Product ions detected at m/z 302, 217, and 145 (B2) confirmed that tert-leucine and indazole moieties remained unchanged, leading to the structure elucidation of a hydroxy-functional group at the 4-position of the butyl side chain by oxidative defluorination. The product ion m/z 336 (loss of methyl ester moiety) further confirmed the presence of dihydroxylated metabolites. The precursor ion, m/z 364 (B14, B5/B6) had a loss of 2 Da from m/z 366 indicated further dehydrogenation of the ester hydrolysis plus monohydroxylated metabolites. The presence of the product ion m/z 320, likely formed from a loss of carbon dioxide, indicated monohydroxylation at the tert-leucine in B8 (m/z 219), butyl side chain in B9 (m/z 145) and indazole moiety in B13 (m/z 161). The precursor ion, m/z 350 showed a loss of 14 Da explaining the hydrolysis of methyl ester from 4F-MDMB-BINACA.
Fig. 2.
The precursor ion m/z 396 (B10, B12/B15) was 32 Da higher than the parent drug, 4F-MDMB-BINACA, suggesting the addition of two hydroxy groups. All the below explanations for transformations into metabolites are based on the data shown in Fig. Metabolites were identified according to their precursor ions, product ions, and fragmentation patterns (Fig. 1). Traditional in-vivo metabolism studies to generate human metabolites of drugs relied heavily on the use of whole animal model systems, which are expensive, limited by drug administration amount, influenced by species variation and faced by many ethical issues. Eight in-vivo metabolites tentatively identified were mainly products of ester hydrolysis with or without additional dehydrogenation, N-dealkylation, monohydroxylation and oxidative defluorination with further oxidation to butanoic acid.
Fig. 1.
This outcome was anticipated since CES-mediated hydrolysis is commonly 4F ADB reported as the major metabolic pathway among the SCBs impacting the terminal ester group . Glucosides and sulfate metabolites have been reported with other SCBs where C. From these three samples, sample 2 contained only an ester hydrolysis metabolite (m/z 350). Both ester hydrolysis followed by oxidative defluorination to butanoic acid (B4, m/z 362) and monohydroxylation at tert-leucine moiety (B8, m/z 366) metabolites were found in 16/20 urine samples (Table 2). A In-vitro metabolites observed in common among respective seven most abundant metabolites in b C. The product ion detected at m/z 235, indicating loss of sulfate, confirmed the identity of the sulfation metabolite.
Fungus C. elegans
Concentrations of 4F-MDMB-BINACA in the postmortem blood samples were 2.50 and 2.34 ng/mL, which are in line with published data. Although the lethal dose of 4F-MDMB-BINACA is unknown, its concentration in postmortem blood samples was found to range between 0.10 and 2.90 ng/mL . In SCRA-related cases in which the deceased suffered from heart disease, the SCRA concentration in the postmortem blood was less than 1 ng/mL . Concentrations of SCRAs in postmortem cases cover a wide range ; however, some reports of survival have also been published—even at relatively high blood SCRA concentrations [19, 20
Acute kidney damage and even kidney failure have been reported following use of synthetic cannabinoids (Davidson, et al., 2017). One recent study has looked at other mechanisms of action in some of the older synthetic cannabinoids and reported that some produced varying amounts of activity at sites which are related to cardiotoxicity and heart disease (Wiley et al., 2016). It is not known whether the increased toxicity is due only to activation of CB1 cannabinoid receptors more strongly than Δ9-THC or whether these "super-strength" cannabinoids produce effects at other receptors. A major cause of concern is that some of the more recently seen synthetic cannabinoids are more likely to produce extremely toxic effects than the older synthetics (Tai and Fantegrossi, 2017
The current study indicates that the test compounds produce locomotor depression similar to that of Δ9-THC, and fully substitute for the discriminative stimulus effects of Δ9-THC. In summary, these 5F-MDMB-PINACA, MDMB-CHIMICA, MDMB-FUBINACA, ADB-FUBINACA, and AMB-FUBINACA have similar abuse liability as Δ9-tetrahydrocannabinol and should be controlled in a similar fashion. Much of the in vivo 4F ADB testing of the synthetic cannabinoid compounds have been pre-clinical studies focused on their cannabinoid-like effects or like the present study, focused on their abuse liability. 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
4. Drugs
Short-onset, short-acting compounds have a greater abuse liability, and long-acting compounds pose problems of long-acting adverse effects and interactions with other drugs. The duration of action of the synthetic cannabinoids tested using the 8-h protocol have varied widely, with some producing a duration of action no longer than 1 h, others producing a duration of action between 1–2 h, and others lasting more than 2 h. There seems to be a trend of newer synthetic cannabinoids being more potent than earlier compounds. All of the compounds tested in the present study depressed locomotor activity as is typical for other synthetic cannabinoids (see review by Wiley et al., 2017). Average horizontal activity counts/10 min as a function of time (10 min bins) and dose. Depressant effects of 1.33 mg/kg were observed within 10 min following administration and peak depressant effects were observed between 0–30 min.
