Optical rotations of 1 –6 were measured on a JASCO P-1020 digital polari meter (Jasco Corp., Tokyo, Japan). The NMR spectra of compounds 3 –6 were recorded on a Bruker AV spectrometer (400 MHz for 1H and 100 MHz for 13C, Bruker Corp., Karlsruhe, Germany). The NMR spectra of compounds 1 and 2 were recorded on a JEOL JEM-ECP NMR spectrometer (600 MHz for 1H and 150 MHz for 13C, JEOL, Tokyo, Japan). HRESIMS spectra of compounds 1 –5 were measured on a Q-TOF Ultima Global GAA076 LC mass spectrometer (Waters Corp., Milford, MA, USA). CD spectra were recorded on a MOS-450 spectrometer. Semi-preparative HPLC was performed on an Agilent 1260 LC (Agilent Corp., Santa Clara, CA, USA) series with a DAD detector using an Agilent Eclipse XDB-C18 (Agilent Corp., Santa Clara, CA, USA) column (9.4 × 250 mm, 5 μm). Silica gel ODS and Sephadex LH-20 (Qing Dao Hai Yang Chemical Group Co., Qingdao, China) were used for open-column chromatography (CC). Precoated silica gel plates (Yan Tai Zi Fu Chemical Group Co., Yan Tai, China; G60, F-254) were utilized for thin-layer chromatography (TLC).
Agilent eclipse xdb c18
Manufactured by Agilent Technologies
Sourced in United States
The Agilent Eclipse XDB-C18 is a reversed-phase liquid chromatography column designed for the separation and analysis of a wide range of chemical compounds. It features a high-purity silica-based stationary phase with a C18 alkyl bonding for enhanced retention and selectivity.
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Lab products found in correlation
Agilent 1260 lc, by Agilent Technologies (2 mentions)
Av spectrometer, by Bruker (2 mentions)
Jem ecp nmr spectrometer, by JEOL (1 mentions)
P 1020 digital polarimeter, by Jasco (1 mentions)
Q tof ultima global gaa076 lc mass spectrometer, by Waters Corporation (1 mentions)
1260 infinity quaternary lc system, by Agilent Technologies (1 mentions)
Boilogic mos 500 spectrometer, by Jasco (1 mentions)
Apex 2 spectrometer, by Bruker (1 mentions)
Precoated silica gel plates, by Qingdao Marine Chemical (1 mentions)
Agilent 1290 infinity uhplc, by Agilent Technologies (1 mentions)
Agilent 6530 accurate mass q tof lc ms, by Agilent Technologies (1 mentions)
Agilent 1100 binary pump instrument, by Agilent Technologies (1 mentions)
Sphereclone ods, by Phenomenex (1 mentions)
V 730 spectrophotometer, by Jasco (1 mentions)
Agilent chemstation, by Agilent Technologies (1 mentions)
Agilent 1260, by Agilent Technologies (1 mentions)
Avance 3 400 mhz, by Bruker (1 mentions)
Tripletof 5600 mass spectrometer, by AB Sciex (1 mentions)
Agilent 1260 hplc system, by Agilent Technologies (1 mentions)
Rp18 guard column, by Phenomenex (1 mentions)
18 protocols using agilent eclipse xdb c18
1
Structural Characterization of Compounds
2
RP-HPLC Analysis of Amino Acids
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O-Phthalaldehyde (OPA) regent (4 mg/ml) and borate buffer (0.4 M, pH 10.4) were used for precolumn derivatization. Solvent A (pH 5.8) consisted of 25 mM sodium acetate buffer and tetrahydrofuran (95/5, v/v), and Solvent B of methanol (Zhao et al. 2012) .
Twenty microliters of the enzymatic reaction solution was diluted to an appropriate concentration (10-100 pmol/μl) with ultrapure water. Then 100 μl of diluted enzymatic reaction solution or standard amino acid dilution (10-100 pmol/μl) was injected into a 1.5-ml centrifuge tube, followed by the addition of 600 μl of borate buffer and 300 μl OPA derivatization reagent once the timing began. After being mixed adequately, the solution was filtered through a 0.22 μ m organic membrane. Five minutes later, the sample was injected into the column for RP-HPLC analysis.
