Trimeric and Dimeric Carbazole Alkaloids from Murraya microphylla.

Area of Science:

• Natural Product Chemistry
• Organic Chemistry
• Pharmacognosy

Background:

• Carbazole alkaloids are a significant class of natural products with diverse biological activities.
• Murraya species are known sources of bioactive secondary metabolites.
• The chemical investigation of *Murraya microphylla* is crucial for discovering novel compounds.

Purpose of the Study:

• To isolate and characterize new carbazole alkaloid derivatives from *Murraya microphylla*.
• To elucidate the structures of these novel compounds using spectroscopic techniques.
• To determine the absolute configurations of the isolated optically pure isomers.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation via High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS) and Nuclear Magnetic Resonance (NMR) spectroscopy.
• Separation of enantiomers and determination of absolute configurations using chiral High-Performance Liquid Chromatography (HPLC) and electronic circular dichroism (ECD) analysis.

Main Results:

• Seventeen new carbazole alkaloid derivatives were isolated, including one trimeric and sixteen dimeric compounds.
• The structures were confirmed through comprehensive spectroscopic data analysis (HRESIMS, NMR).
• Optically pure isomers were obtained, and their absolute configurations were successfully assigned using ECD data.

Conclusions:

• This study expands the known diversity of carbazole alkaloids.
• The findings highlight *Murraya microphylla* as a rich source of structurally complex natural products.
• The established methodologies provide a framework for the characterization of similar alkaloid compounds.