Leonurusoleanolides E-J, minor spirocyclic triterpenoids from Leonurus japonicus fruits

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Pharmacology

Background:

• The dried fruits of Leonurus japonicus are a source of bioactive compounds.
• Nortriterpenoids with a 19(18→17)-abeo-28-noroleanane skeleton have been previously isolated.
• Structural variations, including trans/cis acyl substituents and isomer mixtures, are characteristic of these compounds.

Purpose of the Study:

• To isolate and characterize new and known nortriterpenoids from Leonurus japonicus.
• To evaluate the cytotoxic potential of these compounds against a panel of human cancer cell lines.

Main Methods:

• Isolation and structural elucidation of nortriterpenoids using spectroscopic techniques.
• Cytotoxicity assays using the CellTiter-Glo luminescent cell viability assay.
• Testing against BGC-823, KE-97, Huh-7, Jurkat T, and MCF-7 cancer cell lines.

Main Results:

• Six new (leonurusoleanolides E-J, 1-6) and five known (7-11) nortriterpenoids were identified.
• Compounds 1-4 were observed as trans/cis isomer mixtures.
• Leonurusoleanolide J (6) exhibited potent cytotoxicity with IC50 values < 10 μM against tested cancer cell lines.

Conclusions:

• Leonurus japonicus yielded novel nortriterpenoids with a unique spirocyclic skeleton.
• Leonurusoleanolide J demonstrates promising cytotoxic activity, warranting further investigation for cancer therapy.
• The study contributes to understanding the chemical diversity and bioactivity of Leonurus japonicus constituents.