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Dive into the research topics where Klára Szentmihályi is active.

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Featured researches published by Klára Szentmihályi.


Bioresource Technology | 2002

Rose hip (Rosa canina L.) oil obtained from waste hip seeds by different extraction methods

Klára Szentmihályi; Peter Vinkler; Béla G. Lakatos; Vendel Illés; Mária Then

From the rose hip seed, which is generally a waste material, valuable oil can be obtained for medicinal use. Various extraction methods have been compared: traditional solvent extraction with ultrasound-, microwave-, sub- and supercritical fluid extraction (SFE). Unsaturated fatty acid (UFA: oleic-, linoleic- and linolenic acid; 16.25-22.11%, 35.94-54.75%, 20.29-26.48%) and polyunsaturated fatty acid (PUFA:linoleic- and linolenic acid) content were over 90% and 60% in the recovered oils. The oils contained different amounts of metals. The concentration of some metals, particularly iron in microwave oil (27.11 microg g(-1)) is undesirable from the aspect of stability. By traditional solvent extraction, oil was obtained in 4.85 wt/wt%. Subcritical FE appeared to be the best method for the recovery of rose hip oil with highest oil yield (6.68 wt/wt%), carotene- (145.3 microg g(-1)) and linoleic acid content (54.75%). Supercritical FE without organic solvent is suitable for mild recovery of oil. The oil was rich in UFA and PUFA (92.7% and 76.25%) and contained the lowest amount of carotene and pheophytin (36.3 and 45.8 microg g(-1)). Oil yield in most new extraction methods (microwave extraction, super- and subcritical FE) was higher than in the case of traditional Soxhlet extraction. The main benefit of supercritical FE with CO2 is the solvent free oil while in the case of other extractions evaporation of the solvent is needed. Although the content of bioactive compounds in oils was different, all oils may be appropriate for medicinal use.


Journal of Pharmaceutical and Biomedical Analysis | 2003

Herbal remedies of Solidago--correlation of phytochemical characteristics and antioxidative properties.

P. Apáti; Klára Szentmihályi; Sz. T. Kristó; I Papp; P Vinkler; É Szoke; Ágnes Kéry

In this study the correlation of phytochemical characteristics and antioxidative properties of classical herbal tea extracts-Infusum solidaginis, Decoctum solidaginis, Maceratum solidaginis-and tinctures prepared by various concentration of ethanol (40, 70, 96% v/v) have been examined for the release of flavonoids and their antioxidant activity. Quantitative and composition determination of flavonoids were carried out by spectrophotometry, high-performance liquid chromatography and capillary electrophoresis, respectively. Hydrogen-donating ability and reducing power properties were used to define in vitro radical scavenging activity of Solidago extracts, but integral antioxidative capacity was determined by luminometry (Photochem), calculating the ascorbic acid equivalents. Chlorogenic acid, quercetin-3-O-beta-D-rutinoside, quercetin-3-O-beta-D-galactoside, quercetin-3-O-beta-D-glucoside, quercetin-3-O-beta-D-rhamnoside, kaempferol-3-O-alpha-L-rhamnoside and quercetin were confirmed by retention times and UV spectra. Based on the dissolution rate, variance of flavonoid release and ascorbic acid equivalents it was concluded, that Tinctura solidaginis (70% v/v ethanol) and Infusum solidaginis are the most appropriate preparations.


Food Chemistry | 2002

Comparative evaluation of Helichrysi flos herbal extracts as dietary sources of plant polyphenols, and macro- and microelements

Éva Lemberkovics; Erika Czinner; Klára Szentmihályi; Andrea Balázs

Abstract The inflorescence of Helichrysum arenarium (L.) Moench ( Helichrysi flos syn. Stoechados flos ) has long been known in herbal medicine in Europe for its choleretic, diuretic, antiinflammatory and detoxifying activities. Organic bioactive compounds and the inorganic element content of Helichrysi flos drugs of different origin (from cultivation or from the commercial network) and their water extracts were examined. The polyphenol and flavonoid content in the drug (61.4–92.3 and 9.4–12.7 g kg −1 , respectively) and tea samples (1200–1730 and 47–71 mg l −1 , respectively) were determined by a spectrophotometric method. The concentration of 23 macro- and microelements was measured in crude drugs and their water extracts by inductively coupled plasma–atomic emission spectrometry (ICP–AES). The cultivated drug sample from 1999 (Hungary) contained aluminum (353 mg kg −1 ), chromium (6 mg kg −1 ), copper (19 mg kg −1 ), manganese (349 mg kg −1 ) and phosphorus (2907 mg kg −1 ) in highest level, while the concentration of barium (19 mg kg −1 ), calcium (7575 mg kg −1 ), iron (159 mg kg −1 ), and zinc (59 mg kg −1 ) was highest in a commercial sample from 1998 (Poland).


