chromatographic technique
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2021 ◽  
Vol 66 (1) ◽  
Author(s):  
Abimael López-Pérez ◽  
Jesús Hernández Juárez ◽  
Rodolfo Solano ◽  
Pedro Antonio Hernández Cruz ◽  
Luicita Lagunez-Rivera

Abstract. Laelia furfuracea is an endemic orchid from Mexico, with antioxidant activity. The objective of this study was to evaluate the effect of hydroethanolic extract and fractions obtained from the orchid leaves on the clotting times of patients with venous thromboembolic disease (VTD) and to identify their tentative compounds. The anticoagulant activity was evaluated by determining prothrombin (PT), thrombin (TT) and, activated partial thromboplastin (APTT) times. Identification of the compounds was carried out using a chromatographic technique with an ultra-high-performance liquid chromatographic analyzer coupled with electrospray ionization with quadrupole time of flight-mass-mass spectrometry. The extract prolonged the clotting times depending on the concentration-response (5-60 mg / mL); 25 mg/mL prolonged the PT (33.2 ± 2.3 s) and TT (33.1 ± 0.3 s); and APTT (61.8 ± 3.4 s) at a concentration of 15 mg/mL. The main groups tentatively identified were xanthine, carboxylic acid, amino acid, and phenolic compounds. These compounds or the synergy between them prolong clotting times. Laelia furfuracea is an orchid with research potential in the search for new anticoagulant agents.   Resumen. Laelia furfuracea es una orquídea endémica de México, la cual posee actividad antioxidante. El objetivo de este estudio fue evaluar el efecto del extracto hidroetanólico y fracciones obtenidas de hojas de la orquídea sobre los tiempos de coagulación de pacientes con enfermedad tromboembólica venosa (ETV) e identificar sus posibles compuestos. La actividad anticoagulante se evaluó determinando los tiempos de protrombina (TP), trombina (TT) y tromboplastina parcial activada (TTPA). La identificación de los compuestos se realizó usando una técnica cromatográfica con un analizador cromatográfico líquido de Ultra Alta Resolución con Ionización por electroespray acoplado a espectrometría de masas con Cuadrupolo y Tiempo de Vuelo. El extracto prolongó los tiempos de coagulación dependiente de la concentración-respuesta (5-60 mg/mL); 25 mg/mL prolongó el TP (33.2±2.3 s) y TT (33.1±0.3 s); y TTPA (61.8±3.4 s) a una concentración de 15 mg/mL. Los principales grupos de posibles compuestos identificados fueron xantina, ácido carboxílico, aminoácido y compuestos fenólicos. Estos compuestos o la sinergia entre ellos prolongan los tiempos de coagulación. Laelia furfuracea es una orquídea con potencial en investigación para la búsqueda de nuevos agentes anticoagulantes.


Separations ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 243
Author(s):  
Adel Ehab Ibrahim ◽  
Sami El Deeb ◽  
Emad Mahmoud Abdelhalim ◽  
Ahmed Al-Harrasi ◽  
Rania Adel Sayed

A green liquid chromatographic method is considered in this work to minimize the environmental impact of waste solvents. One important principle is to replace or eliminate the use of hazardous organic solvents. Organic impurities in any active pharmaceutical ingredient could arise either during the process of its synthesis, or as degradation products developed throughout the shelf-life. Remdesivir (RDS) is an antiviral drug, approved by the US Food and Drug Adminstration (-FDA), to treat SARS-Cov-2 virus during its pandemic crisis. We studied the stability of remdesivir against several degradation pathways using the organic solvent-free liquid chromatographic technique. Separation was performed on RP-C18 stationary phase using mixed-micellar mobile phase composed of a mixture of 0.025 M Brij-35, 0.1 M sodium lauryl sulfate (SLS), and 0.02 M disodium hydrogen phosphate, adjusted to pH 6.0. The mobile phase flow rate was 1 mL min−1, and detection was carried out at a wavelength of 244 nm. We profiled the impurities that originated in mild to drastic degradation conditions. The method was then validated according to International Conference of Harmonization (ICH) guidelines within a linearity range of 5–100 μg mL−1 and applied successfully for the determination of the drug in its marketed dosage form. A brief comparison was established with reported chromatographic methods, including a greenness assessment on two new metrics (GAPI and AGREE). This study is the first to be reported as eco-friendly, solvent-free, and stability indicating LC methodology for RDS determination and impurity profiling.


