Khalid A. Al-Rashood

Compositional and thermal characterization of genuine and randomized lard: A comparative study

Composition and thermal characterization of genuine and randomized lard were investigated comparatively in an attempt to find common merits that assess lard detection. The investigation included compositional and positional distribution of fatty acids, triacylglycerol profiling by gas chromatography (GC) and reversed-phase high-performance liquid chromatography (RP-HPLC), as well as thermal behavior by differential scanning calorimetry (DSC) of both samples. Individual and total saturated and unsaturated fatty acid composition in total fats of both genuine and randomized lard were identical. On the other hand, the results of pancreatic lipolysis/GC analysis showed that the average percent palmitic acid [PAEF(%)] and myristic acid [MAEF(%)] enrichment factors of genuine (280 and 270) and randomized lard (110 and 98) were quite different. Thus, application of PAEF to detect randomized lard is of no value. However, normalization of fatty acid distribution by randomization in 2-monoacylglycerols made the individual and total saturated and unsaturated fatty acids almost identical to that of total fat and neutral triacylglycerols (TG) of lard. TG compositional analysis by GC revealed that both genuine and randomized lard had six dominant TG (C46′C48′C50′C52′C54′ and C56) with quite different concentrations. TG with C52 represent the major constituent of genuine and randomized lard. TG profiling of samples was also carried out by RP-HPLC with a refractive index detector. The same peaks were eluted in both samples, but the area % of major peaks changed due to randomization. 2-Palmitooleostearin (SPO) was found in high proportion in lard. However, the ratios of SPO to 2-palmitooleolinolein of both genuine and randomized lard are close (0.6±0.05) and significantly distinguishable from that of beef (4.24), mutton (6.17), chicken (0.21), and turkey (0.14) fats. The DSC thermogram and thermodynamics of phase transitions of both samples were quite different and do not reveal common characteristic(s) that could be used for immediate detection of lard substances in fat admixtures.

Thiazolo(3,2-a)benzimidazoles: Synthetic Strategies, Chemical Transformations and Biological Activities

The present review covers the recent synthetic strategies and chemical transformations of thiazolo[3,2-a]benzimidazoles and it also presents the highlights of the biological activities of these compounds.

Synthesis and anticancer potential of certain novel 2-oxo-N'-(2-oxoindolin-3-ylidene)-2H-chromene-3-carbohydrazides

Treatment of ethyl 3-hydrazinyl-3-oxopropanoate (6) with indoline-2,3-dione derivatives 7a-g gave ethyl 3-oxo-3-(2-(2-oxoindolin-3-ylidene)hydrazinyl)propanoates 8a-g which were allowed to react with the appropriate salicyaldehyde 9a and/or 9b to furnish the chromene-based hydrazones 10a-i. Compounds 10a-i displayed a significant activity against HT-29 colon cancer cell line and a moderate activity against leukemia K562 cell line. Compound 10f emerged as the most active congener toward HT-29 colon cancer cell line with IC₅₀ = 7.98 ± 0.05 μM whereas compound 10c exhibited the best antiproliferative activity against leukemia K562 cell line with IC₅₀ = 9.44 ± 0.02 μM. Moreover, compound 1e showed 87.81 ± 7% inhibition of side population (SP) HT-29 colon cancer stem cells.

Synthesis of N-benzenesulfonamide-1H-pyrazoles bearing arylsulfonyl moiety: novel celecoxib analogs as potent anti-inflammatory agents.

The reaction of arylsulfones 11a-d with hydrazonoyl chloride derivative 13 furnished celecoxib analogs 4-(3-acetyl-5-aryl-4-(arylsulfonyl)-1H-pyrazol-1-yl)benzenesulfonamides 15a-d, respectively. Oximes 16a, b and hydrazones 17a, b were prepared by reacting sulfones 11a, b with hydroxyl amine and phenyl hydrazine, respectively. The anti-inflammatory activity of the synthesized compounds showed that, 5-(4-bromophenyl)-4-(phenylsulfonyl)pyrazole 15c and 5-(4-bromophenyl)-4-(4-tolylsulfonyl)pyrazole 15d exhibited excellent anti-inflammatory activity with ED50 = 68 ± 2.2 and 51 ± 0.7 μM/kg, respectively, higher than that of celecoxib (ED50 = 86 ± 1.1 μM/kg) after 3 h with acceptable ulcer index. In addition, the LD50 of 15c and 15d is 7.1 mM/kg for each, and 9.8 mM/kg for celecoxib. Compound 15d appeared selectivity index (COX-2/COX-1) almost the half of celecoxib while 15c is non-selective for COX-2. Compound 15c with ED50 = 80 ± 2.8 μM/kg showed a significant analgesic activity when compared with celecoxib (ED50 = 70 ± 3.9 μM/kg) after 2 h whereas 15b (ED50 = 50 ± 1.2 μM/kg) and 15d (ED50 = 69 ± 2.7 μM/kg) seemed to be more potent than celecoxib (ED50 = 156 ± 4.8 μM/kg) but with a shorter duration (0.5 h).

