A new polyacetylene glucoside from Vernonia scorpioides and its potential antihyperglycemic effect

Abstract

Natural polyacetylene compounds have been found mainly in seven botanical families and remain underexplored and understudied, despite its inherent chemical and biological reactivity, due to the presence of conjugated triple bonds. Some polyacetylene glucosides have been found to stimulate glucose uptake in C5BL/ks-db/db obese diabetic mice, and since polyacetylene glucosides previously found in Vernonia scorpioides showed little to none cytotoxicity, in this study the antihyperglycemic potential of a new V. scorpioides polyacetylene glucoside has been accessed in order to shine a new light on the biological activity of this unique scaffold. For the isolation of this new compound an optimized method of Centrifugal Partition Chromatography (CPC) is for the first time described together with its X-ray data. The results demonstrate that 3,4-dihydrovernoniyne-4-O-β-glucoside has significant effect on glycaemia at low dose 0.5 mg/kg, and pointing that the anti-hyperglycemic effect may be due in part to the inhibition of intestinal disaccharidases.

Anticancer Properties of Lobetyolin, an Essential Component of Radix Codonopsis (Dangshen)

“…3) has shown a mild cytotoxic activity against U2OS osteosarcoma cells but not against two other cancer cell lines [73]. Polyacetylene glycosides from Vernonia scorpioides [74,75] and Launaea capitata [76] showed little or no cytotoxic activity. The mechanism of action of these compounds should be further investigated, not in terms of cytotoxic potency but as modulators of amino acid transport, with reference to the mechanism of action of LBT mentioned above.…”

Polyacetylene Glycosides: Isolation, Biological Activities and Synthesis

“…PAGs are usually extracted from plant material by polar solvents, such as water, [66] methanol, [67] ethanol, [25] or using a mixture of these solvents, [68] with or without heating [44,69] followed by fractionation by chromatography using Sephadex LH-20, Diaion HP-20 and/or silica gel using a wide range of solvents. [25,[67][68] Different analytical methods for the isolation and qualitative and quantitative determination of PAGs in plants include HSCCC (High Speed Counter Current Chromatography), [70] HPLC-UV (High Performance Liquid Chromatography with Ultraviolet Detection), [27] HPLC-PDA (High Performance Liquid Chromatography Coupled with Photo Diode Array Detector), [28] and LC-DAD-MS (Liquid Chromatography Coupled to Diode Array Detection and Mass Spectrometry) [29] among others. [30] The structural elucidation of some PAGs isolated from plants was performed indirectly by acidic hydrolysis of the glycosidic bond [64] followed by the analysis of the corresponding sugar and the polyacetylene units by optical rotation, [71] UV, [72] MS, [73] and 1D-NMR and 2D-NMR.…”

“…The ability of PAGs to reduce blood glucose levels, and therefore their application in the treatment of diabetes, has been the target of a large number of investigators. [25,30,[76][77][78][79][80][81] a The corresponding structures can be seen in the Supporting Information.…”

“…The hydrophilic sugar unit facilitates the cellular and tissue transport of PAGs in living organisms since the polyacetylene unit is usually lipophilic, [25] while the carbohydrate unit plays a "protective" role, stabilizing the polyacetylene part and masking its biological activity until the breakdown of the glycosidic bond by a glycosidase enzyme. [24] It is well known that environmental conditions greatly affect the biosynthesis of secondary metabolites, and the amounts of these compounds increase under limiting conditions.…”

Vernonia polysphaera Baker: Anti-inflammatory activity in vivo and inhibitory effect in LPS-stimulated RAW 264.7 cells

“…In folk medicine its leaves and roots are used in decoction or infusion for diuretic, balsamic, anti-rheumatic purposes, and in cases of flu, bronchitis, pneumonia, and persistent coughs[12]. Most studies with species of Vernonia genus in animal models are related to diabetes[13], inflammation[14] and malaria[15].…”