Demospongic acids revisited.

Area of Science:

• Biochemistry
• Marine Biology
• Organic Chemistry

Background:

• Fatty acids with a delta-5,9 unsaturation system were historically termed demospongic acids, due to their initial discovery in marine Demospongia sponges.
• These fatty acids have since been identified in diverse marine organisms and some terrestrial plants, exhibiting a wide range of chain lengths.

Purpose of the Study:

• To review the occurrence of delta-5,9 fatty acids in marine and terrestrial environments.
• To elucidate the biosynthetic relationships between delta-5,9 fatty acids and other non-methylene-interrupted fatty acids (NMI FAs).

Main Methods:

• Literature review of studies on fatty acid occurrence and biosynthesis.
• Analysis of fatty acid chain lengths and unsaturation patterns.

Main Results:

• Delta-5,9 fatty acids are a specific class of non-methylene-interrupted fatty acids (NMI FAs).
• These fatty acids are found in marine sponges (C16-C32) and terrestrial plants (C18-C19).

Conclusions:

• The term 'demospongic acids' is outdated; 'delta-5,9 fatty acids' is more accurate and inclusive.
• Understanding the biosynthesis of delta-5,9 fatty acids provides insights into broader NMI FA metabolic pathways.