ent-Pimarane derivatives from Dysoxylum hainanense

Area of Science:

• Natural Product Chemistry
• Organic Chemistry
• Phytochemistry

Background:

• The bark of Dysoxyhum hainanense Merr. is a potential source of novel bioactive compounds.
• Diterpenoids and triterpenoids are classes of natural products with diverse chemical structures and biological activities.

Purpose of the Study:

• To isolate and elucidate the structures of chemical constituents from the bark of Dysoxyhum hainanense Merr.
• To characterize new ent-pimarene diterpenoids and known damarane triterpenoids.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation employing spectroscopic methods (e.g., NMR, MS).
• Determination of absolute configurations via chemical transformations and optical rotation measurements.

Main Results:

• Four new ent-pimarene diterpenoids were identified: ent-18-acetoxy-8(14)-pimarene-15S, 16-diol, ent-18-acetoxy-16-hydroxy-8(14)-pimaren-15-one, ent-16,18-dihydroxy-8(14)-pimaren-15-one, and ent-19-nor-4,16,18-trihydroxy-8(14)-pimaren-15-one.
• Three known damarane triterpenoids (richenoic acid, eichleriainic acid, shoreic acid) were also isolated.
• The absolute configurations of the four diterpenoids were confirmed as ent-pimarene type.

Conclusions:

• Dysoxyhum hainanense Merr. bark contains a rich source of ent-pimarene diterpenoids and damarane triterpenoids.
• The identified compounds contribute to the known chemical diversity of natural products from this plant genus.
• Spectroscopic analysis and chemical methods are effective for structural determination of complex natural products.