- Synthesis of the suicide substrate D-propargylglycine stereospecifically labelled with deuterium and investigation of its oxidation by D-amino acid oxidase
-
Stereospecifically deuteriated samples of D-propargylglycine 1 have been prepared by reaction of the labelled Pmc-protected aziridine free acids 22 with a lithium acetylide followed by deprotection. These samples have been used to show that D-amino acid oxidase, in converting D-propargylglycine to the lactone 5, deprotonates C-3 in a non-stereospecific manner. This strongly supports the idea that non-enzymic deprotonation is a key step in the formation of this compound.
- Church, Nicola J.,Young, Douglas W.
-
p. 1475 - 1482
(2007/10/03)
-
- 3-Bromo-2-fluoropropene - a fluorinated building block. 2-fluoroallylation of glycine and alanine ester imines
-
3-Bromo-2-fluoropropene (4) is prepared in a new three-step synthesis from ammonium α-fluoroacrylate (1) in 31% overall yield. Glycine and alanine ester imines are efficiently alkylated by 4 to give, after deprotection, 2-amino-4-fluoropent-4enoic acid (9) in 63% overall yield, and the α-methylated derivalive 13 in 26% overall yield, respectively. Preliminary results indicate that 4 is potentially a new a-carbonyl cation equivalent.
- Laue, Klaus W.,Haufe, Guenter
-
p. 1453 - 1456
(2007/10/03)
-
- Components of the Green Deathcap Toadstool Amanita phalloides, LVIII. - Some Dithiolanes Derived from Ketophalloidin as Reagents in Biochemical Research
-
Ketophalloidin (2), obtained from phalloidin (1) by oxidation with periodate, was transformed into the dithiolanecarboxylic acid 3 by reaction with 2,3-dimercaptopropionic acid, and into the (aminomethyl)dithiolane 4 by reaction with 3-amino-1,2-propanedithiol.Compound 4 was the starting material for the following derivatives: the N-(3-carboxypropionyl) compound 5, the N-iodoacetyl compound 6 and, by nucleophilic substitution of iodide by azide, for the azidoacetyl compound 8.A fluorescent phallotoxin (7) was obtained by reaction of 4 with fluorescein isothiocyanate.All phallotoxins described in this paper specifically bind, like phalloidin, to the receptor protein actin.Derivatives 6 and 7, as radioactively labeled molecules, are suitable for a covalent fixation to actin (affinity labeling); the functional derivatives 3,4 and 5 have been conjugated to bovine serum albumin, and the amino compound 4 has been covalently attached to activated sepharose in order to generate an adsorbent for affinity chromatography
- Wieland, Theodor,Deboben, Axel,Faulstich, Heinz
-
p. 416 - 424
(2007/10/02)
-
