Immobilization to improve the properties of Pseudomonas fluorescens lipase for the kinetic resolution of 3-aryl-3-hydroxy esters

Lipase AK “Amano” 20 from Pseudomonas fluorescens (PFL) was immobilized using diverse immobilization techniques. The methods developed, especially the optimized sol-gel procedure, enabled the fine tuning of enzymatic activity and enantioselectivity for the kinetic resolution of racemic ethyl 3-aryl-3-hydroxypropanoates. The aryl moieties of the racemates include furan-2 and 3-yl, thiophen-2 and 3-yl, benzofuran-2-yl, benzo[b]thiophen-2-yl, as well as phenyl and 4-chloro- and 4-methoxyphenyl groups. The optimized PFL sol-gel preparation (encapsulation from the aqueous solution of PFL, sucrose and Celite in situ) was shown to be efficiently reusable in ten cycles and highly enantioselective with E > 200 to all other substrates except furan-2 and 3-yl and thiophen-2 and 3-yl substituted compounds with E 108-184.     

Baker’s yeast mediated preparation of (10-alkyl-10H-phenothiazin-3-yl)methanols

A series of 10-alkyl-10H-phenothiazine-3-carbaldehydes (2a–h) were obtained by Vilsmeier–Haack formylation from the corresponding 10-alkyl-10H-phenothiazines (1a–h) and reduced to (10-alkyl-10H-phenothiazine-3-yl)methanols (3a–h) by two alternative methods. The baker’s yeast catalyzed reaction proved to be superior over the NaBH₄ reduction and yielded the desired 3-hydroxymethylphenothiazines (3a–h) almost quantitatively.     

Influence of Novel Gallium Complexes on the Homeostasis of Some Biochemical and Hematological Parameters in Rats

Chronic overexposure to cobalt (Co) may result in neurotoxic effects, but the mechanism of Co-induced neurotoxicity is not yet well established. Our study was conducted to determine whether Co is associated to the induction of central nervous system damage in pregnant rats and their progeny. Twelve pregnant female rats were randomly divided into 2 groups: group I served as controls and group II received Co (350 mg/L, orally). Treatments started from the 14th day of pregnancy until day 14 after delivery. Co concentration in plasma was higher in the treated groups than in the controls. Exposure to Co also increased the levels of MDA, PCO, H₂O₂, and AOPP, while Na⁺K⁺-ATPase and Mg²⁺-ATPase, AChE, and BuChE activities decreased in the cerebrum and cerebellum of suckling pups. A smear without ladder formation on agarose gel was also shown in the cerebrum and cerebellum, indicating random DNA degradation. A reduction in GPx, SOD, CAT, GSH, NPSH, and vitamin C values was observed. The changes were confirmed by histological results. In conclusion, these data showed that the exposure of pregnant and lactating rats to Co resulted in the development of oxidative stress and the impairment of defense systems in the cerebrum and cerebellum of their suckling pups.