Rational redesign of Candida antarctica lipase B for the ring opening polymerization of D,D-lactide

Based on molecular modelling, the enzyme Candida antarctica lipase B was redesigned as a catalyst for the ring opening polymerization of D,D-lactide. Two mutants with 90-fold increased activity as compared to the wild-type enzyme were created. In a preparative synthesis of poly(D,D-lactide) the mutants greatly improved the rate and the degree of polymerization.     

Direct experimental evidence for an enamine radical cation in SOMO catalysis

SOMO catalysis has lately obtained large interest as a new and powerful version of enantioselective organocatalysis which includes radical steps initiated by a one-electron oxidation. The intermediate enamine radical cation has been postulated, but has not been observed directly so far. This communication now reports the direct detection of this key intermediate.     

PHOTODYNAMIC ALTERATIONS OF THE CELL ENVELOPE OF PROTEUS MIRABILIS AND THEIR REPAIR

Abstract— Photodynamic treatment of Proteus mirabilis gives rise to changes in the cell envelope as can be detected by the behaviour of cells during lysis: lysis of cells proceeds more readily than that of untreated cells, measured by the liberation of labelled DNA. After photodynamic treatment the cell envelope is restored to the control levels. This repair process takes place within 5 min in broth as well as in buffer solutions.     

Organic transformations via metal silane reagents: syntheses of vinyl ethers from dimethyl ketals and (CO)5MnSi(CH3)3

The reaction of dimethyl ketals with (CO)₅MnSi(CH₃)₃ ($\text{1}$ at 50 °C in CH₃CN affords methyl enol ethers, generally in 75–95% yields.