L-Serine and glycine were assayed by RP-HPLC (1260 infinity quaternary LC system, Agilent Technologies) on a column of Agilent Eclipse XDB-C18 (250 mm×4.6 mm, The cycle no. and thermal condition were the same as the secondary reaction.
5 μm) as described by Jiang et al. (Jiang et al. 2013) , with moderate modifications.
Twenty microliters of the enzymatic reaction solution was diluted to an appropriate concentration (10-100 pmol/μl) with ultrapure water. Then 100 μl of diluted enzymatic reaction solution or standard amino acid dilution (10-100 pmol/μl) was injected into a 1.5-ml centrifuge tube, followed by the addition of 600 μl of borate buffer and 300 μl OPA derivatization reagent once the timing began. After being mixed adequately, the solution was filtered through a 0.22 μ m organic membrane. Five minutes later, the sample was injected into the column for RP-HPLC analysis.
L-Serine and glycine were assayed by RP-HPLC (1260 infinity quaternary LC system, Agilent Technologies) on a column of Agilent Eclipse XDB-C18 (250 mm×4.6 mm, The cycle no. and thermal condition were the same as the secondary reaction.
5 μm) as described by Jiang et al. (Jiang et al. 2013) , with moderate modifications.
3
Phytochemical Analysis of a Natural Extract
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Optical rotations were acquired by an Anton paar MCP 5100 modular circular polarimeter (JASCO, Tokyo, Japan). CD spectra and UV spectra were obtained from a Boilogic Mos-500 spectrometer (JASCO, Tokyo, Japan). The 1D and 2D NMR (COSY, HSQC, and HMBC) spectra were recorded on a Bruker AV spectrometer (400 MHz for 1H and 100 MHz for 13C, (Bruker Corporation, Switzerland) instrument using DMSO-d6 as a solvent. Tetramethyl silane (TMS) was used as an internal standard. HR-ESI-MS spectra were made on a Bruker APEX II spectrometer (Billerica, MA, USA). Semi preparative HPLC was carried out with Agilent 1260 prep-HPLC system, using Agilent Eclipse XDB-C18 (9.4 × 250 mm, 5 μm, Agilent Corporation, Santa Clara, CA, USA), respectively. Silica gel (200–300 mesh, 300–400 mesh Qingdao Marine Chemical Factory, Qingdao, China) and octadecylsilyl silica gel (YMC; 12–50 μm) were used for column chromatography (CC). Precoated silica gel plates (GF-254, Qingdao Marine Chemical Factory, Qingdao, China) were used for thin layer chromatography (TLC). All solvents used for extractions and chromatographic separations were of analytical grade and purchased from Xilong Chemical Reagent Factory (Guangzhou, China), with the exception of HPLC grade solvents used for HPLC separations.
4
UHPLC-Q/TOF-MS Analysis of TMAE
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Dissolve 4 mg of TMAE in 1 mL of 80% methanol (Merck) solution. After mixing, centrifuge the solution at 8000 r/min for 10 min and collect the supernatant. The supernatant samples were filtered using nylon membranes (13 mm × 0.22 μm, ANPEL Laboratory Technologies Inc.) and separated on an Agilent 1290 Infinity UHPLC (Agilent Technologies, Santa Clara, CA, USA) in series with an Agilent 6530 Accurate-Mass Q-TOF LC/MS (Agilent Technologies, Santa Clara, CA, USA) system equipped with Agilent Eclipse XDB-C18 (4.6 × 150 mm, 5 μm). The UHPLC-Q/TOF-MS test conditions are based on the method of Pieczykolan, A. et al. (38 (link)) with some modifications. The mobile phases used in this experiment were water containing 0.1% formic acid (solvent A) and acetonitrile containing 0.1% formic acid (solvent B). The gradient elution program followed the schedule below: 0-1.5 min, 13% B; 2-15 min, 20% B; 16-23 min, 25% B; 25-28 min, 33% B; 30-33 min, 60% B; 34-37 min, 13% B. The flow rate was 0.35 mL/min, and the column temperature was maintained at 25°C. The negative ion source voltage was set at -4.5 kV, the capillary temperature at 500°C, the spray gas at 55 psi, and the Curtain Gas at 30 psi. The mass-to-charge ratios of primary and secondary fragments of isolated compounds were screened in the MS-DIAL database and literature reports to identify compounds in extracts (39 (link), 40 (link)).