Author(s):  
K. Bhavya Sri ◽  
G. Sri Vani Shailaja ◽  
Mogili. Sumakanth

The birth of two-dimensional gas chromatography is assumed to be the ninetieth year of the last century. Two-dimensional gas chromatography is a rapidly developing analytical technique. GCxGC is a truly hyphenated chromatographic technique which employs a pair of GC column. GCxGC analyses, such as the identification of trace compounds that would not be perceived by 1D-GC. The use of 2D-GC compared to that of 1D-GC has been discussed. The paper presents the introduction, principle of operation, working, uses, application, case studies has been discussed.


2021 ◽  
Author(s):  
Shanzay Saleem ◽  
Mehreen Sarfraz ◽  
Zohaib Ahmad ◽  
Nuzhat Munawar ◽  
Zeeshan Rehman ◽  
...  

Abstract Background and AimsThe importance of L-lysine as an essential amino acid in the nutrition of human beings has made it desirable supplement of the diet in recent years. It can be produced in different ways among them fermentation is the most economical and practical means of producing lysine. In this method low temperature, low pressure and low-cost carbon sources are used and a biological form of lysine (L-lysine) is produced. MethodsIn the present study, the production of L-lysine was achieved through fermentation developed from locally isolated bacterial strains. In total, twenty-nine (29) bacterial strains were isolated and tested using paper chromatographic technique. Six different parameters for optimization were scrutinized for improved bacterial growth and significant yield of lysine was obtained using selected strains.Key ResultsFor Streptococcus sp. molasses media with vitamins (w) formed 24.4 g/L, 40º C generated 24.4 g/L, addition of 1mM solution of metal ion (Mg) yielded 20.4 g/L, pH 6.5 delivered 6 g/L, fermentation period of 96 hours engendered 24.4 g/L, and 0.3 mL of inoculum results in 9.2 g/L of lysine. ConclusionsLaboratory scale production of L-lysine was carried out using 1 L Erlenmeyer flask. For Streptococcus sp. 23.4 g/L of lysine was produced after optimized conditions.


2021 ◽  
Vol 11 (5-S) ◽  
pp. 57-62
Author(s):  
Basant Lal ◽  
Manish Jaimini ◽  
Devesh Kapoor

New liquid chromatographic technique was established for the simultaneous estimation of tinidazole, omeprazole and amoxicillin in the fixed dose combination (HP-KIT by Sun Pharma). RP-HPLC elution has performed by using the Phenomenex Luna column (250 mm x 4.6 mm) having internal diameter and the packing material of size 5µm) in isocratic mobile phase of solution A: acetonitrile at a ratio of 80:20 v/v (Solution A consists of Buffer: Acetonitrile: Methanol: Triethylamine in the ratios of 68:22:10:0.01 respectively). The selected flow rate was kept as 1 ml/min and selected wavelength was 230 nm was for detection of the drugs in UV detector. As per the ICH guidelines, the method validation was carried out. Moreover, the different parameters of method such as precision, specificity, linearity, robustness and accuracy were established. The time of retention for the tinidazole, amoxicillin, and omeprazole were 4.021 2.324, and 7.332 minutes respectively. The RP-HPLC approach was robust and accurate, so it is appropriate for repetitive assay of drugs and quality control. This method is effectively used for the assessment of marketable dosage form preparation. Keywords: RP-HPLC, Amoxicillin, Tinidazole, Omeprazole, Method Development, Method Validation.


2021 ◽  
pp. 100010
Author(s):  
Priyanka Pahade ◽  
Devasish Bose ◽  
Juan Peris-Vicente ◽  
Samuel Carda-Broch ◽  
Abhilasha Durgbanshi

2021 ◽  
Vol 1 (2) ◽  
pp. 39-44
Author(s):  
Olivier Ndogo Eteme ◽  
Nkwengoua Tchouboun Zondegoumba Ernestine ◽  
Soh Desire ◽  
Oladimeji Taiwo Babatunde ◽  
Barthelemy Nyasse

Background: Prolyl oligopeptidase is a cytosolic serine peptidase that hydrolyzes peptides containing proline at the carboxy terminus of proline residues. It has been associated with several neurodegenerative diseases. Therefore, it is a target in the management of these disease conditions. Methods: Allexis obanensis was taken through cold extraction, subjected to column chromatography and flavonoids isolated via high-performance liquid chromatographic technique. The flavonoids obtained were investigated for their in vitro prolyl oligopeptidase inhibitory activity. Results: The flavonoids isolated include: 4.4'''- dimethoxylophirone A [1] and 7-hydroxy-3-(3-hydroxy-4 méthoxyphenyl)-5- méthoxy-4H chromen-4-one [2]. They inhibited prolyl oligopeptidase at low IC50 concentrations of 7.201±3.021 µM and 6.223±2.002 µM respectively. Conclusion: The results obtained from this study proves the potential of these flavonoids as prolyl oligopeptidase inhibitors, by inference, their potentiality in the management of neuropsychiatric disorders.


