Detection of flavonoids in microalgae from different evolutionary lineages.

Area of Science:

• Biochemistry
• Phytochemistry
• Evolutionary Biology

Background:

• Flavonoids are key secondary metabolites primarily found in terrestrial plants.
• Previous detection of phenolics in microalgae suggested potential flavonoid presence.
• The evolutionary origin and distribution of flavonoids remain incompletely understood.

Purpose of the Study:

• To investigate the presence and diversity of flavonoids in microalgae.
• To determine if microalgae possess the necessary biochemical pathways for flavonoid biosynthesis.
• To explore the evolutionary implications of flavonoid presence in microalgae.

Main Methods:

• Screening of diverse microalgal lineages (Cyanobacteria, Rhodophyta, Chlorophyta, Haptophyta, Ochrophyta).
• Utilizing advanced ultra-high performance liquid chromatography-two-dimensional mass spectrometry (UHPLC-MS/MS).
• Analysis of flavonoid precursors, intermediates, and end products.

Main Results:

• Unequivocal detection of a wide array of flavonoids in microalgae across different evolutionary groups.
• Evidence of a functional enzyme pool for flavonoid biosynthesis within microalgae.
• Identification of complex flavonoid profiles in some microalgae, mirroring pathways in higher plants.

Conclusions:

• Microalgae harbor a diverse range of flavonoids, expanding their known ecological distribution.
• The presence of flavonoids indicates that microalgae possess the complete biosynthetic machinery.
• The findings suggest the flavonoid biosynthesis pathway is ancient, originating earlier in evolutionary history than currently accepted.