Natural Occurring Terpene Cyclic Anhydrides: Biosynthetic Origin and Biological Activities

Area of Science:

• Natural Product Chemistry
• Organic Chemistry
• Biochemistry

Background:

• Cyclic acid anhydrides are rare but crucial in natural products.
• Terpenes featuring cyclic anhydrides have not been previously reviewed.
• Over 100 such compounds require systematic reporting.

Purpose of the Study:

• To systematically review known cyclic anhydride terpenes and related compounds.
• To organize these compounds based on their terpene skeletons.
• To propose biosynthetic pathways and identify precursors.

Main Methods:

• Literature review and systematic organization of compounds by terpene skeleton.
• Analysis of reported sources and bioactivities.
• Proposal of biosynthetic routes (A, B, C) and precursor identification.

Main Results:

• Identification and cataloging of over 100 terpenic cyclic anhydrides and related structures.
• Systematic organization based on terpene skeletons, from smallest to largest.
• Description of sources, bioactivities, and proposed biosynthetic pathways.
• Inclusion of imide derivatives and a proposed biosynthesis for cantharidin.

Conclusions:

• This review provides the first comprehensive overview of cyclic anhydride terpenes.
• Proposed biosynthetic pathways offer insights into the formation of these heterocyclic compounds.
• The study highlights the significance of these compounds, including cantharidin, and their derivatives.