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.     

Self-assembly of chromotropic acid – a plausible explanation for monodisperse oligomer formation

The sodium salt of 4,5-dihydroxy-2,7-naphthalene disulphonic acid (chromotropic acid, DCA) self-assembles in aqueous media above its critical aggregate concentration (above 11 mM) to form organized aggregates as confirmed by conductometric, pH-metric and densitometric techniques. The molecular size of the aggregate was determined from gel filtration chromatographic studies. The molecular weight obtained in the postaggregate concentration region (100 mM) is about 1,660. The molecular weight of the aggregate indicates that four molecules of DCA constitute the aggregate. The results suggest that aggregate formation at high concentrations could explain the monodisperse spontaneous oligomerization in phenolic compounds.     

Dual Fluorescence and Photoprototropic Characteristics of 2-Aminodiphenylsulphone-β-Cyclodextrin Inclusion Complex

The absorption and fluorescence spectral characteristics of 2-aminodiphenylsulphone (2ADPS) have been investigated in the presence of β-cyclodextrin (β-CDx) in water. Dual emission is observed upon the complexation of 2ADPS in β-CDx. The stoichiometry of the host:guest inclusion complex is found to be 2:1. Steady state and time-resolved fluorescence spectral analysis support the formation of 2:1 complex between β-CDx and 2ADPS. The large enhancement in fluorescence intensity of twisted intramolecular charge transfer (TICT) band in aqueous β-CDx solution is due to the decrease in non-radiative processes. The ground and the excited state pK _a values for the monocation-neutral equilibrium of 2ADPS in β-CDx are found to be different from the pK _a values in aqueous solution. In the presence of β-CDx, 2ADPS is found to be less basic in the ground and the excited states.     

Experimental studies on inclined PV panel solar still with cover cooling and PCM

Journal of Thermal Analysis and Calorimetry - This work presents the experimental studies on the effect of mass stream rate of water (mf), phase change material and cover cooling of an inclined...     

Effect of magnesium doping on the properties and crystalline perfection of bis(thiourea)zinc(II) chloride crystals

In this article, the effect of magnesium doping on the properties of bis(thiourea)zinc(II) chloride (BTZC) crystals has been described. The incorporation of Mg(II) into the crystal lattice was confirmed by energy dispersive X-ray spectroscopy and quantified by inductively coupled plasma technique. The powder X-ray diffraction and FT-IR spectral analyses indicate that the crystal undergoes considerable stress as result of doping. SEM studies of pure and doped samples indicate the formation of structural defect centers in BTZC crystals. The TG?CDTA studies reveal the purity of the materials, and no decomposition is observed up to the melting point. Improved crystalline perfection by doping is observed by high-resolution X-ray diffraction. High transmittance is observed, and the cutoff ?? is ~295?nm.     

An extensive review on thermodynamic aspect based solar desalination techniques

Journal of Thermal Analysis and Calorimetry - The shortage of freshwater is becoming a major threat to sustainable environmental development. Water desalination techniques provide solutions for...     

Polyethylene glycol-assisted growth of Ni3S4 closely packed nanosheets on Ni-foam for enhanced supercapacitor device

Journal of Solid State Electrochemistry - Rich redox peaks, high surface area, good surface wettability, fast ion passage channels, high rate capability and excellent stability are some of the...     

Water soluble Ru (II)–p‐cymene complexes of chiral aroylthiourea ligands derived from unprotected D/L‐alanine as proficient catalysts for asymmetric transfer hydrogenation of ketones

The newfangled chiral aroylthiourea ligands (L1‐L6) were produced from unprotected D/L‐alanine and their water soluble Ru (II) organometallic catalysts ( 1 – 6 ) were designed from their reaction with [RuCl₂(η⁶‐p‐cymene)]₂. The analytical and spectral methods were used to confirm the structure of the ligands and complexes. The solid state structure of L1, 5 and 6 was confirmed by single crystal XRD. The organometallic compounds ( 1 – 6 ) catalyzed the asymmetric transfer hydrogenation of aromatic, heteroaromatic and bulky ketones to yield respective enantiopure secondary alcohols with admirable conversions (up to 99%) and attractive enantiomeric excesses (ee up to 98%), in presence of formic acid and triethylamine in water medium under non‐inert atmospheric conditions.