Flavonoids enantiomer distribution in different parts of goldenrod (Solidago virgaurea L.), lucerne (Medicago sativa L.) and phacelia (Phacelia tanacetifolia Benth.)

Plant material is a rich source of valuable compounds such as flavanones. Their different forms influence bioavailability and biological activity, causing problems with the selection of plant material for specific purposes. The purpose of this research was to determine selected flavanone (eriodictyol, naringenin, liquiritigenin, and hesperetin) enantiomer contents in free form and bonded to glycosides by an RP‐UHPLC‐ESI‐MS/MS method. Different parts (stems, leaves, and flowers) of goldenrod (Solidago virgaurea L.), lucerne (Medicago sativa L.), and phacelia (Phacelia tanacetifolia Benth.) were used. The highest content of eriodictyol was found in goldenrod flowers (13.1 μg/g), where it occurred mainly as the (S)‐enantiomer, and the greatest proportion of the total amount was bonded to glycosides. The richest source of naringenin was found to be lucerne leaves (4.7 μg/g), where it was mainly bonded to glycosides and with the (S)‐enantiomer as the dominant form. Liquiritigenin was determined only in lucerne, where the flowers contained the highest amount (1.2 μg/g), with the (R)‐enantiomer as dominant aglycone form and the (S)‐enantiomer as the dominant glycosylated form. The highest hesperetin content was determined in phacelia leaves (0.38 μg/g), where it was present in the form of a glycoside and only as the (S)‐enantiomer. A comparison of the different analyte forms occurring in different plant parts was performed for the first time.     

Effect of hyperthermia and ionizing radiation on the erythrocyte membrane

Spin-label studies of the effects of hyperthermia on the erythrocyte membrane revealed a decrease in the fluidity of lipids and changes in the state of membrane proteins. The rate of haemolysis in iso-osmotic glycerol solution was increased. Changes of most of the parameters studied when plotted in Arrhenius coordinates revealed a discontinuity (critical hyperthermic transition in the membrane) between 46 and 50 degrees C. Studies of the combined action of ionizing radiation (100 Gy) and hyperthermia (43 degrees C) showed the same direction of changes for (Na-K-Mg)-ATPase activity and spectra of membrane-bound maleimide spin label for both agents, but the additivity of changes depended on the parameter studied.     

Aging of the erythrocyte

In contrast to situation found in other cell types, no linear dependence of product fluorescence vs time is observed when fluoresceine diacetate (FDA) is hydrolysed by erythrocytes and hemolysates. The rate of hydrolysis is increased by high concentrations of sucrose suggesting a positive effect of viscosity on the rate of the reaction. These peculiarities can be explained by assumption of a two-step hydrolysis of FDA. The FDA-hydrolytic activity decreases with increasing cell density (age).     

The influence of oxygen on the survival and yield of DNA double-strand breaks in irradiated yeast cells.

Survival and induction of DNA double-strand breaks were studied in cells of Saccharomyces cerevisiae irradiated under oxic or anoxic conditions with 30 MeV electrons. A linear relationship between DNA double-strand breakage and dose was found in both cases. The o.e.r.-value for colony forming ability was found to be 1.9 +/- 0.2, whereas the o.e.r.-value for DNA double-strand breakage was 3.0 +/- 0.1. These results are not inconsistent with the idea that DNA double-strand breaks are involved in killing of yeast cells. The frequency of induction of DNA double-strand breaks was found to be 0.74 x 10(-11) double-strand breaks per g/mol per Gy when cells were irradiated under oxygen and 0.24 x 10(-11) double-strand breaks per g/mol per Gy under nitrogen.     

Applications of self-organizing map for patterning macrofungal diversity of xerothermic swards

Macrofungal communities were investigated in four associations of xerothermic swards: Festucetum pallentis, Origano-Brachypodietum, Adonido-Brachypodietum pinnati and Diantho-Armerietum elongatae in a Jurassic area of the Częstochowa Upland (southern Poland). A total of 47 species were recorded. The self-organising map (SOM)—an unsupervised algorithm for artificial neural networks—was used to recognise patterns in the macrofungal communities of diverse xerothermic swards. Only two associations were mycologically similar: Origano-Brachypodietum and Adonido-Brachypodietum pinnati. Species with high and significant IndVal (the species indicator value) for each investigated phytocoenoses are presented. The presence of macrofungal species and the participation of indicator species were connected with habitat factors of plant associations, as documented by the IndVal application. In the least fertile phytocoenoses, macrofungal communities were poor with few indicator species. The more fertile phytocoenoses had richer and more varied communities of macrofungi with higher numbers of indicator species. The ordering methods applied in this study were very effective for analyzing the macrofungal communities existing in plant associations.