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Prunus spinosaleaf extracts in solvents of different polarity (water, ethanol and acetone), their phenol,flavonoid and anthocyanin contents and biological properties were the object of this study. The richest in phenols as well as in flavonoids was acetone extract with 181.19 mg GAE and 80.10 mg QE per gram of dry extract, respectively. Moreover, the quantity of anthocyanins obtained byHPLC analysis was also the highestin acetone sample. Examined samples possessed antioxidant properties evaluated through fourin vitroassays(DPPH, ABTS, FRAP and TRC). The acetone extract wasproved to be the best antioxidant among testedsamples, which could be ascribed to polyphenols, especially anthocyanins. The aqueous and the ethanolextractexhibited antibacterial effects, being particularlyactive againstB. cereusandE. cloacaeT. viride P.funiculosum,P. ochrochloronP. verrucosumvar.cyclopiumwere the most susceptible among fungalmicroorganisms examined. Both, the aqueous and theethanol extract expressed inhibitory activity towardsenzymes linked to diabetes mellitus type II. Additionally, the ethanol extract showedsignificantly higherpotential in inhibitingα-glucosidase than the drug used as the positive control. Furthermore, the aqueoussample revealed antitumor effects on following malignant cell lines: HeLa, K562 and MDA-MB-453. Theresults presented herein suggest thatP. spinosaleaves should be considered as a natural source ofbioactivecompounds with potential application in phytopharmacy and food industry.

The presented study was aimed at exploring the bioactive properties (antioxidant, antimicrobial and food preserving) and chemical composition of R. discolor fruits collected from 2 geographically distinct wild-growing populations and extracted by using different solvents (methanol, ethanol, acetone and water). The total phenol (TPC), flavonoid (TFC) and anthocyanin (TAC) content varied from 52.7 to 186.8 mg GAE/g, 3.5 to 7.0 mg QE/g and 11.1 to 28.2 mg/g dry weight (dw), respectively. HPLC-DAD analysis identified cyanidin-3-glucoside (Cy-3-Glu) as the dominant anthocyanin that ranged in concentration from 18.4 to 32.2 mg/g dw. The acetone extract revealed the highest antioxidant activity through the ferric reducing antioxidant power (FRAP), total reducing power (TRC) and ß-carotene bleaching in vitro methods. The examined extracts showed antimicrobial activity, being more effective against Gram-positive (G+) than Gram-negative (G-) bacteria. Furthermore, Candida glabrata was the most susceptible among the pathogenic yeasts. The ethanol fruit extract was the most active against Listeria monocytogenes and thus chosen for incorporation in yoghurt and further analyses regarding its food preserving properties, which confirmed its efficacy towards this food-borne pathogen. Additionally, panelists gave high marks to the novel product regarding color, taste, texture flavor and overall acceptance. The obtained results indicated that R. discolor fruit extracts exhibits notable bioactivity and might therefore be considered as a good platform for the development of new preparations to be used in the food industry.

In this work were examined aqueous, methanol, ethanol and acetone leaf extracts of Rubus discolor, wild growing blackberry, for their antioxidant properties and total phenol and flavonoid content. The total phenol content (TPC) varried from 250.05 to 446.61 mg GAE/g of dry extract, while total flavonoid content (TFC) was in range between 22.44 and 61.15 mg QE/g of dry extract. Aqueous extracts were the richest in phenols, as well as in flavonoids. In vitro antioxidant capacity of leaf extracts was evaluated by 2,2-diphenyl-1-picrylhydrazil (DPPH), 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging procedures and ferric reducing ability of plasma (FRAP) assay. Aqueous extracts were the most effective through all antioxidant tests. The total phenol content highly correlated with antioxidant activity of extracts. Moreover, weak correlation was established between total phenol and total flavonoid content. The results presented in this work indicate that phenol compounds contribute to antioxidant ability of extracts. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173029]

In this study, the antioxidant properties and total phenolic and flavonoid contents of Rubus caesius L. var. aquáticus Weihe & Nees leaf extracts were examined. The radical scavenging capacity of four leaf extracts (methanol, ethanol, acetone and aqueous) was estimated against 2,2-diphenyl-1-picrylhydrazil (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assays. Total antioxidant capacity was tested by ferric reducing ability of plasma (FRAP) and total reducing capacity (TRC) procedures. Total contents of phenols and flavonoids were also determined. Total phenol content in the extracts was determined using Folin-Ciocalteu reagent and amounts ranged between 263.74 for ethanol to 366.27 mg gallic acid (GA)/g for acetone extracts. The amounts of flavonoids varied from 10.73 mg quercetin equivalent (QE)/g for aqueous to 75.83 mg QE/g for acetone extract. The highest antioxidant activity against DPPH and ABTS●+ radicals was that of the acetone extract. Values for FRAP varied between 3.00 μmol Fe+2/mg for the ethanol extract and 5.31 μmol Fe+2/mg for the methanol extract. The results obtained for total reducing capacity indicate that the acetone extract has the highest antioxidant potential. [Projekat Ministarstva nauke Republike Srbije, br. 173029]