Prepared from high quality Dermatan Sulfate (porcine origin) by partial GAG-endolyase scission and isolated by high resolution gel filtration.

General formula:
 
∆UA - GalNAc,4S - (IdoA – GalNAc,4S)_n - IdoA - GalNAc,4S

where n is number of disaccharide units
n = 0 in a tetrasaccharide (dp4)
n =1 in a hexasaccharide (dp6)
n = 2 in an octasaccharide (dp8) etc…..

Uronic acid (∆UA) at the non-reducing ends of the oligosaccharides has a C4-C5 double bond as a result of endolytic scission.
The main disaccharide in the original dermatan sulfate was IdoA – GalNAc,4S (88%) with minor quantities of 6-sulfated and 2,4 disulfated units (5% and 7% respectively) also present.