Mohammad Shoaib

Antioxidant and relaxant activity of fractions of crude methanol extract and essential oil of Artemisia macrocephala jacquem

AbstractBackgroundThe current work is an attempt to know about additional chemical profile of Artemisia macrocephala. Antioxidant activity is performed as the plant is reported to contain flavonoids, which have antioxidant activity in general. Relaxant activity of fractions of crude methanol extract is performed to know in which fraction(s) the relaxant constituents concentrate as we have already reported that its crude methanol has relaxant activity. Antispasmodic activity of essential oil is also performed as the plant is rich with essential oil.MethodsPhytochemical profile of the plant is performed. Free radical scavenging activity was performed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH). Relaxation activity tests of fractions and essential oil of Artemisia macrocephala were performed on sections of rabbits’ jejunum. Calcium chloride curves were constructed to investigate the mode of action of plant extracts and its essential oil.ResultsWe detected carbohydrates, flavonoids and saponins in A. macrocephala. At concentration 0.005 mg/ml, free radical scavenging activity of ethyl acetate fraction was 121.5 ± 2.02% of ascorbic acid. n- hexane fraction relaxed spontaneous activity with EC50 0.74 ± 0.04 mg/ml. Essential oil relaxed spontaneous activity with EC50 0.8 ± 0.034 mg/ml. Chloroform and ethylacetate fractions relaxed both spontaneous and KCl-induced contractions suggesting its possible mode through calcium channels. Constructing calcium chloride curves, the test fractions showed a right shift in the EC50. Essential oil at concentration 0.1 mg/ml produced right shift with EC50 (log [Ca++]M) -2.08 ± 0.08 vs. control with EC50 -2.47 ± 0.07. The curve resembled the curves of verapamil, which caused a right shift at 0.1 μM, with EC50 -1.7 ±0.07 vs. control EC50 (log [Ca++]M) -2.45 ± 0.06.ConclusionsCrude methanol and its fractions (ethyl acetate, chloroform and butanol) are rich sources of antioxidant constituents. The relaxing constituents following calcium channel blocking mechanisms are more concentrated in n-hexane, chloroform and ethyl acetate fractions that warrant isolation.

Development of a biocompatible creatinine-based niosomal delivery system for enhanced oral bioavailability of clarithromycin

Abstract Context: Nonionic surfactant vesicles have gained increasing scientific attention for hydrophobic drugs delivery due to their biocompatibility, stability and low cost. Objective: The aim of the present study was to synthesize and evaluate a novel creatinine-based nonionic surfactant in terms of its ability to generate biocompatible niosomal system for the delivery of Clarithromycin. Materials and Methods: The surfactant was synthesized by reacting creatinine with lauroyl chloride followed by characterization using 1HNMR and MS. The drug-loaded niosomal vesicles of the surfactant were characterized for drug encapsulation efficiency (EE) using LC-MS, vesicle size using dynamic light scattering (DLS) and vesicle shape using atomic force microscopy (AFM). The surfactant was also investigated for blood hemolysis, in vitro cytotoxicity against different cell lines and in vivo acute toxicity in mice. Furthermore, the in vivo bioavailability of Clarithromycin encapsulated in the novel niosomal formulation was investigated using rabbits and quantified through validated LC-MS/MS method. Results and discussion: Findings showed that vesicles were able to entrap up to 67.82 ± 1.27% of the drug, and were rounded in shape with a size around 202.73 ± 5.30 nm and low polydispersity. The surfactant caused negligible blood hemolysis, very low cytotoxicity and was found to be safe up to 2500 mg/kg body weight using mice. The niosomal formulation showed twofold enhanced oral bioavailability of Clarithromycin as compared to commercial formulations of the drug. Conclusion: The study has shown that the creatinine-based niosomes developed in our laboratory were biocompatible, safe and increased the oral bioavailability of the model hydrophobic Clarithromycin using experimental animals.

Hydrophilically modified self-assembling α-tocopherol derivative as niosomal nanocarrier for improving clarithromycin oral bioavailability

Abstract Synthesis of biocompatible and cost-effective novel nonionic surfactants from renewable resources has been the subject of greater scientific interest for enhancing the bioavailability of less water-soluble drugs. The present study focuses on the synthesis of α-tocopherol-based novel biocompatible nonionic surfactant and its evaluation for forming clarithromycin-loaded niosomal drug delivery system. α-tocopherol was hydrophilically modified through multistep reactions and characterized using mass and 1H NMR spectroscopic techniques. Drug-loaded niosomal vesicles were investigated for entrapment efficiency (%EE), size, polydispersity index (PDI), zeta potential (ζ) and morphology using LC-MS, dynamic light scattering (DLS) and atomic force microscopy (AFM). Blood haemolysis, cell culture and acute toxicity tests were performed to investigate its biocompatibility. In vivo oral bioavailability of clarithromycin loaded in niosomal formulation was studied in rabbits. The vesicles were spherical in shape and entrapped up to 75 ± 2.57% of the drug. They exhibited a homogeneous size distribution with a mean diameter of 245 ± 4.66 nm. The surfactant was quite haemocompatible, low cytotoxic and safe in mice. Improved oral bioavailability of clarithromycin was achieved when carried in α-tocopherol-based niosomes. Results obtained showed that the synthesized amphiphile is biocompatible and has excellent capability for formation of niosomal vesicles and enhancing oral bioavailability of less water-soluble drugs like clarithromycin.

