PubMed Health⌕ Search

Biomedical subjects

P Nánási

Publications and source records attributed to P Nánási.

15 recordsLinked to original sources
PubMed2001

[Comparative study of Glycyrrhiza glabra L. and Glycyrrhiza echinata L. of different origin. Medicinal plant polysaccharides III].

Comparative study was carried out among the polysaccharides of Chinese, Lithuanian and Hungarian origin Glycyrrhiza glabra L. as well as the Hungarian origin Glycyrrhiza echinata L. Monosaccharide composition, measured as alditol acetates, of Chinese and Hungarian G. glabra was very similar, but the Lithuanian G. glabra and the G. echinata were quite different. The monosaccharides of polysaccharides isolated from root and stem of G. echinata show significant differences (Table II.). All investigated samples contain glucuronic acid, the G. echinata contains also galacturonic acid (Table II.). Some fractions with higher uronic acid content and the acidic polysaccharides isolated from these fractions were studied and their monosaccharide composition was determined (Table III. and IV.).

China↗
PubMed1998

[Investigation of polysaccharides of Echinops species. Medicinal plant polysaccharides I].

Polysaccharides isolated from Echinops sphaerocephalus, Echinops ruthenicus, Echinops exaltatus, Echinops commutatus and Echinops orientalis (Asteraceae family) were investigated to study their qualitative and quantitative relations. The extracts of these studied plants have been used in traditional Chinese medicine as drugs with anti-inflammatory effect and anti-tumor promoting action in the osseous system [1]. We suppose that these biological effects are related to the polysaccharides especially to the acidic ones. The plant material was successively extracted with boiling water and six fractions were collected. The yield was 40-45%. The uronic acid content of these fractions, measured by the Bitter method, was relatively high 15-35% (Table I.). In case of Echinops sphaerocephalus different parts of the plant were investigated. The root and the stem are useful from a practical point of view because of the high uronic acid content. Some fractions, which seemed to be interesting on the basis of the measured uronic acid content, were dialyzed then concentrated, lyophilized and their uronic acid, protein and carbohydrate contents were determinated (Table III). The Echinops orientalis root fraction 6. was separated by ion-exchange chromatography. The monosaccharide composition of the neutral and the acidic fractions was measured by gas chromatography (Table IV).

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

[Polysaccharides of Glycyrrhiza glabra L. and Glycyrrhiza echinata L. Medicinal plants II].

Comparative study was carried out among the polysaccharides of Chinese, Lithuanian and Hungarian origin Glycyrrhiza glabra root samples as well as the Hungarian origin Glycyrrhiza echinata, which has not been studied earlier. The plant material was extracted with boiling water and the yield, the carbohydrate and the uronic acid content was measured by the alpha-naphtol and the Bitter method [21], respectively. Although the yield of Hungarian origin species was found lower than the yield of eastern species, the uronic acid content was similar. (Table I.) Our results show that to extract polysaccharides containing uronic acids needed longer extraction time, about 4 hours. The stem of Glycyrrhiza echinata might be useful from a practical point of view because of its large size and easy of access. (Table I. II.) Some fractions containing uronic acid in higher amount were separated on DEAE Sepharose CL-6B anion exchange column. After hydrolysis, reduction and acetylation the monosaccharide composition of this fractions was analysed by GC. (Table IV.).

China↗
PubMed1991

Influence of the redox-state potential of biophase on electrically stimulated skeletal muscles (myographic and voltage-clamp analysis).

Redox modulation of cholinergic and adrenergic mechanisms of excitatory tissues have been analyzed rather satisfactorily until recently. The aim of the present work is to give some initial guiding information about the redox modulation of electrogenic excitatory processes in skeletal muscles. It was observed, that on increasing the tissue redox-state potential (E0'), the amplitudes of muscle contractions are higher by 18.5 per cent than controls, but decreasing E0', the amplitudes of muscle contractions are lower by 10.5 per cents than controls. It means, that muscle contractions elicited by electric stimulation are also under redox control. One of the mechanisms responsible for this phenomenon is that following increased E0' values both peak current (Ip) and steady-state current (ISS) increases, but after decreased E0' values ISS decreases. The role of other site of actions and mechanisms, i.e. ion channels, active transport, excitation-contraction coupling, and Na(+)-Ca2+ exchange diffusion processes, are also discussed.

Animals↗
PubMed1990

Studies on the N-acetyl-beta-D-hexosaminidase B from germinating Lupinus luteus L. seeds. I. Purification and characterization.

The N-acetyl-beta-D-hexosaminidase B of germinating Lupinus luteus L. seeds (McFarlane et al. (1984) Phytochemistry 23, 2431-2433) was partially purified with a six-step purification procedure following extraction. This enzyme consists of one protein chain (Mr 69,000, as determined by SDS-PAGE and 62,500, as obtained by gel filtration on Bio-Gel P-60 Gel) and has a neutral isoelectric point (pI = 7.05, as determined by chromatofocusing). Moreover, it was found to be very sensitive to low ionic strength, especially in the presence of different gels based on Sephadex. Considering the substrate specificity, the enzyme splits both p-nitrophenyl-2-acetamido-2-deoxy-beta-D-glucosaminide and -galactosaminide substrates, but lacks N,N'-diacetylchitobiase activity. A new mixed-substrate procedure was developed and is presented here to demonstrate that a common active site is responsible for the splitting of both synthetic substrates.

Acetylgalactosamine↗
PubMed1989

Kinetic investigation of the substrate specificity of the cyanogenic beta-D-glucosidase (linamarase) of white clover.

Partially purified linamarase from Trifolium repens (genotype Lili acac) plants was kinetically characterized. Kinetic evidence was found to support the assumption that this cyanogenic beta-D-glucosidase has a broad substrate spectrum. p-Nitrophenyl-beta-D-xylopyranoside and p-nitrophenyl-alpha-L-arabinopyranoside substrates bound almost as tightly to the active center of the enzyme as the glucono(1----5)lactone transition-state analog inhibitor. Substrate specificity investigation also indicated that positions C-4 and C-6 on the pyranoside ring play an essential role in both substrate orientation and splitting. Recently very similar kinetic characteristics were reported on some mammalian cytosolic beta-D-glucosidases and a possible physiological interpretation of this coincidence is discussed. Inhibition studies with glucono(1----5)lactone revealed that the carbohydrate moiety of each substrate attached to the same binding site in the active center. Inhibition experiments with 1-thio substrate analogs demonstrated that the aglycon and the angular arrangement around the glycosidic linkage were the major determinants in the observed substrate specificity.

Binding, Competitive↗
PubMed1986

Synthesis of the tetrasaccharide repeating-unit of the lipopolysaccharide isolated from Pseudomonas maltophilia.

The title tetrasaccharide having the structure 3-O-Me-beta-L-Xylp-(1----4)- alpha-L-Rhap-(1----4)-alpha-L-Rhap-(1----2)-L-Rhap was obtained by reaction of the alpha-acetobromo derivative of 4-O-(3-O-methyl-beta-L-xylopyranosyl)-L-rhamnopyranose and benzyl 3,4-di-O-benzyl-2-O-(2,3-O-isopropylidene-alpha-L-rhamnopyranosyl)- alpha-L-rhamnopyranoside, followed by removal of the protecting groups. The synthesised compounds were characterised on the basis of n.m.r. data.

Carbohydrate Sequence↗