8,11-Dihydroxytetrahydrocannabinol
8,11-Dihydroxytetrahydrocannabinol (8β,11-diOH-Δ9-THC) is an active metabolite of THC, the main active component of cannabis. The 8β enantiomer retains psychoactive effects in animal studies with only slightly lower potency than THC, while the 8α enantiomer is much weaker.
Source: Wikipedia — 8,11-Dihydroxytetrahydrocannabinol (CC BY-SA 4.0)