5
Analysis of Organic Compounds by UV-Vis, NMR, and LC-MS
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Ultraviolet–visible (UV–Vis) spectra were recorded on a Jasco V-730 spectrophotometer (Lecco, Italy).
Nuclear magnetic resonance (NMR) spectra were recorded at 400 MHz on a Bruker instrument (Milan, Italy).
HPLC analyses were performed on an Agilent 1100 binary pump instrument (Agilent Technologies, Milan, Italy) equipped with a UV–Vis detector, using an octadecylsilane-coated column, 250 mm × 4.6 mm, 5 µm particle size (Phenomenex SphereClone ODS, Bologna, Italy) at 0.7 mL/min, and the following gradient: 0.1% formic acid (eluent a)/methanol (eluent b): 40% b, 0–10 min; from 40 to 80% b, 10–47.5 min. The detection wavelength was set at 280 nm.
Liquid chromatography–mass spectrometry (LC–MS) analysis was performed on an HPLC 1100 VL series instrument (Agilent Technologies) with an electrospray ionization source in positive ion mode (ESI+). An Agilent Eclipse XDB-C18, 150 mm × 4.60 mm, 5 µm (Agilent Technologies) was used, with the same eluent used for the HPLC analysis at a flow rate of 0.4 mL/min. Mass spectra were registered under the following conditions: nebulizer pressure 50 psi; drying gas (nitrogen) flow 10 L/min, at 350 °C; and capillary voltage 4000 V.
Nuclear magnetic resonance (NMR) spectra were recorded at 400 MHz on a Bruker instrument (Milan, Italy).
HPLC analyses were performed on an Agilent 1100 binary pump instrument (Agilent Technologies, Milan, Italy) equipped with a UV–Vis detector, using an octadecylsilane-coated column, 250 mm × 4.6 mm, 5 µm particle size (Phenomenex SphereClone ODS, Bologna, Italy) at 0.7 mL/min, and the following gradient: 0.1% formic acid (eluent a)/methanol (eluent b): 40% b, 0–10 min; from 40 to 80% b, 10–47.5 min. The detection wavelength was set at 280 nm.
Liquid chromatography–mass spectrometry (LC–MS) analysis was performed on an HPLC 1100 VL series instrument (Agilent Technologies) with an electrospray ionization source in positive ion mode (ESI+). An Agilent Eclipse XDB-C18, 150 mm × 4.60 mm, 5 µm (Agilent Technologies) was used, with the same eluent used for the HPLC analysis at a flow rate of 0.4 mL/min. Mass spectra were registered under the following conditions: nebulizer pressure 50 psi; drying gas (nitrogen) flow 10 L/min, at 350 °C; and capillary voltage 4000 V.
6
Quantifying PTX and SPIO Loading in PLMCs
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To determine the PTX loading content, preweighed freeze-dried PLMCs were redissolved in methanol/water (70/30, v/v) and filtered to remove Fe3O4 NPs if applied. Concentration of PTX was determined on a high-performance liquid chromatography system (1260; Agilent Technologies, Santa Clara, CA, USA) equipped with an Agilent Eclipse XDB-C18 (4.6×150 mm; Agilent Technologies) column and the detector wavelength was set at 227 nm. Mixture of methanol and water (70/30, v/v) was used as the mobile phase at a flow rate of 1.0 mL/min. The area under the peak was calculated by numerical integration (Simpson’s rule). A standard curve was preestablished using known amounts of PTX dissolved in the same methanol/water mixture. The drug-loading content (DLC) and encapsulation efficiency (EE) :
The SPIO loading contents of PLMCs were determined using a polarized Zeeman Atomic Absorption Spectrophotometer (Hitachi Z-2000 series, Hitachi Ltd, Tokyo, Japan). PLMCs were first weighed before being suspended in 1 M HCl solution to allow for cerasome-forming lipid degradation and complete dissolution of the PLMCs. The iron concentration was then determined at the specific Fe absorption wavelength (248.3 nm) based on a preestablished calibration curve. SPIO loading content was calculated as the ratio of iron oxide over the total weight of PLMCs.
