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Characterization of Phyto-Constituents
Published in Rohit Dutt, Anil K. Sharma, Raj K. Keservani, Vandana Garg, Promising Drug Molecules of Natural Origin, 2020
Himangini, Faizana Fayaz, Anjali
The perfect separation condition for the HPLC relies on pump pressures, different compositions of the mobile phases, pH modification, and so on. So as to accomplish the great division, a few new methods have been found in the research field of chromatography. Presently, recently created logical techniques like high-speed counter-current chromatography (HSCCC), electrokinetic capillary chromatography (MECC), low-pressure size exclusion chromatography (SEC), reversed-phase ion-pairing HPLC (RP IPC-HPLC), and strong anion-exchange HPLC (SAX-HPLC) are being used. In some examples, the examination of non-chromophoric mixes now shown by utilizing HPLC combined with evaporative light scattering detection (ELSD), is an extraordinary recognition strategy. This new detector focused just on the size, shape, and number of eluate particles rather ultraviolet detector helps in examination of chromophore or structure of constituent. Moreover, the subjective examination or structure illustration of the compound segments might be shown by utilizing hyphenated HPLC systems, for example, HPLC-IR, HPLC–MS, HPLC-NMR (Lazarowych et al., 1998; Li et al., 1999; Li et al., 2003)
Chemical Constituents of Ginseng Plants
Published in Joseph P. Hou, The Healing Power of Ginseng, 2019
Chemically, several differences exist between Asian ginseng and American ginseng. An important parameter used for this differentiation is the presence of ginsenoside Rf in Asian ginseng but pseudoginsenoside F11 in American ginseng. High-performance liquid chromatography–evaporative light scattering detector (HPLC-ELSD) or high-performance liquid chromatography–mass spectrometry (HPLC-MS) can be used to detect both F11 and Rf. In addition, ratios of Rg1/Rb1 and Rb2/Rb1 are useful. Both ratios less than 0.4 is indicative of American ginseng, while a high value of ratios is characteristic of Asian ginseng. One exception is wild American ginseng, which may have a high Rg1-to-Rb1 ratio.
Artemisia annua and Its Bioactive Compounds as Anti-Inflammatory Agents
Published in Tariq Aftab, M. Naeem, M. Masroor, A. Khan, Artemisia annua, 2017
Bianca Ivanescu, Andreia Corciova
Data from the relevant literature show that, for the analysis of A. annua compounds, generally, the reversed-phase column is used. The preferred mobile phase systems contain acetonitrile, water, acetic acid, and formic acid, and for type of elution, both gradient and isocratic are used. As combinations HPLC/UV, HPLC/Diode Array Detector (DAD), HPLC/Evaporative Light Scattering Detector (ELSD), Liquid Chromatography coupled with Mass Spectrometry (LC/MS), Liquid Chromatography/Diode Array Detector-Atmospheric Pressure Chemical Ionization/Mass Spectrometry (LC/DADAPCI/MS) and Gas Chromatography coupled with Mass Spectrometry (GC/MS) are used.
A novel micellar carrier to reverse multidrug resistance of tumours: TPGS derivatives with end-grafted cholesterol
Published in Journal of Drug Targeting, 2023
Zhaowei Qi, Jia Shi, Yanzhi Song, Yihui Deng
In this study, the HPLC-ELSD method was used to determine the purity of the crude product before purification and TPGS-CHMC after purification. The chromatographic conditions were as follows: chromatographic column, DiamonsilTM ODS column (200 mm × 4.6 mm, 5 μm); mobile phase, methanol-dichloromethane (volume ratio 70:30); flow rate: 1.0 ml·min−1; column temperature, 25 °C; sample size, 20 μL. Conditions of evaporative light scattering detector: drift tube temperature, 40 °C; N2 pressure, 0.3 MPa; the impact position, OFF; the gain, 6. An appropriate amount of the crude product and purified TPGS-CHMC was weighed, dissolved in methanol and diluted to an appropriate concentration. The above solution was filtered through a 0.22 μm microporous filter membrane, the samples were injected according to the above chromatographic conditions, and the peak area was recorded.
