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001-es BibID:	BIBFORM065243
Első szerző:	Gonda Sándor (gyógyszerész)
Cím:	Myrosinase Compatible Simultaneous Determination of Glucosinolates and Allyl Isothiocyanate by Capillary Electrophoresis Micellar Electrokinetic Chromatography (CE-MEKC) / Sándor Gonda, Attila Kiss-Szikszai, Zsolt Szűcs, Nhat Minh Nguyen, Gábor Vasas
Dátum:	2016
ISSN:	0958-0344
Megjegyzések:	Introduction. The functional food Cruciferous vegetables contain glucosinolates which aredecomposed by the myrosinase enzyme upon tissue damage. The isothiocyanates are the most frequentdecomposition products. Because of their various bioactivities, these compounds and the myrosinase isof high interest to many scientific fields.Objective. Development of a capillary electrophoresis method capable of myrosinase-compatible, simultaneous quantification of glucosinolates and isothiocyanates.Methods. Capillary electrochromatography parameters were optimized, followed byoptimization of a myrosinase-compatible derivatization procedure for isothiocyanates. Vegetableextracts (Brussels sprouts, horseradish, radish and watercress) were tested for myrosinase activity,glucosinolate content and isothiocyanate conversion rate. Allyl isothiocyanate was quantified in somefood products.Results. The method allows quantification of sinigrin, gluonasturtiin and allyl isothiocyanateafter myrosinase compatible derivatization in-vial by mercaptoacetic acid. The chromatograhpicseparation takes 2.5 minutes (short end injection) or 15 minutes (long end injection). For the testedvegetables, measured myrosinase activity was between 0.960 ? 27.694 and 0.461 ? 26.322 ?mol min-1mg-1 protein, glucosinolate content was between 0 ? 2291.8 and 0 ? 248.5 ?g g-1 fresh weight forsinigrin and gluconastrutiin, respectively. The possible specificity of plants to different glucosinolateswas also shown. Allyl isothiocyanate release rate was different in different vegetables (73.13 to 102.13%). The method could also be used for quantification of allyl isothiocyanate from food products.Conclusions. The presented capillary electrophoresis method requires a minimal amount ofsample and contains only a few sample preparation steps, and can be used in several applications(glucosinolate determination, myrosinase activity measurement, isothiocyanate release estimation).
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban myrosinase assay in-vial derivatization Brassicaceae vegetables allyl isothiocyanate phenethyl isothiocyanate
Megjelenés:	Phytochemical Analysis 27 : 3-4 (2016), p. 191-198. -
További szerzők:	Kiss-Szikszai Attila (1975-) (vegyész) Szűcs Zsolt (1990-) (gyógyszerész) Nguyen, Minh Nhat (1984-) (gyógyszerész) Vasas Gábor (1975-) (biológus-vegyész)
Pályázati támogatás:	PD 112374 OTKA TÁMOP 4.2.2.A-11/1/KONV-2012-0043 TÁMOP
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001-es BibID:	BIBFORM030998
Első szerző:	Gonda Sándor (gyógyszerész)
Cím:	Effect of High Relative Humidity on Dried Plantago lanceolata L. Leaves during Long-term Storage : Effects on Chemical Composition, Colour and Microbiological Quality / Sándor Gonda, László Tóth, Gyöngyi Gyémánt, Mihály Braun, Tamás Emri, Gábor Vasas
Dátum:	2012
ISSN:	0958-0344
Megjegyzések:	Introduction : Modern phytotherapy and quality assurance requires stability data on bioactive metabolites to identify andminimise decomposing factors during processing and storage. A compound's stability in a complex matrix can be differentfrom the stability of the purified compound.Objective To test the stability of iridoids and acteoside and quantify changes in colour and microbiological quality in acommon herbal tea, dried P. lanceolata leaves during exposure to high?humidity air. To test the contribution of fungi tometabolite decomposition.Methodology ? Dried P. lanceolata leaves were exposed to atmospheres of different relative humidity (75, 45 and 0%) for24 weeks. Changes in aucubin and catalpol concentration were determined by CE?MEKC, and those in acteoside on TLC.Colour and chlorophyll?like pigments were measured by different spectrophotometric methods. The number of fungi wasmonitored; 10 strains were isolated from the plant drug, and their ability to decompose the analytes of interest was tested.Results ? During incubation at 75% relative humidity (RH), aucubin, catalpol and acteoside concentrations decreased by 95.7,97.0 and 70.5%, respectively. Strong shifts were detected in CIELAB parameters a* and b* (browning) as a result ofconversion of chlorophyll to pheophytin. Intensive microbial proliferation was also observed. Changes at 45 or 0% RH weretypically insignificant. Seven of the 10 isolated fungal strains could decompose both iridoids, and five could decomposeacteoside in vitro.Conclusion It was shown that exposure to water results in loss of bioactive molecules of P. lanceolata dried leaves, and thatcolonising fungi are the key contributors to this loss.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban Plantago lanceolata L. verbascoside iridoid stability long-term storage microbiological contamination
Megjelenés:	Phytochemical Analysis. - 23 : 1 (2012), p. 88-93. -
További szerzők:	Tóth László Gyémánt Gyöngyi (1960-) (vegyész) Braun Mihály (1966-) (vegyész, analitikus) Emri Tamás (1969-) (biológus) Vasas Gábor (1975-) (biológus-vegyész)
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