Comparative Study on the Volatile Metabolites of Two Marine Sponge Species of the GenusPlakortis

Abstract

The volatile secondary metabolites of the morphologically similar marine sponges Plakortis lita and P. angulospiculatus, obtained by means of dynamic headspace and hydrodistillation, were analyzed and quantified by GC, GC/MS and NMR techniques. Comparison of the chemical profiles based on the headspace volatiles of the two species showed significant differences. The majority of the volatile constituents of P. lita were found to be oxygenated hydrocarbons and (E)-7-methyl-4-octen-3-one was identified as the main constituent. Most of the identified P. angulospiculatus were non-oxygenated hydrocarbons and 1-butyl-2-ethyl cyclopentane was the major constituent of the essential oil. The differences observed in the chemical composition of the two organisms, when combined with the morphoanatomical characters, can be a valuable identification tool.