Erika Liktor-Busa

Three new steroids from the roots of Serratula wolffii

Investigation of the methanol extract of the roots of Serratula wolffii resulted in an ecdysone-related compound, 2beta,3beta,20R,22R,25-pentahydroxy-5beta-cholest-6,8(14)-dien (1), a new ecdysteroid, 24-methylene-shidasterone (2), the known compound stachysterone B (3) and its 14,15-alpha-epoxide (4), a novel natural product. The structures of compounds 1-4 were established by spectral analysis ((1)H NMR, (13)C NMR, COSY, NOESY, HMQC, HMQC-TOCSY and HMBC).

Metabolic Effects of Mulberry Leaves: Exploring Potential Benefits in Type 2 Diabetes and Hyperuricemia

The leaves of Morus alba L. have a long history in Traditional Chinese Medicine and also became valued by the ethnopharmacology of many other cultures. The worldwide known antidiabetic use of the drug has been suggested to arise from a complex combination effect of various constituents. Moreover, the drug is also a potential antihyperuricemic agent. Considering that type 2 diabetes and hyperuricemia are vice-versa in each others important risk factors, the use of mulberry originated phytotherapeutics might provide an excellent option for the prevention and/or treatment of both conditions. Here we report a series of relevant in vitro and in vivo studies on the bioactivity of an extract of mulberry leaves and its fractions obtained by a stepwise gradient on silica gel. In vivo antihyperglycemic and antihyperuricemic activity, plasma antioxidant status, as well as in vitro glucose consumption by adipocytes in the presence or absence of insulin, xanthine oxidase inhibition, free radical scavenging activity, and inhibition of lipid peroxidation were tested. Known bioactive constituents of M. alba (chlorogenic acid, rutin, isoquercitrin, and loliolide) were identified and quantified from the HPLC-DAD fingerprint chromatograms. Iminosugar contents were investigated by MS/MS, 1-deoxynojirimycin was quantified, and amounts of 2-O-alpha-D-galactopyranosyl-1-deoxynojirimicin and fagomine were additionally estimated.

Structure and stereochemistry of novel ecdysteroids from the roots of Serratula wolffii.

Three new natural ecdysteroids viz. 22‐dehydro‐20‐deoxy‐ajugasterone C (1), 1‐hydroxy‐22‐deoxy‐20,21‐didehydro‐ecdysone (2) and 22‐deoxy‐20,21‐didehydro‐ecdysone (3) were isolated from the methanol extract of the roots of Serratula wolffii. The structures of compounds 1–3 were established by various spectroscopic techniques, including one‐ and two‐dimensional NMR, circular dichroism and mass spectroscopic methods. Copyright

Role of Preparative Rotation Planar Chromatography in the Isolation of Ecdysteroids

Abstract A reliable isolation procedure is elaborated for the purification of ecdysteroids from Serratula wolffii. The procedure is also applicable to other plant sources. The general ecdysteroid isolation procedure was improved by the introduction of preparative rotation planar chromatography (RPC) to the purification process. Effective and simple cleanup and vacuum reversed‐phase column chromatographic separation was completed with RPC, or repeated RPC, to obtain pure ecdysteroids (ajugasterone C, dacryhainansterone, 22‐deoxy‐integristerone A, 20‐hydroxyecdysone, and 2 new ecdysteroids) from the crude extract. This paper discusses the advantages of this method as the final step of ecdysteroid isolation.

Investigation of Hungarian mushrooms for antibacterial activity and synergistic effects with standard antibiotics against resistant bacterial strains.

This study aimed to screen the antibacterial activity of 160 extracts of 40 mushroom species, collected in Hungary, against 11 standard bacterial strains and 9 clinical isolates. The further objective of this work was to evaluate the capacity of active fungal extracts to potentiate the action of antibiotics against resistant pathogens. Disc‐diffusion method was applied for screening of antibacterial activity of extracts. Microdilution method was used to determine minimum inhibitory concentrations. The active extracts were applied to different resistant micro‐organisms (multiresistant Acinetobacter baumannii and Pseudomonas aeruginosa, vancomycin‐resistant Enterococcus faecium and MRSA), combined with commercial drugs. The synergism between extracts and antibiotics was assessed by double‐disc synergy assay and determination of fractional inhibitory concentration (FIC) with checkerboard technique. From 40 mushrooms included in this experiment, 16 species exhibited antibacterial effects with moderate to high potential. In general the chloroform extracts proved to be most active, while the aqueous and aqueous‐methanolic extracts demonstrated low or no activity. Fistulina hepatica, Tapinella atrotomentosa (syn. Paxillus atrotomentosus) and Rhodocybe popinalis were the most active species; moreover, they can potentiate the action of cefuroxime against MRSA.

