Detail of "95713-52-3"

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Efficient, racemization-free amidation of protected amino acids

Efficient, racemization-free amidation of protected amino acids.Several substances are used for example 95713-52-3 and 141076-78-0 which are their cas registry numbers. Somlai, Csaba; Szokan, Gyula; Balaspiri, Lajos (Inst. Med. Chem., Szent-Gyorgyi Albert Med. Univ., Szeged H-6720, Hung.). Synthesis, (3), 285-7 (English) 1992. CODEN: SYNTBF. ISSN: 0039-7881. DOCUMENT TYPE: Journal CA Section: 34 (Amino Acids, Peptides, and Proteins) N-tert-Butoxycarbonyl amino acid derivs. Boc-X-OH [Boc = Me3CO2C; X = Leu, Cys(CH2Ph), His(Dnp); Dnp = 2,4-(O2N)2C6H3] were amidated with cryst. ammonium salts of 3-hydroxy-1,2,3-benzotriazin-4(3H)-one and N-hydroxysuccinimide to give the corresponding amino acid amides Boc-X-NHR (R = H, Me, Et) in good yield and with good optical purity. .

A nonempirical method using LC/MS for determination of the absolute configuration of constituent amino acids in a peptide: elucidation of limitations of Marfey's method and of its separation mechanism

A nonempirical method using LC/MS for determination of the absolute configuration of constituent amino acids in a peptide: elucidation of limitations of Marfey's method and of its separation mechanism. Fujii, Kiyonaga; Ikai, Yoshitomo; Mayumi, Tsuyoshi; Oka, Hisao; Suzuki, Makoto; Harada, Ken-ichi (Faculty of Pharmacy, Meijo University, Tempaku 468, Japan). Analytical Chemistry, 69(16), 3346-3352 (English) 1997 American Chemical Society. CODEN: ANCHAM. ISSN: 0003-2700. DOCUMENT TYPE: Journal CA Section: 34 (Amino Acids, Peptides, and Proteins) Section cross-reference(s): 9, 22, 80 As the first step in establishing the author's proposed method, the advanced Marfey's method, which is planned for the simultaneous detn. of the abs. configuration of amino acids in a peptide, Marfey's method was applied to com. available amino acids, and the sepn. behavior was examd. in detail. Although good resoln. of the diastereomeric pair of an individual amino acid was obtained for all amino acids tested and the applicability of the method was confirmed, the (1-fluoro-2,4-dinitrophenyl)-5-L-alaninamide (FDAA) deriv. of the L-amino acid was not always eluted prior to its corresponding D-amino acid deriv. Because this proposed method relies on the elution order of a derivatized amino acid with FDAA to det. 95713-52-3 is the cas registry number. This chemical is also mentioned in this article. its abs. configuration, its sepn. mechanism was carefully investigated using UV and NMR spectral techniques. The results suggested that the resulting conformations of the L- and D-amino acid derivs. are stable and that the resoln. between the L- and D-amino acid derivs. is due to the difference in their hydrophobicity, which is derived from the cis- or trans-type arrangement of two more hydrophobic substituents at both a-carbons of an amino acid and L-alanine amide, so that the FDAA deriv. of the cis (Z)-type arrangement interacts more strongly with ODS silica gel and has a longer retention time than that of the trans (E)-type arrangement. Therefore, the L-amino acid deriv. is usually eluted from the column before its corresponding D-amino acid deriv. in Marfey's method. According to this sepn. mechanism, the elution order of a desired amino acid can be elucidated from the av. retention time of the L- and D-amino acid derivs., and the DL-serine and DL-asparagine derivs. are crit.Except for chemicals metioned above, 95713-52-3 is also used. for Marfey's method. ..