Sukhmeet Kaur

Rational Design of Small Peptides for Optimal Inhibition of Cyclooxygenase-2: Development of a Highly Effective Anti-Inflammatory Agent

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.

Transformation of gas‐phase amino acid clusters to dipeptides: a nice approach to demonstrate the formation of prebiotic peptides

RATIONALE Exploring prebiotic developments is a fascinating area of research which is continually drawing the attention of the scientific community. It is probable that first the biomolecules were formed and then they became aggregated to generate life. Formation of one such biomolecules (peptide ions) is shown in the present experiments. METHODS All amino acid solutions for recording mass spectra were prepared in 3:6.9:0.1 (v/v/v) acetonitrile/water/formic acid at a concentration of 50 μM. The studies were performed using a Bruker MicroTOF QII mass spectrometer. Before carrying out experiments in the collision cell, atmospheric pressure in-source fragmentations were also performed. The formation of different chemical species was detected with high-resolution mass spectrometry. RESULTS Here, we show experimentally the formation of amino acid cluster ions of varied populations, when a solution of an amino acid was injected into an electrospray ionization quadrupole time-of-flight (ESI-QTOF) mass spectrometer. During in-source fragmentation/collision cell fragmentation, the non-covalent interaction between two identical amino acids forms either the [M2 + H](+) dimer cluster ion and/or the [M2 + K](+) adduct ion which, by elimination of one molecule of water, form the covalent linked dipeptide. CONCLUSIONS 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.

TNF-α and IL-6 inhibitors: Conjugates of N-substituted indole and aminophenylmorpholin-3-one as anti-inflammatory agents

The conjugates obtained by the combination of indole and aminophenyl morpholinone were screened for TNF-α and IL-6 inhibition in microglial cells. Compound 4 was found to be the most potent anti-inflammatory agent as it reduced LPS induced level of inflammatory cytokines TNF-α and IL-6 by 71% and 53%, respectively. A significant decrease in NO and MMPs release from BV2 cells in culture pretreated with this compound as well as inhibition of nuclear translocation of NF-κB and AP-1 was observed. 75% inhibition of acetic acid induced algesia in swiss albino mice was noticed in the presence of compound 4. Experimental data and molecular docking studies indicate that the compounds are targeting TNF-α, iNOS and IL-6.

Stitching of tyrosine and 10H-acridin-9-one: turn-ON fluorescence in the narrow pH range 7.4–8.5 and intracellular labelling of cancer cells

We tailored 10H-acridin-9-one and (S)-tyrosine into 3-(4-hydroxyphenyl)-2-[(9-oxo-9,10-dihydroacridine-4-carbonyl) amino]propionic acid (2). 2 underwent pH dependent protonation/deprotonation and the effect was harnessed in terms of change in the fluorescence. The characteristic fluorescence change in the molecule in the pH 7.5 ± 1 range and its cell permeability allowed us to label cancer cells.

Tailoring the Substitution Pattern on 1,3,5-Triazine for Targeting Cyclooxygenase-2: Discovery and Structure–Activity Relationship of Triazine–4-Aminophenylmorpholin-3-one Hybrids that Reverse Algesia and Inflammation in Swiss Albino Mice

Here, we report analgesic and anti-inflammatory activity of a series of compounds obtained by appending 4-aminophenylmorpholin-3-one and acyclic, cyclic, or heterocyclic moieties on 1,3,5-triazine. The structures of compounds 4b and 6b are optimized for the best inhibition of COX-2 with IC50 values of 0.06 and 0.08 μM, respectively, and selectivity over COX-1 of 166 and >125, respectively. At the dose of 5 mg kg-1, these compounds significantly reduced acetic acid induced writhings, and their ED50 values were found to be 2.2 and 1.9 mg kg-1, respectively. Besides the cell-based and animal-based experiments showing the modes of action of these compounds targeting COX-2, the interaction behavior of 4b with COX-2 was also characterized, with physicochemical experiments including ITC, NMR, UV-vis, and molecular-modeling studies. Characteristically, these compounds interact with R120, Y355, and W385, the residues responsible for holding the substrate and mediating the process of electron transfer during the metabolic phase of the enzyme.

