caa a22 4500 46318629X CHVBK 20180406164854.0 cr unu---uuuuu 170326e20070901xx s 000 0 eng 10.1007/s00726-006-0387-x doi (NATIONALLICENCE)springer-10.1007/s00726-006-0387-x Optimization of solid-phase synthesis of difficult peptide sequences via comparison between different improved approaches [Elektronische Daten] [S. Abdel Rahman, A. El-Kafrawy, A. Hattaba, M. F. Anwer] Summary.: Different approaches are applied to avoid the strong aggregation of the difficult peptide sequences, which is considered as the main reason for incomplete acylation and deprotection reactions hindering the synthesis of these sequences. Temporary protection of amide nitrogen of peptide bond using 2-hydroxy-4-methoxybenzyl (Hmb) and 2,4,6-timethoxybenzyl (Tmob) amino acid derivatives, introduction of D-Ala or Pro residues in the peptide chain sequences and utilization of microwave energy are proved to be useful methods in the enhancement of solubility and in the hindrance of the aggregation during the solid-phase synthesis of oligoalanine. Oligoalanine is chosen to demonstrate the difficult sequences and to compare the efficiencies of these methods. Springer-Verlag, 2007 Keywords: Difficult peptide sequences - Solid-phase peptide synthesis - Oligo-alanine - N-amide protection - Microwave energy nationallicence DCM : Dichloromethane nationallicence DIC : N,N-diisopropylcarbodiimide nationallicence DMAP : 4-dimethylaminopyridine nationallicence DMF : dimethylformamide nationallicence Fmoc : 9-fluorenylmethoxycarbonyl nationallicence Hmb : 2-hydroxy-4-methoxybenzyl nationallicence HOBt : 1-hydroxybenzo-triazole nationallicence Ps-PEG : polystyrene-polyethyleneglycol nationallicence TFA : trifluoroacetic acid nationallicence Tmob : 2,4,6-timethoxybenzyl nationallicence Abdel Rahman S. Faculty of Science, Zagazig University, Zagazig, Egypt aut El-Kafrawy A. Faculty of Science, Zagazig University, Zagazig, Egypt aut Hattaba A. Faculty of Science, Zagazig University, Zagazig, Egypt aut Anwer M. F. Faculty of Science, Zagazig University, Zagazig, Egypt aut Amino Acids Springer-Verlag 33/3(2007-09-01), 531-536 0939-4451 33:3<531 2007 33 726 https://doi.org/10.1007/s00726-006-0387-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00726-006-0387-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Abdel Rahman S. Faculty of Science, Zagazig University, Zagazig, Egypt aut NATIONALLICENCE 700 1- El-Kafrawy A. Faculty of Science, Zagazig University, Zagazig, Egypt aut NATIONALLICENCE 700 1- Hattaba A. Faculty of Science, Zagazig University, Zagazig, Egypt aut NATIONALLICENCE 700 1- Anwer M. F. Faculty of Science, Zagazig University, Zagazig, Egypt aut NATIONALLICENCE 773 0- Amino Acids Springer-Verlag 33/3(2007-09-01), 531-536 0939-4451 33:3<531 2007 33 726 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer