title: Cleavage and deprotection of peptides on MBHA-resin with hydrogen bromide.
abstract: Dilute hydrogen bromide in trifluoroacetic acid containing pentamethylbenzene and thioanisole was used in the cleavage and deprotection of peptides on MBHA-resin. Particular attention was paid to potential applicability of the method to kilogram scale synthesis of thymosin alpha 1. In the HPLC purification of the peptides, acetonitrile was replaced by relatively nontoxic isopropanol. The change should be economically and environmentally very attractive.
authors.affiliation: Alpha 1 Biomedicals, Inc., Foster City, CA.
authors.forename: S S
authors.initials: SS
authors.lastname: Wang
authors.forename: B S
authors.initials: BS
authors.lastname: Wang
authors.forename: J L
authors.initials: JL
authors.lastname: Hughes
authors.forename: E J
authors.initials: EJ
authors.lastname: Leopold
authors.forename: C R
authors.initials: CR
authors.lastname: Wu
authors.forename: J P
authors.initials: JP
authors.lastname: Tam
mesh_terms: D000085:Acetates; D019342:Acetic Acid; D000143:Acids; D000595:Amino Acid Sequence; D001559:Benzhydryl Compounds / Q000737:chemistry*; D002087:Butyrates; D002851:Chromatography, High Pressure Liquid; D045782:Hemiterpenes; D018054:Hydrobromic Acid; D058610:Isobutyrates; D008969:Molecular Sequence Data; D010421:Pentanoic Acids; D010449:Peptide Mapping; D010455:Peptides / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry*; D000077596:Thymalfasin; D013947:Thymosin / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D014269:Trifluoroacetic Acid; D014357:Trypsin
chemical_list: C030545:4-methylbenzhydrylamine resin; D000085:Acetates; D000143:Acids; D001559:Benzhydryl Compounds; D002087:Butyrates; D045782:Hemiterpenes; D058610:Isobutyrates; D010421:Pentanoic Acids; D010455:Peptides; D012117:Resins, Synthetic; C008216:isovaleric acid; D018054:Hydrobromic Acid; D013947:Thymosin; C005566:pivalic acid; C020380:isobutyric acid; D014269:Trifluoroacetic Acid; D014357:Trypsin; D019342:Acetic Acid; D000077596:Thymalfasin