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Pérez P, Rabnecz G, Laufer Z, Gutiérrez D, Tuba Z, Martínez-Carrasco R. Restoration of photosystem II photochemistry and carbon assimilation and related changes in chlorophyll and protein contents during the rehydration of desiccated Xerophyta scabrida leaves. J Exp Bot 2011; 62:895-905. [PMID: 20956360 PMCID: PMC3022389 DOI: 10.1093/jxb/erq317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 09/17/2010] [Accepted: 09/21/2010] [Indexed: 05/07/2023]
Abstract
Recovery of photosynthesis in rehydrating desiccated leaves of the poikilochlorophyllous desiccation-tolerant plant Xerophyta scabrida was investigated. Detached leaves were remoistened under 12 h light/dark cycles for 96 h. Water, chlorophyll (Chl), and protein contents, Chl fluorescence, photosynthesis-CO(2) concentration response, and the amount and activity of Rubisco were measured at intervals during the rehydration period. Leaf relative water contents reached 87% in 12 h and full turgor in 96 h. Chl synthesis was slower before than after 24 h, and Chla:Chlb ratios changed from 0.13 to 2.6 in 48 h. The maximum quantum efficiency recovered faster during rehydration than the photosystem II operating efficiency and the efficiency factor, which is known to depend mainly on the use of the electron transport chain products. From 24 h to 96 h of rehydration, net carbon fixation was Rubisco limited, rather than electron transport limited. Total Rubisco activity increased during rehydration more than the Rubisco protein content. Desiccated leaves contained, in a close to functional state, more than half the amount of the Rubisco protein present in rehydrated leaves. The results suggest that in X. scabrida leaves Rubisco adopts a special, protective conformation and recovers its activity during rehydration through modifications in redox status.
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Affiliation(s)
- P Pérez
- Institute of Natural Resources and Agrobiology of Salamanca, CSIC, Apartado 257, 37071 Salamanca, Spain.
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Fóti S, Nagy Z, Balogh J, Bartha S, Acosta M, Czóbel S, Péli E, Marek M, Tuba Z. Small scale spatial variability and pattern of soil respiration and water content in wet and a dry temperate grasslands and bare soil. ekol 2009. [DOI: 10.4149/ekol_2009_04_389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Wohlfahrt G, Anderson-Dunn M, Bahn M, Balzarolo M, Berninger F, Campbell C, Carrara A, Cescatti A, Christensen T, Dore S, Eugster W, Friborg T, Furger M, Gianelle D, Gimeno C, Hargreaves K, Hari P, Haslwanter A, Johansson T, Marcolla B, Milford C, Nagy Z, Nemitz E, Rogiers N, Sanz MJ, Siegwolf RT, Susiluoto S, Sutton M, Tuba Z, Ugolini F, Valentini R, Zorer R, Cernusca A. Biotic, Abiotic, and Management Controls on the Net Ecosystem CO2 Exchange of European Mountain Grassland Ecosystems. Ecosystems 2008. [DOI: 10.1007/s10021-008-9196-2] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pintér K, Barcza Z, Balogh J, Czóbel S, Csintalan Z, Tuba Z, Nagy Z. Interannual variability of grasslands’ carbon balance depends on soil type. COMMUNITY ECOL 2008. [DOI: 10.1556/comec.9.2008.s.7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Nagy Z, Tuba Z. Effects of elevated air CO2concentration on loess grassland vegetation as investigated in a mini FACE experiment. COMMUNITY ECOL 2008. [DOI: 10.1556/comec.9.2008.s.20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Czóbel S, Szirmai O, Nagy J, Balogh J, Ürmös Z, Péli E, Tuba Z. Effects of irrigation on community composition and carbon uptake in Pannonian loess grassland monoliths. COMMUNITY ECOL 2008. [DOI: 10.1556/comec.9.2008.s.13] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Nagy P, Bakonyi G, Péli E, Sonnemann I, Tuba Z. Long-term response of the nematode community to elevated atmospheric CO2in a temperate dry grassland soil. COMMUNITY ECOL 2008. [DOI: 10.1556/comec.9.2008.s.22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Vodnik D, Maček I, Péli E, Videmšek U, Tuba Z. Elevated CO2affects the content of glomalin related soil protein in xeric temperate loess and temperate semi-desert sand grasslands. COMMUNITY ECOL 2008. [DOI: 10.1556/comec.9.2008.s.21] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Fóti S, Balogh J, Nagy Z, Ürmös Z, Bartha S, Tuba Z. Temporal and spatial variability and pattern of soil respiration in loess grassland. COMMUNITY ECOL 2008. [DOI: 10.1556/comec.9.2008.s.9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Georgieva K, Szigeti Z, Sarvari E, Gaspar L, Maslenkova L, Peeva V, Peli E, Tuba Z. Photosynthetic activity of homoiochlorophyllous desiccation tolerant plant Haberlea rhodopensis during dehydration and rehydration. Planta 2007; 225:955-64. [PMID: 16983535 DOI: 10.1007/s00425-006-0396-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Accepted: 08/22/2006] [Indexed: 05/11/2023]
