USNIC ACID CONTENT AND ANTIOXIDANT ACTIVITY OF THREE LICHEN EXTRACTS

Abstract

s. PHYTOPHARM 2012 M 68 Obzory po kliniceskoj farmacologii i lekarstvennoj terapii [Reviews of clinical pharmacology and drug therapy] ТОМ 10/2012/2 (+)-USNIC ACID CONTENT AND ANTIOXIDANT ACTIVITY OF THREE LICHEN EXTRACTS © Koptina A. , Shcherbakova A. , Soldati F. , Gabdullin M. , Kanarskiy A. , Ulrich-Merzenich G. 3 Mari State Technical University, Yoshkar-ola, Russia Pharmaton SA, 6934 Bioggio, Switzerland Medical Clinic III, University of Bonn, Willhelmstr. 35–37, 53111 Bonn, Germany lichens produce a variety of secondary metabolites which belong to the depsides, depsidones, dibenzofurans and pulvinic acid derivative family. They proved to be a good source of natural antioxidants (1). Usnic acid uniquely found in many lichens has been reported to have analgesic, antimicrobial, anti-inflammatory, antiplatelet/antithrombotic, antiviral, cytotoxic/antiproliferative, gastroprotective, weight loss, and wound healing activity (2). We examined the (+)-usnic acid content and the anti-oxidative properties of the chloroform extract of lichen: Cladonia sylvatica (l.) hoffm., Evernia prunastri (l.) Ach. and Usnea barbata (l.) Wigg. (s. i.) were collected in Mari El Republic of Russian federation in June, 2011. Reverse phase hPlC analysis was carried out (Perkin Elmer Series 200 hPlC instrument; C18 column (C18; 25 cm ×4.6 mm, 5μm); UV/Vid detector; solvent: methanol-water-phosphoric acid (80:20:.9, v/v/v)). The sample injection volume was 20 μl and the flow rate 1.0 ml/min. A standard of (+)-usnic acid was used. The total antioxidant activity of the extracts was evaluated by the phosphomolybdenum method as described Manojlovic et al. (3). The chloroform extracts of C. sylvatica, E. prunastri and U. barbata showed contents of (+)-usnic acid of 8.91 ± 1.18, 5.68 ± 0.47 and 74.49 ± 8.64 % respectively. The antioxidant activities were: 277.1 ± 20.0, 171.1 ± 17.1 and 205.8 ± 7.2 mg of ascorbic acid (AA) per g of extract respectively; in comparison, the antioxidant activity of the (+)-usnic acid standard was determined as 154 ± 6.5 mg AA/g. We can report that U. barbata is a good source of (+)-usnic acid. Other secondary metabolites than (+)-usnic acid present in C. sylvatica and E. prunastri contribute to their high antioxidant activity and need to be further investigated.