The antimicrobial activity of fruits from some cultivar varieties of Rubus idaeus and Rubus occidentalis.

Raspberries, derived from different cultivar varieties, are a popular ingredient of everyday diet, and their biological activity is a point of interest for researchers. The ethanol-water extracts from four varieties of red (Rubus idaeus'Ljulin', 'Veten', 'Poranna Rosa') and black (Rubus occidentalis'Litacz') raspberries were evaluated in the range of their antimicrobial properties as well as phenolic content - sanguiin H-6, free ellagic acid and anthocyanins. The antimicrobial assay was performed with the use of fifteen strains of bacteria, both Gram-negative and Gram-positive. The antimicrobial activity of the extracts varied and depended on the analysed strain of bacteria and cultivar variety, with the exception of Helicobacter pylori, towards which the extracts displayed the same growth inhibiting activity. Two human pathogens Corynebacterium diphtheriae and Moraxella catarrhalis proved to be the most sensitive to raspberry extracts. Contrary to the extracts, sanguiin H-6 and ellagic acid were only active against eight and nine bacterial strains, respectively. The determined MIC and MBC values of both compounds were several times lower than the tested extracts. The highest sensitivity of Corynebacterium diphtheriae to extracts from both black and red raspberries may be due to its sensitivity to sanguiin H-6 and ellagic acid.

HPLC analysis of polyphenols in the fruits of Rubus idaeus L. (Rosaceae).

The separation of anthocyanins present in the fruits of 11 varieties of red raspberries (Rubus idaeus L.) was performed by high performance liquid chromatography (HPLC) with a diode-array detector and evaporative light scattering detection (ELSD). The ELSD parameters--drift tube temperature, nebulising gas flow rate and gain value--were optimised to get the best detection and identification of the anthocyanins. The varieties Heritage and Willamette had the simplest anthocyanin sets consisting of only two predominant anthocyanins--cyanidin-3-O-sophoroside (1) and cyanidin-3-O-glucoside (3), while in the other varieties two other predominant compounds were also present, cyanidin-3-O-rutinoside (4) and cyanidin-3-O-(2(G)-O-glucosylrutinoside) (2). Moreover, using ELSD, simultaneous analysis of anthocyanins and sanguiin H-6 (5), an ellagitannin, was performed. The contents of anthocyanins and sanguiin H-6 (5) were estimated by HPLC with ultraviolet-visible (UV-vis) light detection. The determined concentrations of anthocyanins varied from 76.22 to 277.06 mg per 100 g of dry weight (d.w.). The content of sanguiin H-6 (5) was in the range from 135.04 to 547.48 mg per 100 g of d.w.

Phenolic acids and depsides from some species of the Erodium genera.

Six natural polyphenolic compounds, brevifolin carboxylic acid, brevifolin, ellagic acid, methyl gallate, gallic acid and protocatechuic acid have been isolated from the methanol extract of the whole plant of Erodium cicutarium (L.) L.'Hérit. (Geraniaceae). Structures were determined by conventional methods of analysis and confirmed by MS and NMR spectral analysis. The distribution of these compounds in the other species of the Erodium genera (E. botrys, E. chium, E. ciconium, E. cicutarium, E. glutinosum subsp. dunense, E. gruinum, E. manescavi, E. pelargoniiflorum, E. petraeum) were examined by HPLC with a RP-18 column, and MGD-TLC methods on unmodified silica gel and silica gel chemically modified with polar and nonpolar groups (HPTLC-Si 60 LiChrospher, HPTLC-NH2, HPTLC-DIOL, HPTLC RP-18W).