New bioactive labdane diterpenoids from Marrubium aschersonii.

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Pharmacology

Background:

• Marrubium aschersonii Magnus (Lamiaceae) is a plant species native to Tunisia.
• Natural products are a rich source of novel chemical structures with potential therapeutic applications.

Purpose of the Study:

• To isolate and characterize phytochemicals from Marrubium aschersonii.
• To evaluate the inhibitory effects of isolated compounds on nitric oxide production.

Main Methods:

• Phytochemical investigation using ethanol extract of Marrubium aschersonii.
• Structure elucidation by High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS) and Nuclear Magnetic Resonance (NMR) techniques.
• In vitro evaluation of nitric oxide production inhibition in RAW 264.7 macrophage cells stimulated with lipopolysaccharide (LPS).

Main Results:

• Two new labdane diterpenoids, marrubaschs A (1) and B (2), were isolated and identified.
• Two known compounds (3 and 4) were also identified.
• Compound 2 demonstrated weak inhibition of nitric oxide production with an IC50 value of 35 ± 1.0 μM.

Conclusions:

• The phytochemical analysis of Marrubium aschersonii yielded novel labdane diterpenoids.
• Marrubaschs B exhibits weak anti-inflammatory properties by inhibiting nitric oxide production.