King Faisal Specialist Hospital & Research Centre

About: King Faisal Specialist Hospital & Research Centre is a healthcare organization based out in Riyadh, Saudi Arabia. It is known for research contribution in the topics: Medicine & Detection limit. The organization has 58 authors who have published 157 publications receiving 3527 citations.

Determination of Antioxidant Activity of Marshmallow Flower (Althaea officinalis L.)

Abstract: The antioxidant properties of marshmallow (Althaea officinalis L., Fam. Malvaceae) ethanolic extract was evaluated using different antioxidant tests, including reducing power, free radical scavenging, superoxide anion radical scavenging, and metal chelating activities. The extract of marshmallow (A. officinalis L.) exhibited strong total antioxidant activity. The concentration of 50, 100, and 250 µg/mL of ethanol extract of marshmallow (A. officinalis L.) showed 85.5%, 91.2%, and 96.4% inhibition on peroxidation of linoleic acid emulsion, respectively. On the other hand, 100 µg/mL of standard antioxidant such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and α‐tocopherol exhibited 94.5%, 99.1%, and 80% inhibition on peroxidation of linoleic acid emulsion, respectively. The extract of marshmallow (A. officinalis L.) had effective reducing power, free radical scavenging, superoxide anion radical scavenging, and metal chelating activities at same concentration (50, 100, and 250 ...

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) lyase deficiency in Saudi Arabia.

Abstract: Deficiency of 3-hydroxy-3-methylglutaryl-CoA lyase has been studied in 11 Saudi infants. The diagnosis was established by the measurement of enzyme activity in lymphocytes, in fibroblasts and, in seven patients, by the gas chromatography/mass spectrometer pattern of excreted organic acids in the urine. In seven infants the disease caused a devastating acidotic attack within the first day of life, while in two the crisis occurred by the third day of life. In two infants from one family the disease appeared later in infancy. The clinical presentation of an acidotic attack is lethargy, hyperpnoea, tachypnoea and seizures, either at birth (two infants), following first feeding (in five infants), or following vomiting or refusal of food in later infancy. The acidotic attacks recurred later in life following minor illness or refusal to eat. The acidosis of this enzyme deficiency progresses rapidly, leading to cardiopulmonary arrest and death within hours of onset unless treated promptly. In four surviving infants diagnosed and treated early, development is normal. Magnetic resonance and computerized tomography brain scans in these infants, however, show white matter lesions and mild atrophy.

Recent Developments and Applications of Chemiluminescence Sensors

Abstract: Chemiluminescence sensors are important tools in analytical chemistry due to their high sensitivity selectivity. This review presents the instrumentation involved in their design, including light detection and flow injection analysis system used. Various applications for the analysis of inorganic and organic compounds from gaseous samples and solutions indicate that these sensors are used with good reproducibility and selectivity of the analytes at low concentration level.

Chiral derivatization reagents for drug enantioseparation by high-performance liquid chromatography based upon pre-column derivatization and formation of diastereomers: enantioselectivity and related structure

