In Silico Analysis and Functional Characterization of Antimicrobial and Insecticidal Vicilin from Moth Bean (Vigna aconitifolia (Jacq.) Marechal) Seeds

Vicilin has nutraceutical potential and different noteworthy medicative health-promoting biotic diversions, and it is remarkable against pathogenic microorganisms and insects. In this study, Vigna aconitifolia vicilin (VacV) has been identified and characterized from the seed of Vigna aconitifolia (Jacq.) Marechal (Moth beans). LC-MS/MS analysis of VacV provided seven random fragmented sequences comprising 238 residues, showing significant homology with already reported Vigna radiata vicilin (VraV). VacV was purified using ammonium sulfate precipitation (60%) followed by size exclusion chromatography on Hi-Load 16/60 Superdex 200 pg column and anion-exchange chromatography (Hi trap Q FF column). Purified VacV showed a major ~50 kDa band and multiple lower bands on 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under both reduced and non-reduced conditions. After all, a three-dimensional molecular structure of VacV was predicted, which showed β-sheeted molecular conformation similar to crystallographic structure of VraV. All Vicilins from V. aconitifolia and other plants were divided into six sub-groups by phylogenetic analysis, and VacV shared a high degree of similarity with vicilins of Vigna radiata, Pisum sativum, Lupinus albus, Cicer arietinum and Glycine max. Additionally, VacV (20 μg) has significant growth inhibition against different pathogenic bacteria along strong antifungal activity (50 μg). Likewise, VacV (3.0 mg) produced significant growth reduction in Rice Weevil Sitophilus oryzae larvae after 9 days compared with control. Furthermore, by using MMT assay, the cytotoxicity effect of VacV on the growth of HepG2 liver cancerous cells was tested. VacV showed cytotoxicity against the HepG-2 line and the acquired value was 180 µg after 48 h. Finally, we performed molecular docking against caspase-3 protein (PDB ID: 3DEI) for VacV bioactive receptor interface residues. Hence, our results reveal that VacV, has nutraceutical potential and moth beans can be used as a rich resource of functional foods.     

Facile Synthesis of 5-Aryl-N-(pyrazin-2-yl)thiophene-2-carboxamides via Suzuki Cross-Coupling Reactions,Their Electronic and Nonlinear Optical Properties through DFT Calculations

Synthesis of 5-aryl-N-(pyrazin-2-yl)thiophene-2-carboxamides (4a–4n) by a Suzuki cross-coupling reaction of 5-bromo-N-(pyrazin-2-yl)thiophene-2-carboxamide (3) with various aryl/heteroaryl boronic acids/pinacol esters was observed in this article. The intermediate compound 3 was prepared by condensation of pyrazin-2-amine (1) with 5-bromothiophene-2-carboxylic acid (2) mediated by TiCl₄. The target pyrazine analogs (4a–4n) were confirmed by NMR and mass spectrometry. In DFT calculation of target molecules, several reactivity parameters like FMOs (E_HOMO, E_LUMO), HOMO–LUMO energy gap, electron affinity (A), ionization energy (I), electrophilicity index (ω), chemical softness (σ) and chemical hardness (η) were considered and discussed. Effect of various substituents was observed on values of the HOMO–LUMO energy gap and hyperpolarizability. The p-electronic delocalization extended over pyrazine, benzene and thiophene was examined in studying the NLO behavior. The chemical shifts of ¹H NMR of all the synthesized compounds 4a–4n were calculated and compared with the experimental values.     

Three-dimensional MHD flow over a shrinking sheet: Analytical solution and stability analysis

The magnetohydrodynamic(MHD) steady and unsteady axisymmetric flows of a viscous fluid over a two-dimensional shrinking sheet are addressed. The mathematical analysis is carried out in the presence of a large magnetic field. The steady state problem results in a singular perturbation problem having an infinite domain singularity. The secular term appearing in the solution is removed and a two-term uniformly valid solution is derived using the Lindstedt–Poincaré technique. This asymptotic solution is validated by comparing it with the numerical solution. The solution for the unsteady problem is also presented analytically in the asymptotic limit of large magnetic field. The results of velocity profile and skin friction are shown graphically to explore the physical features of the flow field. The stability analysis of the unsteady flow is made to validate the asymptotic solution.     

