Cadinane sesquiterpenes from the mushroom Lyophyllum transforme

Area of Science:

• Natural Product Chemistry
• Organic Chemistry
• Mycology

Background:

• Mushrooms are a rich source of diverse bioactive compounds.
• Sesquiterpenes, particularly cadinane-type, exhibit a wide range of biological activities.
• Lyophyllum transforme is a mushroom species with potential for novel compound discovery.

Purpose of the Study:

• To isolate and characterize rare cadinane-type sesquiterpenes from Lyophyllum transforme.
• To elucidate the chemical structures of the isolated compounds using comprehensive spectroscopic techniques.
• To determine the absolute configuration of the key compound, lyophyllone A, using theoretical calculations.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation via Nuclear Magnetic Resonance (NMR) spectroscopy (1D and 2D), Mass Spectrometry (MS), and UV-Visible (UV-Vis) spectroscopy.
• Determination of absolute configuration using ab initio theoretical Circular Dichroism (CD) calculation via Density Functional Theory (DFT).

Main Results:

• Two rare cadinane-type sesquiterpenes, lyophyllone A (1) and lyophyllanetriol A (2), were successfully isolated.
• The structures of both compounds were fully elucidated using a combination of spectroscopic data.
• The absolute stereochemistry of lyophyllone A was confidently assigned through comparison of experimental and theoretical CD spectra.

Conclusions:

• Lyophyllum transforme is a source of novel cadinane-type sesquiterpenes.
• Advanced spectroscopic and computational methods are effective for structural and stereochemical determination of natural products.
• The findings contribute to the understanding of sesquiterpene diversity in fungi.