No abstract

Betacyanins and their decarboxylated derivatives from fresh and dried edible leaves of Atriplex hortensis L. var. “Rubra” were fractionated for the first time by high‐speed countercurrent chromatography. Pigments present in fresh leaf extract were separated in systems: ethanol – acetonitrile – n‐propanol – ammonium sulphate – water (0.5:0.5:0.5:1.2:1.0, v/v/v/v/v) (tail‐to‐head mode) and tert‐butyl methyl ether – n‐butanol – acetonitrile – water with 0.7% heptafluorobutyric acid (2:2:1:5, v/v/v/v) (head‐to‐tail mode). The mobile phase flow rate was 2 mL/min and the retention of the stationary phase was 79.8 and 75.2%, respectively. Pigments from dried leaves were separated in a similar ion‐pair system with heptafluorobutyric acid in different volume proportions 1:3:1:5 (head‐to‐tail mode) and the flow rate of the mobile phase 3 mL/min. The stationary phase retention was 64.0%. The application of the countercurrent chromatography for the fractionation of betacyanins from leaves of Atriplex hortensis enabled to isolate and pre‐concentrate the pigments for further low‐ and high‐resolution liquid chromatographic–tandem mass spectrometric detection. This study revealed the presence of 10 betacyanins in fresh and 16 in dried leaves of Atriplex hortensis. Two compounds were not previously identified in the whole Amaranthaceae family. Additionally, instead of (iso)amaranthin, celosianin and its epimer were dominant betacyanins in the Atriplex hortensis.

The aim of the study was to evaluate the possible correlation between the bioactivity and the phytochemical profile of four betalain-rich extracts from Portulaca grandiflora Hook. The HPLC-DAD-ESI-MS analysis indicated the presence of 19 betaxanthins and two betacyanins. The highest concentrations of betaxanthins (982 mg/100 g DE) and betacyanins (650 mg/100 g DE) were noticed in orange and purple flowers extracts, respectively. The HPLC-DAD-ESI-HRMS/MS analyses revealed the presence of a total of 71 compounds. Fifteen new betaxanthins and fifty other metabolites were identified for the first time. The antioxidant activity of the studied flower extracts increased in the sequence of yellow < orange < purple < red (0.066–0.176 mM TE/g DE). Betalains showed less effect on the antioxidant activity of extracts than other metabolites did. Extracts from yellow and orange flowers were more active against Gram-positive bacteria (MIC = 4–16 mg/L), whereas extracts from red and purple flowers were slightly more active against Gram-negative bacteria (MIC = 16–32 mg/L). All the extracts showed the same activity against yeasts (MIC = 32 mg/L). Betaxanthins were active against Gram-positive bacteria, whereas betacyanins were active against Gram-negative bacteria. Remaining metabolites also exhibited antimicrobial activities. The cytotoxicity assessment showed that the P. grandiflora extracts were non-toxic to normal VERO cells. No significant antiviral activity towards Human Herpesvirus type 1 was observed (62 µg/mL). Among the tested varieties, the purple one showed anticancer selectivity towards colon carcinoma cells (RKO).

Beta vulgaris L. is an important source of bioactive saponins -a group of secondary metabolites -that have spurred a growing interest due to their health-promoting properties. This study aimed to gain information on triterpene saponin profile of the peel and flesh of white, yellow and red beet of six cultivars -Snow Ball, Boldor, Ceryl, Chrobry, Forono and Tytus -harvested in Poland, in the same region. Twenty four saponins with oleanolic acid, hederagenin, akebonoic acid and gypsogenin as aglycons were identified and quantified by liquid chromatography/tandem mass spectrometry (LC--ESI-MS/MS). Among them, betavulgaroside I, II, III and IV were the major compounds, but the quantitative profile of saponins was found to be dependent on beet cultivar and root part, respectively. The highest content of saponins was found in the peel of yellow B. vulgaris Boldor (20812 mg/kg fresh weight, fw), while the lowest saponin content was determined in the flesh of white B. vulgaris Snow Ball (497 mg/kg fw). In addition, the total saponin content in peel and flesh in yellow beet (26054 mg/kg fw) was much higher than the total content in peel and flesh in red beet Tytus (8364 mg/kg fw) and white beet Snow Ball (1204 mg/kg fw). This is the first report on the profile of saponins in white and yellow beets.

Amaranth is used as a spinach replacement; therefore, it is sometimes called Chinese Spinach. So far, the activity of the plant has not been associated with the presence of specific compounds. Three cultivars of Amaranthus tricolor L. were investigated for their antioxidant and antimicrobial activities. The correlation between the bioactivity and metabolite profiles was investigated in order to indicate active compounds in A. tricolor. The phytochemical profile of a total of nine extracts was studied by HPLC-DAD-ESI/HRMS, revealing the presence of 52 compounds. The highest antioxidant activity was noticed in the Red cultivar (0.06 mmol TE/g DE (Trolox Equivalent/Dry Extract Weight) and was related to the presence of amino acids, flavonoids and phenolic acids, as well as individual compounds such as tuberonic acid hexoside. All studied extracts revealed antimicrobial activity. Gram-positive bacteria were more susceptible to N-(carboxyacetyl) phenylalanine, phenylalanine, tuberonic acid and succinic acid and Gram-negative bacteria to dopa, tryptophan, norleucine, tuberonic acid hexoside, quercetin-O-hexoside, luteolin-O-rhamnosylhexoside, luteolin-6-C-hexoside succinic acid, gallic acid-O-hexoside, dihydroxybenzoic acid and hydroxybenzoic acid. Maleic acid showed promising antifungal activity. In summary, A. tricolor is a good source of antioxidant and antimicrobial compounds.