Orsolya Orbán-Gyapai

Flavonoids Isolated from Rumex aquaticus Exhibit Neuroprotective and Neurorestorative Properties by Enhancing Neurite Outgrowth and Synaptophysin

There is heightened interest in the field of stroke recovery as there is need for agents that would prevent the debilitating effects of the disorder, thereby tremendously reducing the societal and economic costs associated with it. In this study, the isolation of two flavonoids--quercetin-3-O-galactoside (1) and quercetin-3-O-arabinoside (2)--from Rumex aquaticus (western dock) and their neuroprotective effects were reported in the oxygen-glucose deprivation (OGD) model of in vitro ischemia using rat pheochromocytoma (PC12) cell line. Bioassay-guided fractionation of the ethyl-acetate extract of Rumex aquaticus L. afforded the isolation of compounds 1 and 2. The structures of compounds were established on the basis of spectroscopic analyses (UV, mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). Both compounds were isolated for the first time from this species. In the course of the pharmacological experiments it was detected that these flavonoids at 10 µM concentration significantly improved cell survival in the oxygen-glucose deprivation model of ischemia. Moreover, they also increased neurite outgrowth in differentiated PC12 cells subjected to ischemic insult. Investigations on the cellular mechanism for the observed effect revealed that compound 1 (10 µM) enhances the expression of synaptophysin - a marker of synapses, and an indicator of synaptic plasticity. Rapid restoration of neurological function following injury is paramount to the prevention of debilitating consequences of ischemic stroke. This combination of neuroprotection and neuritogenic potential could be particularly useful in the recovery phase of stroke.

Xanthine Oxidase Inhibitory Activity of Extracts Prepared from Polygonaceae Species

The xanthine oxidase (XO) inhibitory activity of aqueous and organic extracts of 27 selected species belonging in five genera (Fallopia, Oxyria, Persicaria, Polygonum and Rumex) of the family Polygonaceae occurring in the Carpathian Basin were tested in vitro. From different plant parts (aerial parts, leaves, flowers, fruits and roots), a total of 196 extracts were prepared by subsequent extraction with methanol and hot H2O and solvent–solvent partition of the MeOH extract yielding n‐hexane, chloroform and 50% MeOH subextracts. It was found that the chloroform subextracts and/or the remaining 50% MeOH extracts of Fallopia species (F. bohemica, F. japonica and F. sachalinensis), Rumex species (R. acetosa, R. acetosella, R. alpinus, R. conglomeratus, R. crispus, R. hydrolapathus, R. pulcher, R. stenophyllus, R. thyrsiflorus, R. obtusifolius subsp. subalpinus, R. patientia) and Polygonum bistorta, Polygonum hydropiper, Polygonum lapathifolium and Polygonum viviparum demonstrated the highest XO inhibitory activity (>85% inhibition) at 400 µg/mL. The IC50 values of the active extracts were also determined. On the basis of the results, these plants, and especially P. hydropiper and R. acetosella, are considered worthy of activity‐guided phytochemical investigations. Copyright

Xanthine oxidase inhibitory activity of hungarian wild-growing mushrooms

Mushrooms represent a remarkable and yet largely unexplored source of new, biologically active natural products. In this work, we report on the xanthine oxidase (XO) inhibitory activity of 47 wild‐growing mushrooms native to Hungary. Aqueous and organic (n‐hexane, chloroform, and 50% methanol) extracts of selected mushrooms from different families were screened for their XO inhibitory activities. Among the 188 extracts investigated, the chloroform and 50% methanol fractions proved to be the most effective. Some species exhibited high inhibitory activity, e.g., Hypholoma fasciculare (IC50 = 67.76 ± 11.05 µg/mL), Suillus grevillei (IC50 = 13.28 ± 1.58 µg/mL), and Tricholoma populinum (IC50 = 85.08 ± 15.02 µg/mL); others demonstrated moderate or weak activity. Additional studies are warranted to characterize the compounds responsible for the XO inhibitory activity of mushroom extracts. Copyright

Three New Iridoid Glycosides from the Aerial Parts of Asperula involucrata

Three new iridoid glycosides, named involucratosides A – C (1 – 3), were isolated from the H2O subextract of crude MeOH extract prepared from the aerial parts of Asperula involucrata along with a known iridoid glycoside (adoxoside), three flavone glycosides (apigenin 7‐O‐β‐glucopyranoside, luteolin 7‐O‐β‐glucopyranoside, apigenin 7‐O‐rutinoside) as well as two phenolic acid derivatives (chlorogenic acid and ferulic acid 4‐O‐β‐glucopyranoside). Their chemical structures were established by UV, IR, 1D‐ (1H, 13C and JMOD) and 2D‐ (COSY, HSQC, HMBC and NOESY) NMR experiments and HR‐ESI‐MS. In addition, the crude extract, subextracts and isolates were evaluated for their xanthine oxidase inhibitory and antioxidant activities in in vitro tests. This is the first report on the chemical composition and bioactivities of A. involucrata.

Phytochemical and pharmacological investigation of Spiraea chamaedryfolia : a contribution to the chemotaxonomy of Spiraea genus

ObjectiveDiterpene alkaloids are secondary plant metabolites and chemotaxonomical markers with a strong biological activity. These compounds are characteristic for the Ranunculaceae family, while their occurrence in other taxa is rare. Several species of the Spiraea genus (Rosaceae) are examples of this rarity. Screening Spiraea species for alkaloid content is a chemotaxonomical approach to clarify the classification and phylogeny of the genus. Novel pharmacological findings make further investigations of Spiraea diterpene alkaloids promising.ResultsSeven Spiraea species were screened for diterpene alkaloids. Phytochemical and pharmacological investigations were performed on Spiraea chamaedryfolia, the species found to contain diterpene alkaloids. Its alkaloid-rich fractions were found to exert a remarkable xanthine-oxidase inhibitory activity and a moderate antibacterial activity. The alkaloid distribution within the root was clarified by microscopic techniques.

Phytochemical investigation of Rumex thyrsiflorus Fingerh.

In the course of our pharmacological screening of Polygonaceae species occurring in the Carpathian Basin the extracts prepared from the roots of Rumex thyrsiflorus showed promising antiproliferative, xanthine oxidase inhibitory and antibacterial activities. The present work deals with the isolation of compounds from the root of the plant. After multistep separation process, four compounds were obtained from the n-hexane, chloroform and ethyl acetate soluble fractions of the methanol extract of the root. The structures of the isolated compounds were determined as 1-palmitoylglycerol, β-sitosterol, (-)-epicatechin, and procyanidin B5.