Abstract
The functional state of the photosynthetic apparatus of flowering homoiochlorophyllous desiccation tolerant plant Haberlea rhodopensis during dehydration and subsequent rehydration was investigated in order to characterize some of the mechanisms by which resurrection plants survive drought stress. The changes in the CO2 assimilation rate, chlorophyll fluorescence parameters, thermoluminescence, fluorescence imaging and electrophoretic characteristics of the chloroplast proteins were measured in control, moderately dehydrated (50% water content), desiccated (5% water content) and rehydrated plants. During the first phase of desiccation the net CO2 assimilation decline was influenced by stomatal closure. Further lowering of net CO2 assimilation was caused by both the decrease in stomatal conductance and in the photochemical activity of photosystem II. Severe dehydration caused inhibition of quantum yield of PSII electron transport, disappearance of thermoluminescence B band and mainly charge recombination related to S2QA- takes place. The blue and green fluorescence emission in desiccated leaves strongly increased. It could be suggested that unchanged chlorophyll content and amounts of chlorophyll-proteins, reversible modifications in PSII electron transport and enhanced probability for non-radiative energy dissipation as well as increased polyphenolic synthesis during desiccation of Haberlea contribute to drought resistance and fast recovery after rehydration.
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Affiliation(s)
- Katya Georgieva
- Acad. M. Popov Institute of Plant Physiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, Sofia 1113, Bulgaria.
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Georgieva K, Maslenkova L, Peeva V, Markovska Y, Stefanov D, Tuba Z. Comparative study on the changes in photosynthetic activity of the homoiochlorophyllous desiccation-tolerant Haberlea rhodopensis and desiccation-sensitive spinach leaves during desiccation and rehydration. Photosynth Res 2005; 85:191-203. [PMID: 16075320 DOI: 10.1007/s11120-005-2440-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Accepted: 02/14/2005] [Indexed: 05/03/2023]
Abstract
The functional peculiarities and responses of the photosynthetic system in the flowering homoiochlorophyllous desiccation-tolerant (HDT) Haberlea rhodopensis and the non-desiccation-tolerant spinach were compared during desiccation and rehydration. Increasing rate of water loss clearly modifies the kinetic parameters of fluorescence induction, thermoluminescence emission, far-red induced P700 oxidation and oxygen evolution in the leaves of both species. The values of these parameters returned nearly to the control level after 24 h rehydration only of the leaves of HDT plant. PS II was converted in a non-functional state in desiccated spinach in accordance with the changes in membrane permeability, malondialdehyde, proline and H(2)O(2) contents. Moreover, our data showed a strong reduction of the total number of PS II centers in Haberlea without any changes in the energetics of the charge recombination. We consider this observation, together with the previously reported unusually high temperature of B-band (S(2)Q(B)-) emission of Haberlea to reflect some specific adaptive characteristics of the photosynthetic system. As far as we know this is the first time when such adaptive characteristics and mechanism of the photosynthetic system of a flowering HDT higher plant is described. These features of Haberlea can explain the fast recovery of its photosynthesis after desiccation, which enable this HDT plant to rapidly take advantage of frequent changes in water availability.