In Vitro Enzyme Inhibition Potentials and Antioxidant Activity of Synthetic Flavone Derivatives

Free radicals are produced by an important chemical process known as oxidation that in turn initiates chain reactions to damage the cells and originate oxidative stress. Flavones have got special position in research field of natural and synthetic organic chemistry due to their biological capabilities as antioxidant. The antioxidants are known to possess extensive biological effects that include antiviral, antibacterial, anti-inflammatory, antithrombotic, and vasodilatory activities. The simple flavone (F1) and substituted flavone derivatives (F2–F5) have been synthesized from o-hydroxyacetophenone and benzaldehyde derivatives in good yield. The structures have been established by different spectroscopic techniques like 1H NMR, 13C NMR, IR, and elemental analysis. Antioxidant profile of these compounds was established using DPPH and H2O2 free radical scavenging assay. The findings showed that halogenated flavones showed more enzyme inhibitions and antioxidant activities than simple flavones and are potential candidates for the treatment of wide range of diseases.

Crystal structure of 3-[(2-acetyl-phen-oxy)carbon-yl]benzoic acid.

In the title compound, C16H12O5, synthesized from isopthaloyl chloride and 2′-hydroxyacetophenone, the dihedral angle between the planes of the aromatic rings is 71.37 (9)°. In the crystal, carboxylic acid inversion dimers generate R 2 2(8) loops. The dimers are linked by C—H⋯O interactions, generating (101) sheets.

Synthesis and Pharmacological Properties of 1,3-Bis[(S)Phenylethyl]Imidazolidine-2-Thione

Enantiomerically and diastereomerically pure thiourea derivative (compound I) has been synthesized in two steps starting from (S)-1-phenylethanamine and 1,2-dibromoethane. Compound I was screened for various biochemical parameters including blood glucose level, serum total cholesterol level, serum bilirubin and triglyceride levels, serum glutamate pyruvate transaminase (SGPT) and alkaline phosphatase (ALP) activity in New Zealand White (NZW) rabbits. Compound I was also screened for brine shrimp cytotoxicity, antileishmanial and antioxidant activity. Acute toxicity tests in NZW rabbits were performed and the results showed that compound I was safe up to 2 mg/mL/kg rabbit body weight. For the blood parameters, it was found that compound I caused slightly reduced blood glucose level, increased blood serum bilirubin, ALP and SGPT levels, and caused no changes in cholesterol and triglyceride levels. Thus, results show that compound I possesses good cytotoxic, poor antileishmanial activity, and no prominent antioxidant activity.

N-Methyl-pyrrolidine-1-carbothio-amide.

There are two independent molecules in the asymmetric unit of the title compound, C6H12N2S, in which the N-methylthioformamide unit and the pyrrolidine ring mean plane are oriented at dihedral angles of 5.9 (5) and 5.9 (4)°. In the crystal, zigzag C(4) chains extending along the a axis are formed due to N—H⋯S hydrogen bonds between alternate arrangements of molecules. The chains are interlinked by C—H⋯S hydrogen bonds.

1-(Pyridin-2-yl)-2-[2-(trifluoro­meth­yl)benz­yl]-3-[2-(trifluoro­meth­yl)phen­yl]propan-1-one

The title compound, C23H17F6NO, crystallizes with two molecules in the asymmetric unit. The molecules assume an approximate propellar shape, with the three aromatic rings being bent with respect to the plane formed by the C atoms that are connected to the methine C atom [dihedral angles: pyridyl 67.49 (3)°, phenyl 56.82 (4)° and phenyl 77.21 (6)° in one molecule, and corresponding angles of 71.60 (6), 53.68 (4) and 77.53 (6)° in the second molecule].

1,3-Bis(1-cyclo­hexyl­eth­yl)imidazolidine-2-thione

The complete molecule of the title compound, C19H34N2S, is generated by crystallographic twofold symmetry, with the C=S group lying on the rotation axis. A short C—H⋯S contact occurs in the molecule. The five-membered ring is twisted and the cyclohexyl ring adopts a chair conformation. The dihedral angle between the mean plane of the five-membered ring and the basal plane of the cyclohexyl ring is 75.32 (13)°.

1,3-Bis(1-phenyl­eth­yl)imidazolidine-2-thione

The complete molecule of the title compound, C19H22N2S, is generated by crystallographic twofold symmetry with the C=S group lying on the rotation axis. The imidazolidine ring adopts a flattened twist conformation. The dihedral angle between the asymmetric part of the imidazolidine-2-thione fragment and the benzene ring is 89.49 (17)°.