LC-MS/MS as a tool for identification of bioactive compounds in marine sponge Spongosorites halichondriodes (Dendy 1905).

The sensitivity, specificity and selectivity of liquid chromatography/mass spectrometry tandem mass spectrometry (LC-MS/MS) make it an essential tool for the characterization and identification of low molecular compounds such as fatty acids, sterols, cholastane derivatives, nucleosides etc. In the current work, the marine sponge Spongosorites halichondriodes (order Halichondrida, Family Halichondriidae); a particularly rich source of cytotoxic compounds is studied for the initial characterization of bioactive compounds. The composition of ethyl acetate and butanol extracts were subjected to LC-MS and LC-MS/MS. Many novel sterol derivatives compounds which were not reported in any marine sponge mainly belonged to the group of C₂₅-C₂₈ saturated and unsaturated esters like 3β, 4β, 7α, 12α-tetrahydroxy-5β-cholan-24-oic acid methyl ester, 7 α, 12 β-dihydroxy-5 β-cholan24-oic acid methyl ester, novel isocoumarin citrinolactone A, a triterpenoid glycyrrhetinic acid as well as other unknown compounds in this species such as nucleoside inosine was identified. Other compound investigated was 3β, 6β, 7α-trihydroxy-5β-cholan-24-oic acid methyl ester. All the sterol ester derivatives are reported here for the first time in marine sponge belonging to family Halichondriidae. However, the literature report supports the occurrence of 3β-hydroxy sterols which is considered as a biomarker for this family.