Flavonoid glucosides from licorice

Two new flavanone glycosides, liquiritigenin 4′-apiosyl(1 → 2)-glucoside and liquiritigenin 7,4′-diglucoside together with a known flavone, apigenin 6,8-di-C-glucoside, have been isolated from licorice.     

Distribution of charged flavones and caffeylshikimic acid in Palmae

Identification of the phenolic constituents in flowers of nine palm species has revealed that charged C-glycosylflavones and caffeylshikimic acid are characteristically present. Flavonol glycosides are also common; the 3-glucosides, 3-rutinosides and 3,4′-diglucosides of quercetin and isorhamnetin and the 7-glucoside and 3,7-diglucoside of quercetin are all variously present. Tricin 7-glucoside, luteolin 7-rutinoside and several unchanged C-glycosylflavones were also detected. Male flowers of Phoenix canariensis differ from female flowers in having flavonol glycosides. As expected, in most species studied, flavonoid patterns in the flowers vary considerably from those found in the leaves.     

Flavonol glycosides from Asplenium bulbiferum

From aerial parts of the fern Asplenium bulbiferum, besides kaempferol 3,7-diglucoside and kaempferol 3-O-rhamnoside- 7-O-glucoside, the new glycoside kaempferol 3-O-β-glucoside-7-O-β-galactoside has been characterized.     

Secondary metabolites from Centaurea ensiformis P.H. Davis

Centaurea ensiformis P.H. Davis was evaluated for its secondary metabolites. 20 different compounds have been isolated and identified; four phenolic compounds, one aminoacid, two acetophenone glycosides, three phenylpropanoide glycosides, one coumarin glucoside, four flavon glycosides, two neolignan glycosides, two megastigmane glycosides and schikimic acid methyl ester.     

Occurrence of steryl glycosides and acylated steryl glycosides in some marine algae

There is some controversy concerning the presence of steryl glycosides and acylated steryl glycosides in eucaryotic algae. These two classes of sterol compounds were investigated in species belonging to the three major groups of eucaryotic algae: green algae (Ulva gigantea, Cladophora rupestris), brown algae (Fucus vesiculosus, Ascophyllum nodosum), and red algae (Rhodymenia palmata, Porphyridium sp.). All these algae contain both steryl glycosides and acylated steryl glycosides. The sterol components of these compounds vary according to the alga but they are always the same as the free sterols of the alga in question. The most common sugar moiety is glucose. In the acylated steryl glycosides, the fatty acid is mainly palmitic acid. The percentage of these compounds (as a percentage of the total sterol content) is often low.     

Cardiac glycosides of the root bark of Nerium odorum

In addition to the known odorosides, the β-d-digitaloside and β-d-glucosyl-(1 → 4)-β-d-digitaloside of uzarigenin were isolated from the root bark of Nerium odorum. Odoroside B was obtained in remarkably high yield among the digitoxigenin and uzarigenin glycosides. With the aid of polyamide column chromatography, oleandrigenin β-gentiobiosyl-(1 → 4)-β-d-digitaloside ( = 16-O-acetylneogitostin) was isolated along with other oleandrigenin glycosides.     

Four new glycosides from the seeds of Cassia obtusifolia

Four new glycosides, including one anthraquinone glycoside (1), one naphthalene glycoside (2), and two naphthopyrone glycosides (3–4), with 10 known compounds (5–14) were isolated from the seeds of Cassia obtusifolia L. The new structures were determined by spectroscopic analysis and chemical transformations.     

Flavonoid glycosides of Tribulus pentandrus and T. Terrestris

Twenty-five flavonoid glycosides were detected in Tribulus pentandrus and T. terrestris. The glycosides belong to the common flavonols, kaempferol, quercetin and isorhamnetin, with the 3-gentiobiosides as the major glycosides. Traces of a flavone (tricin) glycoside was also present in T. pentandrus. The separation of Tribulaceae as a distinct family from Zygophyllaceae is discussed.     

Die flavonolglykoside von Equisetum telmateja

Nine kaempferol glycosides, including the hitherto unkown 3-β-d-(6-O-acetylglucoside)-7-β-d-glucoside and 3-β-d-(6-O-acetylglucoside)-7-α-l-rhamnoside, have been isolated from Equisetum telmateja of European origin.     

New tetraacetylated iridoid glycosides from Sambucus ebulus L. leaves

Two new minor “Valeriana type” iridoid glycosides (1) and (2) along with 3 known flavonol glycosides [quercetin-3-O-β-glucopyranosyl-7-O-α-rhamnopyranoside (3), quercetin-3-O-β-glucopyranoside (4) and isorhamnetin-3-O-β-glucopyranoside (5)] were isolated from Sambucus ebulus L. leaves. Their structures were unambiguously elucidated by means of 1D- and 2D-NMR, and UPLC-TOF MS. Compound 2 is a rare representative of iridoid diglycosides, containing uncommon ribohexo-3-ulopyranosyl sugar moiety.     

The occurrence of acylated flavonol glycosides in the cruciferae

Nine acylated glycosides of kaempferol or quercetin were identified in Sisymbrium gilliesii, and in three Crambe spp. They were usually present together with the related unacylated glycosides. Acylation is a very common characteristic of the four crucifer species studied.     

Oligofurostanosides from Solanum nigrum

One spirostanol glycoside and two furostanol glycosides have been isolated from a methanol extract of the stems and roots of Solanum nigrum and ide     

Die flavonolglykoside von Equisetum silvaticum

Ten glycosides of kaempferol and quercetin, including the hitherto unknown kaempferol and quercetin 3-rutinoside-7-rhamnosides, have been isolated from Equisetum silvaticum L.     

