glucosamine sulfate   (link)

http://www.vitaminuk.com/pages/articles/glucosaminesulphate.htm
The main component of ligaments, tendons, cartilages and spinal discs is collagen, which is the most abundant protein found in mammals, with its purpose being to actually connect cells together. The name collagen is derived from Greek, and means to ‘produce glue’.

The tissues mentioned above are also rich in proteoglycans, which are 95% glycosaminoglycans (GAGS) and 5% protein. These GAGs act as a framework for collagen to model onto, and consequently are responsible with collagen for continuously building and rebuilding ligaments, tendons, cartilages and spinal discs. The major precursor in GAG production is glucosamine, which is the rate-limiting step and hence supplementation, especially after tissue injury, helps the body to speed up synthesis of GAGs and consequently new connective tissue.