72744-87-7Relevant articles and documents
N-terminal dipeptides of D(-)-penicillamine as sequestration agents for acetaldehyde
Cohen, Jonathan F.,Elberling, James A.,DeMaster, Eugene G.,Lin, Renee C.,Nagasawa, Herbert T.
, p. 1029 - 1033 (2000)
Since acetaldehyde (AcH), a toxic oxidation product of ethanol, may play an etiologic role in the initiation of alcoholic liver disease, we had earlier pioneered the development of β,β-disubstituted-β-mercapto-α-amino acids as AcH-sequestering agents. We now report the synthesis of a series of N-terminal dipeptides of D(-)-penicillamine, prepared from the synthon 3- formyl-2,2,5,5-tetramethylthiazolidine-4S-carboxylic acid (3), a cyclized N- protected derivative of D(-)-penicillamine. These dipeptides were equally or more effective than penicillamine in trapping AcH in a cell-free system. In experiments using a hepatocyte culture system, two of the dipeptides, D- penicillamylglycine (6a) and D-penicillamyl-β-alanine (6d), at 1/20 the molar concentration of ethanol, lowered the concentration of ethanol-derived AcH by 79% and 84%, respectively, at 2 h. The presence of cyanamide (an inhibitor of aldehyde dehydrogenase) in the incubation medium resulted in a 45-fold increase in ethanol-derived AcH; nevertheless, dipeptides 6a and 6c (D-penicillamyl-α-aminoisobutyric acid) were able to reduce this AcH level by approximately one-third.
Gas/Solid Reactions with Acetone
Kaupp, Gerd,Pogodda, Uwe,Schmeyers, Jens
, p. 2249 - 2262 (2007/10/02)
Gas/solid reactions of acetone vapor with neutral organic compounds, salts, or host crystals with strict exclusion of solvents are reported.This gas/solid technique largely avoids waste formation and saves resources.Starting hydrochlorides or hydrobromides are also synthesized by gas/solid techniques.Dihydrohalides of o-phenylenediamines give 1,5-benzodiazepines 3, aromatic and aliphatic 1,2-aminothiols (o-aminothiophenol, penicillamines, cysteine) yield five-membered thiazolines and thiazolidines 7, 9, 11, 13.Virtually all carbonyl reagents of the primary amino type 14 give quantitatively the imino derivatives 15 and water.Salt formation may be helpful for increasing melting points and sometimes reactivity as in 8, 10, and 12 if surface passivation has to be overcome.In the case of solid 14 the free bases react equally well.Acetone (2) may be quantitatively removed from exhaust gases by using hydroxylaminium phosphate with formation of free acetone oxime at high flow rates.Inclusion of acetone into various hosts (17-20, but not 16) is more efficient by imbibition from the gas phase than by crystallization from acetone as the solvent.This advantage may be utilized for gas separations.Some further gases (vapors) coexist in imbibed clathrates whereas others do not.The mechanisms of the gas/solid reactions are elucidated using atomic force microscopy (AFM).Phase rebuildings involve anisotropic movements of molecules over large distances and the formation of characteristic features.In some cases surface hydrates catalyze the gas/solid reaction.Solid-state mechanisms for imbibition from the gas phase into host crystals with formation of clathrates are similar in nature to those of the covalent reactions.These results are correlated with known X-ray crystal structures where available. - Key Words: Gas/solid reactions / Imbibition / Acetone derivatives / Atomic force microscopy / Anisotropic phase rebuilding / Waste prevention
(S)-2,2,5,5-Tetramethylthiazolidine-4-carboxylic acid: a compound which exists in the amino acid rather than the zwitterion form
Howard-Lock, Helen Elaine,Lock, Colin James Lyne,Smalley, Philip Stuart
, p. 2411 - 2419 (2007/10/02)
The X-ray crystal structure of (S)-2,2,5,5-tetramethylthiazolidine-4-carboxylic acid, 1, has been determined.Crystals are monoclinic, P21, with cell dimensions a = 11.351(4), b = 8.303(2), c = 11.969(3) Angstroem, β = 116.69(2)o, and Z = 4.The structure was solved by standard methods and refined to R1 = 0.0774, R2 = 0.0670 for 2388 independent reflections.Compound 1 exists in the amino-acid form as shown by two distinctly different C-O bond lengths, 1.209 and 1.309 Angstroem, typical of the COOH group, and by the positions of the hydrogen atoms.The amino-acid form of 1 found in the solid also exists in solution as shown by infrared and Raman spectra.The mass spectra, and 1H and 13C nmr spectra are reported, as well as detailed infrared and Raman spectra for the title compound and several deuterated species.
