| dc.description.abstract | Research on lichens in North Sumatra is still limited; in fact, lichens have potential that can be utilized in the fields of health and pharmaceuticals. This study aims to identify liken species found in the Sicike-cike Nature Park, Dairi Regency, North Sumatra, and to analyze the secondary metabolite content and antioxidant activity of several commonly occurring species. The research was conducted through field exploration and laboratory analysis. Liken samples were collected from various substrates, including soil, rocks, and tree bark, followed by morphological identification, qualitative screening of secondary metabolites, and antioxidant activity testing using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) method. A total of 109 liken species were recorded, 32 of which are new records for North Sumatra. These species belong to 25 families and 50 genera, with the family Graphidaceae being dominant and characterized by a crustose thallus type. One species with a high flavonoid content was Usnea trichodea, based on strong positive reactions in the flavonoid screening test. The highest antioxidant activity was found in the methanol extract of Parmotrema hypotropum, with an IC₅₀ (Inhibitory Concentration 50%) value of 42.32 µg/mL, indicating very strong antioxidant potential. These findings highlight the high biodiversity of likens in the Sicike-cike Nature Park and their potential as natural sources of bioactive compounds, particularly antioxidants. This study provides a scientific foundation for the development of likens as natural ingredients in pharmaceuticals and supports biodiversity conservation efforts in the region. | en_US |