Flavonoid glycosides of Artemisia monosperma and A. herba-alba

Ten flavonoid glycosides were isolated and identified from Artemisia monosperma: vicenin-2, lucenin-2, acacetin 7-glucoside, acacetin 7-rutinoside, the 3-glucosides and 3-rutinosides of quercetin and patuletin, and the 5-glucosides of quercetin and isorhamnetin. From Artemisia herba-alba eight flavonoid glycosides were isolated and identified: isovitexin, vicenin-2, schaftoside, isoschaftoside and the 3-glucosides and 3-rutinosides of quercetin and patuletin.     

Two new flavonoid glycosides from Iris tectorum

Phytochemical investigation of the ethanol extract of rhizomes of Iris tectorum resulted in the isolation and characterization of two new flavonoid glycosides, tectorigenin-7-O-β-d-fucopyranoside (1), 3,5,4′-trihydroxy-7,3′-dimethoxyflavanone-5-O-α-l-rhamnopyranoside (2), together with two known ones (3, 4). The rhamnose substituent at C-5 displayed uncommon connection in naturally occurring flavonoid glycosides. Their structures were elucidated on the basis of extensive spectroscopic analysis. All of the isolates were evaluated for their in vitro inhibitory activity against aldose reductase.     

Flavonoid glycosides and the chemosystematics of Eucalyptus camaldulensisis

Leaf flavonoid glycosides of Eucalyptus camaldulensis were identified as kaempferol 3-glucoside and 3-glucuronide; quercetin 3-glucoside, 3-glucuronide, 3-rhamnoside, 3-rutinoside and 7-glucoside, apigenin 7-glucuronide and luteolin 7-glucoside and 7-glucuronide. Two chemical races were observed based on the flavonoid glycosides. These races correspond to the northern and southern populations of species growing in Australia. The Middle Eastern species examined were found to belong to the southern Australian chemical race. The major glycosides of E. occidentalis proved to be quercetin and myricetin 3-glucuronide.     

Steroidal saponins of Asparagus adscendens

From the methanol extract of the fruits of Asparagus adscendens sitosterol-β-d-glucoside, two spirostanol glycosides (asparanin A and B) and two furostanol glycosides (asparoside A and B) were isolated and characterized as 3-O-[β-d-glucopyranosyl (1→2)-β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl}-(25S)-5β-spirostan-3β-ol,3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl|} -26-O-(β- d-glucopyranosyl)-22α-methoxy-(25S)-5β-furostan-3β,26-diol and 3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl}-26-O-(β-d-glucopyranosyl)- 25S)-5β-furostan-3β,22α, 26-triol, respectively.     

Two chromone glycosides from Cassia multijuga

Two new 2-methylchromone glycosides have been identified in the leaves of Cassia multiluga.     

Leaf flavonoids of Amborella trichopoda

The leaf flavonoids of Amborella trichopoda were examined and two kaempterol glycosides were detected. Procyanidin was also present. These results are similar to the flavonoid pattern in other families of the Laurales and it is suggested that simple flavonol glycosides are a primitive feature in the order.     

Effect of chito-oligosaccharide on the intestinal absorptions of phenylethanoid glycosides in Fructus Forsythiae extract

Phenylethanoid glycosides, the main active ingredients in Fructus Forsythiae extract possesses strong antibacterial, antioxidant and antiviral effects, and their contents were higher largely than that of other ingredients such as lignans and flavones, but their absolute bioavailability orally was significantly low, which influenced clinical efficacies of its oral preparations seriously. In the present study, the absorption mechanism of phenylethanoid glycosides was studied using in vitro Caco-2 cell model. And the effect of chito-oligosaccharide (COS) on the intestinal absorption of phenylethanoid glycosides in Fructus Forsythiae extract was investigated using in vitro, in situ and in vivo models. The pharmacological effects such as antiviral activity improvement by COS were verified by MDCK cell damage inhibition rate after influenza virus propagation. The observations from in vitro Caco-2 cell showed that the absorption of phenylethanoid glycosides in Fructus Forsythiae extract so with that in monomers was mainly restricted by the tight junctions, and influenced by efflux transporters (P-gp and MRP2). Meanwhile, the absorption of phenylethanoid glycosides in Fructus Forsythiae extract could be improved by COS. Besides, COS at the same low, medium and high concentrations caused a significant, concentration-dependent increase in the P_app-value for phenylethanoid glycosides compared to the control group (p < 0.05), and was all safe for the Caco-2 cells. The observations from single-pass intestinal perfusion in situ model showed that the intestinal absorption of phenylethanoid glycosides can be enhanced by COS. Meanwhile, the absorption enhancing effect of phenylethanoid glycosides might be saturable in different intestine sites. In pharmacokinetics study, COS at dosage of 25 mg/kg improved the bioavailability of phenylethanoid glycosides in Fructus Forsythiae extract to the greatest extent, and was safe for gastrointestine from morphological observation. In addition, treatment with Fructus Forsythiae extract with COS at dosage of 25 mg/kg prevented MDCK cell damage upon influenza virus propagation better than that of control. All findings above suggested that COS at dosage of 25 mg/kg might be safe and effective absorption enhancer for improving the bioavailability of phenylethanoid glycosides and the antiviral activity in vitro in Fructus Forsythiae extract.