HPLC-NMR chemical profiling and dereplication studies of the marine brown alga, Cystophora torulosa

Abstract

A chemical profiling/dereplication exercise, involving the use of HPLC-NMR and mass spectrometry in combination with the MarinLit database, was conducted on the crude dichloromethane extract of the southern Australian marine brown alga Cystophora torulosa. This strategy was successful in identifying a total of nine secondary metabolites representing two principle structure classes, including seven resorcinol (1-7) and two polyene derivatives (8 and 9). Validation of this on-line dereplication strategy was supported by the isolation and complete 2D NMR assignment of the major secondary metabolite (1). This methodology was concluded to be suitable for the rapid on-line identification of the resorcinol and polyene structure classes that are frequently encountered in the genus Cystophora.