Unusually cyclized triterpenoids: occurrence, biosynthesis and chemical synthesis

Area of Science:

• Natural Product Chemistry
• Organic Synthesis
• Biosynthesis

Background:

• Triterpenes are typically synthesized via squalene (S) or 2,3-oxidosqualene (OS) cyclization.
• Unusual cyclization pathways yield diverse mono-, di-, tri-, and tetracyclic triterpenoids.
• Natural sources provide a rich array of these uncommon triterpenoid structures.

Purpose of the Study:

• To review advances in the identification of unusual cyclized triterpenoids from 2009 to 2021.
• To categorize and discuss newly isolated compounds, their biogenetic pathways, syntheses, and biological effects.
• To provide a comprehensive overview of progress in this field.

Main Methods:

• Literature review of scientific publications from 2009 to 2021.
• Categorization of 180 newly identified unusual cyclized triterpenoids.
• Analysis of reported biogenetic pathways, synthetic routes, and biological activities.

Main Results:

• Identification of 180 novel unusual cyclized triterpenoids.
• Significant progress in understanding their unique biosynthetic pathways.
• Advances in synthetic methodologies and elucidation of diverse biological effects.

Conclusions:

• The field of unusual cyclized triterpenoids has seen substantial growth between 2009-2021.
• These compounds represent a diverse class with complex structures and significant biological potential.
• Further research into their biosynthesis, synthesis, and applications is warranted.