Multifaced Assessment of Antioxidant Power,Phytochemical Metabolomics,In-Vitro Biological Potential and In-Silico Studies of Neurada procumbens L.: An Important Medicinal Plant

This work was undertaken to explore the phytochemical composition, antioxidant, and enzyme-inhibiting properties of Neurada procumbens L. extracts/fractions of varying polarity (methanol extract and its fractions including n-hexane, chloroform, n-butanol, and aqueous fractions). A preliminary phytochemical study of all extracts/fractions, HPLC-PDA polyphenolic quantification, and GC-MS analysis of the n-hexane fraction were used to identify the phytochemical makeup. Antioxidant (DPPH), enzyme inhibition (against xanthine oxidase, carbonic anhydrase, and urease enzymes), and antibacterial activities against seven bacterial strains were performed for biological investigation. The GC-MS analysis revealed the tentative identification of 22 distinct phytochemicals in the n-hexane fraction, the majority of which belonged to the phenol, flavonoid, sesquiterpenoid, terpene, fatty acid, sterol, and triterpenoid classes of secondary metabolites. HPLC-PDA analysis quantified syringic acid, 3-OH benzoic acid, t-ferullic acid, naringin, and epicatechin in a significant amount. All of the studied extracts/fractions displayed significant antioxidant capability, with methanol extract exhibiting the highest radical-scavenging activity, as measured by an inhibitory percentage of 81.4 ± 0.7 and an IC₅₀ value of 1.3 ± 0.3. For enzyme inhibition experiments, the n-hexane fraction was shown to be highly potent against xanthine oxidase and urease enzymes, with respective IC₅₀ values of 2.3 ± 0.5 and 1.1 ± 0.4 mg/mL. Similarly, the methanol extract demonstrated the strongest activity against the carbonic anhydrase enzyme, with an IC₅₀ value of 2.2 ± 0.4 mg/mL. Moreover, all the studied extracts/fractions presented moderate antibacterial potential against seven bacterial strains. Molecular docking of the five molecules β-amyrin, campesterol, ergosta-4,6,22-trien-3β-ol, stigmasterol, and caryophyllene revealed the interaction of these ligands with the investigated enzyme (xanthine oxidase). The results of the present study suggested that the N. procumbens plant may be evaluated as a possible source of bioactive compounds with multifunctional therapeutic applications.     

Toplayer-dependent crystallographic orientation imaging in the bilayer two-dimensional materials with transverse shear microscopy

Nanocontact properties of two-dimensional (2D) materials are closely dependent on their unique nanomechanical systems, such as the number of atomic layers and the supporting substrate. Here, we report a direct observation of toplayer-dependent crystallographic orientation imaging of 2D materials with the transverse shear microscopy (TSM). Three typical nanomechanical systems, MoS₂ on the amorphous SiO₂/Si, graphene on the amorphous SiO₂/Si, and MoS₂ on the crystallized Al₂O₃, have been investigated in detail. This experimental observation reveals that puckering behaviour mainly occurs on the top layer of 2D materials, which is attributed to its direct contact adhesion with the AFM tip. Furthermore, the result of crystallographic orientation imaging of MoS₂/SiO₂/Si and MoS₂/Al₂O₃ indicated that the underlying crystalline substrates almost do not contribute to the puckering effect of 2D materials. Our work directly revealed the top layer dependent puckering properties of 2D material, and demonstrate the general applications of TSM in the bilayer 2D systems.     

Sol–gel synthesis of tetragonal ZrO2 nanoparticles stabilized by crystallite size and oxygen vacancies

In this letter, we present a facile route to produce metastable tetragonal zirconia (ZrO₂) nanoparticles via pH-controlled precipitation of dilute zirconyl nitrate dihydrate [ZrO(NO₃)₂·2H₂O] solution in liquid NH₃ under ambient conditions and calcination at 500 °C for 2 h. The phase pure tetragonal ZrO₂ nanoparticles are obtained at pH 9. The effect of pH on metastable phase stabilization in precipitated ZrO₂ nanoparticles is demonstrated with the help of XRD, SEM/EDX, and X-ray photoelectron spectroscopy techniques. The stability of tetragonal ZrO₂ phase is attributed to the smaller crystallite size and greater oxygen deficiency in phase-pure tetragonal ZrO₂.     

CRISPR-Cas13a mediated nanosystem for attomolar detection of canine parvovirus type 2

The CPV-2 DNA extracted from dog's intestine was amplified using RPA and transcribed into an RNA copy. The RNA copy was incubated with Cas13a and crRNA, upon activation collateral cleavage activity of Cas13a cleaves all the target RNA and nonspecific RNA in the vicinity producing fluorescent signals within 30 min.     

Synthesis of polyketide-type phenols by domino ‘Michael/retro-Michael/Aldol’ reactions of 3-formylchromones with silyl enol ethers derived from ethyl 3,5-dioxohexanoate

Highly functionalized polyketide-type phenols were prepared by domino ‘Michael/retro-Michael/aldol’ reactions of 3-formylchromones with 1-ethoxy-1,3,5-tris(trimethylsilyloxy)-1,3,5-hexatriene and its synthetic precursor, ethyl 3,5-bis(trimethylsilyloxy)-2,4-hexadienoate.