Abstract: Structures and related enantioselectivities of the respective chiral derivatization reagents (CDRs) for drug enantioseparation by high-performance chromatography based upon pre-column derivatization and diastereomeric formation are reviewed. The elution order of diastereomers caused reaction of some CDRs with enantiomeric amino acids and carboxylic acids. The development of new CDRs available for indirect HPLC methods is also discussed. Copyright © 2001 John Wiley & Sons, Ltd. Abbreviations used: ABD-APy 4-(aminosulfonyl)-7-(3-aminopyrrolidin-1-yl)-2,1,3-benzoxadiazole Ace-L-Cys N-acetyl-L-cysteine Ace-D-Pen N-acetyl-D-penicillamine AITC 2,3,4-tri-O-acetyl-α-D-arabinopyranosyl isothiocyanate AEA 1-(1-anthryl)ethylamine or 1-(2-anthryl)ethylamine APH 2-amino-7-phosphonoheptanoic acid APB 2-amino-4-phosphonobutanoic acid APV 2-amino-5-phosphonvaleric acid APMB 2-[4-(1-aminoethyl)phenyl]-6-methoxybenzoxazole Boc-L-Cys N-tert-butoxycarbonyl-L-cysteine Bz-L-Cys N-benzoyl-L-cysteine But-But tert-butyl 3-(chloroformoxy)butyrate BZOP-Cl benoxaprofen chloride BEIT 1-(2-naphthyl)ethyl isothiocyanate BGIT 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate CAZT-Ala-NH2 N2-[2-(4-chloro-6-(4-phenylazoanilino)-1,3,5-triazinyl)]-L-alanine amide 2-Chl-L-ISMN 2-chlorocarbonyl-L-isosorbide 5-mononitrate 5-Chl-L-ISMN 5-chlorocarbonyl-L-isosorbide 2-mononitrate 5-Chl-L-IMMN 5-chlorocarbonyl-L-isomannide 2-mononitrate 5-Chl-L-ISMA 5-chlorocarbonyl-L-isosorbide 2-monoacetate CMNT-Ala-NH2 N2-[2-(4-chloro-6-(4-methoxy-1-naphthyl)-1,3,5-triazinyl)]-L-alanine amide CMOT-Ala-NH2 N2-[2-(4-chloro-6-methoxy-1,3,5-triazinyl)]-L-alanine amide CNOT-Ala-NH2 N2-[2-(4-chloro-6-(2-naphthoxy)-1,3,5-triazinyl)]-L-alanine amide DATAAAN (R,R)-O,O-diacetyl tartaric acid anhydride DBOSAAN (R,R)-O,O-dibenzyl tartaric acid anhydride DBTAAN (R,R)-O,O-dibenzoyl tartaric acid anhydride DEOSAAN (R,R)-O,O-diethyl tartaric acid anhydride DMTAAN (R,R)-O,O-dimethyl tartaric acid anhydride DTTAAN (R,R)-O,O-di-p-toluoyl tartaric acid anhydride DANE 1-(4-dimethylamino-1-naphthyl)ethylamine DBD-Apy 4-(N,N-dimethylaminosulfonyl)-7-(3-aminopyrrolidin-1-yl)-2,1,3-benzoxadiazole DBD-CO-Hz N-hydra-zinoformylmethyl-N-methylamino-4,4-N,N-dimethylamino sulphonyl-2,1,3-benzoxadiazole DBD-Pz 4-N,N-dimethylamino sulphonyl-7-piperazino-2,1,3-benzoxadiazole DBD-Pro 4-(2-carboxypyrrolidin-1-yl)-7-(N,N-dimethylamino-sulphonyl)-2,1,3-benzoxadiazole DBD-N-Me-Ala 4-(N-1-carboxyethyl-N-methyl)amino-7-N,N-dimethylamino-2,1,3-benzoxadiazole DBD-Pro-COCl 4-(N,N-dimethyl aminosulfonyl)-7-(2-chloroformylpyrrolidin-1-yl)-2,1,3-benzoxadiazole DBD-PyNCS 4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole ECF 1-(cyclohexyl)ethyl chloroformate Eth-But ethyl 3-(chloroformoxy)butyrate FLEC (+)-1-(9-fluorenyl)ethyl chloroformate FLOP-Cl flunoxaprofen chloride FDNP-Ala-NH2 N2-(5-fluoro-2,4-dinitrophenyl)-L-alanine amide FDNP-Phe-NH2 N2-(5-fluoro-2,4-dinitrophenyl)-L-phenylalanine