Diels-Alder cycloadditions in water for the straightforward preparatio
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《核酸研究医学期刊》
The following paragraph contained an error in the original publication
Synthesis of maleimide-peptide-NH2
All the amino acids of the peptide sequence were subsequently coupled on a Rink amide p-methylbenzhydrylamine resin (44) (100 mg, loading: 69 mmol NH2/mg) following the standard procedures of solid-phase peptide synthesis (10 min treatment with 20% piperidine in N,N-dimethylformamide and reaction with 3 equivalent of Fmoc-amino acid and DCC for 1–1.5 h were used for the deprotection and coupling steps, respectively), with the addition of 3 equivalent of HOBt for the incorporation of 3-maleimidepropanoic acid, and in all couplings in the octapeptide assembly (DCC 1/4 N,N0-dicyclohexylcarbodiimide, HOBt 1/4 1-hydroxybenzotriazole). Cleavage and deprotection were effected by reaction with TFA/H2O 95:5 in the case of the dipeptides (30 min), and with a TFA/H2O/TIS 90:5:5 mixture (5 h) in the case of the octapeptide (TIS 1/4 triisopropylsilane). Most of the TFA was removed by bubbling N2 into the solution, and the resulting residue was either diluted with H2O and lyophilized (dipeptides) or poured onto cold ether to precipitate the target molecule (octapeptide). Crude maleimide-octapeptide was obtained after centrifugation and solvent removal. All maleimide-peptides were purified by MPLC eluting with a gradient from 0 to 100% of B (A: 0.1% TFA in H2O, B: , 600 ml of each solvent).
The corrected version is as given below
Synthesis of maleimide-peptide-NH2
All the amino acids of the peptide sequence were subsequently coupled on a Rink amide p-methylbenzhydrylamine resin (44) (100 mg, loading: 0.69 μmol NH2/mg) following the standard procedures of solid-phase peptide synthesis (10 min treatment with 20% piperidine in N,N-dimethylformamide and reaction with 3 eq. of Fmoc-amino acid and DCC for 1–1.5 h were used for the deprotection and coupling steps, respectively), with the addition of 3 eq. of HOBt for the incorporation of 3-maleimidepropanoic acid, and in all couplings in the octapeptide assembly (DCC=N,N'-dicyclohexylcarbodiimide, HOBt=1-hydroxybenzotriazole). Cleavage and deprotection were affected by reaction with TFA/H2O (95:5) in the case of the dipeptides (30 min), and with a TFA/H2O/TIS (90:5:5) mixture (5 h) in the case of the octapeptide (TIS = triisopropylsilane). Most of the TFA was removed by bubbling N2 into the solution, and the resulting residue was either diluted with H2O and lyophilized (dipeptides) or poured onto ice-cold ether to precipitate the target molecule (octapeptide). Crude maleimide-octapeptide was obtained after centrifugation and solvent removal. All maleimide-peptides were purified by MPLC eluting with a gradient from 0 to 100% of B (A: 0.1% TFA in H2O; B: ; 600 ml of each solvent).(Vicente Marchan, Samuel Ortega, Daniel P)
Synthesis of maleimide-peptide-NH2
All the amino acids of the peptide sequence were subsequently coupled on a Rink amide p-methylbenzhydrylamine resin (44) (100 mg, loading: 69 mmol NH2/mg) following the standard procedures of solid-phase peptide synthesis (10 min treatment with 20% piperidine in N,N-dimethylformamide and reaction with 3 equivalent of Fmoc-amino acid and DCC for 1–1.5 h were used for the deprotection and coupling steps, respectively), with the addition of 3 equivalent of HOBt for the incorporation of 3-maleimidepropanoic acid, and in all couplings in the octapeptide assembly (DCC 1/4 N,N0-dicyclohexylcarbodiimide, HOBt 1/4 1-hydroxybenzotriazole). Cleavage and deprotection were effected by reaction with TFA/H2O 95:5 in the case of the dipeptides (30 min), and with a TFA/H2O/TIS 90:5:5 mixture (5 h) in the case of the octapeptide (TIS 1/4 triisopropylsilane). Most of the TFA was removed by bubbling N2 into the solution, and the resulting residue was either diluted with H2O and lyophilized (dipeptides) or poured onto cold ether to precipitate the target molecule (octapeptide). Crude maleimide-octapeptide was obtained after centrifugation and solvent removal. All maleimide-peptides were purified by MPLC eluting with a gradient from 0 to 100% of B (A: 0.1% TFA in H2O, B: , 600 ml of each solvent).
The corrected version is as given below
Synthesis of maleimide-peptide-NH2
All the amino acids of the peptide sequence were subsequently coupled on a Rink amide p-methylbenzhydrylamine resin (44) (100 mg, loading: 0.69 μmol NH2/mg) following the standard procedures of solid-phase peptide synthesis (10 min treatment with 20% piperidine in N,N-dimethylformamide and reaction with 3 eq. of Fmoc-amino acid and DCC for 1–1.5 h were used for the deprotection and coupling steps, respectively), with the addition of 3 eq. of HOBt for the incorporation of 3-maleimidepropanoic acid, and in all couplings in the octapeptide assembly (DCC=N,N'-dicyclohexylcarbodiimide, HOBt=1-hydroxybenzotriazole). Cleavage and deprotection were affected by reaction with TFA/H2O (95:5) in the case of the dipeptides (30 min), and with a TFA/H2O/TIS (90:5:5) mixture (5 h) in the case of the octapeptide (TIS = triisopropylsilane). Most of the TFA was removed by bubbling N2 into the solution, and the resulting residue was either diluted with H2O and lyophilized (dipeptides) or poured onto ice-cold ether to precipitate the target molecule (octapeptide). Crude maleimide-octapeptide was obtained after centrifugation and solvent removal. All maleimide-peptides were purified by MPLC eluting with a gradient from 0 to 100% of B (A: 0.1% TFA in H2O; B: ; 600 ml of each solvent).(Vicente Marchan, Samuel Ortega, Daniel P)