Diterpenoid alkaloids from Delphinium davisii

Area of Science:

• Natural Product Chemistry
• Organic Chemistry
• Pharmacognosy

Background:

• Delphinium species are known sources of biologically active alkaloids.
• Diterpenoid alkaloids, particularly hetisane-type, exhibit diverse pharmacological properties.
• The chemical investigation of Delphinium davisii Munz. is crucial for discovering novel compounds.

Purpose of the Study:

• To isolate and characterize new hetisane-type diterpenoid alkaloids from Delphinium davisii Munz.
• To elucidate the structures of these novel compounds using comprehensive spectroscopic methods.
• To provide accurate spectroscopic assignments for known related alkaloids.

Main Methods:

• Isolation of alkaloids using chromatographic techniques.
• Structure elucidation via detailed 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopy.
• Mass spectrometry for molecular weight determination.

Main Results:

• Three new hetisane-type diterpenoid alkaloids: davisinol (6), 18-benzoyldavisinol (7), and Davisin (9) were identified.
• Structures of these new compounds were established through extensive spectroscopic analysis.
• Accurate 1H and 13C-NMR assignments were made for kobusine (8) and karakoline (5).
• Known alkaloids, including 14-acetylperegrine (4), 6-deacetylperegrine (3), karakoline (5), hetisine, and hetisinone, were also isolated.

Conclusions:

• The study successfully identified and characterized novel diterpenoid alkaloids from Delphinium davisii Munz.
• The findings expand the known chemical diversity of Delphinium alkaloids.
• This research provides valuable spectroscopic data for future studies on related natural products.