Polysaccharides from Fabaceae. V. α-Glucan from Sophora flavescens roots

Caucasian Dragonheads: Phenolic Compounds, Polysaccharides, and Bioactivity of Dracocephalum austriacum and Dracocephalum botryoides

Dracocephalum botryoides Steven and Dracocephalum austriacum L. are unexplored species of the Dracocephalum genus (Lamiaceae family) with a distribution in the Caucasus, where they are used in folk medicine and local cuisine. There are no data on the chemical composition of these Dracocephalum species. In this study, the application of a liquid chromatography-mass spectrometry technique for the metabolite profiling of methanol extracts from herbs and roots of D. austriacum and D. botryoides resulted in the identification of 50 compounds, including benzoic acid derivatives, phenylpropanoids, flavonoids and lignans. Water-soluble polysaccharides of the herbs and roots of D. austriacum and D. botryoides were isolated and characterized as mostly pectins with additive arabinogalactan-protein complexes and starch-like compounds. The antioxidant potential of the studied extracts of Dracocephalum and selected phenolics and water-soluble polysaccharides were investigated via radical-scavenging and ferrous (II) ion chelating assays. This paper demonstrates that herbs and roots of D. austriacum and D. botryoides are rich sources of metabolites and could be valuable plants for new biologically active products. To the best of our knowledge, this is the first study of whole plant metabolites and their antioxidant activity in D. austriacum and D. botryoides.

Effect of Low Temperature Cultivation on the Phytochemical Profile and Bioactivity of Arctic Plants: A Case of Dracocephalum palmatum

The influence of climatic factors, e.g., low temperature, on the phytochemical composition and bioactivity of the arctic plant Dracocephalum palmatum Steph. ax Willd. (palmate dragonhead), a traditional food and medical herb of Northern Siberia, was investigated. D. palmatum seedlings were grown in a greenhouse experiment at normal (20 °C, NT) and low (1 °C, LT) temperature levels and five groups of components that were lipophilic and hydrophilic in nature were characterized. The analyses indicated that D. palmatum under NT demonstrates high content of photosynthetic pigments, specific fatty acid (FA) profile with domination of saturated FA (53.3%) and the essential oil with trans-pinocamphone as a main component (37.9%). Phenolic compounds were identified using a combination of high performance liquid chromatography with diode array detection and electrospray ionization mass-spectrometric detection (HPLC-DAD-ESI-MS) techniques, as well as free carbohydrates and water soluble polysaccharides. For the first time, it was established that the cold acclimation of D. palmatum seedlings resulted in various changes in physiological and biochemical parameters such as membrane permeability, photosynthetic potential, membrane fluidity, leaf surface secretory function, reactive oxygen species-antioxidant balance, osmoregulator content and cell wall polymers. In brief, results showed that the adaptive strategy of D. palmatum under LT was realized on the accumulation of membrane or surface components with more fluid properties (unsaturated FA and essential oils), antioxidants (phenolic compounds and enzymes), osmoprotectants (free sugars) and cell wall components (polysaccharides). In addition, the occurrence of unusual flavonoids including two new isomeric malonyl esters of eriodictyol-7-O-glucoside was found in LT samples. Data thus obtained allow improving our understanding of ecophysiological mechanisms of cold adaptation of arctic plants.

Meadowsweet Teas as New Functional Beverages: Comparative Analysis of Nutrients, Phytochemicals and Biological Effects of Four Filipendula Species

In recent years, the increased popularity of functional beverages such as herbal teas and decoctions has led to the search for new sources of raw materials that provide appropriate taste and functionality to consumers. The objective of this study was to investigate the nutritional, phytochemical profiles and bioactivities of possible functional beverages produced from F. ulmaria and its alternative substitutes (F. camtschatica, F. denudata, F. stepposa). The investigated decoctions were analyzed regarding their macronutrient, carbohydrate, organic acid, amino acid and mineral composition. Quantification of the main phenolic compounds in the decoctions of meadowsweet floral teas was performed by a microcolumn RP-HPLC-UV procedure; the highest content was revealed in F. stepposa tea. The investigation of the essential oil of four meadowsweet teas revealed the presence of 28 compounds, including simple phenols, monoterpenes, sesquiterpenes and aliphatic components. The dominance of methyl salicylate and salicylaldehyde was noted in all samples. Studies on the water soluble polysaccharides of Filipendula flowers allowed us to establish their general affiliation to galactans and/or arabinogalactans with an admixture of glucans of the starch type and galacturonans as minor components. The bioactivity data demonstrated a good ability of meadowsweet teas to inhibit amylase, α-glucosidase and AGE formation. Tea samples showed antioxidant properties by the DPPH•, ABTS•+ and Br• free radicals scavenging assays and the carotene bleaching assay, caused by the presence of highly active ellagitannins. The anti-complement activity of the water-soluble polysaccharide fraction of meadowsweet teas indicated their possible immune-modulating properties. Filipendula beverage formulations can be expected to deliver beneficial effects due to their unique nutritional and phytochemical profiles. Potential applications as health-promoting functional products may be suggested.

