- Enzymatic C-terminal amidation of amino acids and peptides
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Herein, we describe two versatile and high yielding enzymatic approaches for the conversion of semi-protected amino acid and peptidyl C-terminal α-carboxylic acids into their corresponding amides. In the first approach, the lipase Candida antarctica lipase-B (Cal-B), and in the second approach, the protease Subtilisin A, are used, respectively. We found that by using the ammonium salt of the α-carboxylic acid instead of separate ammonia sources, the enzymatic amidation reactions proceeded much faster without side reactions and gave near to quantitative yields of products.
- Nuijens, Timo,Piva, Elena,Kruijtzer, John A.W.,Rijkers, Dirk T.S.,Liskamp, Rob M.J.,Quaedflieg, Peter J.L.M.
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experimental part
p. 3777 - 3779
(2012/09/22)
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- A Modified Benzhydrylamine as a Handle Reagent for the Solid Phase Synthesis of Peptide Amides Based on the Fluorenylmethoxycarbonyl Method
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An easily preparable dimethoxybenzhydrylamine derivative, 3-(α-Fmoc-amino-4-methoxybenzyl)-4-methoxyphenyl propionic acid (Fmoc=fluoren-9-ylmethoxycarbonyl) is a useful precursor of the C-terminal amide, when applied to Fmoc-based solid phase peptide synthesis; as a cleavage reagent from the resine, thioanisole-mediated trimethylsilyl bromide in trifluoroacetic acid is recommended.
- Funakoshi, Susumu,Murayama, Eigoro,Guo, Lili,Fujii, Nobutaka,Yajima, Haruaki
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p. 382 - 384
(2007/10/02)
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- A MODIFIED BENZHYDRYLAMINE - A USEFUL HANDLE REAGENT FOR Fmoc BASED SOLID PHASE SYNTHESIS OF PEPTIDE AMIDES
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Usefulness of a dimethoxybenzhydrylamine derivative, 3-(3-(Fmoc-amino-4-methoxyphenylmethyl)-4-methoxyphenyl)propionic acid, for Fmoc-based solid phase synthesis of peptide amides was demonstrated by preparation of three biologically active peptide amides, i.e. tetragastrin, neuromedin B and vasopressin. 1M trimethylsilyl bromide-thioanisole (molar ration 1 : 1) in trifluoroacetic acid was recommended as a deprotecting reagent for releasing the peptide amides from the resin.
- Funakoshi, Susumu,Murayama, Eigoro,Guo, Lili,Fujii, Nobutaka,Yajima, Haruaki
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p. 2791 - 2800
(2007/10/02)
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- Studies on Peptides. CXLIII. Evaluation of β-Menthylaspartate for Peptide Synthesis
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The β-l-menthyl ester of aspartic acid, Asp(OMen), was found to be stable to trifluoroacetic acid (TFA) in an ice-bath for 3 h, but to be cleaved by HF or 1 M trifluoromethanesulfonic acid-thioanisole in TFA in an ice-bath within 60 min.Asp(OMen) was employed for the synthesis of tetragastrin, for which the use of diphenylsulfide, as an additional scavenger, is recommended to accelerate the acidolytic cleavage of this protecting group.This protecting group is superior to other available protecting groups so far examined in terms of suppression of base-catalyzed succinimide formation.Keywords - β-menthylaspartate; base-catalyzed succinimide formation; acid-catalyzed succinimide formation; hydrogen fluoride deprotection; trifluoromethanesulfonic acid deprotection; cation scavenger; diphenylsulfide; tetragastrin
- Yajima, Haruaki,Futaki, Shiroh,Otaka, Akira,Yamashita, Takeyoshi,Funakoshi, Susumu,et. al.
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p. 4356 - 4361
(2007/10/02)
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