natural products, including primary and secondary metabolites, are small molecules produced by any organism. as important sources of drug components, natural products may be isolated to small fractions with different biological activities and chemical structures. although lots of natural metabolites have been screened and yielded pharmaceutical properties, many potential sources of these products still need to be investigated, including lichens. as symbiotic fungi and algae organisms, lichen produces variety of unique secondary compounds and has been used as ingredients in ancient medicine for decades. the demonstrated biological activities of the lichens include antibiotics, anti-proliferative, antioxidants, and anticancer. the bioactivities of the crude extracts, fractions obtained, and the types of compounds depend on biosynthetic pathways in different areas and environments. although north america is one of the areas to find variety of the lichen species, there is limited research to study the lichens' potential biological activities. in our present work, the study of the lichen umbilicaria muhlenbergii crude extract and active fraction would provide important information about their potential uses. [...]