Michael B Gat
Fig. 2.
The precursor ion m/z 396 (B10, B12/B15) was 32 Da higher than the parent drug, 4F-MDMB-BINACA, suggesting the addition of two hydroxy groups. All the below explanations for transformations into metabolites are based on the data shown in Fig. Metabolites were identified according to their precursor ions, product ions, and fragmentation patterns (Fig. 1). Traditional in-vivo metabolism studies to generate human metabolites of drugs relied heavily on the use of whole animal model systems, which are expensive, limited by drug administration amount, influenced by species variation and faced by many ethical issues. Eight in-vivo metabolites tentatively identified were mainly products of ester hydrolysis with or without additional dehydrogenation, N-dealkylation, monohydroxylation and oxidative defluorination with further oxidation to butanoic acid.
Fig. 1.
This outcome was anticipated since CES-mediated hydrolysis is commonly 4F ADB reported as the major metabolic pathway among the SCBs impacting the terminal ester group . Glucosides and sulfate metabolites have been reported with other SCBs where C. From these three samples, sample 2 contained only an ester hydrolysis metabolite (m/z 350). Both ester hydrolysis followed by oxidative defluorination to butanoic acid (B4, m/z 362) and monohydroxylation at tert-leucine moiety (B8, m/z 366) metabolites were found in 16/20 urine samples (Table 2). A In-vitro metabolites observed in common among respective seven most abundant metabolites in b C. The product ion detected at m/z 235, indicating loss of sulfate, confirmed the identity of the sulfation metabolite.
Fungus C. elegans
Concentrations of 4F-MDMB-BINACA in the postmortem blood samples were 2.50 and 2.34 ng/mL, which are in line with published data. Although the lethal dose of 4F-MDMB-BINACA is unknown, its concentration in postmortem blood samples was found to range between 0.10 and 2.90 ng/mL . In SCRA-related cases in which the deceased suffered from heart disease, the SCRA concentration in the postmortem blood was less than 1 ng/mL . Concentrations of SCRAs in postmortem cases cover a wide range ; however, some reports of survival have also been published—even at relatively high blood SCRA concentrations [19, 20
Acute kidney damage and even kidney failure have been reported following use of synthetic cannabinoids (Davidson, et al., 2017). One recent study has looked at other mechanisms of action in some of the older synthetic cannabinoids and reported that some produced varying amounts of activity at sites which are related to cardiotoxicity and heart disease (Wiley et al., 2016). It is not known whether the increased toxicity is due only to activation of CB1 cannabinoid receptors more strongly than Δ9-THC or whether these "super-strength" cannabinoids produce effects at other receptors. A major cause of concern is that some of the more recently seen synthetic cannabinoids are more likely to produce extremely toxic effects than the older synthetics (Tai and Fantegrossi, 2017
The current study indicates that the test compounds produce locomotor depression similar to that of Δ9-THC, and fully substitute for the discriminative stimulus effects of Δ9-THC. In summary, these 5F-MDMB-PINACA, MDMB-CHIMICA, MDMB-FUBINACA, ADB-FUBINACA, and AMB-FUBINACA have similar abuse liability as Δ9-tetrahydrocannabinol and should be controlled in a similar fashion. Much of the in vivo 4F ADB testing of the synthetic cannabinoid compounds have been pre-clinical studies focused on their cannabinoid-like effects or like the present study, focused on their abuse liability. 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
4. Drugs
Short-onset, short-acting compounds have a greater abuse liability, and long-acting compounds pose problems of long-acting adverse effects and interactions with other drugs. The duration of action of the synthetic cannabinoids tested using the 8-h protocol have varied widely, with some producing a duration of action no longer than 1 h, others producing a duration of action between 1–2 h, and others lasting more than 2 h. There seems to be a trend of newer synthetic cannabinoids being more potent than earlier compounds. All of the compounds tested in the present study depressed locomotor activity as is typical for other synthetic cannabinoids (see review by Wiley et al., 2017). Average horizontal activity counts/10 min as a function of time (10 min bins) and dose. Depressant effects of 1.33 mg/kg were observed within 10 min following administration and peak depressant effects were observed between 0–30 min.
Michael B Gat