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Affiliation(s)
- Katya Georgieva
- Acad. M. Popov Institute of Plant Physiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
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Otvös E, Kozák IO, Fekete J, Sharma VK, Tuba Z. Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in mosses (Hypnum cupressiforme) in Hungary. Sci Total Environ 2004; 330:89-99. [PMID: 15325161 DOI: 10.1016/j.scitotenv.2004.02.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/13/2004] [Indexed: 05/24/2023]
Abstract
The atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) was investigated in Hungary by analyzing a moss (Hypnum cupressiforme) species as a bioindicator. In the autumn of 1997, samples were collected at 29 sites distributed across Hungary. The concentrations of total PAH at these sites were in the range of 0.1567-10.45 x 10(4) microg kg(-1) with a mean value of 1.87 x 10(4) microg kg(-1). More than 99% of the total PAHs atmospheric deposition were low molecular weight PAHs (up to 3 ring compounds). The total PAH values showed no correlation with metal concentrations. However, most of the sites in this region showed a positive linear relationship between PAHs levels and traffic volume (r2 = 0.83; P < 0.001) while no relationship existed between PAH levels and population (r2 = 0.01; P > 0.1). Atmospheric deposition of PAHs at different regions in Hungary may be due to incomplete combustion of fuel. The total concentrations of PAHs were compared to the PAH levels in vegetation samples collected from different regions around the world. The highest PAHs concentrations accumulated were found in Hypnum cupressiforme than other vegetation species. A greater affinity for PAH compounds by Hypnum cupressiforme than other moss species probably caused larger amounts of accumulation. A relationship between accumulations of PAH compounds in Hypnum cupressiforme and octanol-air partition coefficients was obtained and is briefly discussed.
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Affiliation(s)
- E Otvös
- Institute of General and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellért tér 4, H-1111, Hungary
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Singh M, Tuba Z, Jordán F, Scheuring I, Podani J. Book reviews. COMMUNITY ECOL 2004. [DOI: 10.1556/comec.5.2004.1.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Abstract
The atmospheric deposition of Cd, Cr, Cu, Fe, Ni, Pb, V and Zn in Hungary was investigated by using moss species as bioindicators. Our research was part of an international mapping project (Atmospheric Heavy Metal Deposition in Europe) [NORD 21 (1987) 1-44; NORD 9 (1994)] carried out in the most European countries in the 1990s to determine and to compare atmospheric heavy metal background pollution by standardized methods. Sampling was performed at 116 sites distributed over Hungary in the autumn of 1997. Moss species of Hypnum cupressiforme (72.4%) were preferred. But where it could not be collected, other species were taken. Unwashed, dried samples were digested with H(2)O(2)/HNO(3), and the concentrations of heavy metals were determined by ICP-AES. The results reflect local emission points. Background mean levels of Cd, Fe and Ni were mildly elevated in comparison to European means [NORD 9 (1994)]. Probably, that was due not only to pollution, but to the use of Hypnum cupressiforme, which can accumulate higher concentrations of heavy metals compared to other species. The results are presented on colored contour maps obtained with the SURFER program (Golden Software Inc. Co).
