Characterization and distribution of bombesin-like peptides in the rat brain and gastrointestinal tract

1990 ◽  
Vol 68 (9) ◽  
pp. 1142-1145 ◽  
Author(s):  
Angel Hernanz
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Gastrointestinal Tract ◽  
Rat Brain ◽  
Retention Time ◽  
High Performance ◽  
Reverse Phase ◽  
Whole Brain ◽  
Gastrin Releasing Peptide ◽  
Peptide Peak

Extracts of rat brain and gastrointestinal tract, analyzed by reverse-phase high-performance liquid chromatography and radioimmunoassay, contained two bombesin-like immunoreactivity peaks with similar retention times as porcine gastrin-releasing peptide (GRP) and its COOH-terminal decapeptide, neuromedin C or GRP(18–27). However, the GRP-like peptide peak did not elute with exactly the same retention time as porcine GRP. The highest concentration of bombesin-like immunoreactivity was found in extracts of antrum, whereas the lowest was found in whole brain. Neuromedin C was present at lower concentrations than the GRP in antrum, duodenum, and ileum, while similar amounts of each were found in brain.Key words: gastrin-releasing peptide, neuromedin C, rat, brain, intestine.

Fractionation of bovine caseins by reverse phase high performance liquid chromatography: identification of a genetic variant

1986 ◽  
Vol 53 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Christophe Carles
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Genetic Variant ◽  
Sodium Dodecyl ◽  
Reverse Phase ◽  
Peptide Peak ◽  
Rp Hplc ◽  
Main Components ◽  
Two Peaks

SUMMARYSamples of reduced whole casein from genetically typed individual cows were quantitatively separated into their main components, αsl-, αs2-, β- and κ-caseins by reverse phase high performance liquid chromatography (RP-HPLC) using a mobile phase of phosphate-buffered aqueous propan-2-ol containing sodium dodecyl sulphate and an octadecylsilyl stationary phase. One casein sample was found to give two peaks of β-casein of approximately equal areas. RP-HPLC of tryptic digests of the two separated peak fractions gave identical patterns with the exception of one peptide peak with different retention times. Amino acid analyses performed on both fractions showed that they corresponded to peptide 114–169 of β-casein A1. The atypical β-casein differed from the typical one by a Pro→Leu substitution in region 114–169.

scholarly journals Reverse-phase High-Performance Liquid Chromatography Method Development and Validation for Estimation of Glimepiride in Bulk and Tablet Dosage Form

2020 ◽  
Vol 11 (02) ◽  
pp. 296-302
Author(s):  
Aseem Kumar ◽  
Anil Kumar Sharma ◽  
Rohit Dutt
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Flow Rate ◽  
Retention Time ◽  
Mobile Phase ◽  
High Performance ◽  
Hplc Method ◽  
Reverse Phase ◽  
Rp Hplc ◽  
Development And Validation

The present work demonstrates a simple, rapid, precise, specific, and sensitive reverse-phase high-performance liquid chromatography (RP-HPLC) method for analyzing glimepiride in pure and tablet forms. The present method was developed using a C18 column 150 × 4.6 mm, with 5 μm, and packing L1 maintained at a temperature of 30°C. The mobile phase was prepared by dissolving 0.5 gram of monobasic sodium phosphate in 500 mL of distilled water, pH of the solution adjusted to 2.1 to 2.7 with 10% phosphoric acid, and added 500 mL of acetonitrile. The mobile phase was pumped in the highperformance liquid chromatography (HPLC) system at a flow rate of 1 mL/min, and separation was carried out at 228 nm, using an ultraviolet (UV) detector. The chromatographic separation was achieved with peak retention time (RT) at about 9.30 minutes, and the method was found to be linear over a concentration range of 40 to 140 μg/mL. The specificity of the method represented no interference of the excipients during the analysis, and stability testing after 24 hours also showed that the method is suitable and specific. The accuracy was between 99.93 to 99.96%, with limit of detection (LOD) and limit of quantitation (LOQ) being 0.354 μg/mL, 1.18 μg/mL, respectively. Satisfactory results were found for precision and robustness parameters during the development and validation stage for the analytical method. The proposed method was also adopted for the analysis of glimepiride tablets to improve the overall quality control. Using this method, symmetric peak shape was obtained with reasonable retention time. The retention time of glimepiride for six repetitions is 9.3 ± 0.1 minutes; the run time is 21 minutes. The proposed RP-HPLC method is a modification of the United States Pharmacopeia (USP) method, and it was found to be valid for glimepiride within concentration ranges 40 to 140 μg/mL, using C18 analytical columns, and isocratic elution with UV detection, and at 1 mL/min of flow rate.

Separation and purification of individual neurofilament proteins by reverse-phase high-performance liquid chromatography

1986 ◽  
Vol 153 (2) ◽  
pp. 230-234 ◽  
Author(s):  
Koon-Sea Hui ◽  
Maria Hui ◽  
Fung-Chow Chiu ◽  
Miriam Banay-Schwartz ◽  
Teresita Deguzman ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Separation And Purification ◽  
Neurofilament Proteins ◽  
Reverse Phase
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