HU-211

(dexanabinol, (6aS,10aS)-9-(hydroxymethyl)-6,
6-dimethyl-3-(2-methyloctan-2-yl)-
6a,7,10,10a-tetrahydrobenzo[c]chromen-1-ol )

[Purported Ingredient of "Spice"]

July 2009 
DEA/OD/ODE

Introduction:

HU-211 is structurally similar to Δ9-tetrahydrocannabinol (Δ9-THC), the main active ingredient of marijuana. It was synthesized around 1988. It is used in scientific research as a pharmacological tool to study the brain, and is being explored for several therapeutic uses. It was recently purported to be found in the herbal mixture "Spice", sold in European countries mainly via internet shops. HU-211 is not a controlled substance in the U.S.

HU-211 is used in basic scientific research as a NMDA receptor blocker. It is also being explored in pre-clinical and clinical research for several therapeutic applications including brain damage related to stroke, traumatic brain injury, glaucoma and multiple sclerosis.

HU-211 ((6aS,10aS)-9-(hydroxymethyl)-6,6-dimethyl-3-(2-methyloctan-2-yl)-6a,7,10,10a-tetrahydrobenzo[c]chromen-1-ol; (+)-11-OH-Δ8-THC-DMH, dexanabinol; Chemical Abstract Service Number 112924-45-5) is categorized as a tetrahydrocannabinol (THC) similar in chemical structure to Δ9-THC, Δ8-THC, and other THC substances controlled under the Controlled Substances Act (CSA). The chemical structures of HU-211 (left) and Δ8-THC (right), a compound found in Cannabis sativa L. (marijuana) and representative of the THC structural class, are shown below.

Based on the structural analysis of HU-211, it is categorized as a THC substance and is similar to those THC substances that occur naturally in marijuana. Worth noting, the enantiomer HU-210 [ (6aR,10aR)-9-(hydroxymethyl)-6,6-dimethyl-3-(2-methyloctan-2-yl)-6a,7,10,10a-tetrahydrobenzo[c] chromen-1-ol); with the only distinguishing difference is the opposite orientation of two hydrogen atoms at positions 6a and 10a; is also categorized as a THC substance.

Behavioral pharmacology studies show that HU-211 does not have Δ9-THC-like activity in animals. In mice, it had no effect on overall activity, analgesia, body temperature and catalepsy. Together, these four effects are used by scientists to predict Δ9-THC-like psychoactivity in humans. HU-211’s lack of activity in all four tests suggests that it is unlikely to have Δ9-THC-like psychoactive effects in humans.

In drug discrimination studies in rats and pigeons, HU-211 did not generalize to Δ9-THC, i.e. did not produce the same subjective effects as Δ9-THC.

In vitro studies show that HU-211 has low affinity for the brain cannabinoid receptor CB1 and the peripheral cannabinoid receptor CB2.

Phase I, phase II and phase III clinical studies of HU-211’s safety and efficacy in traumatic brain injury patients did not observe any psychotropic effects in humans.

HU-211 is purported to be an ingredient in the herbal mixture "Spice" which may be smoked for its psychoactive effects. No information on the illicit use of HU-211 in the U.S. is available at this time.

Information on user population in the U.S. is very limited. HU-211 abuse is not currently monitored by any national drug abuse surveys.

The System to Retrieve Drug Evidence (STRIDE), a federal database for the seized drugs analyzed by DEA forensic laboratories, and the National Forensic Laboratory System (NFLIS), a system that collects drug analysis information from state and local forensic laboratories, do not contain reports of HU-211. Seizures of herbal mixtures called "Spice" were reported in Ohio and Florida. "Spice" is purported to contain HU-211 and other substances that are similar in pharmacological activity to Δ9-THC.

HU-211 is currently not controlled under the CSA.

Comments and additional information are welcomed by the Drug and Chemical Evaluation Section, Fax 202-353-1263, telephone 202-307-7183, or E-mail ODE@usdoj.gov.

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