A Selective Colorimetric Method for the Determination of Penicillins and Cephalosporins with α-Aminoacyl Functions

A simple, sensitive and selective colorimetric method is described for the assay of ampicillin, amoxicillin, cephalexin, cefadroxil and cefaclor in their pharmaceutical preparations. The method is based on measuring the color obtained when the alkaline degradation products of these agents are allowed to react with ascorbic acid. The factors affecting the color generation and determination were studied and optimized. The reaction is selective to β-lactam antibiotics having amino acid side-chains with free amino functions and thus allow interference-free quantitation of some preparations containing these agents in combination with other β-lactam agents. The procedure is also successfully adopted as stability-indicating method for cephalosporins. A tentative mechanism of the color reaction is proposed.

Rapid determination of canagliflozin in rat plasma by UHPLC-MS/MS using negative ionization mode to avoid adduct-ions formation.

Canagliflozin is the first sodium-glucose co-transporter-2 inhibitor, approved by the US Food and Drug Administration for the treatment of type 2 diabetes mellitus. In this study, a sensitive UHPLC-MS/MS assay for rapid determination of canagliflozin in rat plasma was developed and validated for the first time. Chromatographic separation of canagliflozin and zafirlukast (IS) was carried out on Acquity BEH C18 column (100×2.1 mm, i.d. 1.7 µm) using acetonitrile-water (80:20, v/v) as mobile phase at a flow rate of 0.3 mL min(-1). Canagliflozin and IS were extracted from plasma by protein precipitation method using acetonitrile. The mass spectrometric detection was performed using electrospray ionization source in negative mode to avoid canagliflozin adduct ions formation. Multiple reaction monitoring were used for quantitation of precursor to product ion at m/z 443.16 >364.96 for canagliflozin and m/z 574.11>462.07 for IS, respectively. The assay was fully validated in terms of selectivity, linearity, accuracy, precision, recovery, matrix effects and stability. The validated method was successfully applied to the characterization of oral pharmacokinetic profiles of canagliflozin in rats. The mean maximum plasma concentration of canagliflozin of 1616.79 ng mL(-1) was achieved in 1.5 h after oral administration of 20 mg kg(-1) in rats.

3-(1-Adamant­yl)-1-{[4-(2-meth­oxy­phen­yl)piperazin-1-yl]meth­yl}-4-methyl-1H-1,2,4-triazole-5(4H)-thione

The title compound, C25H35N5OS, is a functionalized triazoline-3-thione with substituted piperazine and adamantyl substituents attached at the 2- and 5-positions, respectively, of a triazole spacer with an approximately C-shaped conformation of the molecule. The piperazine ring adopts a chair conformation.

TRIACYLGLYCEROLS-PROFILING BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY: A TOOL FOR DETECTION OF PORK FAT (LARD) IN PROCESSED FOODS

Abstract A rapid high-performance liquid chromatographic procedure for separation of the triacylglycerols (TG) of animal fats using refractive index detection is described. A LiChrospher-100 RP-18 (5 μm) column was used for the TG-profiling of pork, beef, mutton, chicken and turkey fats. Detection of pork fat in processed foods and lard in fat-admixtures is also discussed. TG-separation and checking genuinity and adulteration was achieved isocratically in ∼ 15 min. by using CH3CN/CH2Cl2 (58:42, v/v) at ambient temperature.

Colorimetric Method for the Determination of Ampicillin and Amoxicillin

A simple colorimetric procedure is described for the quantitation of ampicillin and amoxicillin in their pharmaceutical preparations. The color production is based on the reaction of the oxidation product of ascorbic acid, dehydroascorbic acid, with the corresponding penicillenic acids obtained by the degradation of the antibiotics after heating under acidic conditions. The reaction demonstrated selectivity towards the penicillins having amino acid side chains and thus allowed interference-free quantitation of ampicillin and amoxicillin in combination with cloxacillin or clavulenic acid. The procedure showed good accuracy and precision and offers advantages over the official and many other reported analytical procedures.

High performance liquid chromatographic determination of ranitidine in human plasma

Abstract A rapid reversed phase HPLC method for determination of ranitidine in human plasma has been developed. The procedure involved extraction of the drug from alkalinized plasma spiked with the internal standard (procainamide) using 4% v/v isopropanol in ethylacetate. The extract was evaporated under nitrogen and the residue was reconstituted with methanol and injected onto U-Bondapak C18 column. The mobile phase is 8% v/v acetonitrile in 10 mM potassium phosphate buffer (pH 5.1); at a flow rate of 2.5 ml/min and UV detection at 330 nm. The efficiency of extraction was 90% with a detection limit of 20 ng/ml. The within-day coefficient of variations ranged from 4.09% to 5.81%, whereas those of between-day were from 7.5% to 9.51%.