Phytochemical profiling and antibacterial activities of extracts from five species of Sumatran lichen genus Stereocaulon
Authors
Friardi Ismed
Hanif Putra
Nurwahidatul Arifa
Deddi Putra
Abstract
In continuing the inventory and investigation of Sumatra lichen, a collection of five species from the genus Stereocaulon has been carried out. In metabolite profiling analysis, the four main compounds, i.e. atranorin, MOC, lobaric acid, and stictic acid, were rapidly isolated as marker compounds by chromatography methods from S. halei and S. montagneanum. Then, the extracts from each species were analyzed using HPTLC densitometry measured at five wavelengths of 220, 254, 280 320, and 365 nm. Atranorin and MOC are two compounds found in all five Stereocaulon species tested. Subsequently, atranorin quantification was done by densitometric scanning at 254 nm from the ethyl acetate extract of each Stereocaulon species. The highest atranorin concentration was detected from S. graminosum (325,498 mg/g extract) and equivalent to 0.065 mg/g dried whole thallus, while the lowest was from S. verruculigerum (23,356 mg/g extract) and 0.023 mg/g dried whole thallus. Furthermore, all extracts and main compounds resulting from the isolation were evaluated for their antibacterial activity by the microdilution method. Ethyl acetate and acetone extracts from S. massartianum (1) showed the highest antibacterial activity against E. faecalis (MIC = 1.25 mg/mL).