Terphenyl Derivatives from Allantophomopsis lycopodina

Area of Science:

• Natural Product Chemistry
• Mycology
• Organic Chemistry

Background:

• Fungi are a prolific source of structurally diverse secondary metabolites.
• The ascomycete Allantophomopsis lycopodina is a potential source for novel bioactive compounds.
• Benzo[b]naphtho[2,1-d]furan derivatives represent an interesting class of natural products.

Purpose of the Study:

• To isolate and characterize novel secondary fungal metabolites from Allantophomopsis lycopodina.
• To elucidate the complex structures of these compounds using advanced spectroscopic methods.
• To verify the proposed structures through computational analysis.

Main Methods:

• Submerged cultivation of the fungus Allantophomopsis lycopodina.
• Isolation and purification of fungal metabolites using chromatographic techniques.
• Structure elucidation using Nuclear Magnetic Resonance (NMR) spectroscopy, including HSQC-TOCSY and LR-HSQMBC experiments.
• Computational analysis of NMR chemical shifts using quantum chemical calculations and DP4/DP4+ probabilities for structure verification.

Main Results:

• Three secondary fungal metabolites, compounds 1-3, featuring a benzo[b]naphtho[2,1-d]furan skeleton were successfully isolated.
• Structure elucidation was challenging due to low hydrogen-to-carbon (H/C) ratios (0.64 and 0.68).
• The combination of multi-solvent NMR data and advanced NMR experiments, alongside computational verification, enabled definitive structure assignment.

Conclusions:

• The study successfully identified and characterized three new benzo[b]naphtho[2,1-d]furan derivatives from A. lycopodina.
• Advanced NMR techniques and computational methods are crucial for elucidating complex natural product structures, especially those with low H/C ratios.
• This research expands the known chemical diversity of fungal secondary metabolites and highlights the potential of A. lycopodina as a source of novel compounds.