Taken together these data further confirmed the structure elucidation of B16. The precursor ion m/z 276 (B1) detected, which was 74 Da lower than that for the 4F-MDMB-BINACA ester hydrolysis metabolite (B22), indicated N-dealkylation of B22. The precursor ion m/z 348 and product ion detected at m/z 217 (B2) identified was 2 Da less than the 4F-MDMB-BINACA ester hydrolysis metabolite (B22), indicating oxidative defluorination (loss of fluorine with addition of hydroxy JWH-210 powder group

4. Drugs
In general, the locomotor depressant and discriminative stimulus effects have been observed at doses that do not produce adverse effects, although tremors were observed upon handling in mice that received JWH-210 (Gatch et al., 2016), and 5F-AMB produced sustained vocalization and convulsions in rats (Gatch et al., 2018). All of the synthetic cannabinoids tested in the present study fully substituted for the discriminative stimulus effects of Δ9-THC. Subsequently, a one-way analysis of variance was conducted on horizontal activity counts for the 30-min period of maximal effect, and planned comparisons were conducted for each dose against the vehicle control using single degree-of-freedom F tests. A two-way analysis of variance, with dose as a between groups factor and time as a within subject factor, was conducted on horizontal activity counts/10 min interval. Locomotor activity in mice was tested to screen for locomotor depressant effects and to identify behaviorally-active dose ranges and times of peak effect. Previous studies have demonstrated that these compounds have chemical structures similar to synthetic cannabinoids known to have substantial abuse liability and act at the CB1 receptor.
Michael B Gatch
Substantial depressant effects were observed within the first 10 min, and maximal depression was observed between 0–30 min following administration. Tremors were observed 30 minutes following 1 mg/kg AMB-FUBINACA in 3 of 8 mice (data not shown). Substantial depressant effects were observed within the first 10 min, and maximal depression was observed between 10–40 min and lasted up to 2.5 to 3 h at the JWH-210 powder highest dose tested (0.5 mg/kg).
Figure 1.
There is indication that at least some of the first-generation synthetic cannabinoids act at receptors other than cannabinoid CB1 and CB2 (Wiley et al., 2016), and a compound from the present study, 5F-MDMB-PINACA, was found to activate midbrain dopamine neurons, but not serotonin neurons (Asaoka et al., 2016). As previously mentioned, all of the compounds tested in the present study (MDMB-PINACA, MDMB-CHMICA, MDMB-FUBINACA, ADB-FUBINACA, and AMB-FUBINACA) act as agonists at CB1 receptors (Banister et al., 2015, 2016; Gamage et al., 2018), which suggests these compounds will produce Δ9-THC-like effects, including abuse liability. Tremors were not observed following AMB-FUBINACA during the drug discrimination study, but the maximum dose tested was only 0.1 mg/kg, which is 10-fold lower than the dose that produced tremors in the mice.
Michael B Gat

Similarly, precursor ion identified at m/z 380 (B19/B21, B23/B25) was 16 Da higher than the 4F-MDMB-BINACA, indicating monohydroxylation at the butyl side chain (B19/B21) and indazole (B23/B25) moieties with product ions m/z 145 and 161, respectively. Metabolites identified at m/z 366 (B8, B9, B13), which was 16 Da higher than the 4F-MDMB-BINACA ester hydrolysis metabolite (B22), confirmed monohydroxylation upon ester hydrolysis. Death involving these drugs have been reported [5,6,7,8,9], and this raises public health and social concerns. Due to their similar physiological effects to the principal psychoactive component of cannabis, Δ9-tetrahydrocannabinol (THC), SCBs are gaining popularity and are often abused as recreational drugs. The fact that similar 4F-MDMB-BINACA and ethanol concentrations were detected in the postmortem blood samples of both victims suggests that both substances played a role in the fatal outcom

In general, the locomotor depressant and discriminative stimulus effects JWH-210 powder have been observed at doses that do not produce adverse effects, although tremors were observed upon handling in mice that received JWH-210 (Gatch et al., 2016), and 5F-AMB produced sustained vocalization and convulsions in rats (Gatch et al., 2018). All of the synthetic cannabinoids tested in the present study fully substituted for the discriminative stimulus effects of Δ9-THC. Subsequently, a one-way analysis of variance was conducted on horizontal activity counts for the 30-min period of maximal effect, and planned comparisons were conducted for each dose against the vehicle control using single degree-of-freedom F tests. A two-way analysis of variance, with dose as a between groups factor and time as a within subject factor, was conducted on horizontal activity counts/10 min interval.
Michael B Gatch
These findings are in agreement with earlier studies showing the synthetic cannabinoids substitute for the discriminative stimulus effects of Δ9-THC (see review by Wiley et al., 2017). Pretreatment times and dose ranges for the drug discrimination assay were selected based on the time of peak depression in the locomotor activity assay in mice. As mentioned previously, short-onset compounds have a greater abuse liability; further, compounds that have fewer adverse effects while they are active are likely to be preferred. All five of the compounds in the present study fully substituted with a pretreatment time of 15 min, suggesting a rapid onset of the discriminative stimulus effects. All of the cathinones fully substituted for the discriminative stimulus effects of Δ9-tetrahydrocannabinol (≥80% drug-appropriate responding). Because response suppression may compromise stimulus control, rats failing to complete at least ten responses during the test session were excluded from the analysis of the discriminative stimulus effects of that dose of test compoun