinuclear complexes with unperturbed L1, imino-carboxamido (L2⁻), and bis(carboxamido) (L3²⁻)-bridged isovalent {Ru^II(μ-L1)Ru^II}, 1/ {Ru^III(μ-L3²⁻)Ru^III}, 3 and mixed-valent {Ru^II(μ-L2⁻)Ru^III}, 2 . Authentication of the complexes along with the redox non-innocence behavior of their bridge have been validated through structure, spectroelectrochemistry and DFT calculations. Kinetic and isotope labelling experiments together with DFT analyzed transition states justified the consideration of redox shuttling at metal/L1 interface for ³O₂ activation despite of the closed shell configuration of 1 (S=0) to give carboxamido derived 2 / 3 .     

ZnO Nanoparticles of Rubia cordifolia Extract Formulation Developed and Optimized with QbD Application,Considering Ex Vivo Skin Permeation,Antimicrobial and Antioxidant Properties

The objective of the current research is to develop ZnO-Manjistha extract (ZnO-MJE) nanoparticles (NPs) and to investigate their transdermal delivery as well as antimicrobial and antioxidant activity. The optimized formulation was further evaluated based on different parameters. The ZnO-MJE-NPs were prepared by mixing 10 mM ZnSO₄·7H₂O and 0.8% w/v NaOH in distilled water. To the above, a solution of 10 mL MJE (10 mg) in 50 mL of zinc sulfate was added. Box–Behnken design (Design-Expert software 12.0.1.0) was used for the optimization of ZnO-MJE-NP formulations. The ZnO-MJE-NPs were evaluated for their physicochemical characterization, in vitro release activity, ex vivo permeation across rat skin, antimicrobial activity using sterilized agar media, and antioxidant activity by the DPPH free radical method. The optimized ZnO-MJE-NP formulation (F13) showed a particle size of 257.1 ± 0.76 nm, PDI value of 0.289 ± 0.003, and entrapment efficiency of 79 ± 0.33%. Drug release kinetic models showed that the formulation followed the Korsmeyer–Peppas model with a drug release of 34.50 ± 2.56 at pH 7.4 in 24 h. In ex vivo studies ZnO-MJE-NPs-opt permeation was 63.26%. The antibacterial activity was found to be enhanced in ZnO-MJE-NPs-opt and antioxidant activity was found to be highest (93.14 ± 4.05%) at 100 µg/mL concentrations. The ZnO-MJE-NPs-opt formulation showed prolonged release of the MJE and intensified permeation. Moreover, the formulation was found to show significantly (p < 0.05) better antimicrobial and antioxidant activity as compared to conventional suspension formulations.     

Quality by Design enabled enhanced bioanalytical extraction and UFLC determination of vilazodone from rat serum

An ultrafast liquid chromatographic bioanalytical method was developed and validated for the determination of vilazodone in Wistar rat serum. Principles of quality by design were implemented for enhancing the bioanalytical liquid–liquid extraction of vilazodone from rat serum. A Box–Behnken design was utilized in the studies by selecting extraction time, centrifugation speed, and vortex time as the critical method variables for evaluating their effect on the analytical attribute, i.e., %recovery of vilazodone. Chromatographic separation was achieved within a run time of 10?min using a C-18 column and mobile phase comprising of methanol:phosphate buffer of pH 7 (85:15 v/v) flowing at 1.5?mL/min. Photodiode array detection was performed at 242?nm. Results of validation studies were satisfactory. The method was linear over a concentration of 100–2,000?ng/mL with acceptable accuracy and precision. Limits of detection and quantitation for the developed method were 50 and 100?ng/mL, respectively. This QbD-based approach was found suitable for routine bioanalysis of vilazodone in the biological matrix.