China
Africa
Explore chapters and articles related to this topic
Approaches for Identification and Validation of Antimicrobial Compounds of Plant Origin: A Long Way from the Field to the Market
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Lívia Maria Batista Vilela, Carlos André dos Santos-Silva, Ricardo Salas Roldan-Filho, Pollyanna Michelle da Silva, Marx de Oliveira Lima, José Rafael da Silva Araújo, Wilson Dias de Oliveira, Suyane de Deus e Melo, Madson Allan de Luna Aragão, Thiago Henrique Napoleão, Patrícia Maria Guedes Paiva, Ana Christina Brasileiro-Vidal, Ana Maria Benko-Iseppon
Ion exchange chromatography, affinity and molecular exclusion are efficient in promoting the purification of active proteins because they explore structural characteristics such as charge, biospecificity and size without promoting denaturation (Feng et al. 2021; Benedini et al. 2019). Reverse-phase chromatography is advisable only for small molecules such as AMPs since the hydrophobic matrix and organic eluents used can result in the denaturation of larger proteins by the interaction with nonpolar amino acid residues (Feng et al. 2021). The reverse-phase procedure that separates based on hydrophobicity and uses denaturation conditions is used to determine the impurity profile and prepare samples for mass spectrometry (Soares et al. 2011).
High-Performance Liquid Chromatography
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Joel J. Kirschbaum, Adorjan Aszalos
Sulfaquinoxaline in animal tissues was determined using a silica column and a mobile phase of n-hexane-n-hexane saturated with water-chloroform-acetonitrile-methanol-25% (w/v) ammonia (36:30:15:14.5:4.5:0.05), flowing at 0.83 ml/min, with detection at 254 nm [350], The limit of detection was 1.2 ng per injection. In this same paper, reversed-phase chromatography was performed using an octadecylsilane column and a mobile phase of 0.01 M ammonium carbonate-methanol (90:10) also flowing at 0.83 ml/min through a 254 nm detector.
Peptide Separation by Reverse-Phase High-Performance Liquid Chromatography
Published in Roger L. Lundblad, Chemical Reagents for Protein Modification, 2020
The original expectation in development of HPLC was that existing thin-layer and column chromatographic separation methods would be transferred to columns packed with small, uniform-sized, rigid particles. This implied a stationary phase of unmodified silica. However, the retention properties of a silica surface are very sensitive to moisture levels. Elution times may be difficult to reproduce, and long column equilibration times may be required following solvent changes. Attempts to improve reproducibility of retention properties by masking the surface silanol groups led to the development of packing materials having covalently bonded surface phases. The most successful of these have been the so-called C-18 or ODS (octadecylsilyl) packings, which have 18-carbon hydrocarbon chains bonded to the surface silanols. The use of these and other hydrophobic bonded-phase packings is known as “reverse-phase” chromatography because the stationary phase is nonpolar and the mobile phase polar, which happens to be the reverse of most older methods of partition liquid chromatography.
Serum Concentrations of Carotenoids and Fat-Soluble Vitamins in Relation to Nutritional Status of Patients with Ovarian Cancer
Published in Nutrition and Cancer, 2021
Katarzyna M. Terlikowska, Bozena Dobrzycka, Maciej Kinalski, Slawomir J. Terlikowski
Decreased concentrations of individual serum fat-soluble vitamins are commonly diagnosed in a wide range of diseases. The obtained results demonstrate interactions between vitamins and antioxidants, however, simultaneous quantity measurement of these substances using one method tends to be highly complicated, specifically when it comes to vitamin A and D together. Several methods have been proposed for the separation of hydrophobic vitamins and carotenoids in different biological matrices. These methods are mainly based on reversed-phase chromatography (HPLC). In the present study, we used an innovative procedure based on the efficient fat-soluble vitamin and carotenoids extraction from OC patients’ serum – as previously mentioned, our method is based on the method described by Lazarrino et al. (15).
Cardiac extracellular matrix modulation in a rat-diabetic model: biochemical and anti-oxidant beneficial effect of pomegranate (Punica granatum) peel extract
Published in Biomarkers, 2022
Houcine Dab, Amel Chehidi, Mounira Tlili, Anwar Ben Saad, Abdelmajid Khabir, Lazhar Zourgui
HPLC analyses of PP ethanolic extract were performed using a Varian ProStar HPLC System (Varian 330/Vis Detector and Varian 230 SDM) (Saad et al.2016). A reverse-phase chromatography performed under gradient conditions with C18 column (4.6 mm × 250 mm) was used. The solvent system used was A: acetic acid at 2% in water and solvent B: 40% acetonitrile, 2% acetic acid, and 58% water. The gradient was composed of 0–80% B for 25 min, 80–100% B for 10 min and 100–0% B for 5 min. The extract was utilised in the concentration of 1 mg/mL. The flow rate was 0.8 mL/min and the volume injected was 40 μL. Retention times and peak areas (λmax = 254 nm) for sample and standard were detected and compared by the use of DAD spectra (200–600 nm).
Meta-inhibition of ocular and gastrointestinal dysfunctions by phenolic-rich fraction of Croton zambsicus leaves in a rat model exposed to chronic mixed metals
Published in Cutaneous and Ocular Toxicology, 2021
J. K. Akintunde, O. R. Omoniyi, O. E. Folorunsho, C. A. Moses
High pressure liquid chromatography (HPLC) was used to quantify the phenolic compound in Croton zambiscus leaves. Reverse phase chromatography analyses were examined under gradient environments using a C18 column (4.63 150 mm) and a mobile phase following our previous method25. Shimadzu Prominence Auto Sampler (SIL-20A) HPLC system (Shimadzu, Kyoto, Japan), equipped with Shimadzu LC-20AT reciprocating pumps connected to a DGU 20A5 degasser with a CBM 20 A Integrator, SPD-M20A diode array detector and LC solution 1.22 SP1 software was used for the analysis. The limit of detection (LOD) and limit of quantification (LOQ) were considered based on the standard deviation of the responses.