Abstract:

An approach based on liquid chromatography-tandem mass spectrometry was developed for the quantification of monosialogangliosides (MG) in sea cucumbers and sea urchins. The gangliosides of sea cucumbers and sea urchins were extracted according to the Svennerholm method and cleaned up by C8 solid phase extraction column. The extracts were separated on an APS-2 NH₂ column (150 mm×2.1 mm, 3 μm) with the mobile phases of acetonitrile and 50 mmol/L ammonium acetate (pH 5.6) under gradient elution. Multiple reaction monitoring(MRM) was performed for quantification of each analyte in the samples. The method was capable to distinguish gangliosides with different types of sialic acid in a single run. The limit of quantification was 0.22 ng for nonsulfated monosialoganglioside (NMG) and 0.29 ng for sulfated monosialoganglioside (SMG), and the linear range was 1-40 ng for both compounds. Only NMG was detected in sea cucumbers while both NMG and SMG were detected in sea urchins. Quantification results suggested that NMG was most abundant in Parastichopus californicus among all the sea cucumbers detected and SMG was most abundant in Anthocidaris crassispina among all the sea urchins. The contents of MGs in sea urchins (4.30-6.40 mg/g) were much higher than those in sea cucumbers (8-131 μg/g). The method is suitable for the quantification of monosialogangliosides in sea urchins and sea cucumbers.

Key words: liquid chromatography-tandem mass spectrometry (LC-MS/MS), monosialoganglioside, multiple reaction monitoring (MRM), sea cucumber, sea urchin