Cerebrosides from a Far-Eastern Glass Sponge Aulosaccus sp

Area of Science:

• Marine Natural Products Chemistry
• Biochemistry
• Organic Chemistry

Background:

• Marine sponges, particularly glass sponges (Hexactinellida), are a rich source of structurally diverse bioactive compounds.
• Cerebrosides, a class of sphingolipids, play crucial roles in biological membranes and have shown various pharmacological activities.
• The chemical diversity of lipids from deep-sea organisms remains largely unexplored.

Purpose of the Study:

• To isolate and characterize novel cerebrosides from the Far-Eastern glass sponge Aulosaccus sp.
• To elucidate the structures of these new compounds, including their sphingoid bases and fatty acid moieties.
• To develop a simplified method for determining the absolute configuration of 2-hydroxy fatty acids.

Main Methods:

• Extraction and isolation of cerebrosides from sponge tissues.
• Structure elucidation using spectroscopic techniques such as Nuclear Magnetic Resonance ((1)H-NMR, (13)C-NMR) and Mass Spectrometry (MS).
• Analysis of optical rotation data and chemical transformations.
• Gas Chromatography (GC) analysis of (2R)- and (2S)-oct-2-yl esters for configuration assignment.

Main Results:

• Isolation and identification of nine new cerebrosides (1a-d, 2a, 2b, 3a-c).
• Characterization of unique sphingoid bases containing monoenoic and cyclopropane structures, previously unreported in sphingolipids.
• Successful application of a simplified GC method for determining the absolute configuration of 2-hydroxy fatty acids.

Conclusions:

• The study expands the known structural diversity of cerebrosides found in marine organisms.
• The identified novel sphingoid bases represent a new class of lipid structures with potential biological significance.
• The proposed GC method offers a more accessible approach for stereochemical analysis of 2-hydroxy fatty acids.