A new and efficient method has been developed for the synthesis of 4-aryl-7-benzylidene-1,3,4,5,6,7-hexahydro-2H-cyclopenta[d]pyrimidin-2-ones through Biginelli-like reaction of cyclopentanone, with urea/thiourea and aromatic aldehyde employing p-dodecylbenzenesulfonic acid (DBSA) as a recyclable catalyst under solvent-free condition. The recovered catalyst was recycled for further runs. The pr...

Electronic structure calculations have been used to investigate possible gas-phase decomposition pathways of α-hydroxyalkyl hydroperoxides (HHPs), an important source of tropospheric hydrogen peroxide and carbonyl compounds. The uncatalyzed as well as water- and acid-catalyzed decomposition of multiple HHPs have been examined at the M06-2X/aug-cc-pVTZ level of theory. The calculations indicate ...

p-Hydroxyphenylacetaldehyde + reduced DPN + p-Hydroxyphenylethanol (tyrosol) + oxidized DPN (3) In reaction (1), the removal of the amino group is effected by transamination; 2-oxoglutarate was found to be essential for this step. This is followed by decarboxylation of the keto acid (reaction 2) to yield the aldehyde, which is reduced in the third stage to give the alcohol. In the first investi...

A new and efficient method has been developed for the synthesis of 4-aryl-7-benzylidene-1,3,4,5,6,7-hexahydro-2H-cyclopenta[d]pyrimidin-2-ones through Biginelli-like reaction of cyclopentanone, with urea/thiourea and aromatic aldehyde employing p-dodecylbenzenesulfonic acid (DBSA) as a recyclable catalyst under solvent-free condition. The recovered catalyst was recycled for further runs. The pr...

In the developing retina, a retinoic acid (RA) gradient along the dorso-ventral axis is believed to be a prerequisite for the establishment of dorso-ventral asymmetry. This RA gradient is thought to result from the asymmetrical distribution of RA-generating aldehyde dehydrogenases along the dorso-ventral axis. Here, we identified a novel aldehyde dehydrogenase specifically expressed in the chic...

Cyclophosphamide is converted by enzymes of mouse liver into two metabolites. Production of the first (aldophosphamide), which is uncharged, requires TPNH, is inhibited by CO, and is accomplished predominantly by the microsomal fraction. With the microsomal enzyme, the Km for Cyclophosphamide is 0.5 mM; nicotine, atropine, ephedrine, apomorphine, and cocaine are potent inhibitors. Phénobarbita...

Various mechanisms for the reversible formation of a covalent tetrahedral complex (TC) between papain and peptidyl aldehyde inhibitors were simulated by DFT calculations, applying the quantum mechanical/self consistent reaction field (virtual solvent) [QM/SCRF(VS)] approach. Only one mechanism correlates with the experimental kinetic data. The His-Cys catalytic diad is in an N/SH protonation st...