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Affiliation(s)
- E Otvös
- Szent István University, Faculty of Agricultural & Environmental Sciences, Department of Botany & Plant Physiology, Páter K. u. 1., Gödöllo 2103, Hungary
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Vizi ES, Tuba Z, Mahó S, Foldes FF, Nagano O, Dóda M, Takagi S, Chaudhry IA, Saubermann AJ, Nagashima H. A new short-acting non-depolarizing muscle relaxant (SZ1677) without cardiovascular side-effects. Acta Anaesthesiol Scand 2003; 47:291-300. [PMID: 12648195 DOI: 10.1034/j.1399-6576.2003.00033.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND In order to facilitate rapid tracheal intubation, the development of a rapid onset, short duration, non-depolarizing muscle relaxant without cardiovascular side-effects would be a significant accomplishment in the field of anesthesiology. The aim of the present study was to test the action of a new non-depolarizing muscle relaxant (SZ1677) on neuromuscular transmission, muscarinic (M2, M3) receptors and cardiovascular reactions and to compare it with clinically used muscle relaxants. METHODS Neuromuscular transmission was studied by recording muscle contractions elicited by indirect electrical stimulation, using (i). in vitro isolated phrenic nerve-hemidiaphragm preparation of mice, rats and guinea pigs and (ii). in vivo sciatic nerve-anterior tibial muscle preparation of anesthetized rats, guinea pigs and cats. Cardiovascular effects of muscle relaxants were evaluated on the grounds of their effects on changes of blood pressure and heart rate induced by electrical stimulation of the right vagal nerve in anesthetized cats. To study postsynaptic antimuscarinic affinity of muscle relaxants on M3 receptors, oxotremorine-induced contractions of longitudinal muscle strip of guinea pig ileum were registered in their presence and absence. RESULTS One of more than 120 newly synthesized non-depolarizing muscle relaxants compounds, 1-3[alpha-hydroxy-17beta-acetyloxy-2beta-(1,4-dioxa-8-azaspiro[4,5]dec-8-yl)-5alpha-androstane-16beta-il] -1-(2-propenyl)pyrrolidinium bromide (SZ1677), excelled with its advantageous pharmacological properties: relatively short duration of action, no accumulation and lack of unwanted side-effects. Pharmacodynamic studies show that SZ1677 is a non-depolarizing neuromuscular blocking agent with a relatively short duration and rapid onset of action in a variety of laboratory animal species. It is without cumulative effect, does not reduce blood pressure, and fails to produce tachycardia. Significant cardiac vagal blocking effects were not observed even at concentrations or dosages of 8 times the ED90. This compound, unlike many other muscle relaxants, does not have atropine-like effects on human atrial tissue; it does not increase the release of NA from sympathetic innervation in the heart. In all practical ways, at least from the vantage point of the preclinical study, SZ1677 compares favorably with all presently available short-acting muscle relaxants, including rapacuronium. CONCLUSION In experiments, SZ1677 proved to be a short-acting neuromuscular blocking compound having a large safety margin between the doses required to produce neuromuscular block and those likely to lead to cardiovascular side-effects.
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Affiliation(s)
- E S Vizi
- Department of Pharmacology, Institute of Experimental Medicine, Budapest, Hungary.
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17
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Abstract
The first use of neuromuscular blocking agents (muscle relaxants) in clinical practice (1942) revolutionised the practice of anaesthesia and started the modern era of surgery. Since 1942 introduction of tubocurarine (18) neuromuscular blocking agents have been used routinely to provide skeletal muscle relaxation during surgical procedures allowing access to body cavities without hindrance from voluntary or reflex muscle movement. After the introduction of tubocurarine and the depolarizing suxamethonium chloride (4) (1949) several nondepolarizing steroidal and nonsteroidal neuromuscular blocking agents with different onset time and duration of effect were introduced e.g. gallamine triethiodide (1) (1949), methocurine (2) (1949), alcuronium chloride (3) (1963), pancuronium bromide (9) (1968), vecuronium bromide (11) (1982), pipecuronium bromide (10) (1982), atracurium besylate (5) (1982), doxacurium chloride (6) (1991), mivacurium chloride (8) (1992), rocuronium bromide (12) (1994) cisatracurium besylate (7) (1996), and rapacuronium bromide (13) (2000). SZ 1677 (14) a steroid type nondepolarizing neuromuscular blocking agent under development (preclinical phase). This review article deals with a comprehensive survey of the progress in chemical, pharmacological and, in some respects, of clinical studies of neuromuscular blocking agents used in the clinical practice and under development, including the synthesis, structure elucidation, pharmacological actions, structure activity relationships studies of steroidal and nonsteroidal derivatives.
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Affiliation(s)
- Zoltan Tuba
- Steroid Research Section, Chemical Works of Gedeon Richter Ltd.,10, POB 27, Budapest, H-1475, Hungary.
