Gentianose

Ameliorative Effects of Thunbergia erecta L. Leaves Against the Initiation of Hepatocarcinogenesis Induced by Diethylnitrosamine in the Rat Model.[Pubmed:36708488]

Appl Biochem Biotechnol. 2023 Oct;195(10):5881-5902.

Thunbergia erecta L. contains cytotoxic and liver-protective compounds. Thunbergia erecta L. leaves were macerated in 70% aqueous ethanol, then fractionated with ethyl acetate (9.3 g) and butanol (12.7 g), and attenuated Den-induced liver cancer in a Wistar rat experimental model. Ethyl acetate and butanol fractions were chromatographed using column chromatography and solid-phase extraction (SPE); Vicenin-II (1), kaempferol (2), biochanin A, sissotrin 7-O-beta-glucopyranoside (3), Gentianose (4), acacetin 7-O-beta-glucopyranoside (5), apigenin 7-O-beta-glucopyranoside (6), and rosmarinic acid (7) were extracted, and their structures were determined using NMR spectroscopy and ESI-mass spectrometry. Sixty rats were divided into six groups (ten each): control group, Den group, doxorubicin/Den-treated group, butanol fraction/Den-treated group, and isolated acacetin 7-O-beta-glucopyranoside/Den-treated group. The liver enzymes and proinflammatory biomarkers were used to estimate the liver function. In addition, liver tissues were collected for analysis of oxidative stress markers, gene expression, and histopathology. There is a significant increase in the levels of liver enzymes, AFP, and TNF-ἁ. This was conveyed by a significant increase of IL-1 and caspase-3, elevation of MDA and reduction of GSH, and suppression of Bcl2 and elevation of Bax expression. All parameters in butanol, ethyl acetate fractions, and isolated acacetin 7-O-beta-glucopyranoside (major constituents) of T. erecta L. were significantly improved to values close to those of the control group.

Gentianose: Purification and structural determination of an unknown oligosaccharide in grape seeds.[Pubmed:33229151]

Food Chem. 2021 May 15;344:128588.

Grape seeds are among the main constituents of grape pomace, ranging between 20% and 30% of the wet matrix; however, their oligosaccharide composition has not been studied. This paper describes the purification and the identification of low molecular weight oligosaccharides contained in an EtOH/water extract of grape seeds. A sequential two-step purification by size exclusion chromatography was carried out to fractionate compounds according to molecular weights. Chemical characterization of the combined fractions was performed by Magnetic Resonance Spectroscopy and Gas Chromatography-Mass Spectrometry analyses. The separation process gave two fractions abundant in sucrose and glucose. A third fraction containing trisaccharides was acetylated allowing the purification of the main trisaccharide. The structure elucidation of the acetylated product made it possible to identify Gentianose, a predominant carbohydrate reserve found in the storage roots of perennial Gentiana lutea. Grape seeds are wine industry by-products and the obtained results suggest the importance of their recovery.

Bitter Gentian Teas: Nutritional and Phytochemical Profiles, Polysaccharide Characterisation and Bioactivity.[Pubmed:26556333]

Molecules. 2015 Nov 5;20(11):20014-30.

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 mug/mL) and flavonoids (89.15-405.71 mug/mL). Additionally, mangiferin was detected in samples of G. triflora tea (19.89 mug/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-beta-d-glucoside, isoorientin, isoorientin-4'-O-beta-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.

The gentio-oligosaccharide gentiobiose functions in the modulation of bud dormancy in the herbaceous perennial Gentiana.[Pubmed:25326293]

Plant Cell. 2014 Oct;26(10):3949-63.

