Structural characterisation of aliphatic, non-hydrolyzable biopolymers in freshwater algae and a leaf cuticle by ruthenium tetroxide degradation

Abstract

Aliphatic, non-hydrolyzable biopolymers were subjected to RuO4-oxidation in order to examine the potential of this method in revealing details on their structures. The method was tested on model compounds first and found to cleave alkyl chains of aromatic moieties, double bonds and ether bonds. Oxidation of the biopolymer cutan derived from cuticles of Agave americana and the algaenans isolated from the cell walls of the freshwater algae, Botryococcus braunii (race A and L) and Tetraedron minimum, resulted in the formation of specific oxidation products. In the case of B. braunii, the results confirmed previously suggested structures. Results obtained for cutan and T. minimum algaenan enabled, for the first time, the reconstruction of the building blocks of these biopolymers. These blocks consist of unsaturated long-chain hydroxy fatty acids, which are cross-linked via ether-bonds or ester-bonds.