The compositional analysis of recent cephalopod shell carbohydrates by Fourier transform infrared spectrometry and high performance anion exchange-pulsed amperometric detection

The organic matrix of four living cephalopod skeletons was extracted, purified, separated in a soluble and an insoluble fraction. These fractions were submitted to infrared analysis. After a light hydrolysis, their monosaccharide content was determined by HPAE-PAD. The results were treated by principal component analysis.Infrared analysis has been used to estimate the protein/sugar ratios and showed a high amount of chitin within the insoluble fractions. This was corroborated by their high content of glucosamine. The composition of soluble matrices appeared more heterogeneous: the general tendency is an increase of glucosamine from the most mineralized shell (Nautilus) to the non-mineralized one (Loligo), and a decrease in glucose and galactose. These data would be in agreement with the evolutionary tendency towards shell reduction and disappearance among cephalopods.