NMR spectra including 1H, 13C, HSQC, HMBC, COSY, NOESY, and TOCSY were recorded in a Varian Inova spectrometer at 400 (1H) and 95 MHz (13C) or a Bruker DMX500 spectrometer operated at 500 MHz (1H) or 125 MHz (13C); chemical shifts were recorded as δ values. ESI-MS were recorded on a Thermo Scientific LTQ Orbitrap XL hybrid FTMS (Fourier transform mass spectrometer). Data were collected in both positive and negative ionization modes via a liquid chromatographic/autosampler system that consisted of an Agilent HPLC system. Analytical and preparative HPLC analyses were performed in an Agilent 1260 Infinity system equipped with a G1311B Quaternary Pump, a G1367E Autosampler, and a G1315C DAD VL+ and controlled by Agilent ChemStation software. For analytical and semipreparative HPLC, Phenomenex (Luna Omega Polar C18, 50 × 2.1 mm id., 1.6 μm) and Macherey-Nagel (Nucleosyl C18, 250 × 4.6 mm id., 5 μm and Nucleosyl C18, 250 × 10 mm id., 5 μm) columns, respectively, were used. Column chromatography (CC) was conducted on silica gel (70-230 mesh, Merck) or Sephadex LH-20 (Sigma-Aldrich Chemical). Thin-layer chromatography analyses were carried out on silica gel 60 F254 plates (Macherey & Nagel) using ceric sulfate (10%) solution in H2SO4 as the color reagent.
Dmx 500 spectrometer
Manufactured by Bruker
Sourced in Germany, United States
The DMX-500 spectrometer is a nuclear magnetic resonance (NMR) instrument designed for analytical applications. It operates at a frequency of 500 MHz and is capable of performing various NMR experiments to characterize the chemical structure and properties of samples.
Automatically generated - may contain errors
Lab products found in correlation
Sephadex lh 20, by Merck Group (2 mentions)
1260 infinity system, by Agilent Technologies (1 mentions)
Inova spectrometer, by Bruker (1 mentions)
G1311b quaternary pump, by Agilent Technologies (1 mentions)
G1367e autosampler, by Agilent Technologies (1 mentions)
Luna omega polar c18, by Phenomenex (1 mentions)
Nucleosyl c18, by Phenomenex (1 mentions)
Agilent g6230 tof mass spectrometer, by Agilent Technologies (1 mentions)
Dionex ultimate 3000 system, by Thermo Fisher Scientific (1 mentions)
O tolyl isothiocyanate, by Merck Group (1 mentions)
C18 column, by YMC (1 mentions)
Silica gel, by Qingdao Haiyang Chemical (1 mentions)
Gf254, by Qingdao Haiyang Chemical (1 mentions)
Ultracentrifuge, by Beckman Coulter (1 mentions)
Pd 10 desalting column, by GE Healthcare (1 mentions)
Spectrum 400 ftir instrument, by PerkinElmer (1 mentions)
Unity plus 500 spectrometer, by Agilent Technologies (1 mentions)
Silica gel 60, by Merck Group (1 mentions)
Silica gel 60 f254 plate, by Merck Group (1 mentions)
Pr 4100 microplate reader, by Bio-Rad (1 mentions)
20 protocols using dmx 500 spectrometer
1
Detailed NMR and Mass Spectroscopic Characterization
2
Chromatographic Purification and Characterization of Natural Compounds
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Column chromatography (CC) was performed using silica gel (200–300 mesh, 300–400 mesh, Qingdao Haiyang Chemical Group Co., Qingdao, China). Thin-layer chromatography was performed on silica gel GF254 (Qingdao Haiyang Chemical Group Co., Qingdao, China). MCI was purchased from Mitsubishi Chemical Group Co. (Tokyo, Japan) Semi-preparative HPLC was performed on a DIONEX Ultimate 3000 system equipped with a diode array detector and a C18 column (250 mm × 10 mm, 5 μm, YMC Co. Ltd., Kyoto, Japan). HR-EI-MS was measured on a Waters Autospec Premier 776 mass spectrometer (Waters, Milford, MA, USA). HR-ESI-MS was recorded on an Agilent G6230 TOF mass spectrometer (Agilent Technologies, Santa Clara, CA, USA). NMR spectra were obtained on a Bruker DMX-500 spectrometer (Bruker, Karlsruher, Germany) using TMS as an internal reference. l -cysteine methyl ester and standard monosaccharides (d -glucose and d -xylose) used in HPLC experiments were purchased from Aladdin industrial Co. Ltd. (Shanghai, China). O-Tolyl-isothiocyanate was obtained from Sigma-Aldrich Co. Ltd (Sigma-Aldrich China, Shanghai, China). Other chemical reagents were purchased from Sinopharm Chemical Reagent Co. Ltd. Shanghai, China.
