Reference

Extraction Behavior of Amino Acids by Calix[6]arene Carboxylic Acid Derivatives

Extraction Behavior of Amino Acids by Calix[6]arene Carboxylic Acid Derivatives. Oshima, Tatsuya; Goto, Masahiro; Furusaki, Shintaro (Graduate School of Engineering, Department of Chemical Systems and Engineering, Kyushu University, Hakozaki, Fukuoka 812-8581, Japan). Journal of Inclusion Phenomena and Macrocyclic Chemistry, 43(1-2), 77-86 (English) 2002 Kluwer Academic Publishers. CODEN: JIPCF5. ISSN: 1388-3127. DOCUMENT TYPE: Journal CA Section: 68 (Phase Equilibriums, Chemical Equilibriums, and Solutions) Section cross-reference(s): 34, 73, 77 A series of calixarene carboxylic acid derivs. were synthesized for the extn. of amino acids. A calix[6]arene carboxylic acid deriv. showed the highest extractability to the target tryptophan ester. The main driving force for the complexation was the interaction between the ammonium cation of the amino acid and the oxygen atoms of the host mol. Stripping of amino acids was also accomplished by contacting the org. soln. with a fresh acidic soln. Based on slope and Job method analyses, it was confirmed that the calix[6]arene forms a 1:1 complex with the amino acid ester. The structure of the complex between the calix[6]arene and the amino acid was investigated by 1H-NMR and CD spectra. The calix[6]arene includes a guest mol. 7524-52-9 and 485821-49-6 which are cas registry numbers of substances are two of reagents here. in the cavity, and the inclusion induces the asymmetrization of the host mol. This host compd. functions as a novel recognition tool for amino acids. .

An improved synthesis of methyl and benzyl esters as well as hydrazide of L-pyroglutamyl-L-histidyl-L-tryptophan

An improved synthesis of methyl and benzyl esters as well as hydrazide of L-pyroglutamyl-L-histidyl-L-tryptophan. Rzeszotarska, B.; Masiukiewicz, E. (Inst. Chem., Pedagog. Univ., Opole 45-052, Pol.). Org. Prep. Proced. Int., 16(5), 384-7 (English) 1984. CODEN: OPPIAK. ISSN: 0030-4948. 7524-52-9 which is the cas registry number of some chemical is mentioned. DOCUMENT TYPE: Journal CA Section: 34 (Amino Acids, Peptides, and Proteins) Title esters pyroGlu-His-Trp-R (I; R = OMe, OCH2Ph) were prepd. by sapong. pyroGlu-His-OMe by 1N NaOH/MeOH and coupling the resulting pyroGlu-His-OH with H-Trp-OR.HCl by DCC/1-hydroxybenzotriazole in DMF. I (R = OMe) was treated with NH2NH2 to give 99% I (R = NHNH2). .