Author(s):  
Suman Acharyya ◽  
Si, Abhik ◽  
H. K. Sundeep Kumar

The present research provides a new proven ultra-high-performance liquid chromatographic technique for isavuconazole in both bulk and capsule dosage forms. DIKMA Waters BEH C18(50 x 2.6mm, 1.7m) column was used for chromatographic separation. With the isocratic elution mode, a mixture phosphate buffer: methanol 40:60 v/v, was used as the mobile phase, and the eluent was measured at 253 nm using a UV detector. The strategy has been maintained and validated in accordance with the International Conference on Harmonization Guidelines. Stressed deterioration has also been investigated in acidic, alkaline, peroxide, thermal, and photolytic conditions. Isavuconazole was eluted with the retention time 0.861 minute in this procedure. The calibration curve plots for isavuconazole were found to be linear within the concentration ranges of 1-25µg/mL. With a percentage recovery of 100.18 percent, the limit of detection was 0.025g/ml and the value for limit of quantification was 0.50µg/mL. In a force degradation analysis, the current approach was also determined to be stable. Based on the experiential evidence, the present method was found appropriate of isavuconazole estimation in the form of bulk and capsule.


2021 ◽  
Vol 16 (9) ◽  
pp. 1934578X2110421
Author(s):  
Khan Viet Nguyen ◽  
Thu Oanh Thi Nguyen ◽  
Duc Viet Ho ◽  
Jyrki Heinämäki ◽  
Ain Raal ◽  
...  

Knowledge of the bioactivity of Alphonsea tonkinensis A.DC is limited. We have investigated the in vitro acetylcholinesterase inhibitory and antioxidant activities of extracts and pure compounds isolated from stems and leaves of this species collected from Dakrong district, Quang Tri Province, Vietnam. Extracts and isolated compounds were obtained by using an in-house extraction and chromatographic technique. The in vitro acetylcholinesterase inhibitory and antioxidant activities were evaluated using an Ellman test and 2,2-diphenyl-1-picryl-hydrazyl test, respectively. The total MeOH and CH2Cl2 extracts, the MeOH portion of the CH2Cl2 extract, pseudocolumbamine, and pseudopalmatine showed potential inhibitory activity against acetylcholinesterase with IC50 values of 22.7, 32.9, 14.6, 18.9, and 8.6 μM, respectively. The aqueous phase (pH 9), MeOH portion of the CH2Cl2 extract, and N- trans-feruloyltyramin exhibited significant antioxidant activities with IC50 values of 24.5, 72.1, and 61.2 µM, respectively. This is the first study showing such bioactivities of various extracts obtained from A. tonkinensis.


2021 ◽  
Vol 25 (9) ◽  
pp. 79-88
Author(s):  
Suresh Gandi ◽  
Manikandan Ayyar ◽  
Venkat Rao Sirugubattula

A fast, precise, accurate and steady isocratic liquid chromatographic technique was created for the synchronous assurance of the Emtricitabine, Darunavir, Tenofovir and Cobicistat in bulk and in formulation. To optimize a column HSS C18 100 x 2.1 mm, 1.8mm, mobile phase including Buffer 0.01N KH2PO4(5.4pH): Acetonitrile pick in the proportion 60:40v/v was pumped through column at a flow rate of 0.3 ml/min at 260nm. The retention times of Emtricitabine, Darunavir, Tenofovir and Cobicistat were initiated to be 1.066 min, 1.727 min, 2.574 min and 2.977 min. % recovery was 99.75%, 100.05%, 100.42% and 100.59% for Emtricitabine, Darunavir, Tenofovir and Cobicistat respectively. LOD and LOQ values got from relapse formula of Emtricitabine, Darunavir, Tenofovir and Cobicistat and were 0.18, 0.54, 0.71,2.14, 0.01,0.05 0.44 and 1.32 correspondingly. Relapse equation of Emtricitabine is y = 13375x + 2577.4, for Darunavir it is y = 7196.3x + 2981.2, for Tenofovir it is y = 66663x + 1338.9 and y = 22723x + 6978.7 for Cobicistat.


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