DNA degradation in isolated rat liver nuclei

Purified rat liver nuclei were incubated at 4°C. After different intervals of incubation aliquots of the nuclear suspension were taken and DNA was extracted by a common SDS-phenol-chloroform procedure. The fractionation of DNA by agar gel electrophoresis revealed large DNA fragments. It was shown that the well-known DNA degradation to monomers and its multiples is preceeded by an earlier breakdown of DNA into characteristic large fragments.     

Gastroprotective action of glucocorticoids during the formation and the healing of indomethacin-induced gastric erosions in rats.

The aim of the present study consisted of the investigation of glucocorticoid role in the formation and the healing of indomethacin-induced (25 mg/kg, s.c.) gastric erosions in rats. The effect of deficiency of glucocorticoid production followed by corticosterone replacement on the formation and the healing of the gastric erosions was evaluated. Glucocorticoid production was decreased by adrenalectomy or by delayed inhibitory action after a single pharmacological dose of cortisol (300 mg/kg i.p.) injected 1 week before the onset of ulcerogenic stimulus. Indomethacin induced corticosterone rise and caused gastric erosions. The loss of indomethacin-induced plasma corticosterone rise potentiated the formation of indomethacin-induced erosions in both models. The area of gastric erosions in rats with glucocorticoid deficiency was considerably larger than that in control animals 4 h after indomethacin administration as well as during 48 h after the drug administration (period of erosion healing). Injecting corticosterone in rats with glucocorticoid deficiency significantly decreased the formation of indomethacin-induced gastric erosions and promoted their healing. Thus, the present data support the gastroprotective action of glucocorticoids in the formation and in the healing of indomethacin-induced mucosal injury.     

A Comparative Study of Nitrilases Identified by Genome Mining

Escherichia coli strains expressing different nitrilases transformed nitriles or KCN. Six nitrilases (from Aspergillus niger (2), A. oryzae, Neurospora crassa, Arthroderma benhamiae, and Nectria haematococca) were arylacetonitrilases, two enzymes (from A. niger and Penicillium chrysogenum) were cyanide hydratases and the others (from P. chrysogenum, P. marneffei, Gibberella moniliformis, Meyerozyma guilliermondi, Rhodococcus rhodochrous, and R. ruber) preferred (hetero)aromatic nitriles as substrates. Promising nitrilases for the transformation of industrially important substrates were found: the nitrilase from R. ruber for 3-cyanopyridine, 4-cyanopyridine and bromoxynil, the nitrilases from N. crassa and A. niger for (R,S)-mandelonitrile, and the cyanide hydratase from A. niger for KCN and 2-cyanopyridine.     

Nitrile- and Amide-converting Microbial Enzymes: Stereo-, Regio- and Chemoselectivity

Biotransformations using microbial nitrile- and amide-converting enzymes have developed considerably in the recent years. Most processes profited from the stereo-, regio- and chemoselectivity of nitrile hydratases, nitrilases and amidases specific for primary or secondary amides. The aim of this review is to discuss the developments in this branch of biotransformations in the last ca. 5 years by taking highlights from research journals, patents and industrial applications.     

Terpenoid metabolites from the aerial part of Artemisia lagocephala

Six naturally occurring terpenoids were isolated from the hexane extract of rabbit-head wormwood Artemisia lagocephala (Fisch. ex Besser) DC. The terpenoids’ structures were elucidated by spectroscopic and chemical methods as 3β-acetoxycycloartan-24-ozonide (1), 3β-acetoxycycloartan-24-al (2), 25,26,27-trisnor-3β-acetoxycycloartan-24-ol (3), 24,25,26,27-tetranor-3β-acetoxycycloartan-23-ol (4), and the previously known caryophyllene oxide (5) and (1R,4S)-p-menth-2-en-1-ol (6).