Prevention of False-Positive Results: Development of an HPTLC Autographic Assay for the Detection of Natural Tyrosinase Inhibitors

Article Article scientifique Article Prevention of False-Positive Results: Development of an HPTLC Autographic Assay for the Detection of Natural Tyrosinase Inhibitors eng 2015 author Taibon Judith author Ankli Anita author Schwaiger Stefan author Magnenat Camille 641645 author Boka Vasilik-Ioanna author Simoes Avello Claudia 630402 author Aligiannis Naktarios author Cuendet Muriel 0000-0002-1523-1907 686755 author Skaltsounis Alexios-Leandros author Reich Eike author Stuppner Hermann 1198-1204 10.1055/s-0035-1546250 26218339 0032-0943 A simple and rapid high-performance thin-layer chromatography-based autographic assay was established to screen plant extracts for the presence of tyrosinase-inhibiting substances. Three mobile phases were selected for the chromatographic separation of different types of extracts. After development, the plate was sprayed with the substrate solution Levodopa followed by a solution of the enzyme tyrosinase. Several known tyrosinase inhibitors were tested simultaneously as positive controls. They were detected as white spots with white light in remission from the plate as well as with white light transmitted through the plate. Some of the investigated extracts included spots showing a different behaviour; some lipophilic substances appeared as white spots in white light remission but were black in white light transmission. This behaviour, which could lead to false-positive results, was due to poor wettability of the corresponding spots. False-positive results were eliminated by adding Triton X-100 to the Levodopa solution and drying the plate after 10 minutes incubation with a molecular sieve. Tyrosinase inhibitors can be clearly identified as white spots against a dark background in white light remission as well as in white light transmitted through the plate. The established high-performance thin-layer chromatography autographic assay was validated and can be used as a standard method for the detection of tyrosinase inhibitors in plant extracts without causing false-positive results. Agaricales/enzymology Chromatography Thin Layer/methods False Positive Reactions Levodopa/chemistry Mass Spectrometry Monophenol Monooxygenase/antagonists & inhibitors Plant Extracts/analysis/chemistry Dewey 615 31 Section des sciences pharmaceutiques 17 false Planta medica 81 12-13 44975351-f019-4515-aba0-da5a1a514215 Article (Published version) Restricted Taibon et al_Planta Med 2015.pdf 821430 application/pdf restrictedAccess Faculté des sciences / Section des sciences pharmaceutiques

Title	Published in	Year	Views	Downloads

Prevention of False-Positive Results: Development of an HPTLC Autographic Assay for the Detection of Natural Tyrosinase Inhibitors	Planta medica	2015	528	0
Development of an HPTLC autobiographic assay for tyrosinase inhibition		2013	318	2

Archive ouverte UNIGE

Magnenat, Camille