Natural tricyclic and hyper-polycyclic aromatic hydrocarbons: structure, biosynthesis, bioactivity, and synthesis

Area of Science:

• Natural Product Chemistry
• Organic Chemistry
• Biochemistry

Background:

• Polycyclic aromatic hydrocarbons (PAHs) are secondary metabolites with diverse biological activities.
• Natural products with tricyclic and greater ring systems (hyper-PAHs) have been historically understudied.
• PAHs feature at least two fused aromatic ring systems, adhering to Hückel's rule.

Purpose of the Study:

• To review the isolation and structural characteristics of tricyclic and hyper-PAHs.
• To explore the bioactivities, biosynthetic pathways, and chemical synthesis of these compounds.
• To consolidate current knowledge on anthracene, phenanthrene, acenaphthalene, pyrene, fluoranthene, and tetraphene natural products.

Main Methods:

• Literature review of studies from 1950 to 2024.
• Analysis of isolation techniques and structural elucidation methods.
• Synthesis of information on biological activities and biosynthetic routes.

Main Results:

• Detailed summary of identified tricyclic and hyper-PAHs.
• Compilation of their known biological effects and metabolic origins.
• Overview of synthetic strategies employed for these molecules.

Conclusions:

• Tricyclic and hyper-PAHs represent a significant, yet underexplored, area of natural product chemistry.
• This review provides a foundational understanding for future research in their discovery and application.
• Further investigation into these compounds is warranted due to their potential pharmacological relevance.