Eremophilane sesquiterpenes from capsidiol

Area of Science:

• Natural Product Chemistry
• Organic Synthesis
• Biochemistry

Background:

• Capsidiol is a phytoalexin with known antifungal properties.
• Eremophilane sesquiterpenes are a class of natural products with diverse biological activities.
• Mechanistic studies require well-defined substrates and inhibitors.

Purpose of the Study:

• To synthesize a series of eremophilane sesquiterpene alcohols and hydrocarbons from capsidiol.
• To investigate the mechanisms of epiaristolochene synthase and epiaristolochene dihydroxylase.
• To evaluate the antifungal potencies of capsidiol and its synthetic derivatives.

Main Methods:

• Selective derivatization and reductive cleavage were used to prepare 3-deoxycapsidiol.
• Novel aristolochene and eremophilene isomers were synthesized.
• Conjugate reduction, sulfinate elimination, and diimide rearrangement were employed for specific syntheses.
• Bioassays were conducted to determine minimum inhibitory concentrations (MICs).

Main Results:

• A series of eremophilane sesquiterpenes, including novel isomers, were successfully synthesized.
• 3-Deoxycapsidiol was obtained through selective chemical modifications.
• The antifungal activity of capsidiol was significantly higher than its synthetic derivatives.
• Capsidiol's MIC was lower than ketoconazole, nystatin, and propiconazole.

Conclusions:

• The synthesized eremophilane derivatives provide valuable tools for mechanistic studies.
• Capsidiol exhibits potent antifungal activity, outperforming its synthetic analogs.
• This study contributes to understanding sesquiterpene biosynthesis and antifungal mechanisms.