C-Ring Aromatized Abietane Diterpenoids From Lycopus lucidus.

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Pharmacology

Background:

• Lycopus lucidus is a plant known for its medicinal properties.
• Diterpenoids are a class of natural compounds with diverse biological activities.

Purpose of the Study:

• To isolate and characterize aromatic C-ring abietane diterpenoids from Lycopus lucidus.
• To evaluate the cytotoxic and anti-tumor potential of these isolated compounds.

Main Methods:

• Phytochemical investigation using High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS) and Nuclear Magnetic Resonance (NMR).
• Elucidation of absolute configurations through ECD calculations.
• Cytotoxicity assays using HEL cells and flow cytometry analysis.

Main Results:

• Twelve aromatic C-ring abietane diterpenoids were identified, including three novel compounds (1-3).
• Compound 1 is a rare 17-norditerpenoid; compound 2 is a 19-norditerpenoid; compound 3 is a rearranged 18(4→3)-abeo-abietane diterpenoid.
• Compound 9 exhibited significant cytotoxicity against HEL cells (IC50 = 0.93 ± 0.11 μM), surpassing doxorubicin.
• Compound 3 showed moderate cytotoxicity (IC50 = 14.59 ± 0.55 μM).

Conclusions:

• Lycopus lucidus is a rich source of structurally diverse diterpenoids.
• Compound 9 possesses potent anti-cancer properties, likely mediated through the induction of apoptosis in HEL cells.
• Further investigation into compound 9 as a potential anti-tumor agent is warranted.