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Planta Med 2015; 81(12/13): 1198-1204
DOI: 10.1055/s-0035-1546250
Analytical Studies
Original Papers
Georg Thieme Verlag KG Stuttgart · New York

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

Authors

  • Judith Taibon

    1   Institute of Pharmacy/Pharmacognosy, University of Innsbruck, CMBI, CCB – Center of Chemistry and Biomedicine, Innsbruck, Austria

  • Anita Ankli

    2   CAMAG Laboratory, Muttenz, Switzerland

  • Stefan Schwaiger

    1   Institute of Pharmacy/Pharmacognosy, University of Innsbruck, CMBI, CCB – Center of Chemistry and Biomedicine, Innsbruck, Austria

  • Camille Magnenat

    3   School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland

  • Vasilik-Ioanna Boka

    4   Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens, Panepistimiopolis Zografou, Athens, Greece

  • Claudia Simões-Pires

    3   School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland

  • Naktarios Aligiannis

    4   Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens, Panepistimiopolis Zografou, Athens, Greece

  • Muriel Cuendet

    3   School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland

  • Alexios-Leandros Skaltsounis

    4   Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens, Panepistimiopolis Zografou, Athens, Greece

  • Eike Reich

    2   CAMAG Laboratory, Muttenz, Switzerland

  • Hermann Stuppner

    1   Institute of Pharmacy/Pharmacognosy, University of Innsbruck, CMBI, CCB – Center of Chemistry and Biomedicine, Innsbruck, Austria
Further Information

Publication History

received 02 March 2015
revised 10 May 2015

accepted 27 May 2015

Publication Date:
28 July 2015 (online)

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Abstract

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.

Key words

autographic assay - HPTLC-MS - tyrosinase inhibitors - false positive results

* Dedicated to Professor Dr. Dr. h. c. mult. Adolf Nahrstedt on the occasion of his 75th birthday.


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