Lanostane triterpenoids from the Sri Lankan basidiomycete Ganoderma applanatum

Area of Science:

• Natural Products Chemistry
• Mycology
• Organic Chemistry

Background:

• Ganoderma applanatum is a fungus known for its medicinal properties.
• Triterpenoids are a class of compounds with diverse biological activities.
• Fungal secondary metabolites represent a rich source of novel chemical structures.

Purpose of the Study:

• To isolate and characterize chemical constituents from the fruiting body of Ganoderma applanatum.
• To identify new lanostane-type triterpenoids from this fungal species.
• To contribute to the chemotaxonomic understanding of Ganoderma species.

Main Methods:

• Extraction of the fruiting body of Ganoderma applanatum using ethyl acetate.
• Isolation of compounds using chromatographic techniques.
• Structure elucidation of isolated compounds via spectroscopic data interpretation (NMR, MS) and comparison with literature.

Main Results:

• Two new lanostane-type triterpenoids, 3alpha,16alpha-dihydroxylanosta-7,9(11),24-trien-21-oic acid (1) and 3alpha,16alpha,26-trihydroxylanosta-7,9(11),24-trien-21-oic acid (2), were identified.
• Three known lanostanoids, 16alpha-hydroxy-3-oxolanosta-7,9(11),24-trien-21-oic acid (3), 3alpha-carboxyacetoxy-24-methylen-23-oxolanost-8-en-26-oic acid (4), and 3alpha-carboxyacetoxy-24-methyl-23-oxolanost-8-en-26-oic acid (5), were also isolated.
• Structures of compounds 1-3 were determined by direct spectroscopic analysis, while 4 and 5 were identified by comparison with literature data.

Conclusions:

• The study successfully isolated and identified five lanostane-type triterpenoids from Ganoderma applanatum, including two novel compounds.
• The structural characterization provides new chemical insights into the metabolites of this fungus.
• These findings expand the knowledge of fungal triterpenoids and may serve as a basis for further pharmacological investigations.