Infinity 6120 single quadrupole lc ms system

The 2-chlorotrytil resin, O-Benzotriazole-N,N,N,N′-tetramethyl-uronium-hexafluoro-phosphate (HBTU), and Fmoc protected N-trityl-l-histidine and d-phenylalanine were purchased from GL Biochem (Shanghai) Ltd. (Shanghai, China). All solvents were purchased of analytical grade from Merck (Milan, Italy). Drugs and chemicals were from Sigma (Milan, Italy). High purity Milli-Q-water (MQ water) with a resistivity greater than 18 MΩ·cm was obtained from an in-line Millipore RiOs/Origin system (Merck, Milan, Italy). The ¹H-NMR spectra were recorded at 400 MHz, and the ¹³C-NMR spectra were recorded at 100 MHz on a Varian Innova Instrument (Agilent Technologies, Milan, Italy) with chemical shift reported as ppm (in dimethyl sulfoxide (DMSO) with tetramethylsilane as internal standard). ESI-MS spectra were recorded on an Infinity 6120 single quadrupole LC-MS system (Agilent Technologies, Milan, Italy).

The 2-chlorotrytil resin O-benzotriazole-N,N,N,N-tetramethyl-uronium-hexafluoro-phosphate (HBTU) and Fmoc-protected d-leucine were bought from GL Biochem (Shanghai) Ltd. (Shanghai, China), while Fmoc-protected phenylalanine was bought from Iris Biotech GmbH (Marktredwitz, Germany). All solvents were bought from Merck (Milan, Italy) and were of HPLC grade. Chemical reagents were provided by Sigma (Milan, Italy). Milli-Q-water (MQ water) of high purity and with a resistivity higher than 18 MΩ cm was dispensed by an in-line Millipore RiOs/Origin apparatus (Merck, Milan, Italy). The NMR spectra were recorded on a Varian Innova Instrument (Agilent Technologies, Milan, Italy) at 400 MHz for ¹H, and at 100 MHz for ¹³C. Tetramethylsilane was used as an internal standard and chemical shifts were reported as ppm. Electrospray MS spectra were obtained with an Infinity 6120 single quadrupole LC-MS system (Agilent Technologies, Milan, Italy).