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Seventy-eight collections of species forming the Achillea millefolium group were studied for the aglycone composition of their leaf exudates. 6-Hydroxyflavones, 6-hydroxyflavonols and their methyl ethers predominate in the exudates in various combinations. Within the polyploid complex, the diploid taxa Achillea setacea and Achillea aspleniifolia appeared to be chemically well defined. Among the polyploids, little differentiation of major accumulation trends was observed. Infraspecific variability was low in most cases, thus allowing systematic interpretations of aglycone patterns. Possible pharmacological activities are briefly discussed. 相似文献
996.
Hyperthermic treatment at 43 degrees C suppressed the growth of Ehrlich ascites tumor (EAT) cells in vitro. Incubation of EAT cells at 43 degrees C for as little as 1.5 h totally abolished the transplantability of the tumor. At the same time, the rate of cellular glucose uptake, the density of glucose transporter on the cells as well as the extent of thymidine, uridine and leucine incorporation were significantly reduced. 相似文献
997.
998.
The metal-binding agents (citrate, oxalate, bicarbonate, EDTA) exert dual effects on D-glucose-6-phosphate phosphohydrolase activity in the homogenate as well as in the subcellular fractions. The important differences of the effects are associated with the concentration of the chelator and with time of its addition. The small (appropriate) concentrations of the metal-binding agents stimulate and stabilize the enzyme activity. However, chelators used in higher concentrations exert the inhibitory influence on the activity of glucose-6-phosphatase. Stimulation of the reaction was observed only if the chelator was added before the enzyme-substrate complex formation has been started. The formation of the ternary complex: the enzyme(metal)-chelator substrate exerting a protective influence on the active centre has been suggested. The hypothesis of a similar action of the metal-binding agents and Pi on the glucose-6-phosphatase as a metaloproteid has been proposed. 相似文献
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1000.