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Tuba Z, Bardin CW, Dancsi A, Francsics-Czinege E, Molnár C, Csörgei J, Falkay G, Koide SS, Kumar N, Sundaram K, Dukát-Abrók V, Balogh G. Synthesis and biological activity of a new progestogen, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3, 20-dione acetate. Steroids 2000; 65:266-74. [PMID: 10751638 DOI: 10.1016/s0039-128x(99)00109-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The progestational activity of second- and third-generation progestins in oral contraceptives were markedly increased by addition of an 18-methyl group. A new progestin, the 18-methyl analog of Nestorone, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3,2 0-dione acetate (10), was synthesized. The relative binding affinity and biologic activity of 10 was compared with Nestorone, levonorgestrel, and progesterone using a binding assay for rat progesterone receptors, the Clauberg assay in the rabbit, and by assessing pregnancy maintenance in the rat. These studies, as summarized in Table 4, show that 10 is three to ten times more potent than Nestorone. The addition of the 18-methyl group to Nestorone markedly increased its potency as noted above, but is unlikely to change its rate of delivery from sustained release systems. 10 should be ideally suited for administration by implants or small skin patches.
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Affiliation(s)
- Z Tuba
- Gedeon Richter Ltd., Department of Steroid Research, P.O. Box 27, 1475, Budapest, Hungary
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Mák M, Francsicsné Czinege E, Mahó S, Tuba Z. [Tandem MS/MS combined with different ionization techniques in the study of steroid structures]. Acta Pharm Hung 1999; 69:181-7. [PMID: 10544517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The various mass spectrometric ionisation techniques involve different ionisation energy. Their parallel application may provide complementary information for the structure. By the use of soft ionisation methods, especially when combined with tandem mass spectrometric techniques, stereospecific dissociation can also be detected, as the fragmentation processes of low energy differences result in significant abundance differences. The EI spectra of the stereoisomer compounds 1 and 2 are compared to their FAB-daughter ion spectra. This latter method leads to higher differences in the water elimination, indicating that the beta-hydroxi-isomer is more stable. ESI studies, using the "in-source CID" technique and also combined with MS/MS investigation have provided direct information about the position of substituents for the bis-quaternary salts of amino androstane derivatives, pipecuromium bromide [ARDUAN (3)] and its related compound 4. Due to the complementary information of the different ionisation methods used in mass spectrometry, the exact and detailed structural study requires the combined application of the various ionisation techniques together with MS/MS methods.
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Affiliation(s)
- M Mák
- Richter Gedeon Vegyészeti Gyár Rt., Budapest
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Takács Z, Csintalan Z, Sass L, Laitat E, Vass I, Tuba Z. UV-B tolerance of bryophyte species with different degrees of desiccation tolerance. Journal of Photochemistry and Photobiology B: Biology 1999. [DOI: 10.1016/s1011-1344(99)00029-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gazdag M, Babják M, Brlik J, Mahó S, Tuba Z, Görög S. Estimation of impurity profiles of drugs and related materials Part 18. Impurities and degradation products of mazipredone. J Pharm Biomed Anal 1998; 17:1029-36. [PMID: 9884192 DOI: 10.1016/s0731-7085(98)00068-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Reversed-phase HPLC methods using C-18 and C-8 columns as well as various isocratic and gradient systems with aqueous ammonium acetate, methanol and acetonitrile are described for the separation of the impurities of mazipredone (11beta,17-dihydroxy-21-(4-methyl-1-piperazinyl)-pregna-1,4-diene- 3,20-dione hydrochloride). These methods were used also for the estimation of the hydrolytic and oxidative degradation pathways of mazipredone in 0.1 M hydrochloric acid and sodium hydroxide at 80 degrees C. With the aid of HPLC-(APCI)-MS and HPLC-diode-array UV techniques 15 impurities and degradation products have been identified.
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Affiliation(s)
- M Gazdag
- Chemical Works of Gedeon Richter Ltd., Budapest, Hungary
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Abstract
Heck reactions of some steroid derivatives possessing iodo-alkenyl moiety (17-iodo-androst-16-ene, 1, 17-iodo-4-aza-4-methyl-androst-16-en-3-one, 2, 17-iodo-4-aza-androst-16-en-3-one, 3) were carried out in the presence of palladium catalysts using various olefins (methyl acrylate, ethyl methacrylate, allyl alcohol and allyl acetate) as coupling partners. With methyl acrylate, a side reaction was observed: the coupling product underwent a Diels-Alder reaction with the excess of methyl acrylate resulting in a six-membered carbocyclic E-ring. Reaction conditions of the synthesis of the Heck-product were optimized. Although the coupling with allyl alcohol led to the formation of 21-formyl-16-pregnene derivatives, the synthesis of the corresponding steroidal unsaturated alcohol could be achieved only via hydrolysis of the coupling product of the alkenyl iodide with allyl acetate.
