Demospongic Acids Revisited

Jean-Michel Kornprobst,Gilles Barnathan

doi:10.3390/md8102569

Abstract

The well-known fatty acids with a Δ5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C16–C32) and from some terrestrial plants with short acyl chains (C18–C19). Finally, the Δ5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs). This article reviews the occurrence of these particular fatty acids in marine and terrestrial organisms and shows the biosynthetic connections between Δ5,9 fatty acids and other NMI FAs.

Highlights

The well-known notion of demospongic acid appeared for the first time in 1976 in a historical paper from Litchfield and Morales [1], but at that time only as «demospongiae fatty acids»
Demospongic acids represent a particular type of non-methylene-interrupted FA and, according to Christie’s definition, it could be interesting to consider at least three classes of non-methyleneinterrupted fatty acids (NMI FAs) depending on the number of methylene groups situated between the two first double bonds
All framed NMI FAs have been identified in several marine invertebrates and terrestrial plants

Summary

Introduction

The well-known notion of demospongic acid appeared for the first time in 1976 in a historical paper from Litchfield and Morales [1], but at that time only as «demospongiae fatty acids». In another paper published in 1980 [2], Litchfield et al used the term «demospongic fatty acids» probably for the first time. Since and up until now [3,4,5], this term has widely been used. Litchfield’s work on sponge lipids, the notion of demospongic acid seems to no longer have significance, mainly due to their controversial definition and to their wide distribution among marine invertebrates and some terrestrial plants. Drugs 2010, 8 the function of demospongic acids, in consideration of their biological activities as topoisomerase inhibitors or against cancer cells as recently reviewed [6], whereas the biological interests of terrestrial short-chain 5,9 fatty acids (FAs) had already been demonstrated [7,8]

What Exactly Is a Demospongic Acid?

Occurrence of “Demospongic” Acids among Other Organisms

Towards a Classification of Non-Methylene-Interrupted Fatty Acids?

Conclusion