Enzymatic Resolution of \u3b1-Methyleneparaconic Acids and Evaluation of their Biological Activity

Both enantiomers of three biologically relevant paraconic acids\u2014MB-3, methylenolactocin, and C75\u2014were obtained with enantioselectivities up to 99% by kinetic enzymatic resolutions. Good enantiomeric excesses were obtained for MB-3 and methylenolactocin, using \u3b1-chymotrypsin and aminoacylase as enantiocomplementary enzymes, while C75 was resolved with aminoacylase. They all were evaluated for their antiproliferative, antibacterial, and antifungal activities, showing weak effects and practically no difference between enantiomers in each case. At high concentrations (16\u201364 \u3bcg/mL), (\u2013)- C75 acted as an antimicrobial agent against Gram-positive bacteria

Stereoselective Synthesis of Naturally Occurring <i>α</i>-Methylenebis-<i>γ</i>-butyrolactones: An Application of Novel Oxiranyl “Remote” Anions

Stereospecific deprotonation of the epoxy proton at the β-position of the α,β-epoxy esters 5 and 6 yielded oxiranyl “remote” anions 7 and 8, which could then be used for alkylation. The anions 7 and 8 underwent a consecutive aldol lactonization to give, respectively, epoxy lactones 11 and 13 with high stereoselectivity. Generation of the remote anions as well as their stereoselective reactions served as a new synthetic route to the naturally occurring α-methylenebis-γ-butyrolactones, 1

Neuroprotection against Cerebral Ischemia through Inhibition of Calpain Using Tetracycline Derivatives

Peer reviewed: YesNRC publication: Ye

Chlortetracycline and demeclocycline protect mouse neurons against glutmate toxicity an cerebral ischemia through inhibition of calpains.: J.Neuroscience

NRC publication: Ye