The SPIO loading contents of PLMCs were determined using a polarized Zeeman Atomic Absorption Spectrophotometer (Hitachi Z-2000 series, Hitachi Ltd, Tokyo, Japan). PLMCs were first weighed before being suspended in 1 M HCl solution to allow for cerasome-forming lipid degradation and complete dissolution of the PLMCs. The iron concentration was then determined at the specific Fe absorption wavelength (248.3 nm) based on a preestablished calibration curve. SPIO loading content was calculated as the ratio of iron oxide over the total weight of PLMCs.
7
Purification and Characterization of Organic Compounds
8
Liquid Chromatography-Mass Spectrometry Analysis
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The liquid chromatography analyses were performed on an Agilent 1260 HPLC system (Agilent, Santa Clara, CA, USA). Chromatographic separation was implemented on an Agilent Eclipse XDB C18 (Agilent, Santa Clara, CA, USA) column with detection being carried out at 280 nm with the operating temperatures being kept at 35 °C. The analyses were completed with a gradient elution of methol (A) and 0.1% formic acid in purified water (B). The gradient protocol was: 22–36% A, 0–5 min; 36–52% A, 5–30 min; 52–63% A, 30–65 min; 63–70% A, 65–95 min; 70–80% A, 95–120 min; 80–22% A, 120–122 min. The injected sample volume was 5 μL, and the flow rate was 0.6 mL/min.
An Agilent 1260 HPLC (quaternary pump) system and AB Sciex TripleTOF™ 5600 mass spectrometer were used in the ESI-QTOF-MS/MS system. An electrospray ionization source was used to drive the TOF mass spectrometer. The capillary voltage was set to 4 kV; the collision voltage was set to 135 V; the drying-gas temperature was set to 350 °C; the drying-gas flow rate was set to 10 L/min; the nebulizer pressure was set to 40 psi; the collision gas was nitrogen; the collision energy was set to 30 eV; the full ionic scan mode was used; and the scan range was set to m/z = 50–2000.
An Agilent 1260 HPLC (quaternary pump) system and AB Sciex TripleTOF™ 5600 mass spectrometer were used in the ESI-QTOF-MS/MS system. An electrospray ionization source was used to drive the TOF mass spectrometer. The capillary voltage was set to 4 kV; the collision voltage was set to 135 V; the drying-gas temperature was set to 350 °C; the drying-gas flow rate was set to 10 L/min; the nebulizer pressure was set to 40 psi; the collision gas was nitrogen; the collision energy was set to 30 eV; the full ionic scan mode was used; and the scan range was set to m/z = 50–2000.
9
Formaldehyde Separation Using Reverse-Phase HPLC
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The separation of the formaldehyde was performed on an Agilent Eclipse XDB C18 (150 × 4.6 mm, 5 μm) column (Agilent Technologies, MO, USA) protected by a RP18 guard column (4.0 × 3.0 mm, 5 μm) from Phenomenex (USA), using a mobile phase consisting of HPLC-grade acetonitrile and water (70:30 v/v) mixture prepared in one glass bottle. The flow rate was 0.45 mL/min and the column thermostat was set at 30°C. The injection volume was 5 μL. The UV detection was monitored at 360 nm.
10
Chromatographic Analysis of Compounds
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The chromatographic system was the HP 1100 Series chromatograph (Agilent Technologies, USA) equipped with solvent degasser, auto-sampler with 100 μl loop, quaternary pump, column thermostat, fluorescence detector (FLD) and diode array detector (DAD) system. The chromatographic column was Agilent Eclipse XDB C18 (150 x 4.6 mm, 5 μm Agilent Technologies, USA).
Two SPE cartridges Oasis HLB (60 mg, 3 ml) of Waters (Milford, MA, USA) and BondElut C18 (500 mg, 3 ml) of Agilent Technologies (USA) were used. SPE manifold (J.T. Baker, USA) and a pump as a vacuum source were used.
Two SPE cartridges Oasis HLB (60 mg, 3 ml) of Waters (Milford, MA, USA) and BondElut C18 (500 mg, 3 ml) of Agilent Technologies (USA) were used. SPE manifold (J.T. Baker, USA) and a pump as a vacuum source were used.
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