Improved synthesis of per-O-acetylated C1 hydroxyglycopyranose and structural study as non-covalent organic framework

An improved method for the synthesis of per-O-acetylated C-1-hydroxyglycopyranose was developed by hydrolysis of per-O-acetylated glycopyranosyl α-chlorides derived from sugars with C-2 axial acetates for example l-rhamnose and d-mannose. 2,3,4-Tri-O-acetyl-α-l-rhamnopyranose crystallized in tetragonal space group I4, a rare phenomenon in carbohydrate literature. The three dimensional packing of the molecule with the help of regular hydrogen bond and C–H···O interactions resulted in the formation of porous framework showing channels with pore size 7 Å.     

Inhibitory potential of Hydroxychavicol on Ehrlich ascites carcinoma model and in silico interaction on cancer targets

Abstract

Hydroxychavicol (HC), a major phenolic derivative isolated from the leaves of Piper betle L. is well known for its antibacterial, antifungal and antimutagenic properties. The present study evaluated the in vivo antitumor activity of HC against Ehrlich Ascites Carcinoma (EAC) cells in Swiss albino mice and in silico interaction of HC with the receptors involved in the cancer. Hydroxychavicol (200 and 400?mg/kg bw) was orally administered for 21 consecutive days and was effective in inhibiting the tumor growth in ascitic mouse model. HC consistently reduced the tumor volume, viable cell count, lipid peroxidation and elevated the life span of HC treated mice. Besides the hematological profiles, SGOT and SGPT levels reverted back to normal and oxidative stress markers GSH, SOD and CAT also increased in HC treated groups. In silico docking analysis revealed that HC possessed potent antagonist activity against all the cancer targets demonstrating its inhibitory activity.     

Convenient method for the synthesis of some novel chiral methyl 2-(2-oxo-2H-benzo[e][1,3]oxazin-3(4H)-yl)propanoate derivatives and biological evaluation of their antioxidant,cytotoxic, and molecular docking properties

Ten chiral methyl 2-(2-oxo-2H-benzo[e][1,3]oxazin-3(4H)-yl)propanoate derivatives 6a-6j have been synthesized from optically pure amino methyl phenol 5 and 4-nitrophenyl chloroformate. These derivatives 6a-6j are characterized by ¹H NMR, ¹³C NMR, FT-IR, and HRMS spectral techniques. Optical purity of these derivatives was confirmed by chiral HPLC method. Ten synthesized ester derivatives 6a-6j were screened for their in vitro antioxidant activity. Among the compounds 6b-d and 6h-j have exhibited comparable antioxidant activity with ascorbic acid as a standard. Compounds 6a and 6e-g have shown moderate antioxidant activity. Further, the in vitro cytotoxicity of these compounds were studied through MTT cell proliferation assay in addition the effect on LDH leakage and NO release. Among the derivatives, 6j showed extremely best activity and the IC₅₀ value (12.54 ± 0.71 μM) is very close to doxorubicin (7.2 ± 0.58 μM) as a standard. Compounds 6b , 6h , and 6i showed better inhibition next to compound 6j on the viability of HepG2 cells with an IC₅₀ value (μM) of 56.02 ± 1.4, 41.76 ± 0.58, and 38.17 ± 0.34, respectively. Also, molecular docking studies have been carried out with STAT-3 (PDB ID: 1BG1) and BCL-2 (PDB ID: 4AQ3) proteins against the four active compounds 6b , 6h , 6i , and 6j . The binding energies of the tested compounds were in the range of −7.76 to −8.41 kcal/mol, which is very close to doxorubicin (−8.53 kcal/mol) as a standard. These molecular docking results are in good agreement with the in vitro studies.     

Impact of third-grade nanofluid flow across a convective surface in the presence of inclined Lorentz force: an approach to entropy optimization

Journal of Thermal Analysis and Calorimetry - The current article deals with heat transfer and entropy generation analysis using Cattaneo–Christov heat flux (CCHF) for a flow of third grade...     

