Fl-Amino acids

S)-fl-Amino acids.1 The Mannich reaction of the Schiff base 1, prepared from 2,3,4,6-tetra-O-pivaloyl-fl-D-galactosylamine, reacts with the silyl ketene acetal 2 in... 

J. Tamariz, Bbbgical Activity of fl-Amino Acids and fl-Lactams in Enantioselective Synthesis of fl-Amino Acids, E. Juaristi, ed., Wiley-VCH, New York, 1997, 45-66. 

Some bacteria make their cell walls from unnatural fl-amino acids to make them unassailable by the (S-amino-acid-derived) enzymes used by higher organisms to hydrolyse peptides. 

Liquid chromatographic resolutions based on highly selective host-guest, metal chelate and charge-transfer com-plexations have been described (1,2). Recently, a chiral diamide-bonded stationary phase (I) has been prepared, which relies entirely on hydrogen bond associations for the material to be resolved. Despite the weak and flexible interaction in this system, direct resolution of enantiomeric N-acyl-fl-amino acid esters (II) was accomplished with the advent of a highly efficient column technology (2- ). 

William Howard Stein fl 911-1980) was born in New York City and received his Ph.D. in 1938 from the Columbia College of Physicians and Surgeons. He immediately joined the faculty of the Rockefeller Institute, where he remained until his death. In 1972, he shared the Nobel Prize in chemistry for his work with Stanford Moore on developing methods of amino acid analysis and for determining the structure of ribonuclease. 

Except for cysteine, only S amino acids occur in proteins. Several R amino acids are also found in nature, however. (ft)-Serine is found in earthworms, and (R)-alanine is found in insect larvae. Draw Fischer projections of (fl)-serine and (J )-alanine. Are these Don amino acids ... 

Hughes, GJ. and Frutier, S. 1990 Amino acid analysis protocols, possibilities, and pretensions. In Fini, C, Floridid, A., Finelli, V.N. and Wittman-Leibold, B., eds., Laboratory Methodology in Biochemistry Amino Acid Analysis and Protein Sequencing. Boca Raton, FL, CRC Press, Inc. 44-61. 

NOTE ADDED IN PROOF This manuscript had been submitted shortly after the presentation of the paper at the Fourth Advanced Seminar on Pale-odiet, 1994. Ongoing research, especially stable isotope analysis of single amino acids from inoculated and non-inoculated marten bones (same specimens as in this paper) further and strongly support our conclusion that bacterial modifica-tion causes substantial shifts in collagen stable isotope ratios (Balzer et fl/. 1997). 

Sasagawa, T. and Teller, D. C., Prediction of peptide retention times in re-versed-pahase HPLC, in CRC Handbook of HPLC for the Separation of Amino Acids, Peptides, and Proteins, Vol. II, Hancock, W. S., Ed., CRC Press, Boca Raton, FL, 1984, 53. 

Bartok, T., Szalai, G., Lorincz, Zs., Borcsok, G., and Sagi, F., High-speed RP-HPLC/FL analysis of amino acids after automated two-step derivatization with o-phthaldialdehyde/3-mercaptoproprionic acid and 9-fluorenylmethyl chloroformate, /. Liq. Chromatogr., 17, 4391, 1994. 

Figure 7.5. Peptide array construction by SPOT-synthesis. fl-alanine groups (b-A) interact with the cellulose filter that serves as a planar support. Peptide synthesis then proceeds using Fmoc chemistries using the fl-alanine group as a starting point. The peptide is attached to the filter via its carboxy-terminus. In this case, lysine is added at the second position and various amino acids are present at the amino terminus of the peptide.

G-CSF is also known as pluripoietin and CSI -fl. Two slight variants are known, one consisting of 174 amino acids and the other of 177. The smaller polypeptide predominates and also displays significantly greater biological activity than the larger variant. 

Table 6.1 Abbreviations BAN, BANYULS bHLH, basic helix-loop-helix CHS, chalcone synthase CHI, chalcone isomerase DFR, dihydroflavonol reductase F3H, flavonol 3-hydroxylase F3 H, flavonoid 3 -hydroxylase FLS, flavonol synthase icx, increased chalcone synthase expression LDOX, leucoanthocyanidin dioxygenase LCR, leucoanthocyanidin reductase MATE, multidrug and toxic compound extrusion NR, not yet reported tt, transparent testa ttg, transparent testa glabrous the WD40 and WRKY transcription factors are named for conserved amino acid sequences within these proteins. PC = personal communication.

Huovinen P, Gomez I, Figueroa FL, Ulloa N, Morales V, Lovengreen C (2004) Ultraviolet absorbing mycosporine-like amino acids in red macroalgae from Chile. Bot Mar 47 21-29... 

Karsten U, Sawall T, Hanelt D, Bischof K, Figueroa FL, Flores-Moya A, Wiencke C (1998b) An inventory of UV-absorbing mycosporine-like amino acids in macroalgae from polar to warm-temperate regions. Bot Mar 41 443—453... 

As expected, adsorption of (S)-lys, -his, -om and other amino acids causes the (S)-glu-HCl crystals to grow as thinner and thinner plates, and finally as powder at higher and higher inhibitor concentrations, while the (fl)-gluHCl... 

The short-end injection was also used in a paper by Perrin et al. [28]. They saw a very high chiral recognition capability of highly sulfated cyclodextrins (HS-CD). Using a test set of 27 amino acid derivatives, the application of HS-a-CD, HS-fl-CD, and HS-y-CD in a 5% w/v concentration allowed the separation of 26 compounds, of which 22 had a Rs > 2. From their experiments, a screening and optimization scheme was derived (Figure 3.3), and based on this scheme, a separation strategy was defined... 

Purify the FMLPK-Fl on a Cjg reverse-phase HPLC column by isocratic elution with a solution of 30% acetonitrile and 0.2 M acetic acid. Monitor the effluent at 254 nm. The peak corresponding to FMLPK-Fl should be clearly resolved from unreacted FITC and its breakdown products. Confirm the identity of FMLPK-Fl by performing an amino acid analysis of an acid-hydrolyzed sample. 

The preparation of protected derivatives of D-allo- and L-fl//o-threonine by enzymatic hydrolysis of 5(47/)-oxazolones using hog kidney acylase has also been described. This methodology has been extended to a wide variety of amino acids and, at present, constitutes a general procedure to prepare non-quaternary... 

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