A Triterpene and a Depside from Parmotrema austrocetratum Elix and J. Johnst.

Introduction: Parmotrema austrocetratum Elix and J. Johnst. (syn. Rimelia austrocetrata Elix and J. Johnst.) which belongs to a large genus of lichenized fungi, Parmotrema Massalongo under family Parmeliaceae was investigated for its chemical constituents. Methods: The compounds were isolated by silica gel chromatography and their chemical structures were elucidated by NMR spectroscopy. Results: Chemical investigation of the dichloromethane extract of Parmotrema austrocetratum Elix and J. Johnst. has led to the isolation of zeorin (1) and atranorin (2). Conclusion: P. austrocetratum shares similar chemical characteristic with other Parmotrema species which afforded atranorin. This work highlights the first reported isolation of 1 from P. austrocetratum and the genus Parmotrema.