Chemical composition and antioxidant activity of Geranium macrorrhizum in relation to ploidy level and environmental conditions

Abstract

Geranium macrorrhizum is an aromatic plant native to the Southern Alps and the Balkan Peninsula. In Europe, it is increasingly cultivated for its ornamental flowers, as well as for use in aromatherapy and traditional herbal medicine due to its broad spectrum of biological activities. Essential oil of G. macrorrhizum is highly valued in perfumery and is also used as a food-flavouring agent. In this work, we report the essential oil composition, total phenolics and antioxidant activity of several samples of G. macrorrhizum collected from natural habitats in Croatia (Mt Biokovo) and Greece (Mt Smolikas, Mt Olimbos and Mt Giona). Some of these samples were cultivated in the greenhouse or botanical gardens at separate locations in Bosnia and Herzegovina (Sarajevo), France (Orsay) and Denmark (Copenhagen). Since the plant samples had different cytotypes, a possible correlation between ploidy level, phenolic content and antioxidant activity was examined in this study. It was found that the total phenolic content, as well as the radical scavenging activity of residual water remaining after hydrodistillation of G. macrorrhizum, is related to the plant ploidy level. The essential oil composition, however, clearly depends on environmental factors. The main components of almost all essential oils of cultivated plants were oxygenated sesquiterpenes with germacrone as the most abundant compound (34.7–62.9%), while essential oil of plants growing wild was rich in long-chain alkanes (27.0–40.0%).