3
Solid-State NMR Analysis of α-Synuclein Fibrils
4
Characterization of Natural Product Derivatives
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Melting points were determined using a Fisher-Johns apparatus and are uncorrected. Infrared spectra were obtained in the range of 4000 to 400 cm−1 using a Spectrum 400 FT-IR instrument (Perkin Elmer San Jose, CA, USA). NMR spectra including NOE differential, COSY, HMBC and HMQC experiments were recorded in CDCl3 or CD3OD on a Unity Plus 500 spectrometer (Varian, Palo Alto, CA, USA) or on a DMX500 spectrometer (Bruker, Billerica, MA, USA) operating at 500 or 300 MHz (1H) or 125 or 75 MHz (13C) NMR, using tetramethylsilane as an internal standard. Open column chromatography was carried out on silica gel 60 (70–230 mesh; Merck, Darmstadt, Germany) or Sephadex LH-20 (Sigma-Aldrich Chemical). TLC analyses were performed on silica gel 60 F254 plates (Merck) and spots were visualized by spraying with ceric sulfate (10%) solution in H2SO4, followed by heating. Semi-preparative RP-HPLC was carried out using a Waters (Milford, MA, USA) HPLC instrument equipped with Waters 996 UV photodiode array detector (900) set at 270–400 nm, a Purospher® Star RP-18 endcapped column (10 mm i.d. × 250 mm, 5 μm) and isocratic conditions (CH3CN–H2O 48:52; flow: 2.8 mL/min).
5
NMR and Mass Spectrometry Protocol
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1H NMR and 13C NMR spectra were recorded on a Bruker DMX500 spectrometer. The mass spectra were recorded on a Bruker Esquire 3000 plus ion trap mass spectrometer equipped with an ESI source. The concentration of EM was determined by HPLC using Agilent 1200. The mobile phase was: acetonitrile: 0.4 M NH4H2PO4 = 1 : 2. The microplate reader we used was Bio-Rad PR 4100 microplate reader.
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1H NMR and 13C NMR spectra were recorded on a Bruker DMX500 spectrometer. The mass spectra were recorded on a Bruker Esquire 3000 plus ion trap mass spectrometer equipped with an ESI source. The concentration of EM was determined by HPLC using Agilent 1200. The mobile phase was: acetonitrile: 0.4 M NH4H2PO4 = 1 : 2. The microplate reader we used was Bio-Rad PR 4100 microplate reader.
6
Determination of PLGA-PEG-PLGA Gel Formation
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Experimental data were recorded using a Bruker DMX500 spectrometer (Switzerland) at 500 MHz Deuterated chloroform (CDCl3) was used as a solvent, and tetramethylsilane was used as an internal standard. The sol–gel transition temperature of the PLGA-PEG-PLGA triblock copolymer was determined by the vial inversion test. Different quantities of PLGA-PEG-PLGA polymer were dissolved in phosphate-buffered saline (PBS), and the vial containing 0.5 mL of the polymer solution was stored for 15 min prior to the measurement. The temperature increment was set at 1 °C. The gel was successfully formed when the solution in the vial did not flow after being inverted for 30 s.