An entropy approach of Williamson nanofluid flow with Joule heating and zero nanoparticle mass flux

Journal of Thermal Analysis and Calorimetry - The important focus of this research is to investigate the features of MHD radiative Williamson nanofluid flow caused by a stretchable surface...     

Synthesis of novel β-amino alcohols from phenylacetylcarbinol: cytotoxicity activity against A549 cells and molecular docking

Research on Chemical Intermediates - Synthesis of novel β-amino alcohols 7a–d and 9a–d have been disclosed by in situ formation of Schiff base from phenylacetylcarbinol 1 (PAC),...     

Exploring the Effect of Bioisosteric Replacement of Carboxamide by a Sulfonamide Moiety on N‐Glycosidic Torsions and Molecular Assembly: Synthesis and X‐ray Crystallographic Investigation of N‐(β‐D‐Glycosyl)sulfonamides as N‐Glycoprotein Linkage Region Analogues

N‐Glycoprotein linkage region constituents, 2‐acetamido‐2‐deoxy‐β‐D ‐glucopyranose (GlcNAc) and asparagine (Asn) are conserved among all the eukaryotes. To gain a better understanding for nature’s choice of GlcNAcβAsn as linkage region constituents and inter‐ and intramolecular carbohydrate–protein interactions, a detailed systemic structural study of the linkage region conformation is essential. Earlier crystallographic studies of several N‐(β‐glycopyranosyl)alkanamides showed that N‐glycosidic torsion, ?_N, is influenced to a larger extent by structural variation in the sugar part than that of the aglycon moiety. To explore the effect of the bioisosteric replacement of a carboxamide group by a sulfonamide moiety on the N‐glycosidic torsions as well as on molecular assembly, several glycosyl methanesulfonamides and glycosyl chloromethanesulfonamides were synthesized as analogues of the N‐glycoprotein linkage region, and crystal structures of seven of these compounds have been solved. A comparative analysis of this series of crystal structures as well as with those of the corresponding alkanamido derivatives revealed that N‐glycosidic torsion, ?_N, does not alter significantly. Methanesulfonamido and chloromethanesulfonamido derivatives of GlcNAc display a different aglycon conformation compared to other sulfonamido analogues. This may be due to the cumulative effect of the direct hydrogen bonding between N1 and O1′ and C? H???O interactions of the aglycon chain, revealing the uniqueness of the GlcNAc as the linkage sugar.     

Lie group analysis for thermal-diffusion and diffusion-thermo effects on free convective flow over a porous stretching surface with variable stream conditions in the presence of thermophoresis particle deposition

A study has been carried out to obtain the solutions for heat and mass transfer from natural convection flow along a vertical surface with temperature-dependent fluid viscosity embedded in a porous medium due to thermal-diffusion (Soret) and diffusion-thermo (Dufour) effects. This paper concerns with a steady two-dimensional flow of incompressible fluid over a vertical stretching sheet. The fluid viscosity is assumed to vary as a linear function of temperature. A scaling group of transformations is applied to the governing equations. The impact of thermophoresis particle deposition with chemical reaction in the presence of thermal-diffusion and diffusion-thermo effects plays an important role on the temperature and concentration boundary layer. The results thus obtained are presented graphically and discussed.     

The quadrupole resonance properties of nondetonable explosive formulations for land mine detection machine calibration and testing

Explosive detection machines on the basis of quadrupole resonance (QR) technology are under development for land mine detection and other antiterrorism applications. The QR machines are optimized to detect the actual explosive ingredient in a detonable formulation and to ignore signals from other, benign materials. This presents a safety and logistical challenge for QR land mine detector testing and calibration because of the hazards involved when handling even small amounts of a detonable explosive. The detonation hazard can be mitigated by adding inert materials (desensitizers) to coat the crystalline explosive. The effect on the QR signal of various types of inert material is examined, with a view to developing a safe QR land mine target.