Microbial biotransformation – an important tool for the study of drug metabolism
Published in Xenobiotica, 2019
Rhys Salter, Douglas C. Beshore, Steven L. Colletti, Liam Evans, Yong Gong, Roy Helmy, Yong Liu, Cheri M. Maciolek, Gary Martin, Natasa Pajkovic, Richard Phipps, James Small, Jonathan Steele, Ronald de Vries, Headley Williams, Iain J. Martin
Purification was performed by preparative and semi-preparative reversed-phase HPLC, using two or three orthogonal stationary phases. Initial fractionations typically employed a Waters NovaPak C18 40 × 100 mm RadPak column with a GuardPak C18 40 × 10 mm guard column, eluting with a flow rate of 50 mL/min and a linear gradient starting from 85/10/5% water/acetonitrile/200 mM ammonium formate +2% (v/v) formic acid in water, held for 2 min, then changed to 35/60/5% over the next 10 min and to 0/95/5% over the next 2 min. Fractions containing target metabolites were then subjected to further isocratic or gradient fractionation on a Waters Symmetry Shield RP8 19 × 100 mm column (with Symmetry Shield RP 8 Prep Guard Cartridge, 19 mm ×10 mm), eluting with a flow rate of 17 mL/min using water/acetonitrile acidified with 2%(v/v) formic acid. In cases where >90% purity was not achieved after these two steps, a third stationary phase was used, selected from either Waters Atlantis T3 C18, Waters Xterra C18, Waters XSelect C18, Waters XBridge Prep Phenyl or Agilent PLRPS polymeric phase columns. Occasionally, typically when target product amounts were <1 mg, analytical (4.6 mm diameter) HPLC columns using stationary phases listed above, were employed with fraction collection. UV, MS and evaporative light scattering detection (PL-ELS 2100 Ice, Agilent Polymer Laboratories, Marietta, GA) were used for the detection and purity confirmation of metabolites.
Oleuropein isolated from Fraxinus rhynchophylla inhibits glutamate-induced neuronal cell death by attenuating mitochondrial dysfunction
Published in Nutritional Neuroscience, 2018
Mi Hye Kim, Ju-Sik Min, Joon Yeop Lee, Unbin Chae, Eun-Ju Yang, Kyung-Sik Song, Hyun-Shik Lee, Hong Jun Lee, Sang-Rae Lee, Dong-Seok Lee
Fraxinus rhynchophylla was purchased from Daegu Oriental Pharm Co. (Daegu, Korea). The specimen was stored at the Natural Products Medicine Laboratory, Kyungpook National University, Daegu, Korea (voucher specimen number; KNUNPM-BFR-11-12-001). The dried stem barks of Fraxinus rhynchophylla (4 kg) were extracted twice with 8 l ethanol (EtOH) for 2 hours. The ethanolic extract (510 g) was suspended in distilled water for partition using organic solvents such as dichloromethane (CH2Cl2), ethyl acetate (EtOAc), and normal-butanol (n-BuOH), successively. After concentration by a rotary evaporator, the CH2Cl2 soluble fraction (22 g), EtOAc soluble fraction (45 g), and n-BuOH soluble fraction (10 g) were obtained. The EtOAc soluble fraction was applied to a silica gel column chromatography [Ø 5.5 × 83 cm, chloroform (CHCl3):methanol (MeOH) = 100:1 – 1:1] to yield 9 fractions (Fr. 1–9). Fr. 5 was rechromatographed on a silica gel column (Ø 2.5 × 83 cm, CH2Cl2:MeOH = 20:1 – 1:1) to obtain 6 fractions (Fr. 5–1 ∼ 5–6). Compound 1 (710 mg) was isolated as fine needles from Fr. 5–3 through recrystallization at 4°C in the solvent consisting of CHCl3 and MeOH. For structure determination of compound 1, 1H- (500 MHz) and 13C- (125 MHz) nuclear magnetic resonance (NMR) was measured (solvent, MeOH-d4). Finally, compound 1 was identified as Ole by comparing the NMR spectral data with those of Takenaka et al.14 The purity of Ole was confirmed as more than 91% by high performance liquid chromatography (HPLC) analysis. The HPLC analysis was performed on Agilent 1100 series (Agilent Technologies, Santa Clara, CA, USA) equipped with an evaporative light scattering detector (ELSD, PL-ELS2100, Polymer Laboratories, Church Stretton, UK). The evaporator and nebulizer temperature were 70 and 50°C, respectively. The gas flow rate was 1.85 standard liter per minute. As a stationary phase, a Kintex 5 μm C18 100Å (4.6 × 100 mm, Phenomenex, Torrance, CA, USA) was used. The mixture of water (A) and acetonitrile (MeCN, B) was used as a mobile phase with a gradient condition (5–100% B at 0–30 min). The flow rate was 1.0 ml/min. Ole was dissolved in HPLC grade MeOH (500 μg/ml) and 8 μl was injected into the column.