title: Solvent separating secondary metabolites directly from biosynthetic tissue for surface-assisted laser desorption ionisation mass spectrometry.
abstract: Marine bioactive metabolites are often heterogeneously expressed in tissues both spatially and over time. Therefore, traditional solvent extraction methods benefit from an understanding of the in situ sites of biosynthesis and storage to deal with heterogeneity and maximize yield. Recently, surface-assisted mass spectrometry (MS) methods namely nanostructure-assisted laser desorption ionisation (NALDI) and desorption ionisation on porous silicon (DIOS) surfaces have been developed to enable the direct detection of low molecular weight metabolites. Since direct tissue NALDI-MS or DIOS-MS produce complex spectra due to the wide variety of other metabolites and fragments present in the low mass range, we report here the use of "on surface" solvent separation directly from mollusc tissue onto nanostructured surfaces for MS analysis, as a mechanism for simplifying data annotation and detecting possible artefacts from compound delocalization during the preparative steps. Water, ethanol, chloroform and hexane selectively extracted a range of choline esters, brominated indoles and lipids from Dicathais orbita hypobranchial tissue imprints. These compounds could be quantified on the nanostructured surfaces by comparison to standard curves generated from the pure compounds. Surface-assisted MS could have broad utility for detecting a broad range of secondary metabolites in complex marine tissue samples.
authors.affiliation: Biological Sciences, Faculty of Science and Engineering, Flinders University of South Australia, PO Box 2100, Adelaide, SA 5001, Australia. david.rudd@flinders.edu.au.
authors.forename: David
authors.initials: D
authors.lastname: Rudd
authors.affiliation: Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia. Kirsten.benkendorff@scu.edu.au.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Benkendorff
authors.affiliation: Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Mawson Institute, University of South Australia, GPO Box 2471, Adelaide, South Australia 5001, Australia. Nico.Voelcker@unisa.edu.au.
authors.forename: Nicolas H
authors.initials: NH
authors.lastname: Voelcker
mesh_terms: D000818:Animals; D049851:Gastropoda / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods*; D008970:Molecular Weight; D049329:Nanostructures; D016062:Porosity; D064210:Secondary Metabolism; D012825:Silicon / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D012997:Solvents; D012825:Silicon