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Affiliation(s)
- R Skoda-Földes
- University of Veszprém, Department of Organic Chemistry, Hungary
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Tuba Z, Csintalan Z, Proctor MCF. Photosynthetic responses of a moss, Tortula ruralis, ssp. ruralis, and the lichens Cladonia convoluta and C. furcata to water deficit and short periods of desiccation, and their ecophysiological significance: a baseline study at present-day CO 2 concentration. New Phytol 1996; 133:353-361. [PMID: 29681071 DOI: 10.1111/j.1469-8137.1996.tb01902.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We report the changes in CO2 assimilation, potential photochemical activity (as measured by slow fluorescence), photosynthetic pigment concentrations, and dark respiration of two desiccation-tolerant (DT) lichens (Cladonia convoluta (Lam.) P. Cout. and C. furcata (Huds.) Schrad.), and a DT moss (Tortula ruralis (Hedw.) Gaertn. ssp. ruralis) during slow drying, and on rehydration following a 12 h period of desiccation. Initially there was a two to fourfold increase in net CO., assimilation due to reduction of CO2 -diffusion resistance by elimination of excess water. Optimum water content for photosynthesis was 100-150 % of dry mass (DM) in C. convoluta, c. 100 % DM in C. furcata, and 120-200 % DM in T. ruralis. The intensity of maximum and steady-state slow fluorescence showed little change above water contents of 56%, DM in the lichens and 73 % DM in T. ruralis (corresponding to c. 30-40 % cell relative water content), but fell sharply at lower water content. The variable duorophyll-fluorescence decrease ratio (Rfd) at 690 nm peaked at 56 % DM water content in the two lichens, and at 45% DM in T. ruralis. Photochemical activity ceased at the same point in the experiments as CO, assimilation; dark respiration ceased only when desiccation was complete. In all three species, the photosynthetic apparatus remained in a fully and quickly recoverable state. Chlorophyll and carotenoid concentrations remained substantially unaltered throughout. On rehydration, chlorophyll fluorescence parameters returned within 30 min to pre-desiccation levels, and photosynthesis recovered fully and rapidly (< 1 h). All three species attained a positive carbon balance within 20 min of re-moistening, in spite of high rates of dark respiration. The results confirm the significance of extracellularly-stored water to poikilohydric DT lichens and bryophytes. The measurements, in conjunction with published data on the full-turgor water content of similar mosses and lichens, show that the cell-physiological response of photosynthesis to water deficit is not greatly different from that of either normal or DT vascular plants. Small plant size and small cell volume in DT lichens and mosses, together with rapid recovery of photosynthesis after desiccation, allow the plants to utilize the small amounts of intermittently available water from brief showers or dew.
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Affiliation(s)
- Zoltan Tuba
- Plant Physiological Section, Department of Botany and Plant Physiology, Agricultural University, H-2103 Gödöllö, HungaryDepartment of Biological Sciences, University of Exeter, Hatherly Laboratories, Prince of Wales Road, Exeter, EX4 4PS, UK
| | - Zsolt Csintalan
- Plant Physiological Section, Department of Botany and Plant Physiology, Agricultural University, H-2103 Gödöllö, HungaryDepartment of Biological Sciences, University of Exeter, Hatherly Laboratories, Prince of Wales Road, Exeter, EX4 4PS, UK
| | - Michael C F Proctor
- Plant Physiological Section, Department of Botany and Plant Physiology, Agricultural University, H-2103 Gödöllö, HungaryDepartment of Biological Sciences, University of Exeter, Hatherly Laboratories, Prince of Wales Road, Exeter, EX4 4PS, UK
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Sass L, Csintalan Z, Tuba Z, Vass I. Thermoluminescence studies on the function of Photosystem II in the desiccation tolerant lichen Cladonia convoluta. Photosynth Res 1996; 48:205-212. [PMID: 24271300 DOI: 10.1007/bf00041010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/1995] [Accepted: 12/06/1995] [Indexed: 06/02/2023]
