Conjugation and Other Methods in Polymeric Vaccines
Mesut Karahan in Synthetic Peptide Vaccine Models, 2021
Chromatography is known as an important biophysical technique that can separate, identify, and purify the blend segments for subjective and quantitative investigation. Proteins can be purified based on properties such as size and shape, total charge, hydrophobic groups present on the surface, and the ability to bind to the stationary phase. It is based on molecular properties and interaction type use mechanism, four separation technologies, ion exchange, dispersion, surface adsorption, and size exclusion. Column chromatography is one of the most used and common techniques for protein purification methods. This technique is basically used to purify biological molecules. The application of the method can be summarized as follows. The sample is separated on the column (stationary phase) and then the wash buffer is added to the column (mobile phase). It flows through the column material placed on the fiberglass support. With the help of the wash buffer, the samples are accumulated at the bottom of the column chromatography instrument, based on time and volume (Coskun 2016). Column chromatography is a powerful purification and separation process that is closely controlled to the hydrodynamic diameters of the macromolecules depending on the diameter of the pores in the filling material (see in HPLC Method) (Acar 2006; Fornaguera and Solans 2018).
Drug Design, Synthesis, and Development
Nathan Keighley in Miraculous Medicines and the Chemistry of Drug Design, 2020
Once the synthesis of a drug is complete, the compound is not yet ready for consumption. Thorough purification steps are required to clean the organic compound. Chromatography is a commonly adopted technique for separating a target compound from the rest of the matrix. In chromatography, the column is packed with a solid stationary phase consisting of very fine particles and a solvent is selected, referred to as the mobile phase, in which the target compound dissolves. The desired target product will have a different affinity for the stationary phase than any by-products or unreacted material, and therefore will have different retention times on the column. The product elutes from the column at a different time to the contaminants, so can be isolated. The greater the length of the column, the greater the degree of separation, as in the case of high-performance liquid chromatography (HPLC) and gas chromatography (GC), used for volatile compounds, and even separation of stereoisomers is possible.
Quality Control of Ayurvedic Medicines
D. Suresh Kumar in Ayurveda in the New Millennium, 2020
Shifts in chromatographic retention time interfere with fingerprint analysis. They are caused by successive degradation of the stationary phase, minor changes in the composition of the mobile phase, detector and other instrumental shifts, column overloading or interactions between analytes. To avoid erroneous results, these shifts need to be corrected before the evaluation of similarities and differences between chromatograms (Li et al. 2004a; Liang et al. 2004; Wenzig and Bauer 2009). Peak synchronization is achieved by several methods. A useful method is the addition of an internal standard (Liang et al. 2004). Retention time can be corrected mathematically using local least square analysis or spectral correlative chromatography (Li et al. 2004b; 2004c).
Therapeutic effects of Bombax ceiba flower aqueous extracts against loperamide-induced constipation in mice
Published in Pharmaceutical Biology, 2023
Liuping Wang, Shiyuan Xie, Xuan Jiang, Caini Xu, Youqiong Wang, Jianfang Feng, Bin Yang
In this study, the base peak chromatogram obtained is illustrated in Figure 1. The samples in negative ion mode showed stronger peak signals and rich mass information, so the peaks in negative ion mode we analysed to identification of the chemical composition in BCE. Based on the retention times, molecular formula, the MS/MS data, reference standards and literature data, 12 compounds were identified which include: protocatechuic acid, 1-caffeoylquinic acid, 5-coumaroylquinic acid, neochlorogenic acid, chlorogenic acid, 4-coumaroylquinic acid, 3-coumaroylquinic acid, clovamide, rutin, isoquercetin, quercetin 3-glucuronide and kaempferol-3-glucuronide (Table 2). Among them, three compounds, including protocatechuic acid, chlorogenic acid and rutin were unambiguously identified by comparing with the retention time and MS data of reference standards. In addition to the above compounds, some peaks of fatty acids were found in the chromatogram of BCE after 10 min.
GC-MS metabolites profiling of anethole-rich oils by different extraction techniques: antioxidant, cytotoxicity and in-silico enzymes inhibitory insights
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Dina M. El-Kersh, Nada M. Mostafa, Shaimaa Fayez, Tarfah Al-Warhi, Mohammed A. S. Abourehab, Wagdy M. Eldehna, Mohamed A. Salem
All oil samples (1 µl injection volume, 1% v/v) were analysed on a Shimadzu GCMS-QP 2010 (Kyoto, Japan) system coupled to a mass spectrometer (SSQ 7000 quadrupole; Thermo- Finnigan, Bremen, Germany) according to the methodology of El-Nashar et al.11 and Al-Sayed et al.12. The used column for separation of volatile components was RTX-5MS fused bonded column with specifications as follows (30 m × 0.25 mm i.d. × 0.25 μm film thickness). The initial oven temperature was kept at 50 °C for 3 min (isothermal) then programmed to reach 300 °C at 5 °C/minute for 5 min. Both the injector and detector temperatures were fixed at 280 °C, respectively. Helium was used as the carrier gas at a flow rate of 1.41 ml/min. A splitting ratio of 1:15 was employed. The mass spectra were recorded as per the following conditions: filament emission current was 60 mA, 70 eV was the ionisation voltage whereas the ion source was 220 °C. Identification of components was employed as per their Kovat index (KI) as well as their mass spectra where those data were compared to NIST, Adams13 and other literature data14,15. The KIs were calculated respective to a series of n-alkanes C8–C28 injected under the same GC conditions and compared to those data published in the literature. Each peak represents a volatile component, whereas its area is calculated as the relative percentage of the whole chromatogram area (100%).
Antibacterial activity of essential oils for combating colistin-resistant bacteria
Published in Expert Review of Anti-infective Therapy, 2022
Abdullah M. Foda, Mohamed H. Kalaba, Gamal M. El-Sherbiny, Saad A. Moghannem, Esmail M. El-Fakharany
The total ionization chromatogram showed that the retention time of the components ranged between 4 and 42 min, most of which were concentrated between 5 mins to 22 mins as in Figure 1(b). The retention index of the tested sample and its mass spectrum results were compared with those of standard libraries (NIST and Wiley) and the literature. The analyzed sample of cinnamon oil was found to contain 15 compounds represented as seven major compounds and eight minor ones according to the peak area percentages. The major compounds that are identified in cinnamon oil are benzaldehyde (2.34%), benzene acetaldehyde (1.56%), 3-phenyl propionitrile (4.27%), cinnamaldehyde (E)- (40.91%), 3-phenyl acrylaldehyde (8.70%), cinnamaldehyde dimethyl acetal (37.54%), and trans-cinnamic acid (1.49%). According to the literature, these compounds have different biological activities, such as antimicrobial, antioxidant, anti-inflammatory, anticancer, anti-leishmania, anti-Virulence, anti-acnes, and Insecticidal activities. The bioactive compounds are identified and their retention time, peak area, molecular weight, molecular formula, chemical structure, and biological activity are demonstrated in Table 6.
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