Activation of O-Electrophiles Structural and Solvent Effects: S2@O Reaction of Cyclic Diacyl Peroxides with Enol Acetates.

The reactions of O-electrophiles, such as organic peroxides, with carbon nucleophiles are an umpolung alternative to the common approaches to C-O bond formation. Nucleophilic substitution at the oxygen atom of cyclic diacyl peroxides by enol acetates with the following deacylation leads to α-acyloxyketones with an appended carboxylic acid in 28-87% yields. The effect of fluorinated alcohols on the oxidative functionalization of enol acetates by cyclic diacyl peroxides was studied experimentally and computationally.

Study of total lipid peroxidation and antioxidant activity in pulmonary and mediastinal malignant and benign tumor tissue.

Total lipid peroxidation and antioxidant activity were studied in pulmonary and mediastinal malignant and benign neoplasms. In malignant tumors total lipid peroxidation increased and antioxidant activity decreased; the intensity of these shifts depended on histological characteristics and degree of malignancy: the most pronounced changes were observed in thymoma and adenocarcinoma tissues and minimum changes were found in bronchoalveolar carcinoma tissue.

Activity of glutathione-metabolizing and antioxidant enzymes in malignant and benign tumors of human lungs.

We measured the content of glutathione and activity of glutathione-metabolizing and antioxidant enzymes superoxide dismutase and catalase in samples obtained from 52 patients with malignant lung tumors and 20 patients with benign lung tumors. The content of glutathione and activity of glutathione-metabolizing enzymes underwent similar changes, but these changes were most pronounced in malignant tumors. Antioxidant enzyme activity changed insignificantly in benign tumors, but significantly decreased in malignant tumors (squamous cell carcinoma and adenocarcinoma).

In vitro effects of folic acid on gamma-glutamyltransferase and glutathione reductase activities in malignant lung and thymus tumors.

In vitro effects of folic acid (10(-5), 10(-4), and 10(-3)M) on activities of gamma-glutamyltransferase and glutathione reductase, the enzymes involved in glutathione metabolism, were studied in tissue samples obtained after surgical treatment of the lungs and thymus. Folic acid did not change gamma-glutamyltransferase activity in lung cancer tissue, but in thymoma tissue this substance in a concentration of 10(-3)M inhibited it by 16%. Folic acid had no effects on glutathione reductase activity in benign tumors and normal lung and thymus tissues, but increased this activity in thymoma and lung cancer tissues.

Stabilizating effect of 5-nitroindole (universal base) on DNA duplexes immobilized on gel matrix.

Effect of attachment of 1-(2-deoxy-beta-D-ribofuranosyl)-5-nitroindole (NIDR) to the ends of target sequence of oligonucleotides immobilized on gel micromatrix on stability of duplex formed by hybridization with DNA fragment was studied. It was shown that adjunction of NIDR to 5' as well as to 3' end results in increasing stability of duplexes although in the second case the extent of stabilization effect is essentially lower. Both 5' and 3' terminal NIDR exhibited no selectivity to the opposite base while the stabilizing effect depended dramatically on the nature of the adjacent base especially in the case of 5'-end-attached universal base.