Abstract
The effect of desiccation and rehydration on the function of Photosystem II has been studied in the desiccation tolerant lichen Cladonia convoluta by thermoluminescence. We have shown that in functional fully hydrated thalli thermoluminescence signals can be observed from the recombination of the S2(3)QB (-) (B band), S2QA (-) (Q band), Tyr-D(+)QA (-) (C band) and Tyr-Z(+)(His(+))QA (-) (A band) charge stabilization states. These thermoluminescence signals are completely absent in desiccated thalli, but rapidly reappear on rehydration. Flash-induced oscillation in the amplitude of the thermoluminescence band from the S2(3)QB (-) recombination shows the usual pattern with maxima after 2 and 6 flashes when rehydration takes place in light. However, after rehydration in complete darkness, there is no thermoluminescence emission after the 1 st flash, and the maxima of the subsequent oscillation are shifted to the 3rd and 7th flashes. It is concluded that desiccation of Cladonia convoluta converts PS II into a nonfunctional state. This state is characterized by the lack of stable charge separation and recombination, as well as by a one-electron reduction of the water-oxidizing complex. Restoration of PS II function during rehydration can proceed both in the light and in darkness. After rehydration in the dark, the first charge separation act is utilized in restoring the usual oxidation state of the water-oxidizing comples.
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Affiliation(s)
- L Sass
- Institute of Plant Biology, Biological Research Center of the Hungarian Academy of Sciences, Szeged, Hungary
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26
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Abstract
The palladium-catalyzed coupling of various 17-iodo-delta 16 steroids (17-iodo-androst-16-ene, 17-iodo-4-methyl-4-aza-androst-16-en-3-one, and 17-iodo-4-aza-androst-16-en-3-one) with dialkyl phosphites (dimethyl phosphite, diethyl phosphite, and diisopropyl phosphite) was examined in detail. The only successful condition for homogeneous coupling involved carrying out the reaction in the absence of any solvents. A large excess of dialkyl phosphite was used, which means that the phosphite itself acted as a solvent. Eight new androst-16-ene derivatives with phosphonate groups at C-17 were synthesized and characterized. These steroids are of pharmacological interest as potential 5 alpha-reductase inhibitors. Under the same conditions, methylation of lactam NH was observed using dimethyl phosphite.
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Affiliation(s)
- R Skoda-Földes
- University of Veszprém, Department of Organic Chemistry, Hungary
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Abstract
17-Iodo-delta 16 steroids undergo selective dimerization and carbonylative dimerization in the presence of palladium catalysts in dimethylformamide which result in 16-17'-coupled dienes and 17-carboxylic anhydrides, respectively. Moderate to good yields have been obtained for both types of dimers.
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Affiliation(s)
- R Skoda-Földes
- University of Veszprém, Department of Organic Chemistry, Hungary
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Abstract
Direct and carbonylative coupling reactions of various steroid derivatives possessing iodo- and bromo-alkenyl moiety (17-iodo-androst-16-ene, 1, 17-bromoandrost-2,16-diene, 2, 17-iodo-4-aza-4-methylandrost-16-en-3-one, 3, 17-iodo-4-azaandrost-16-en-3-one, 4) with vinyltributylstannane and ethynyltributylstannane were carried out in the presence of various palladium catalysts. While carbonylation took place only with vinyltributylstannane, 17-vinyl-, and 17-ethynyl-delta 16 steroids were produced via direct coupling with vinyltributylstannane and ethynyltributylstannane, respectively. Activities of some catalysts based on Pd(0) and Pd(II) precursors were compared, and Pd(PPh3)4 was found to be superior to other complexes in most cases. In the coupling of 17-iodoandrost-16-ene with organostannanes Pd2(dba)3 + 8 AsPh3 in situ catalyst was found to be even more effective.
