An amidase (EC 3.5.1.4) in branch 2 of the nitrilase superfamily, from the thermophilic strain Geobacillus pallidus RAPc8, was produced at high expression levels (20 U/mg) in small-scale fermentations of Escherichia coli. The enzyme was purified to 90% homogeneity with specific activity of 1,800 U/mg in just two steps, namely, heat-treatment and gel permeation chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and electron microscopic (EM) analysis of the homogenous enzyme showed the native enzyme to be a homohexamer of 38 kDa subunits. Analysis of the biochemical properties of the amidase showed that the optimal temperature and pH for activity were 50 and 7.0°C, respectively. The amidase exhibited high thermal stability at 50 and 60°C, with half-lives greater than 5 h at both temperatures. At 70 and 80°C, the half-life values were 43 and 10 min, respectively. The amidase catalyzed the hydrolysis of low molecular weight aliphatic amides, with D-selectivity towards lactamide. Inhibition studies showed activation/inhibition data consistent with the presence of a catalytically active thiol group. Acyl transfer reactions were demonstrated with acetamide, propionamide, isobutyramide, and acrylamide as substrates and hydroxylamine as the acyl acceptor; the highest reaction rate being with isobutyramide. Immobilization by entrapment in polyacrylamide gels, covalent binding on Eupergit C beads at 4°C and on Amberlite-XAD57 resulted in low protein binding and low activity, but immobilization on Eupergit C beads at 25°C with cross-linking resulted in high protein binding yield and high immobilized specific activity (80% of non-immobilized activity). Characterization of Eupergit C-immobilized preparations showed that the optimum reaction temperature was unchanged, the pH range was somewhat broadened, and stability was enhanced giving half-lives of 52 min at 70°C and 30 min at 80°C. The amidase has potential for application under high temperature conditions as a biocatalyst for D-selective amide hydrolysis producing enantiomerically pure carboxylic acids and for production of novel amides by acyl transfer.

The aim of this study was to evaluate and compare the content of a number of bioactive compounds and antioxidant activity of fruits of selected local and commercial sweet cherry (Prunus avium L.) cultivars. The experiment showed that the selected cultivars of sweet cherries differ significantly in the content of polyphenolic compounds and carotenoids. The fruits of commercial sweet cherry cultivars were, on average, richer in polyphenols (the sum of phenolic compounds determined chromatographically), flavonoids, as well as anthocyanins and were characterized by higher antioxidant activity when compared to the local, traditional cultivars. In the group of the traditional sweet cherry cultivars, particular attention could be paid to Black Late cv., showing the highest antioxidant activity of fruits. In the group of commercial sweet cherry cultivars, Cordia and Sylvia fruits could be recognized as being rich in bioactive compounds with high antioxidant activity. Yellow skin cultivars were characterized by the highest concentrations of carotenoids. Strong positive correlations between the identified bioactive compounds and antioxidant activity of fruits were also found. Although different cultivars of sweet cherries show a high variability in phenolics and carotenoids profiles as well as in the antioxidant activity of fruits, they all should be, similarly to other types of cherries, recognized as a rich source of bioactive compounds with an antioxidant potential.

Inosine 50 -monophosphate dehydrogenase (IMPDH) is important molecular target for potential anticancer, antiviral, antibacterial and immunosuppressive agents. A lot of compounds were obtained to establish their activity toward this enzyme, and to improve therapeutic properties of IMPDH inhibitors used as the drugs. Some of the recently reported analogs exhibited promising results during in vitro and in vivo examinations in comparison to substances applied in clinic. In this review, we describe synthesis and biological activity evaluations of the newly designed IMPDH inhibitors.

Sour cherry fruits are a perfect source of polyphenols, including flavonols, phenolic acids and anthocyanins. According to the literature, organic fruits contain more bioactive compounds, especially polyphenols, compared to conventional fruits. Given that only one two-year experiment on the status of polyphenols in sour cherry fruits in an organic farm was previously conducted and found in the existing scientific literature, the aim of this study was to analyse and compare the concentration of bioactive compounds in organic and conventional sour cherries and to determine the effects of cultivation year and the proper cultivar. Four sour cherry cultivars (“Oblacińska”, “Kelleris 16”, “Pandy 103” and “Dobroceni Bötermo”) harvested in organic and conventional experimental orchards were assessed in this study. The dry matter and polyphenol contents in the fruits were determined. We observed a significantly higher concentration of dry matter in organic samples only in 2015 and 2017. In the case of total polyphenols, including phenolic acid (2015 and 2017–2018), and total flavonoids, including quercetin-3-O-rutinoside, the higher concentration was found in 2016 and 2018. Two individual anthocyanins were identified in sour cherry fruits. Cyanidin-3-O-rutinoside is the predominant form in the pool of total anthocyanins.

Lisek A., Rozpara E., Głowacka A., Kucharska D., Zawadzka M. (2015): Identification of S-genotypes of sweet cherry cultivars from Central and Eastern Europe. Hort. Sci. (Prague), 42: 13-21.Sweet cherry is a species that is characterized by self-incompatibility, which causes difficulties in obtaining high yields of sweet cherry fruit. Determination of the composition of the S-alleles of sweet cherry cultivars is useful both to growers producing the fruit and breeders when selecting cultivars for cross-fertilizations. In this work, S-alleles have been identified for 47 sweet cherry cultivars from Central and Eastern Europe, mostly from Ukraine and the Czech Republic, with S-genotypes of 43 cultivars identified for the first time. To identify the S-alleles, PCR-based methods were used. In each cultivar, two of the following eight S-alleles were identified: S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 9 and S 13 . In the cultivars from the Czech Republic, the most frequently occurring were the alleles S 3 , S 1 and S 4 . In the cultivars originating in Ukraine, the most frequently found were the alleles S 5 and S 9 , which makes them differ considerably from the sweet cherry cultivars from other regions of Europe. The tested sweet cherry cultivars were assigned to 20 of the existing incompatibility groups.