C-15-functionalized eudesmanolides from Mikania campanulata.

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Organic Chemistry

Background:

• The genus Mikania is known for its diverse chemical constituents, particularly sesquiterpenes.
• Eudesmanolides are a significant class of sesquiterpenoids found in Mikania species, often exhibiting biological activity.

Purpose of the Study:

• To isolate and characterize novel eudesmanolides from the aerial parts of Mikania campanulata Gardner.
• To elucidate the chemical structures of these new compounds using advanced spectroscopic techniques.
• To contribute to the broader understanding of the chemical diversity within the Mikania genus.

Main Methods:

• Extraction and isolation of compounds from Mikania campanulata aerial parts.
• Structure elucidation using 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy.
• Confirmation of structure and absolute configuration using single-crystal X-ray diffraction and Vibrational Circular Dichroism (VCD) spectroscopy.
• Comparison of experimental VCD data with Density Functional Theory (DFT) calculations.

Main Results:

• Isolation and characterization of nine new eudesmanolides, compounds 1-9.
• Detailed structural determination of compounds 1-6 and peracetylated derivatives 7b-9b.
• Confirmation of the structure of major constituent 1 via single-crystal X-ray diffraction.
• Determination of the absolute configuration of compound 1 using VCD and DFT calculations.

Conclusions:

• The study successfully identified nine new eudesmanolides from Mikania campanulata.
• The comprehensive structural analysis provides valuable data on the chemical profile of this species.
• The findings enhance the knowledge of eudesmanolide chemistry and the Mikania genus.