Oxidized welwitindolinones from terrestrial fischerella spp

Area of Science:

• Natural Product Chemistry
• Marine Natural Products
• Cyanobacteria Research

Background:

• Terrestrial cyanobacteria, particularly Fischerella species, are a source of unique bioactive compounds.
• Alkaloids from cyanobacteria exhibit diverse chemical structures and biological activities.
• Previous research has explored the chemical diversity of Fischerella species.

Purpose of the Study:

• To isolate and characterize new alkaloids from terrestrial Fischerella species.
• To investigate the chemical transformations of N-methylwelwitindolinone C isonitrile.
• To identify novel cyclic ether alkaloids.

Main Methods:

• Extraction and isolation of alkaloids from Fischerella spp.
• Spectroscopic analysis (NMR, MS) for structure elucidation.
• Chemical derivatization and reaction monitoring (photooxidation, hydration).

Main Results:

• Three new alkaloids were identified: 3-Hydroxy-N-methylwelwitindolinone C isonitrile (3), 3-hydroxy-N-methylwelwitindolinone C isothiocyanate (4), and N-methylwelwitindolinone D isonitrile (6).
• Compound 6 represents a novel cyclic ether alkaloid structure.
• Photooxidation of N-methylwelwitindolinone C isonitrile (1) yielded compounds 3 and 6.
• Compound 3 was observed to hydrate to its formamide derivative (5) during isolation.

Conclusions:

• Terrestrial Fischerella species are a promising source for novel alkaloid discovery.
• The study expands the known chemical diversity of cyanobacterial alkaloids.
• Understanding artifact formation during isolation is crucial for accurate characterization.