Antibacterial activity of coumarin derivatives

Preliminary tests of antibacterial activity of several coumarin derivatives, substituted at the positions of 3 or 4 of the pyrone cycle. Halogen-containing coumarins do not exhibit antibacterial properties. A sodium salt of 4-mercaptocoumarin is the most active bacteriostatic compounds among sulfur-containing derivatives.     

The Role of Trehalose and Glycogen in the Survival of Aging Saccharomyces cerevisiae Cells

The role of the storage carbohydrates trehalose and glycogen in the survival of aging Saccharomyces cerevisiae cells was studied. Culture aging for one week did not reduce cell viability. During this period, the cells accumulated the storage carbohydrates and showed increased activity of the glycolytic enzymes hexokinase and phosphofructokinase. However, further aging led to a drastic drop in cell viability and to a decrease in the cellular content of trehalose and glycogen and in the activity of hexokinase and phosphofructokinase. The possible reasons for these changes are discussed.     

Effect of ubiquinone on phospholipid metabolism in radiation injury

The synthesis and phospholipid content in the liver, intestine and spleen in normal and irradiated rats administered ubiquinone-9 were studied with the use of 3H-serine. Ubiquinone markedly activated decarboxylation of phosphatidylserine and suppressed transformation of phosphatidylethanolamine to phosphatidylcholine in rat liver and spleen. The effect was also observed in the organs of irradiated animals. In rat intestine, administration of ubiquinone normalized a sharp gamma-irradiation-induced inhibition of transformation of phosphatidylcholine from phosphatidylethanolamine. The catabolism of phospholipids under the action of ubiquinone and radiation was inhibited in the liver and, on the contrary, was activated in radiosensitive organs.