Peptides sulfur-containing

The Dim ester was developed for the protection of the carboxyl function during peptide synthesis. It is prepared by transesterification of amino acid methyl esters with 2-(hydroxymethyl)-l,3-dithiane and Al(/-PrO)3 (reflux, 4 h, 75°, 12 torr, 75% yield). It is removed by oxidation [H2O2, (NH4)2Mo04 pH 8, H2O, 60 min, 83% yield]. Since it must be removed by oxidation it is not compatible with.sulfur-containing amino acids such as cysteine and methionine. Its suitability for other, easily oxidized amino acids (e.g., tyrosine and tryptophan) must also be questioned. It is stable to CF3CO2H and HCl/ether. - ... 

A -Benzyloxycarbonyl groups, catalytic hydrogenolysis in sulfur-containing peptides, 59, 166... 

Removal of N -Benzyloxycarbonyl Groups from Sulfur-Containing Peptides BY Catalytic Hydrogenation in Liquid Ammonia O-tert-BurvL-L-SERYL-S-... 

REMOVAL OF N -BENZYLOXYCARBONYL GROUPS FROM SULFUR-CONTAINING PEPTIDES BY CATALYTIC HYDROGENATION IN LIQUID AMMONIA O-tcrf-BUTYL-L-SERYL-S-tert-BUTYL-L-CYSTEINE ferr-BUTYL ESTER... 

Removal of N -Benzyloxvcarbonyl Groups from Sulfur-Containing Peptides... 

The interaction of palladium(II) complexes with sulfur-containing peptides was studied by electrospray mass spectrometry.331... 

While many sulfur-containing fungal secondary metabolites are known, they are found less frequently than in plants. There is a structural range from CH2S6, 1,2,3,4,5,6-hexathiapane, from Lentinus edodes, to C82Hii4N2oOi7S, a 13-unit peptide containing methionine from Saccharomyces cerevesiae,13... 

CATALYTIC TRANSFER HYDROGENATION AND THE HYDROGENOLYTIC DEPROTECTION OF SULFUR-CONTAINING PEPTIDES... 

G Losse, H-U Stiehl, B Schwenger. Hydrogenolytic debenzylation of sulfur-containing peptides. Int J Pept Prot Res 19, 114, 1982. 

Example Peptides often contain sulfur from cysteine. Provided there are at least two cysteines in the peptide molecule, the sulfur can be incorporated as thiol group (SH, reduced) or sulfur bridge (S-S, oxidized). Often, both forms are contained in the same sample. At ultrahigh-resolution, the contributions of these compositions to the same nominal m/z can be distinguished. The ultrahigh-resolution matrix-assisted laser desorption/ionization (MALDI) FT-ICR mass spectrum of native and reduced [D-Pen jenkephalin gives an example of such a separation (Fig. 3.25). [39] The left expanded view shows fully resolved peaks due to and C2 isotopomers of the native and the all- C peak of the reduced compound at m/z 648. The right expansion reveals the peak of the native plus the... 

Solouki, T. Emmet, M.R. Guan, S. Marshall, A.G. Detection, Number, and Sequence Location of Sulfur-Containing Amino Acids and Disulfide Bridges in Peptides by Ultrahigh-Resolution MALDI-FTICR Mass Spectrometry. Anal. Chem. 1997,69, 1163-1168. 

Marshall, A.G. Detection, Number, and Sequence Location of Sulfur-Containing Amino Acids and Disulfide Bridges in Peptides by Ultrahigh-Resolution... 

Fig. 7 Sulfur-containing cyclic peptides as prodrugs for HDAC inhibition. (Kyushu Institute of Technology)...

The biosynthesis 237,5381 involves enzymatic dehydration of serine and threonine residues in a manner similar to the formation of thiazoles and dihydrothiazoles vide supra) with or without subsequent oxidation to yield the 2-(l-aminoalkyl)oxazole-4-carboxylic acid and 2-(l-aminoalkyl)dihydrooxazole-4-carboxylic acid shown in Scheme 38. These cyclic peptides display interesting physiological properties such as cytotoxicity/541, 569,5831 antitumor activities, or antineoplastic effects/523,5291 but as for the sulfur-containing compounds the mechanism of action is not yet understood despite extensive SAR studies. 515,521,540,5431... 

Thiopeptin is a sulfur-containing peptide antibiotic complex produced by Streptomyces tateyamensis. It is composed of five closely related components, the thiopeptins Ai, A2, A3, A4, and B (8). Commercially available thiopeptin is primarily composed of thiopeptins B. This antibiotic is active against gram-positive bacteria and is used exclusively as a feed additive for pigs. 

Research to date focused on isolating insecticidal prototype leads from marine origin has resulted in the report of about 40 active compounds.44 In an attempt to summarize these compounds and their activity margins, they have been categorized into seven classes of chemical structures polyhalogenated monoterpenes, polyhalogenated C15-metabolites, diterpenes, peptides and amino acids, phosphate esters, sulfur-containing derivatives, and macrolides. 

Because of concern about resistance transfer, however, there is a growing attempt to supplant these drugs with new compounds, such as the sulfur-containing peptide antibiotic... 

In heavily sulfited white wines containing over 0.5 ppm copper and stored in sealed containers, a reddish-brown deposit may form. This occurs in the absence of oxygen and ferric ions but redissolves readily upon exposure to oxygen. Its formation may be accelerated by exposure to sunlight or heat, and it is believed to consist of colloidal cupric sulfide (14, 29). More commonly, copper casse may arise from reactions between copper and sulfur-containing amino acids, peptides, and proteins (15,16,17). 

The poisonous components of the most deadly mushroom Amanita phalloides (the Death Cap) are bicyclic heptapeptides which have an additional covalent bond that connects the ( -sulfur atom of an l-cysteine residue with the carbon atom in position 2 of the indole ring of the L-tryptophan. Phalloidin (or phalloidine) is the most abundant member of a whole family of related cyclic heptapeptides called phallotoxins (for a review, see Wieland1 1). These poisonous peptides, therefore, contain a cross-linking moiety consisting of L-tryptophan coupled to L-cysteine, designated tryptathionine (1), alternatively called 5-(trypto-phan-2-yl)cysteine or 2-(L-3-alanylsulfenyl)-L-tryptophan (Scheme 1). 

Cleavage from the Resin The peptide was simultaneously deprotected and cleaved from the resin by a 30-min treatment with neat TFA (sulfur-containing scavengers have to be absent). The resin was filtered and the soln added to cold MTBE. The precipitated peptide was collected and treated with aq NH3 (pH 9.0-9.5) for 3 h at rt in order to restore the chemical integrity of the nitroxide moiety.1 201 HPLC Purification The peptide was purified by RP-HPLC (MeCN/H20 containing 0.1 % TFA). The above-noted NH3 treatment was repeated immediately after the HPLC elution. 

Synthesis of Peptides with Sulfur-Containing Amide Bond... 

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