Design and Synthesis of Aza-/Oxa Heterocycle-Based Conjugates as Novel Anti-Inflammatory Agents Targeting Cyclooxygenase-2

A library of hybrid molecules was procured by the combination of triazine–indole adduct with morpholine/piperidine/pyrrolidine and pyrazole/pyrimidine/oxindole moieties. Enzyme immunoassays on cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) identified compound 6 having an IC50 value of 20 nM for COX-2 and 3000 nM for COX-1. The significant reduction in the formation of prostaglandin E2 in the lipopolysaccharide-treated (COX-2-activated) human whole blood, almost no change in the production of thromboxane B2 in the calcium ionophore-treated (COX-1-activated) sample of human whole blood, and the mechanistic studies on Swiss albino mice ensured that compound 6 is selective for COX-2. The association constant (Ka) of compound 6 with COX-2 was found to be of the order of 0.48 × 106 M–1. The diffusion spectroscopy experiments and relaxation time (T1) calculations of compound 6 in the presence of COX-2 assisted in identifying the site-specific interactions of 6 with the enzyme, and these results fall into nice correlation with the theoretical data obtained from molecular docking and quantitative structure–activity relationship studies. With maximum tolerable dose >2000 mg kg–1, compound 6 made 68 and 32% reduction in formalin-induced analgesia and carrageenan-induced inflammation in Swiss albino mice.

Rational design, synthesis and working of a tri-ligating receptor: Removal of cyanide from cytochrome-c-oxidase

W have carried out efficient Group based quantitative structure–activity relationships (GQSAR) exploring the relationship between the structures of a new promising family of 2-phenazinamine derivatives and their anticancer activities. We have developed residential evocative model, in order to aid in further optimization and expansion of newer anticancer agents containing novel pharmacophore. G-QSAR was performed on VLife molecular design suite (MDS) 4.2 version software. The extrapolative authority of the G-QSAR was checked through the cross-validation method and also by separating some compounds as fraction for external test set. The synthesis of five novel 2-phenazinamine derivatives was carried out successfully by chemical modifications suggested by the GQSAR model developed and by making use of its molecular descriptors. The screening of in vitro anticancer activity on K562 cell line was done in Tata Memorial Cancer Research Center Mumbai, India. The results display an improvement in anti-cancer activity. Phenazinamine and the analogues have better binding interactions with Oxidoreductase (PDB: 1YYD.) The binding energies of the protein-ligand interactions also confirm that the ligands fit into the active pockets of receptor tightly. The docking scores of PDB cavity (most hydrophobic area) and ligand suggests efficient binding interactions. These studies have been performed by using Autodock 4.2 version software. Thus, the synthesized phenazinamine derivatives can be used as a lead for further preparing promising future anticancer drug candidates.A comparative cross sectional study was conducted during the period from 2013 to 2015 to assess the plasma levels of interleukin 6, high sensitive C reactive protein and lipid profile among Sudanese with type2 diabetes mellitus. Two hundred patients with type2 diabetes mellitus were selected as a test group compared with a control 1 Corresponding author: halfa88@hotmail.com Mohamed A. M. Salih, Yassir B. F. Basher, Mona O. Ahmed, Tagwa A. M. Salih, Mamoun M. ElmannaAssessment of Interleukin 6, High Sensitive C reactive Protein and Lipid Profile Levels among Sudanese with Type2 Diabetes Mellitus EUROPEAN ACADEMIC RESEARCH Vol. III, Issue 11 / February 2016 11969 group which included 100 healthy volunteers. Blood specimens were collected from both groups and glycated hemoglobin, interleukin 6, high sensitive C reactive protein and lipid profile were estimated. Age and gender of the test group were matched with the control group. Spectrophotometeric methods were used for measurement of lipid profile. Glycated hemoglobin was measured by using fluorescence immunoassay technology (sandwich immunodetection method) and the high sensitive C-reactive protein was measured by using immuneturbidmetric method. Furthermore, Sandwich Enzyme-Linked Immunosorbent Assay (ELISA) was used to estimate interleukin 6. Statistical package for social science (SPSS version 16) computer software was used for data analysis. The results of this study indicated a significant increase in mean of the plasma interleukin 6, high sensitive C reactive protein and lipid profile of the test group when compared with the healthy control group, and a significant elevation in mean of the interleukin 6, high sensitive C reactive protein and triacylglycerol in uncontrolled type2 diabetic patients when compared with the mean of those controlled type2 diabetic but there was no significant differences in total cholesterol, high density lipoprotein, low density lipoprotein. Also there was a significant elevation in mean of plasma interleukin 6, high sensitive C reactive protein and lipid profile in obese with type2 diabetes mellitus when compared with the mean of non obese type2 diabetic patients. Furthermore, the result indicated a significant positive correlation between high sensitive C reactive protein in type2 diabetic patients to level of interleukin 6, total cholesterol, low density lipoprotein and triacylglycerol; however, there was a negative correlation between high sensitive C reactive protein to high density lipoprotein cholesterol. Moreover, there was no significant correlation between interleukin 6 and lipid profile.The use of natural products derived from plants for therapeutic purpose is as ancient as human civilization. Sandbox tree, Hura crepitans L. (Euphorbiaceae) is one of such plant and has been reported to have many ethnomedicinal applications especially as antimicrobial, anti-inflammatory and antihepatotoxic effects. This recent study was designed to determine the anti-hepatotoxic activity of the ethylacetate soluble fraction of the leaves and stem bark of H. crepitans and to isolate secondary metabolites. Chromatographic technique was used for isolation and Ultraviolet-Visible (UV), Infra-red (IR) and Nuclear Magnetic Resonance (NMR) spectroscopies were used for structural elucidation. Antihepatotoxicity study was carried out using carbon tetrachloride (CCl4) induced rat model and biochemical parameters: alanine aminotransferase (ALT), aspartate aminotransferase (AST), L-ãglutamyltransferase (GGT), urea and creatinine (CREA) were assayed on the serum. Phytomicrographs of the liver samples were also taken and analyzed. Our present study showed that biochemical studies of blood samples of CCl4 treated rats with value 105.0±0.001 AU inALT showed significant increase in the level of serum enzyme activities reflecting liver injury but, 69.0±13.23 AU for leaves and 53.3±2.52 AU for bark (p<0.05) indicated protection of hepatic cells. AST, GGT, urea and CREA also reduced significantly. Daphnane diterpenes, daphnetoxin acid and huratoxin were isolated from H. crepitans in this recent study along with apocynin and methylpentadecanoate.Conclusion: H. crepitans significantly reduced the level of biochemical parameters indicating protection against hepatocellular injury. Isolates obtained from this plant could also serve as lead compounds in therapy of diseases involving hepatic injury.A efficient and sensitive method based on liquid chromatography coupled with tandem mass spectrometry (LC–MS/ MS) has been developed for the simultaneous determination of meptazinol and its three metabolites, 7-oxomeptazinol (M1), 3-hydroxyethylmeptazinol (M2) and N-desmethylmeptazinol (M3), in human plasma. After enzymolysis and protein precipitation, chromatographic separation within 6.0 min was obtained from Welch Ultimate XB-C18 column using gradient elution. Meptazinol-d3 was used for the internal standard and the analytes were simultaneously determined by using the following [M+H]+ transitions: m/z 234.2→107.2 for meptazinol, m/z 248.2→107.1 for M1, m/z 250.1→107.1 for M2 and m/z 220.2→107.0 for M3. The calibration curves were prepared in the concentration ranges of 100-100000ng/mL for meptazinol, 5-5000ng/mL for M1, 5-500ng/mL for M2 and 50-20000ng/mL for M3. The relative errors ranged from -6.85% to 3.33%, -5.40% to 4.30%, -5.80% to 2.80% and -4.27% to 8.89% for meptazinol, M1, M2 and M3, respectively. This method has been successfully applied to the determination of meptazinol and its metabolites in plasma of eight healthy volunteers who had a single oral administration of 400 mg hydrochloride meptazinol capsule.

