Antioxidant Activity and Total Terpenoid Content of Tropicoporus linteus Cultivar (Agaricomycetes) Cold Water Extract and In Silico Assessment of Potential Neuroprotective Compounds

Tropicoporus linteus (formerly Phellinus linteus) is a medicinal fungus used in China, Korea and Japan for its therapeutic properties. This study assessed the antioxidant capabilities of cold-water extract (xSHTM) from a T. linteus cultivar (SH02), and its terpenoid content. The potential of bioactive compounds in T. linteus as treatment against Alzheimer's disease (AD) was also explored with pharmacokinetic prediction via SwissADME and molecular docking. xSHTM is found to have high superoxide anion scavenging capability (expressed as trolox equivalents (35.10 ± 2.58) mmol/g), and its terpenoid content is expressed as 490.12 ± 31.51 mg LE/g of extract. SwissADME was used to screen all 68 of the compounds contained in T. linteus according to PubChem to identify their pharmacokinetic properties. Nine bioactive compounds are selected based on their gastrointestinal absorption, lipophilicity, water solubility, violation of Lipinski's rule, and the ability to cross the blood-brain barrier (BBB) to proceed with molecular docking against common AD treatment targets, acetylcholinesterase (AChE) and β-secretase (BACE1), which revealed 4 compounds with high binding affinity (expressed as Kcal/mol). Phellilin B and phellilane L showed binding affinities of -8.8 and -8.0, respectively, when docked against AChE, while phellinulin L, phellinulin K and phellilin B showed binding affinities of -7.4, -7.3 and -7.1 respectively when docked against BACE1.