Study of the Accumulation of Toxic and Essential Ultra-Trace Elements in Fruits of Sorbus domestica L.

In the present work, the accumulation of selected toxic and essential ultra-trace elements in fruits of service tree (Sorbus domestica L.) were determined depending on harvest time. Samples were collected from the same sampling area in two different years and within one year in September and October (maturity state). Harvesting the fruits in the same area excludes the influence of metals taken up via roots, thus the impact of airborne contamination by heavy metal translocation can be studied. All samples were dried and digested using an acidic microwave assisted digestion system prior to quantification by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The elements chosen were Arsenic and Cadmium as well as Lithium, Molybdenum, and Selenium. The Arsenic content rose with maturity in mesocarp. Cadmium found in the mesocarp was unaffected by ripeness. For Selenium and Molybdenum, no statistically significant effect of ripeness could be found on their content in mesocarp. Lithium could not be detected in the majority of fruit samples. Differences between the metal concentrations based on the year of harvest were found for Arsenic, Molybdenum, and Selenium, depending on precipitation. The drier the season, the more Arsenic was accumulated. For Molybdenum and Selenium, the opposite effect was observed.

Small molecule probes finely differentiate between various ds- and ss-DNA and RNA by fluorescence, CD and NMR response.

Two small molecules showed intriguing properties of analytical multipurpose probes, whereby one chromophore gives different signal for many different DNA/RNA by application of several highly sensitive spectroscopic methods. Dyes revealed pronounced fluorescence ratiomeric differentiation between ds-AU-RNA, AT-DNA and GC-DNA in approximate order 10:8:1. Particularly interesting, dyes showed specific fluorimetric response for poly rA even at 10-fold excess of any other ss-RNA, and moreover such emission selectivity is preserved in multicomponent ss-RNA mixtures. The dyes also showed specific chiral recognition of poly rU in respect to the other ss-RNA by induced CD (ICD) pattern in visible range (400-500 nm), which was attributed to the dye-side-chain contribution to binding (confirmed by absence of any ICD band for reference compound lacking side-chain). Most intriguingly, minor difference in the side-chain attached to dye chromophore resulted in opposite sign of dye-ICD pattern, whereby differences in NMR NOESY contacts and proton chemical shifts between two dye/oligo rU complexes combined with MD simulations and CD calculations attributed observed bisignate ICD to the dimeric dye aggregate within oligo rU.

Characterisation of Sorbus domestica L. Bark, Fruits and Seeds: Nutrient Composition and Antioxidant Activity.

The aim of this work is to assess the nutritional value of service tree (Sorbus domestica L.) bark, fruit exocarp and mesocarp, and seeds by establishing the levels of macro- and microelements, total phenolics, flavonoids and tannins. Our results revealed that all of the tested service tree samples were rich in potassium. Bark was the best source of calcium and zinc, while seeds were the best source of magnesium. Compared to the bark and seeds, fruit exocarp and mesocarp contained significantly lower amounts of these three elements. Immature exocarp and bark contained the highest amounts of total phenolics and showed the highest antioxidant activity. Maturation significantly decreased the amount of total phenolics in fruits, as well as the antioxidant activity of total phenolics and total tannins from exocarp, but not from mesocarp. Exocarp was the richest in total flavonoids. Based on the obtained data, we have concluded that the under-utilised species S. domestica L. could serve as an important source of mineral elements and antioxidants in the human diet.