This article is protected by copyright. All rights reserved. Comparative analysis of the antioxidant properties of Icelandic and Hawaiian lichens 1 Kehau Hagiwara 1, * , Patrick R. Wright 2, * , Nicole K. Tabandera 1 , Dovi Kelman 1 , Rolf Backofen 2, 3 , Sesselja Ómarsdóttir 4 and Anthony D. Wright 1, # 1: Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, 34 Rainbow Drive, Hilo, HI 96720, USA 2: Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 106, D-79110 Freiburg, Germany 3: BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany 4: Faculty of Pharmaceutical Sciences, School of Health Sciences, University of Iceland, Hagi, Hofsvallagata 53, IS-107 Reykjavik, Iceland *: K.H. and P.R.W. contributed equally to this work. #: To whom correspondence should be addressed; E-Mail: adwright@hawaii.edu; Tel.: +1-808-981-4521; Fax: +1-808-933- 2981. Running title: DPPH and FRAP of Icelandic and Hawaiian lichens Abstract Antioxidant activity of symbiotic organisms known as lichens is an intriguing field of research because of its strong contribution to their ability to withstand extremes of physical and biological stress (e.g., desiccation, temperature, UV radiation, and microbial infection). We present a comparative study on the antioxidant activities of 76 Icelandic and 41 Hawaiian lichen samples assessed employing the DPPH and FRAP based antioxidant assays. Utilizing this unprecedented sample size, we show that while highest individual sample activity is This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/1462-2920.12850 Accepted Article