Ultrahigh-Performance Liquid Chromatography–High-Resolution Quadrupole Time-of-Flight Mass Spectrometry Based Metabolomics Reveals Key Differences between Brachiaria decumbens and B. brizantha, Two Similar Pastures with Different Toxicities

Several species of Brachiaria (Poaceae) currently cover extensive grazing areas in Brazil, providing valuable source of feed for a large cattle population. However, numerous cases of toxicity outbreaks in livestock have raised concerns on safety of using these plants, especially B. decumbens. In this study, chemometric analysis of ultrahigh-performance liquid chromatography–high-resolution quadrupole time-of-flight mass spectrometry (UHPLC–HR-QTOF-MS) data has for the first time uncovered qualitative and quantitative differences between metabolomes of toxic B. decumbens and nontoxic B. brizantha. The steroidal saponin protoneodioscin was established as the main biomarker for B. decumbens when compared to B. brizantha, and therefore the key explanation for their phytochemical differentiation. Quantification of protodioscin in both plants showed no significant differences; consequently, the idea that this compound is solely responsible for toxicity outbreaks must be discarded. Instead, we propose that the added occurrence of its stereoisomer, protoneodioscin, in B. decumbens, can be considered as the probable cause of these events. Interestingly, the greatest concentrations of saponins for both species were reached during winter (B. decumbens = 53.6 ± 5.1 mg·g^–1 dry weight (D.W.); B. brizantha = 25.0 ± 1.9 mg·g^–1 D.W.) and spring (B. decumbens = 49.4 ± 5.0 mg·g^–1 D.W.; B. brizantha = 27.9 ± 1.4 mg·g^–1 D.W.), although in the case of B. decumbens these values do not vary significantly among seasons

Multidirectional characterisation of chemical composition and health-promoting potential of <i>Rosa rugosa</i> hips

<p>Rugosa rose provides one of the largest hips frequently used in the preparation of pharmaceutical and food products. The aim of work was to conduct multidirectional study of biological activity and chemical composition of <i>Rosa rugosa</i> hips. Antiradical, cytotoxic (against cervical and breast cancer cell lines), antibacterial (against eight bacterial strains) and antifungal potential of the species in question was evaluated. Total contents of phenolics, phenolic acids, flavonoids, tannins, carotenoids and ascorbic acid were determined. LC–ESI–MS/MS analysis was performed in order to investigate closely phenolic acids and flavonoid glycosides. As a result, interesting selective cytotoxic effects on cervical (HeLa) and breast cancer (T47D) cell lines, significant antiradical activity (EC₅₀ 2.45 mg mg⁻¹ DPPH^•) and moderate antimicrobial potential (MIC 0.625–1.25 mg mL⁻¹) were observed. Nine phenolic acids and 11 flavonoid glycosides were qualitatively and quantitatively determined, including 7 compounds previously not reported in <i>R. rugosa</i> hips.</p

Triterpenoid Components from Oak Heartwood (<i>Quercus robur</i>) and Their Potential Health Benefits

For centuries oak wood (<i>Quercus robur</i>) has been used in aging of wines and spirits, which is based on pleasant flavors given to beverages by phenolics transferred to the liquid during the maturation process. Other metabolites, such as triterpenoids, can also be released. Searching for extractable triterpenoids in oak heartwood, 12 new, <b>1</b>–<b>12</b>, and five known, <b>13</b>–<b>17</b>, oleanane types were isolated and characterized. Their cytotoxicities were tested against cancer cells (PC3 and MCF-7) and lymphocytes. Breast cancer cells (MCF-7) were the most affected by triterpenoids, with roburgenic acid, <b>4</b>, being the most active compound (IC₅₀ = 19.7 μM). Selectivity was observed for compounds <b>1</b>–<b>3</b>, <b>8</b>, <b>9</b>, and <b>16</b>, exhibiting an IC₅₀ > 200 μM against lymphocytes, while active against cancer cells. A galloyl unit attached to the triterpenoid moiety was established as the key feature for such effect. These results highlight the occurrence of triterpenoids in oak heartwood and their relevance for chemoprevention of breast cancer

Triterpene Saponins from the Aerial Parts of Trifolium medium L. var. <i>sarosiense</i>

Seven previously unreported triterpene glycosides (<b>1</b>–<b>7</b>) were isolated from methanol extract of the aerial parts of Trifolium medium var. <i>sarosiense</i> (zigzag clover). Their structures were established by the extensive use of 1D and 2D NMR experiments along with ESI-MS and HRMS analyses. Compounds <b>1</b>–<b>7</b> are oleanane derivatives characterized by the presence of a keto group at C-22 of an aglycone and a primary alcoholic function at C-24 and differing functions at C-30. Among these, compounds <b>1</b>–<b>3</b> and <b>6</b> showed a secondary alcoholic function at C-11, which is methoxylated in compounds <b>4</b> and <b>7</b>. Compound <b>5</b> was shown to possess a known aglycone, wistariasapogenol A; however, it is described here for the first time as a saponin constituent of the <i>Trifolium</i> genus. Some aspects of taxonomic classification of zigzag clover are also discussed