7
Comprehensive Nanoparticle Characterization Protocol
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The morphologies of the nanoparticles were measured with transmission electron microscopy (TEM, JEM-2100 Plus electron microscope) at an accelerating voltage of 200 kV. The samples were dispersed in ethanol-water or buffer solution and then deposited on copper grids, and then stained with phosphotungstic acid before characterization. The 1H NMR spectra were carried out on a Bruker DMX500 spectrometer, and CDCl3 was used as the solvent and tetramethylsilane was used as an internal reference. Hydrodynamic diameter and zeta potential measurements were done on a dynamic light scattering (DLS) spectrometer (PPS Z3000, Particle Sizing Systems, UK). The acid-base titration was carried out on a ZDJ-4B automatic potentiometric titrator. The Fourier transform infrared (FTIR) spectroscopy was performed on a PerkinElmer Frontier FTIR spectrometer. UV-vis measurements were carried out on a TU-1901 UV-vis spectrophotometer. CLSM images were recorded on a Leica TCS SP8 microscope.
8
Characterization of Natural Compounds
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Optical rotations were measured on a Jasco DIP-1000 Digital polarimeter (Jasco, Kyoto, Japan), and IR spectra (neat) were acquired with a Perkin-Elmer 983G spectrometer (Perkin-Elmer, Waltham, MA, USA). The 1D (1H, 13C, DEPT) and 2D (COSY, NOESY, ROESY, HSQC, HMBC) NMR spectra were obtained from a Burcher DMX-500 spectrometer (Bruker Inc., Bremen, Germany) operated at 500 (1H) and 125 MHz (13C). The HRESIMS data were generated at the Mass Spectrometry Laboratory by a JEOL JMS-H110 mass spectrometer (FAB-MS) (JEOL, Inc. Tokyo, Japan). Extracts were chromatographed on silica gel (Merk 70–230 mesh, 230–400 mesh, ASTM) and purified with a semipreparative normal-phase HPLC column (Merck LichroCART 250 × 10 mm, 7 μm, LiChrosorb Si 60) taken on LDC Analytical-III.
9
NMR Analysis of CAHS1 Protein
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The NMR spectral measurements were made on a Bruker DMX-500 spectrometer equipped with a cryogenic probe. The probe temperature was set to 5 °C. 15N-labeled CAHS1 protein, CAHS1-N, and CAHS1-C were dissolved at a protein concentration of 0.1 mM in 20 mM potassium phosphate buffer (pH 7.0) containing 5% (v/v) 2H2O.
10
Synthesis and Characterization of Trimethylated Chitosan
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TMC was synthesized as reported with some modifications.34 Briefly, chitosan (1% w/v) was dissolved in 250 mL of 1% acetic acid solution. APS (0.045% w/v) and TMAEMC were added, and the mixture was stirred at 60°C under a nitrogen stream. The molar ratio of –NH2 of chitosan and TMAEMC was 2:1. The reaction was terminated after 4 h, and the copolymer solution was dialyzed against deionized water for 48 h and then lyophilized.
The TMC was characterized by 1H NMR. The samples were measured in D2O, using a DMX-500 spectrometer (500 MHz; Bruker, Germany). The degree of quaternization (DQ) was calculated using the followingequation 1 :35 (link)
where ∫TM is the integral of the trimethyl amino group (quaternary amino) peak at 3.3 ppm and ∫H is the integral of the H peaks from 5.0 to 6.0 ppm.
The TMC was characterized by 1H NMR. The samples were measured in D2O, using a DMX-500 spectrometer (500 MHz; Bruker, Germany). The degree of quaternization (DQ) was calculated using the following
where ∫TM is the integral of the trimethyl amino group (quaternary amino) peak at 3.3 ppm and ∫H is the integral of the H peaks from 5.0 to 6.0 ppm.
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