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Affiliation(s)
- R Skoda-Földes
- University of Veszprém, Department of Organic Chemistry, Veszprém, Hungary
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29
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Mák M, Tamás J, Mahó S, Tuba Z. [Mass spectrometry of pipecuronium bromide and some related compounds]. Acta Pharm Hung 1992; 62:103-9. [PMID: 1323910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The mass spectral behaviour of the bis-quaternary salt pipecuronium bromide and some related Cn+ A-n type ammonium salts (n = 1, 2, 3) has been studied and compared. Under EI-MS conditions the evaporation of the samples preceded by in situ dealkylation led to formation of alkyl bromide and amine bases. It has been demonstrated that this technique, completed with quantitation of the relative amount of the decomposition products is applicable to get structure information about the basis part as well as the number and positions of the quaternary centres and the substituents at these centres. The FAB mass spectra of these mono-, bis- and this quaternary ammonium salts were found to be very interesting and provide direct structural information about the salt. They exhibit primary Cn+ intact cations and (Cn+ A-n + 1)+ single charged cluster ions and also fragments characteristic of partial structures at the quaternary centres.
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Affiliation(s)
- M Mák
- MTA Központi Kémiai Kutató Intézete, Budapest
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30
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Tuba Z, Mahó S. [Synthesis of a new neuromuscular blocking agent, pipecuronium bromide (Arduan)]. Acta Pharm Hung 1992; 62:73-81. [PMID: 1323916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A series of bisquaternary ammonio steroids having androstane skeleton have been prepared some of which possessed high neuromuscular blocking activity. One of the series 3 alpha, 17 beta-diacetoxy-2 beta, 16 beta-bis (4,4-dimethyl-1-piperazinyl)-5 alpha-androstane dibromide (19, pipecuronium bromide, ARDUAN) has proved to be a clinically useful agent of long duration of action without side effects. The preparation of pipecuronium bromide and its metabolites and the impurities are also described. The structure of 19 and related compounds was elucidated by spectrometric methods IR, NMR and MS.
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Affiliation(s)
- Z Tuba
- Richter Gedeon Vegyészeti Gyár Rt., Budapest
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31
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Balogh G, Tuba Z. [Excerpts from the investigations of pipecuronium bromide with NMR spectroscopy]. Acta Pharm Hung 1992; 62:97-102. [PMID: 1323919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The synthesis of Pipecuronium bromide together with the investigation of its impurity profile required the solution of a number of analytical and structural problems. NMR spectroscopical methods received a major role in the structure elucidation of the synthesized compounds. The quantitative assessment of contaminations was also realized by 1H NMR spectroscopy. Out of the large amount of undertaken investigations, here we provide the structural characterization of the contaminating regiosimers of an important intermediate (5 alpha-androst-2-en-17-on) formed in the course of the synthesis, together with the NMR signal assignments of the end-product (Pipecuronium bromide) as measured in D2O and a mixture of CDCl3/DMSO-d6. The structure of a minor contamination of the end-product is also given.
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Affiliation(s)
- G Balogh
- Richter Gedeon Vegyészeti Gyár Rt., Budapest
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Görög S, Halmos Z, Herényi B, Georgakis A, Balogh G, Csizér E, Tuba Z. [Analysis of steroids. Part 40. Isolation and identification of unusual impurities in ethynodiol diacetate]. Acta Pharm Hung 1991; 61:77-81. [PMID: 1887802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In the course of the estimation of the impurity profile of ethynodiol diacetate, in addition to common impurities such as norethisterone acetate, ethynodiol-3-acetate and alpha-ethynodiol diacetate, two unknown impurities were detected by analytical reversed phase HPLC (C-18 silica and 80% aq. methanol as the eluent) and isolated by normal phase preparative HPLC (silica and 98:2 mixture of hexane and 2-propanol as the eluent). The 1H- and 13C-NMR spectra of the isolated impurities revealed that their structures could be characterized as the E and Z isomers of an analogue of EDDA containing "trimerised acetyl" group at the 17-hydroxy group (structures 4 and 4a). These structures were in good agreement with the extended UV spectra of the impurities and the mass spectra with the m/z 438 peak which can be derived from 4 and 4a by the loss of ketene.
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Affiliation(s)
- S Görög
- Richter Gedeon Vegyészeti Gyár Rt., Budapest
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Görög S, Tuba Z. Analysis of steroids. XXII. A specific method for the determination of 21-halo corticosteroid derivatives and related compounds. Analyst 1972; 97:523-6. [PMID: 5045054 DOI: 10.1039/an9729700523] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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