Investigation of Antimicrobial and Antioxidant Activity of Tephromela atra Lichen and its Chemical Isolates, α-Alectoronic Acid and α-Collatolic Acid

• Published in: bioRxiv
• Main Authors: Awad Alzebair, Meral Yilmaz Cankilic, Avan, Ilker, Candan, Mehmet
• Format: Paper
• Language: English
• Published: Cold Spring Harbor Cold Spring Harbor Laboratory Press 05.11.2023
• Subjects: Acids; Antibacterial activity; Antioxidants; Dichloromethane; Free radicals; Lichens; Metabolites; Methanol; Petroleum ether; Pharmaceutical industry; Secondary metabolites; Tephromela atra
• DOI: 10.1101/2023.11.05.565661

The lichens and their secondary metabolites have special interest since they can be used as an alternative to synthetic drugs in the treatment of various diseases. The present study was carried out to investigate in vitro antioxidant and antimicrobial activities of acetone, dichloromethane, petroleum ether, and methanol extracts of the lichens Tephromela atra and its major metabolites. α-alectoronic acid and α-collatolic acid were identified as bioactive substances in the lichens Tephromela atra. The antibacterial activity was investigated using disk diffusion method and the minimal inhibitory concentration values were evaluated against eleven species of bacteria, nine species of fungi, and four species of yeasts using broth microdilution method. The antioxidant activity of the methanol extracts of Tephromela atra was measured based on the ability to capture the free radical by using DPPH method. α-Alectoronic acid and α-collatolic acid extracts showed significant inhibitory activity against most of the tested bacteria, especially the lowest MIC values of both acids for Bacillus subtilis. In addition, the antioxidant activity was performed in vitro by measuring the free radical scavenging capacity of extracts on DPPH. The methanol extracts showed significant antioxidant activity and high DPPH scavenging activity with all concentrations. The results offer a perspective that Tephromela atra extracts and the natural substances obtained can be effectively used as a source of antimicrobial and antioxidant agents in the field of pharmaceutical industries.Competing Interest StatementThe authors have declared no competing interest.