Alkaloid N-oxides. A review of recent developments

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Plant Biochemistry

Background:

• Literature on amine N-oxides is more extensive for animals than plants.
• A previous review in 1971 covered 56 naturally occurring N-oxides, primarily pyrrolizidine and indole types.
• Alkaloid N-oxides are a significant class of natural products with diverse chemical structures.

Purpose of the Study:

• To review the preparation, characterization, and chemistry of alkaloid N-oxides.
• To provide a comprehensive overview of naturally occurring alkaloid N-oxides isolated since 1971.
• To discuss the potential roles and biological significance of N-oxides in plants.

Main Methods:

• Literature review and compilation of data on alkaloid N-oxides.
• Chemical characterization and structural elucidation of isolated compounds.
• Comparative analysis of N-oxides found in plant and animal systems.

Main Results:

• Detailed review of 64 naturally occurring alkaloid N-oxides, including pyrrolidine, piperidine, pyrrolizidine, quinolizidine, tropane, isoquinoline, morphinane, and indole types.
• Identification of these N-oxides as distinct from those reported in the 1971 review.
• Summary of pharmacological, metabolic, and toxicological data for N-oxides in animals.

Conclusions:

• Alkaloid N-oxides represent a diverse and expanding field of natural product chemistry.
• Further research is needed to fully elucidate the biological roles and applications of plant-derived N-oxides.
• The study highlights the importance of N-oxidation in alkaloid biosynthesis and function.