amide FDNP-Pro-NH2 N2-(5-fluoro-2,4-dinitrophenyl)-L-proline amide FAZT-Ala-NH2 N2-[2-(4-fluoro-6-(4-phenylazoanilino)-1,3,5-triazinyl)]-L-alanine amide FMOC-L-Pro 9-fluorenylmethyl chloroformate-L-proline FMOC-L-Phe 9-fluorenylmethyl chloroformate-L-phenylalanine FLOPIC flunoxaprofen isocyanate FDNP-Val-NH2 N2-(5-fluoro-2,4-dinitrophenyl)-L-valine amide GITC 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate i-But-L-Cys N-isobutanoyl-L-cysteine i-Val-L-Cys N-isovaleroyl-L-cysteine LA leucinamide methy-BNCC 2′-methyl-1,1′-binaphthalene-2-carbonyl cyanide MCF (−)-methyl chloroformate Me-But methyl 3-(chloroformoxy) butyrate MDL methylated N ϵ -dansyl-L-lysine MDNE-OTf 1-methyl-2-(6,7-dimethoxy-2,3-naphthalimido)ethyl trifluoromethane sulfonate methoxy-BNCC 2′-methoxy-1,1′-binaphthalene-2-carbonyl cyanide MeDAP 2-amino- ω - phosphonoalkanoic acid MNE-OTf 1-methyl-2-(2,3-naphthalimido)ethyl trifluoromethane sulfonate n-But-L-Cys N-butanoyl-L-cysteine NBD-Pro 4-(2-carboxypyrrolidin-1-yl)-7-nitro-2,1,3-benzoxadiazole N-AA N-[2-(chloroformoxy)propyl]acetamide NBD-N-Me-Ala 4-(N-1-carboxyethyl-N-methyl)-amino-7-nitro-2,1,3-benzoxadiazole NBD-Pro-COCl 4-(2-chloroformylpyrrolidin-1-nyl)-7-nitro-2,1,3-benzoxadiazole NAP-IC 1-(6-methoxy-2-naphthyl)ethyl isocyanate NAP-IT 1-(6-methoxy-2-naphthyl)ethyl isothiocyanate NEIT 1-(1-naphthyl)ethyl isothiocyanate NEIC 1-(1-naphthyl)ethyl isocyanate NBD-PyNCS 4-(3-isothiocyanatopyrrolidin-1-yl)-7-nitro-2,1,3-benzoxadiazole NEA 1-(1-naphthyl)ethylamine NBD-APy 4-nitro-7-(3-aminopyrrolidin-1-yl)-2,1,3-benzoxadiazole NPSP-Cl 4-nitrophenylsulfonyl-(s)-prolyl chloride β-ODAP ω-N-oxalyl derivative of L-α, β-diaminopropanoic acid γ-ODAB ω-N-oxalyl derivative of L-α, γ-diminobutanoic acid δ-OORN ω-N-oxalyl derivative of orinithine ϵ-OLYS ω-N-oxalyl derivative of lysine PEA 1-phenylethylamine PEIC 1-phenylethyl isocyanate PEIT 1-phenylethyl isothiocyanate PAA phenyl alanine amide PAME phenyl alanine methyl ester PGIT 2,3,4,6-tetra-O-pivaloyl-β-D-galactopyranosyl isothiocyanate Pro-L-Cys N-propanoyl-L-cysteine Tma-L-Cys N-trimethylacetyl-L-cysteine TFCF tetrahydro-3-furanyl chloroformate Val-L-Cys N-valeroyl-L-cysteine

Determination of chiral ratio of o,p-DDT and o,p-DDD pesticides on polysaccharides chiral stationary phases by HPLC under reversed-phase mode.

Abstract: A simple and reliable HPLC method for the chiral resolution of o,p-DDT and o,p-DDD is described. The enantiomeric resolution of o,p-DDT and o,p-DDD has been achieved on Chiralpak AD-R, Chiralcel OD-R, and Chiralcel OJ-R chiral stationary phases. The mobile phases used were acetonitrile-water (50:50 [v/v]) and acetonitrile-2-propanol (50:50 [v/v]) at a flow rate of 1.0 mL/min. For both pesticides detection was done at 220 nm. The values for o,p-DDT of alpha and R(s) varied from 1.24 to 2.52 and from 0.80 to 2.47, respectively. The values of alpha and R(s) for o,p-DDD were 1.26 and 0.60, respectively.