Phytotherapy Research | 1998

Potassium–sodium ratio for the characterization of medicinal plant extracts with diuretic activity

Klára Szentmihályi; Ágnes Kéry; Mária Then; B. Lakatos; Zoltán Sándor; Peter Vinkler

Atomic emission spectrometry was applied for the determination of potassium and sodium concentrations in crude drugs and decoctions. The content of the two elements and potassium–sodium ratios of medicinal plant extracts were measure as a basis for evaluating diuretic activity. The potassium–sodium ratios were higher in the diuretic plant decoctions, than in crude drug decoctions used for different activities.


Zeitschrift für Naturforschung C | 2004

Antioxidant property of volatile oils determined by the ferric reducing ability

Cristina Lado; Mária Then; Ilona S. Varga; Éva Szoke; Klára Szentmihályi

Some current oils and their main components were studied to determine their antioxidant values. This was done by using the modified method of ferric reducing ability of plasma. It has been established that volatile oils of medicinal plants have on average a reducing capacity of 3.5-220 mmol/kg oil. The reducing capacities of the main constituents of volatile oils are 0.165-65.5 mmol/kg in concentrated oils. The highest reducing capacity was showd for phellandrene (65.438 ± 0.166 mmol/kg) and anethole (50.087 ± 0.160 mmol/kg) while the lowest values were obtained for menthol (0.165 ± 0.023 mmol/kg) and menthone (0.168 ± 0.010 mmol/kg). It has been stated that the antioxidant values of the main constituents are lower than those of volatile oils. The reducing capacity of the main constituents of medicinal plant drugs at different concentrations was also determined.


Journal of Chromatography A | 2000

Effect of sample handling on alkaloid and mineral content of aqueous extracts of greater celandine (Chelidonium majus L.)

Mária Then; Klára Szentmihályi; Ágnes Sárközi; Vendel Illés; E. Forgács

The authors examined the extraction of alkaloids from the greater celandine (Chelidonium majus L.) by different methods (traditional pressing and tea making, microwave and supercritical fluid extraction). The extractants were water and propylene glycol. For comparison of the extraction methods, the yield was evaluated according to total alkaloid content measured by spectroscopy. The highest alkaloid yield was obtained by microwave extraction and by making tea. Distribution of the components was studied by thin-layer chromatography and densitometry. The concentration and the ratio of alkaloid components in extracts are significantly different depending on the extraction method. The solution obtained by supercritical fluid extraction contains coptisine and chelidonine, while berberine could be obtained by microwave extraction only. Extracts with high coptisine content were obtained by supercritical fluid extraction, followed by pressing and microwave extraction. Mineral element content of the drug and extracts was also determined by inductively coupled plasma atomic emission spectrometry. Element content (Na, Ca, Fe) was found to be highest in microwave extracts.


European Journal of Gastroenterology & Hepatology | 2008

Oxidative stress with altered element content and decreased ATP level of erythrocytes in hepatocellular carcinoma and colorectal liver metastases

László Váli; Oszkár Hahn; Péter Kupcsulik; Ágnes Drahos; E. Sárváry; Klára Szentmihályi; Zsolt Pallai; Tímea Kurucz; Péter Sipos; Anna Blázovics

Our aim was to study the possible alterations of redox status (enzymatic and nonenzymatic parameters and metal elements) in erythrocytes of patients with hepatocellular carcinoma (HCC), colorectal liver metastases (CRLM) and benign liver neoplasms. The function of redox homeostasis is closely connected to the energy level of erythrocytes, therefore, the ATP level was also determined. Antioxidant parameters, enzyme activities of superoxide dismutase and glutathione peroxidase were estimated in the erythrocytes of 11 patients with benign tumour, 23 patients with primary malignant and 37 metastatic liver tumour patients and 30 age-matched and sex-matched healthy controls. Element content with inductively coupled plasma optical emission spectrometer and ATP level by the chemiluminometric method were also determined from the samples. Free radical intensity was significantly increased, whereas erythrocyte glutathione peroxidase and superoxide dismutase activities were significantly decreased in the HCC and CRLM groups versus benign groups and controls. Se, Mn and Zn levels were lowered in HCC and CRLM groups versus benign and control groups. The content of Cu, Mg, Se and Zn changed significantly between HCC and CRLM groups. Similarly, ATP concentration decreased in HCC and CRLM versus controls and benign groups. The lowest levels of ATP and antioxidant enzyme activities were found in the case of CRLM patients. These results reveal an alteration in the ATP level of erythrocytes with concomitant changes in the antioxidant defence system in hepatic cancer patients. Altered redox homeostasis (oxidative damage) may lead to decreased ATP level and consequently may play an important role in primary carcinogenesis and generation of metastases, as well.


