HPLC-DAD-MS3 fingerprints of phenolics of selected Polygonum taxa and their chemometric analysis

Many Polygonaceae taxa such as Bistorta officinalis, Persicaria amphibia, Persicaria hydropiper, Persicaria lapathifolia, Persicaria maculosa, Persicaria mitis, Polygonum aviculare occur naturally in the entire territory of Poland and are also common in other European countries. Many of these species are also utilised as medicinal plants. In this manuscript we establish the phytochemical profiles of selected taxa from the Polygonaceae focusing on phenolics. Additionally, we try to find chemophenetic markers for the species investigated. Compounds were detected and characterised based on HPLC-DAD-MS data, quantified, and furtherly analysed using multivariate analyses. Chemophenetic markers were identified also considering previous literature.

Flavonoid, stilbene and diarylheptanoid constituents of Persicaria maculosa Gray and cytotoxic activity of the isolated compounds

Persicaria maculosa (Polygonaceae) has been used as edible and as medicinal plant since ancient times. As a result of multistep chromatographic purifications, chalcones [2'-hydroxy-3',4',6'-trimethoxychalcone (1), pashanone (2), pinostrobin chalcone (3)], flavanones [6-hydroxy-5,7-dimethoxyflavanone (4), pinostrobin (5), onysilin (6), 5-hydroxy-7,8-dimethoxyflavanone (7)], flavonol [3-O-methylgalangin (8)], stilbene [persilben (9)], diarylheptanoids [1,7-diphenylhept-4-en-3-one (10), dihydroyashabushiketol (12), yashabushidiol B (13)] and 3-oxo-α-ionol-glucoside (11) were isolated from P. maculosa. The present paper reports for the first time the occurrence of diarylheptanoid-type constituents in the family Polygonaceae. Cytotoxicity of 1-5, 7 and 9-11 on 4 T1 mouse triple negative breast cancer cells was assayed by MTT test. None of the tested compounds reduced the cell viability to less than 80% of the control. On non-tumorigenic D3 human brain endothelial cells the decrease of cell viability was observed in case of 1 and 2. Further impedance measurements on 4 T1 and D3 cells a concentration-dependent decrease in the cell index of both cell types was demonstrated for 1, while 2 proved to be toxic only on endothelial cells.

Anti-Virulence Potential and In Vivo Toxicity of Persicaria maculosa and Bistorta officinalis Extracts

Many traditional remedies represent potential candidates for integration with modern medical practice, but credible data on their activities are often scarce. For the first time, the anti-virulence potential and the safety for human use of the ethanol extracts of two medicinal plants, Persicaria maculosa (PEM) and Bistorta officinalis (BIO), have been addressed. Ethanol extracts of both plants exhibited anti-virulence activity against the medically important opportunistic pathogen Pseudomonas aeruginosa. At the subinhibitory concentration of 50 µg/mL, the extracts demonstrated a maximal inhibitory effect (approx. 50%) against biofilm formation, the highest reduction of pyocyanin production (47% for PEM and 59% for BIO) and completely halted the swarming motility of P. aeruginosa. Both extracts demonstrated better anti-quorum sensing and antibiofilm activities, and a better ability to interfere with LasR receptor, than the tested dominant extracts’ constituents. The bioactive concentrations of the extracts were not toxic in the zebrafish model system. This study represents an initial step towards the integration of P. maculosa and B. officinalis for use in the treatment of Pseudomonas infections.

Comparison of the chemical composition of three species of smartweed (genus Persicaria) with a focus on drimane sesquiterpenoids

The genus Persicaria is known to include species accumulating drimane sesquiterpenoids, but a comparative analysis highlighting the compositional differences has not been done. In this study, the secondary metabolites of both flowers and leaves of Persicariahydropiper, Persicariamaculosa and Persicariaminor, three species which occur in the same habitat, were compared. Using gas chromatography-mass spectrometry (GC-MS) analysis of extracts, overall 21/29 identified compounds in extracts were sesquiterpenoids and 5/29 were drimanes. Polygodial was detected in all species, though not in every sample of P. maculosa. On average, P. hydropiper flowers contained about 6.2 mg g FW(-1) of polygodial, but P. minor flowers had 200-fold, and P. maculosa 100,000 fold lower concentrations. Comparatively, also other sesquiterpenes were much lower in those species, suggesting the fitness benefit to depend on either investing a lot or not at all in terpenoid-based secondary defences. For P. hydropiper, effects of flower and leaf development and headspace volatiles were analysed as well. The flower stage immediately after fertilisation was the one with the highest content of drimane sesquiterpenoids and leaves contained about 10-fold less of these compounds compared to flowers. The headspace of P. hydropiper contained 8 compounds: one monoterpene, one alkyl aldehyde and six sesquiterpenes, but none were drimanes. The potential ecological significance of the presence or absence of drimane sesquiterpenoids and other metabolites for these plant species are discussed.