Antibacterial screening of Juncaceae species native to the Carpathian Basin against resistant strains and LC-MS investigation of phenanthrenes responsible for the effect.

The main objective of this project was to investigate the antibacterial activity of 19 species (Juncus acutus, J. alpinoarticulatus, J. articulatus, J. compressus, J. conglomeratus, J. effusus, J. filiformis, J. gerardii, J. inflexus, J. maritimus, J. monanthos, J. squarrosus, J. tenuis, J. trifidus, Luzula campestris, L. forsteri, L. luzuloides, L. sudetica and L. sylvatica) belonging to the family Juncaceae against methicillin-resistant S. aureus (MRSA), extended-spectrum β-lactamase (ESBL)-producing C. freundii, E. coli, E. cloacae, K. pneumoniae, and multiresistant A. baumannii and P. aeruginosa. Antibacterial susceptibilities were screened for inhibitory zones and MIC values determined by microdilution method. Among the tested extracts (n=96) 16 extracts prepared from Juncus species and 3 extracts from Luzula species showed mild to strong inhibitory activities against MRSA strains (inhibition zones=6.7mm-14.6mm; MIC values 9.75-156μg/mL). It can be concluded that Juncus and Luzula species demonstrated promising anti-MRSA effect, and J. maritimus, J. tenuis and J. gerardii considered worthy of activity-guided phytochemical investigations. The main bioactive constituents of Juncaceae species are phenanthrenes. Four phenanthrenes [juncuenin D (1), juncusol (2), dehydrojuncuenin B (3), and jinflexin B (4)] isolated previously from J. inflexus with anti-MRSA activity were investigated by LC-MS in extracts proved to be active in antimicrobial test.

Antiproliferative and Antimicrobial Activities of Selected Bryophytes

One-hundred and sixty-eight aqueous and organic extracts of 42 selected bryophyte species were screened in vitro for antiproliferative activity on a panel of human gynecological cancer cell lines containing HeLa (cervix epithelial adenocarcinoma), A2780 (ovarian carcinoma), and T47D (invasive ductal breast carcinoma) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and for antibacterial activity on 11 strains using the disc-diffusion method. A total of 99 extracts derived from 41 species exerted ≥25% inhibition of proliferation of at least one of the cancer cell lines at 10 μg/mL. In the cases of Brachythecium rutabulum, Encalypta streptocarpa, Climacium dendroides, Neckera besseri, Pleurozium schreberi, and Pseudoleskeella nervosa, more than one extract was active in the antiproliferative assay, whereas the highest activity was observed in the case of Paraleucobryum longifolium. From the tested families, Brachytheciaceae and Amblystegiaceae provided the highest number of antiproliferative extracts. Only 19 samples of 15 taxa showed moderate antibacterial activity, including the most active Plagiomnium cuspidatum, being active on 8 tested strains. Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus were the most susceptible to the assayed species. This is the first report on the bioactivities of these 14 species.

Study of in vitro antimicrobial and antiproliferative activities of selected Saharan plants

The aim of the present study was the evaluation of the antimicrobial and antiproliferative activities of selected Saharan species, which are applied in the traditional medicine but not studied thoroughly from chemical and pharmacological point of view. The studied plants, namely Anthyllis henoniana, Centropodia forskalii, Cornulaca monacantha, Ephedra alata var. alenda, Euphorbia guyoniana, Helianthemum confertum, Henophyton deserti, Moltkiopsis ciliata and Spartidium saharae were collected from remote areas of North Africa, especially from the Tunisian region of Sahara. After drying and applying the appropriate extraction methods, the plant extracts were tested in antimicrobial screening assay, performed on 19 Gram-positive and -negative strains of microbes. The inhibition zones produced by plant extracts were determined by disc-diffusion method. Remarkable antibacterial activities were exhibited by extracts of Ephedra alata var. alenda and Helianthemum confertum against B. subtilis, M. catarrhalis and methicillin-resistant and non-resistant S. aureus. Minimum inhibitory concentrations of these two species were also determined. Antiproliferative effects of the extracts were evaluated against 4 human adherent cell lines (HeLa, A431, A2780 and MCF7). Notable cell growth inhibition was found for extract of Helianthemum confertum and Euphorbia guyoniana. Our results provided data for selection of some plant species for further detailed pharmacological and phytochemical examinations.

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.