Densities, F, of glycine, DL-R-alanine, DL-R-amino-n-butyric acid, L-valine, and L-leucine in aqueous and in mixed aqueous solutions of zinc chloride, (0.1, 0.5, 1.0, and 1.5) mol • kg -1 , have been determined by using a vibrating-tube digital densimeter at (288.15, 298.15, 308.15, and 318.15) K. These data have been used to calculate the apparent molar volumes, V 2,φ , of the studied amino acids. The partial molar volumes, V 2 0 , at infinite dilution are evaluated and further used to obtain the corresponding transfer volumes, ∆ t V 0 for amino acids from water to aqueous zinc chloride solutions. Partial molar expansibilities, V 0 E , hydration numbers, n H , interaction coefficients, and side chain group contributions of amino acids have also been calculated. The ∆ t V 0 values for the studied amino acids are positive, and these values increase with an increase in the concentration of zinc chloride as well as with temperature. The parameters obtained from the volumetric study are used to understand various mixing effects due to the interactions between amino acids and zinc chloride in aqueous solutions.

Among the small peptides 2-31, (H)Gly-Gly-Phe-Leu(OMe) (30) reduced prostaglandin production of COX-2 with an IC50 of 60 nM relative to 6000 nM for COX-1. The 5 mg kg(-1) dose of compound 30 rescued albino mice by 80% from capsaicin-induced paw licking and recovered it by 60% from carrageenan-induced inflammation. The mode of action of compound 30 for targeting COX-2, iNOS, and VGSC was investigated by using substance P, l-arginine, and veratrine, respectively, as biomarkers. The interactions of 30 with COX-2 were supported by isothermal calorimetry experiments showing a Ka of 6.10 ± 1.10 × 10(4) M(-1) and ΔG of -100.3 kJ mol(-1) in comparison to a Ka 0.41 × 10(3) ± 0.09 M(-1) and ΔG of -19.2 ± 0.06 kJ mol(-1) for COX-1. Moreover, compound 30 did not show toxicity up to a 2000 mg kg(-1) dose. Hence, we suggest peptide 30 as a highly potent and promising candidate for further development into an anti-inflammatory drug.

After the formation of the amino acid cluster, it was established that the creation of the dipeptides, by a covalent bond resulting from the loss of a water molecule, was the initial step towards the formation of the primordial peptides.

Rationally designed conjugates of chrysin, indole, and barbituric acid were synthesized and screened for their antiinflammatory activities through in vitro and in vivo experiments. Improved over the previously reported chrysin-indole-pyrazole conjugates and also in comparison to the chrysin, indole, and barbituric acid based COX-2 inhibitors, the new compounds have displayed significantly better IC50 for COX-2 and some of them also exhibited inhibition of 5-LOX enzyme. For one of the test compounds, IC50 for COX-2 and 5-LOX was 1 and 1.5 nM, respectively. Investigations of Swiss Albino mice through capsaicin induced paw lickings and dextran induced inflammation showed that these compounds possess appreciable analgesic and antiinflammatory activities. Ki, Ka, and ΔG for the enzyme-compound interaction were calculated and found to be in agreement with the biological data. The experimental results were supported by the molecular docking studies of the compounds in the active site of COX-2 and 5-LOX. Overall, a highly promising antiinflammatory agent was identified.

The apparent molar volumes, apparent molar adiabatic compressibilities, and viscosities of glycine, DL-R-alanine, DL-R-amino-n-butyric acid, L-valine, and L-leucine, in aqueous solutions of cadmium chloride, CdCl 2 , at different concentrations have been determined in the temperature range (288.15 to 318.15) K from density, sound velocity, and time flow measurements, using a vibrating-tube digital densimeter, ultrasonic multifrequency interferometer, and Ubbelohde type capillary viscometer attached with an automatic viscosity measuring unit, respectively. From these data, partial molar volumes V 2 o , partial molar adiabatic compressibilities, K o S,2 , viscosity B-coefficients, and the corresponding transfer parameters (Δ t V o 2 , Δ t K o S,2 , and Δ t B), hydration numbers, n H , and side chain group contributions, dB/dT have been calculated. Transfer parameters are positive and increase with the concentration of CdCl 2 .