Figure 1.

Structures of compounds used in the study. Poly-APS: repeating subunit for the natural poly-APS, characterised as a mixture of polymers with either n = 29 or n = 99. Sample 1: monomeric synthetic compound. Sample 2: Dimeric synthetic compound with additional para-methoxybenzyl terminal group and a hydroxyl group on the terminal chain. Sample 3: Tetrameric synthetic compound with additional para-methoxybenzyl and tetrahydropyranyl group on the terminal chain. Sample 4: Tetrameric synthetic compound with iodide as substituent on the terminal chain.