Rational modification of the lead molecule: Enhancement in the anticancer and dihydrofolate reductase inhibitory activity

By using molecular docking studies, the practice of fragment based drug discovery is conceptualized by introducing oxindole and iso-propanol moieties in our previous lead molecule 1. The resulting compound 2 exhibited competitive inhibition and favorable Ka and Ki for hDHFR. The screening of compound 2 at 60 cell line panel of human tumor cell lines showed its considerably better efficacy than compound 1 and hence put the candidature of 2 on stronghold for further studies.

A rationally designed molecule for removal of cyanide from human blood serum and cytochrome c oxidase

Compound 3 having three dimethoxyphenolic units exhibited excellent selectivity and competitive binding with CN−. Various experiments revealed the capability of this compound to act through all the three dimethoxyphenolic units and efficiently remove cyanide from human blood serum – more precisely from cytochrome c oxidase.

Temperature, pH and H-bond synergism for peptide bond formation: synthesis of sequence specific tetra- and penta-peptides without using coupling reagent

A reaction temperature of 120 °C, pH of 5.0 and reaction time of 6 h were chosen as the best conditions for the condensation of two nonactivated amino acids to form a peptide bond. Role of H-bond in these reactions was anticipated. The method was validated by procuring sequence specific tetrapeptides and pentapeptides without any disturbance to their chirality.