11-COOH-Δ9-THC is a secondary break-down product of THC. 11-COOH-Δ9-THC is not psychoactive and is slowly degraded. The exact physiological functions or therapeutic properties of 11-COOH-Δ9-THC are still under investigation.
http://en.wikipedia.org/wiki/11-nor-9-Carboxy-THC
11-COOH-Δ9-THC is synthesized by degradation of 11-OH-Δ9-THC.
