• N&PD Moderators: Skorpio

Meo-b?

sekio said:
Yes, the 4-methoxy cathinones still inhibit MAO-A. They are much less active than amphetamine, however, and 100fold less active than the comparable amphetamines. Even the 4-alkylthio cathinones have EC50s above amphetamine. The longer 4-alkylchalcogen chains (4-propoxy, 4-propylthio, etc) inhibit MAO-B, however.

It's interesting to note that the norephedrine metabolites are also MAO-A inhibitors with strength comparable to amphetamine.

Thanks for your vast knowledge. :) Now, when we're talking about inhibition of MAO, what level of inhibition should we expect? Were those EC50s you mentioned for efficacy inhibiting MAO? If so, potency around or below amphetamine should be rather trivial.

ebola
 
Here's some IC50s (inhibitory concentration for 50 per cent) for racemic compounds from the paper. R enantiomers are generally more effective at, and selective for, MAO-A.

Cathinone - >100uM at MAO-B
Amphetamine - 11uM @ MAO-A
Norephedrine - >100uM @ MAO-A
p-methyl-cathinone - >100uM at both
p-methyl-amphetamine - (no data)
p-methyl-norephedrine - 12uM @ MAO-A
p-methoxy-cathinone - 77uM @ MAO-A
p-methoxy-amphetamine - 0.3uM at MAO-A (!)
p-methoxy-norephedrine - 9.8uM at MAO-A
p-methylthio-cathinone - 45.5 uM @ MAO-A, >100um @ MAO-B
p-methylthio-amphetamine - 0.2uM at MAO-A (flatliners, indeed)
p-methylthio-norephedrine - 7.3uM @ MAO-A
 
Well, it's still worth being concerned about. Pure amphetamine is usually dosed between 10 and 50mg. What was an average dose of buphedrone?

Edit: Not to mention that ephedrine metabolites are to be expected for these. Unfortunately all of these numbers are for N-unsubstituted derivatives. Not sure how this effects it.
 
I would put good money on N-alkylation decreasing affinity for MAO-A, and increasing affinity for MAO-B. (see: Deprenyl).
 
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