Journal of Molecular Catalysis A-chemical | 2003

Acylation of alcohols and amines with carboxylic acids: a first report catalyzed by iron(III) oxide-containing activated carbon ☆

B. Sreedhar; V. Bhaskar; Ch. Sridhar; T. Srinivas; László Kótai; Klára Szentmihályi

Abstract An efficient and selective acylation of alcohols and amines employing carboxylic acids as acylating agents is realized through the metal oxide containing activated carbon catalyst achieved by carbonization of organic ion-exchangers after incorporation of Fe 3+ -ions with exchangeable cations present in resin for the first time.


Human & Experimental Toxicology | 2014

Protective effect of CV247 against cisplatin nephrotoxicity in rats

Csaba Máthé; Gábor Szénási; Andor Sebestény; Anna Blázovics; Klára Szentmihályi; Péter Hamar; Mihály Albert

CV247 (CV), an aqueous mixture of copper (Cu) and manganese (Mn) gluconates, vitamin C and sodium salicylate increased the antitumour effects of cisplatin (CDPP; cis-diamminedichloroplatinum) in vitro. We hypothesized that the antioxidant and cyclooxygenase-2 (COX-2; prostaglandin-endoperoxide synthase 2) inhibitory components of CV can protect the kidneys from CDPP nephrotoxicity in rats. CDPP (6.5 mg/kg, intraperitoneally) slightly elevated serum creatinine (Crea) and blood urea nitrogen (BUN) 12 days after treatment. Kidney histology demonstrated extensive tubular epithelial damage and COX-2 immunoreactivity increased 14 days after treatment. A large amount of platinum (Pt) accumulated in the kidney of CDPP-treated rats. Furthermore, CDPP decreased renal iron (Fe), molybdenum (Mo), zinc (Zn), Cu and Mn concentrations and increased plasma Fe and Cu concentrations. CDPP elevated plasma free radical concentration. Treatment with CV alone for 14 days (twice 3 ml/kg/day orally) did not influence these parameters. Chronic CV administration after CDPP reduced renal histological damage and slightly decreased COX-2 immunoreactivity, while failed to prevent the increase in Crea and BUN levels. Blood free radical concentration was reduced, that is, CV improved redox homeostasis. CV restored plasma Fe and renal Fe, Mo and Zn, while decreased Pt and elevated Cu and Mn concentrations in the kidney. Besides the known synergistic antitumour effects with CDPP, CV partially protected the kidneys from CDPP nephrotoxicity probably through its antioxidant effect.


Journal of Pharmaceutical and Biomedical Analysis | 2001

In vitro study on the transfer of volatile oil components

Klára Szentmihályi; E. Forgács; M. Hajdú; Mária Then

The following volatile oils were tested in vitro: chamomile (Matricaria recutica L.), peppermint (Mentha piperita L.) and sage (Salvia officinalis L.) to obtain information on which components of volatile oils or minerals are able to pass through the membranes under different conditions. The transfer of chamomile and peppermint oil from aqueous volatile oil to the stomach (pH=1.1) and then to the plasma (pH=7.5) was studied, and the transfer of sage oil through the skin (from pH=5.5 to pH=7.5) was examined. The transfer of some components was more favorable than that of others. The transfer of chamomile oil was faster to buffer pH=1.1 than from buffer pH=1.1 to buffer pH=7.5 and most of the components, except for chamazulene, passed through the membranes. In the case of peppermint the components went through the membranes in the first 15 min although the main components mostly remained in the initial solution. The sage oil transferred showed the same characteristics as the starting oil. A small amount of metal present in the volatile oils also passed through the membranes. The transfer of metals varied, depending on the time, type of the oil, metal quality and the conditions applied.

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Zoltán May

Hungarian Academy of Sciences

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Peter Vinkler

Hungarian Academy of Sciences

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Béla G. Lakatos

Hungarian Academy of Sciences

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E. Rapavi

Semmelweis University

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