Amino acids and peptides. XCIII. Application of the Hammett equation to the optical rotation of substituted β-phenylalanines

1969 ◽  
Vol 34 (9) ◽  
pp. 2852-2856 ◽  
Author(s):  
K. Bláha ◽  
I. Frič
1997 ◽  
Vol 161 ◽  
pp. 505-510
Author(s):  
Alexandra J. MacDermott ◽  
Laurence D. Barron ◽  
Andrè Brack ◽  
Thomas Buhse ◽  
John R. Cronin ◽  
...  

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.


1963 ◽  
Vol 46 (3) ◽  
pp. 353-358 ◽  
Author(s):  
Carl E Vandercook ◽  
Laurence A Rolle ◽  
Robert M Ikeda

Abstract The total amino acid and i-malic acid content of 61 samples of commercial California-Arizona lemon juice and lemon juice concentrates were studied. In characterizing these juices, relationships were observed between the natural citric acid content and the amounts of their total amino acids and l-malic acid. Total amino acids were determined by formol titration, while the l-malic acid was determined by measuring the optical rotation of a uranylmalate complex. Paper chromatograms of the individual amino acids are used to supplement these methods of analysis for characterizing lemon juice.


2007 ◽  
Vol 111 (35) ◽  
pp. 10510-10519 ◽  
Author(s):  
Simona Rossi ◽  
Pierandrea Lo Nostro ◽  
Marco Lagi ◽  
Barry W. Ninham ◽  
Piero Baglioni
Keyword(s):  

1962 ◽  
Vol 15 (1) ◽  
pp. 106 ◽  
Author(s):  
IW Stapleton ◽  
JM Swan

L-Cystine diamide has been synthesized by several different routes and isolated as its crystalline di(trifluor0acetate) and dihydrochloride. The compound has a molecular rotation [M]D21 -630� in 1N HCl, compared to [M]D20 -537� for L-cystine ; the rotation is strongly dependent on pH in the range 5-8, the value of [M]D20 at pH 8 being -120�. The polarographic behaviour of L-cystine diamide is very similar to that of cystine. The amino groups in cystine diamide are only weakly basic, the pK?A values being 5.93 and 6.90 for the successive ionizations of the two NH3+ groups. The latter result is in accordance with the known acigenic properties of both amide and disulphide groups. A possible relation between optical rotation of cystine compounds and the pK? values of ionizable groups present in the molecule is discussed.


Author(s):  
Shuichi Katsumoto ◽  
Manami Mimura ◽  
Tomohiko Ishii ◽  
Genta Sakane ◽  
Kazuyoshi Ogasawara

Sign in / Sign up

Export Citation Format

Share Document