Jms t100lp mass spectrometer

Nuclear magnetic resonance (NMR) spectra (¹H and ¹³C NMR, ¹H-¹H DQF COSY, HMQC, HMBC, and NOESY) were measured using an AVANCE 400 MHz NMR spectrometer (Bruker, Rheinstettern, Germany) utilizing standard programs in TopSpin1.3. Chemical shifts were referenced to solvent signals. HR-ESI-MS (+) was measured using a JMS-T100LP mass spectrometer (JEOL, Tokyo, Japan) and accumulated mass calibration was performed using reserpine [C₃₃H₄₁N₂O₉, m/z 609.2812044 (M+H)⁺].

NMR spectra were recorded on a JEOL JNM-LA 400 spectrometer. UV-Vis spectra were recorded on a SHIMADZU UV-2550UV-Vis spectrophotometer or a UV-Vis Agilent Cary8454 spectrophotometer with a conventional quartz cuvette (path length, l = 1 cm). Spectroelectrochemical studies were performed using a BAS Inc. spectroelectrochemical quartz cell (l = 1 mm) containing Pt gauze (working electrode), a Pt wire (auxiliary electrode) and Ag/Ag⁺ (reference electrode) in conjunction with a CH Instruments potentiostat. Elemental analyses were performed on a J-SCIENCE LAB MICRO CORDER JM10 elemental analyser. ESI-TOF mass spectra were recorded on a JEOL JMS-T100LP mass spectrometer. Gas chromatography analysis of O₂ was performed using a Shimadzu GC-2014 gas chromatograph equipped with a thermal conductivity detector and fitted with a molecular sieve (5 Å) column, and the system was calibrated with air. Dynamic light scattering (DLS) data were measured using a Photal OTSUKA ELECTRONICS ELSZ-1000 zeta-potential and particle size analyser, equipped with a 785 nm red laser source (detection limit: 0.6 nm particle diameter).

The 1D and 2D NMR spectra were recorded on a Bruker AVANCE III 500 spectrometer (Bruker, Rheinstetten, Germany). The mass spectra were measured on a JEOL JMS-T100LP mass spectrometer with ESI as an ionization source. The FTIR spectra were measured using a JASCO FT/IR-6100 UV spectra (Japan Spectroscopic Corporation, Tokyo, Japan) were taken on a Hitachi U-2001 spectrophotometer (Hitachi High-Tech Corporation, Tokyo, Japan). Optical rotation was measured on a Jasco P-1010 polarimeter, and ECD spectra were taken on a Jasco J-820 instrument. The presence of sodium was measured on a Hitachi Z-2010 atomic absorption spectrophotometer. High-performance liquid chromatography (HPLC) was performed on a Hitachi L-6000 pump equipped with a Shodex SE-101 RI monitor (Showa Denko, Tokyo, Japan) and a Hitachi L-4000 UV detector using Imtakt Cadenza CD-C18 (10 mm × 250 mm), or Nacalai Cosmosil 5C₁₈-ARII (4.6 mm × 250 mm), or YMC Pack ODS-AQ (4.6 mm × 100 mm) column. Nacalai Cosmosil 75C₁₈-PREP reversed phase gel was used for vacuum flash chromatography. All solvents used were reagent grade.

NMR spectra were recorded on a Bruker AVANCE III 500 spectrometer (Billerica, MA, USA). ESI mass spectra were taken on a Jeol JMS-T 100LP mass spectrometer (Tokyo, Japan). HPLC separation was done on a unit equipped with a Shimadzu LC-10AD pump (Kyoto, Japan), a Shimadzu SPD-10A UV detector, a Shodex RI-101 refractive index detector (Tokyo, Japan), and a Nacalai Cosmosil 5SL-II column (4.6 × 250 mm) (Kyoto, Japan). Specific rotation was observed on a Jasco P-1010 polarimeter (Tokyo, Japan). FTIR spectrum was measured on a Jasco FT/IR-300 spectrophotometer. ECD spectrum was obtained on a Jasco J-820 spectropolarimeter.

Mass spectra of the fractionated folding intermediates were recorded with the ESI(+) mode on JMS-T100LP mass spectrometer (Jeol, Akishima, Japan). AEMTS-quenched sample solutions were freeze-dried, dissolved in 0.1% formic acid in water and 0.1% formic acid in acetonitrile, and injected through the sample introduction tube. Molecular masses of the analyzed samples were calibrated by using angiotensin I ([M+H]⁺: 1296.685).

The molecular masses for AEMTS‐blocked N, R, and folding intermediates (I‐1, I‐2, 1SS, and 2SS) were measured on a Jeol JMS‐T100LP mass spectrometer (Jeol, Akishima, Japan), operated in the ESI(+) mode, connecting to an Agilent 1200 series HPLC system. Each sample, which had a different molecular mass depending on the number of free SH groups having been modified with AEMTS, was dissolved in a 1 : 1 mixture of 0.1% formic acid in H₂O and 0.1% formic acid in acetonitrile and injected onto the LC‐MS system. Angiotensin I was employed as a standard.