Structurally diverse diterpenoids from Isodon oresbius and their bioactivity.

Area of Science:

• Natural Products Chemistry
• Medicinal Chemistry
• Pharmacology

Background:

• Isodon oresbius is a plant source of bioactive compounds.
• Diterpenoids are a class of natural products with diverse biological activities.

Purpose of the Study:

• To isolate and characterize new diterpenoids from Isodon oresbius.
• To evaluate the biological activities of the isolated compounds, including effects on lysosomal function and cytotoxicity.

Main Methods:

• Isolation and purification of compounds using chromatographic techniques.
• Structure elucidation using spectroscopic data (NMR, MS) and X-ray diffraction.
• Cell-based assays to assess lysosomal function, cytotoxicity, mitochondrial membrane potential, cell cycle, and apoptosis.

Main Results:

• Twelve new diterpenoids, isoresbins A-L, and 28 known diterpenoids were isolated.
• Isoresbins A and B possess novel rearranged skeletons.
• Compound 1 demonstrated potent cytotoxicity against human tumor cell lines (IC50: 2.07-4.04 μM).
• Compound 1 promoted lysosomal function and induced mitochondrial damage, cell cycle arrest, and apoptosis in SW480 cells.

Conclusions:

• The chemical investigation of Isodon oresbius yielded novel diterpenoids with unique structures.
• Compound 1 exhibits promising anti-cancer properties through multiple mechanisms, warranting further investigation for drug development.