Structure, Biological Activities and Metabolism of Flavonoid Glucuronides

Potentilloside A, a New Flavonol-bis-Glucuronide from the Leaves of Potentilla chinensis, Inhibits TNF-α-Induced ROS Generation and MMP-1 Secretion

The major contributor to skin aging is UV radiation, which activates pro-inflammatory cytokines including TNF-α. TNF-α is involved in the acceleration of skin aging via ROS generation and MMP-1 secretion. In our preliminary study, a 30% EtOH extract from the leaves of Potentilla chinensis (LPCE) significantly inhibited TNF-α-induced ROS generation in human dermal fibroblasts (HDFs). Therefore, the objective of this study is to identify the active components in LPCE. A new flavonol-bis-glucuronide (potentilloside A, 1) and 14 known compounds (2-15) were isolated from an LPCE by repeated chromatography. The chemical structure of the new compound 1 was determined by analyzing its spectroscopic data (NMR and HRMS) and by acidic hydrolysis. Nine flavonols (2-9 and 11) and two flavone glycosides (12 and 13) from P. chinensis were reported for the first time in this study. Next, we evaluated the effects of the isolates (1-15) on TNF-α-induced ROS generation in HDFs. As a result, all compounds significantly inhibited ROS generation. Furthermore, LPCE and potentilloside A (1) remarkably suppressed MMP-1 secretion in HDFs stimulated by TNF-α. The data suggested that LPCE and potentilloside A (1) are worthy of further experiments for their potential as anti-skin aging agents.

UPLC-ESI-QTRAP-MS/MS Analysis to Quantify Bioactive Compounds in Fennel (Foeniculum vulgare Mill.) Waste with Potential Anti-Inflammatory Activity

Foeniculum vulgare is a perennial aromatic plant whose cultivation produces large amounts of waste rich in bioactive compounds with promising anti-inflammatory activities. Nine selected metabolites were quantified through Ultra Performance Liquid Chromatography (UPLC) hyphenated to QTRAP mass spectrometry by using MRM (multiple reaction monitoring) was performed on four parts of fennel: bulb, stem, little stem, and leaf. Analysis revealed significant differences in the amount of quantified metabolites, suggesting that little stem and leaf are the most valuable parts of the waste. Phenolic acids and glycosylated flavonoids were quantified for their known possible anti-inflammatory activities; in fact, due to this reason their ability to inhibit COX-1 and COX-2 isoforms was evaluated through a fluorometric assay, resulting in specific inhibitors of COX-2 at certain concentrations. In conclusion, as the leaf of fennel may be beneficial to human health, clinical studies should include it in nutraceuticals or functional foods for human consumption.