Bud dormancy is an adaptive strategy that perennials use to survive unfavorable conditions. Gentians (Gentiana), popular alpine flowers and ornamentals, produce overwintering buds (OWBs) that can persist through the winter, but the mechanisms regulating dormancy are currently unclear. In this study, we conducted targeted metabolome analysis to obtain clues about the metabolic mechanisms involved in regulating OWB dormancy. Multivariate analysis of metabolite profiles revealed metabolite patterns characteristic of dormant states. The concentrations of gentiobiose [beta-D-Glcp-(1-->6)-D-Glc] and Gentianose [beta-D-Glcp-(1-->6)-D-Glc-(1-->2)-d-Fru] significantly varied depending on the stage of OWB dormancy, and the gentiobiose concentration increased prior to budbreak. Both activation of invertase and inactivation of beta-glucosidase resulted in gentiobiose accumulation in ecodormant OWBs, suggesting that gentiobiose is seldom used as an energy source but is involved in signaling pathways. Furthermore, treatment with exogenous gentiobiose induced budbreak in OWBs cultured in vitro, with increased concentrations of sulfur-containing amino acids, GSH, and ascorbate (AsA), as well as increased expression levels of the corresponding genes. Inhibition of GSH synthesis suppressed gentiobiose-induced budbreak accompanied by decreases in GSH and AsA concentrations and redox status. These results indicate that gentiobiose, a rare disaccharide, acts as a signal for dormancy release of gentian OWBs through the AsA-GSH cycle.

Physiological characterization of a microbial sensor containing the yeast Arxula adeninivorans LS3.[Pubmed:9195009]

Antonie Van Leeuwenhoek. 1997 May;71(4):345-51.

The yeast Arxula adeninivorans LS3 is a suitable organism for use as part of a microbial sensor. In combination with an amperometric oxygen electrode the sensor offered a possibility for the physiological characterization of this yeast. About 300-400 measurements could be carried out with a single Arxula sensor. The microbial sensor was remarkably stable for over 35 days, when kept at 37 degrees C during the operation time and at room temperature overnight. The physiological characteristics of Arxula adeninivorans LS3 obtained with the sensor technique were identical to the data obtained with the conventional techniques. However, the sensor technique makes it additionally possible to quantify the physiological data. So the substrates ribose, citric acid, glycerol, oil and benzoate produced signals lower than 10% in comparison to the glucose signal. Fructose, xylose, sucrose, maltose, Gentianose, glucosamine, glutamic acid, tryptophan, butyric acid, lauryl acid and propionic acid reached 10-70%, galactose, alanine, glycine, lysine and methionine signals were similar to the glucose signal whereas acetic acid, ethyl alcohol, capron acid, capryl acid and caproic acid reached the highest signals up to 434%.

Secoiridoids and antifungal aromatic acids from Gentiana algida.[Pubmed:8588862]

Phytochemistry. 1996 Jan;41(1):111-6.

Fractionation of an aqueous acetone extract of the whole herb of Gentiana algida gave one new [2'-(o,m-dihydroxybenzyl)sweroside] and five known secoiridoids, together with anofinic acid, fomannoxin acid, sitosterol, daucosterol, stigmasterol, oleanolic acid, orientin and Gentianose. The structures were determined by spectral methods and a few chemical transformations. Anofinic acid and fomannoxin acid were found to be active against Cladosporium cucumerinum, a plant pathogenic fungus. Preliminary structure-activity studies indicated that the presence of carboxylic moieties in these acids was presumably a precondition for activity, whereas their methyl esters, inactive to the fungus, were active against the human pathogenic yeast Candida albicans. The chemotaxonomic significance of the isolates is discussed briefly.

Differential compartmentation of sucrose and gentianose in the cytosol and vacuoles of storage root protoplasts from Gentiana Lutea L.[Pubmed:24257774]

Plant Cell Rep. 1982 Dec;1(6):274-7.

The storage roots of perennial Gentiana lutea L.plants contain several sugars. The predominant carbohydrate reserve is Gentianose (beta-D-glucopyranosyl-(1 --> 6)-alpha-D-glucopyranosyl-(1 <--> 2)-beta-D-fructofuranoside). Vacuoles were isolated from root protoplasts and purified through a betaine density gradient. The yield was about 75%. Gentianose and gentiobiose were localized to 100% in the vacuoles, fructose and glucose to about 80%, and sucrose to only about 50%. Taking the volumes of the vacuolar and extravacuolar (cytosolic) compartments into account it is inferred that Gentianose is located exclusively in the vacuoles, whilst sucrose is much more concentrated in the cytosol where it may play a role as a cryoprotectant. The concentration of fructose and glucose appeared to be similar on both sides of the tonoplast.