Antinociceptive activity of a polysaccharide from the roots of Sophora flavescens

A polysaccharide (SFWP), with a molecular weight of 51kDa, was successfully purified from the roots of Sophora flavescens and the antinociceptive actions of SFWP were evaluated using acetic acid induced writhing, tail flick, and formalin tests in mice. GC-MS results showed that SFWP had a backbone composed of (1→2)-linked Glc, (1→2,6)-inkedGal and (1→3,6)-inked Man residues, which were terminated with (1→)-inked Xyl and (1→)-inked Ara at O-6 of (1→2,6)-inkedGal and (1→3,6)-inked Man along the main chain, in the ratio of 2.0: 1.02: 1.09: 1.10: 0.98. Data showed that SFWP (100, 200 and 400mg/kg) significantly reduced the number of writhings induced by acetic acid in a dose-dependent manner. However, SFWP did not produce analgesia in tail-flick test. Moreover SFWP strongly attenuated the formalin-induced flinching behaviour in the second phases but not in the first phase in a dose-dependent manner. These results revealed that SFWP could be used safely to attenuate both inflammatory and peripheral neuropathic pain.

Bitter Gentian Teas: Nutritional and Phytochemical Profiles, Polysaccharide Characterisation and Bioactivity

As a result of the wide distribution of herbal teas the data on nutritional characterisation, chemical profile and biological activity of these products are required. The decoctions of Gentiana algida, G. decumbens, G. macrophylla and G. triflora herb teas were nutritionally characterized with respect to their macronutrients, demonstrating the predominance of polysaccharides and low lipid content. Gentian decoctions were also submitted to a microcolumn RP-HPLC-UV analysis of phytochemicals demonstrating a high content of iridoids (177.18-641.04 μg/mL) and flavonoids (89.15-405.71 μg/mL). Additionally, mangiferin was detected in samples of G. triflora tea (19.89 μg/mL). Five free sugars (fructose, glucose, sucrose, gentiobiose, gentianose) were identified in all gentian teas studied, as well as six organic acids (malic, citric, tartaric, oxalic, succinic, quinic). Pectic polysaccharides with a high content of rhamnogalacturonans and arabinogalactans were also identified and characterized in gentian decoctions for the first time. Gentian tea decoctions and their specific compounds (gentiopicroside, loganic acid-6'-O-β-d-glucoside, isoorientin, isoorientin-4'-O-β-d-glucoside, mangiferin, water-soluble polysaccharides) showed a promising antimicrobial, anti-inflammatory and antioxidant potentials. Evidences obtained indicate the prospective use of gentian herb teas as food products and medicines.

Detection of metabolite induction in fungal co-cultures on solid media by high-throughput differential ultra-high pressure liquid chromatography-time-of-flight mass spectrometry fingerprinting

Access to new biological sources is a key element of natural product research. A particularly large number of biologically active molecules have been found to originate from microorganisms. Very recently, the use of fungal co-culture to activate the silent genes involved in metabolite biosynthesis was found to be a successful method for the induction of new compounds. However, the detection and identification of the induced metabolites in the confrontation zone where fungi interact remain very challenging. To tackle this issue, a high-throughput UHPLC-TOF-MS-based metabolomic approach has been developed for the screening of fungal co-cultures in solid media at the petri dish level. The metabolites that were overexpressed because of fungal interactions were highlighted by comparing the LC-MS data obtained from the co-cultures and their corresponding mono-cultures. This comparison was achieved by subjecting automatically generated peak lists to statistical treatments. This strategy has been applied to more than 600 co-culture experiments that mainly involved fungal strains from the Fusarium genera, although experiments were also completed with a selection of several other filamentous fungi. This strategy was found to provide satisfactory repeatability and was used to detect the biomarkers of fungal induction in a large panel of filamentous fungi. This study demonstrates that co-culture results in consistent induction of potentially new metabolites.

Antitumor and immunomodulating activity of a polysaccharide from Sophora flavescens Ait

The immunostimulatory activity of Sophora flavescens polysaccharide (SFPW1) was evaluated by using in vitro cell models and in vivo animal models. The results demonstrated that SFPW1 could effectively inhibit the tumor growth in H22 tumor-bearing mice and promote the splenocyte proliferation, thus resulting in a prolonged life survival. For assay in vitro, SFPW1 significantly strengthened peritoneal macrophages to devour H22 tumor cells and stimulated macrophages to produce nitric oxide (NO) via up-regulation of inducible NO synthase (iNOS) activity. However, no direct cytotoxicity against H22 tumor cells was observed in vitro. These results suggest that SFPW1 might be a strong natural immunomodulator and the antitumor effect of this polysaccharide is associated with its potent immunostimulating effect.