β-Terrecyclene synthase constructs the quadrane backbone in terrecyclic acid biosynthesis

Area of Science:

• Natural Product Chemistry
• Biosynthesis
• Organic Chemistry

Background:

• Quadrane sesquiterpenes possess a unique tricyclic structure.
• These compounds display significant antimicrobial and anticancer properties.
• The biosynthesis and chemical logic behind quadrane scaffold formation are not well understood.

Purpose of the Study:

• To identify the enzyme responsible for generating the quadrane scaffold.
• To elucidate the biosynthetic pathway of fungal quadrane terrecyclic acid.
• To investigate the mechanism of quadrane structure formation.

Main Methods:

• Identification and characterization of a novel sesquiterpene synthase.
• Mutagenesis studies of the identified synthase.
• Isotopically sensitive branching analysis.

Main Results:

• A novel sesquiterpene synthase producing β-terrecyclene with a quadrane scaffold was identified.
• The biosynthetic pathway of terrecyclic acid was characterized.
• Mechanistic insights into quadrane scaffold formation were obtained through mutagenesis and isotopic studies.

Conclusions:

• The study reveals a key enzyme in quadrane sesquiterpene biosynthesis.
• This work clarifies the chemical logic and pathway for generating the complex quadrane structure.
• Findings provide a foundation for understanding and potentially engineering these bioactive natural products.