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L-amphetamine and l-methamphetamine

im one of these people.
im just wondering, because some do seem to prefer the racemic preps.

ebola
 
It should be noted that MDMA hsa the opposite pharmacological profile (I think). The R isomer was more powerful, and usually the S isomer would produce stronger effects from chemicals in the same family. Correct me if I am wrong, its been a while since I discussed such things.

Also, only the racemic MDMA gave the full blown MDMA experience. As if the two isomers were synergistic....

All this info is somewhere in PIHKAL...
 
This is largely heresay, but I corroborate that there is an interesting synergy between d and l MDMA, in that d-mdma is more purely stimulating whereas its racemic mdma that gets you loved-up.

ebola
 
BilZ0r said:
I HATE D,L, R,S !FUCK! :X

Fucking non-IUPAC Americans. *sigh*
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Whatchu talkin bout willis? R and S are iupac approved nomenclature. And although D and L are obsolete descriptors of optical activity they're meanings are still pretty clear.
 
I only have done optical rotation once where we did an experiment to measure the acid catalyzed racemization kinetics of dextrose (not dexedrine) in a physical chemistry practical. I think that L = (-) and D = (+). It is not possible to dictate optical activity on the basis of if the isomer has S or R stereochemistry.

Still drug companies are very keen on selling a single isomers of their drugs. Does anybody know why this is?
 
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- and + are structural, you can designate them from looking at the structure.

Different optical isomers can have different pharmacodynamic and kinetic properties, that's why.
 
I thought that R,S is structurally designated. E.g. smallest group on the chiral C points away from the viewer and other three groups point towards them. Then from smallest to biggest clockwise = R, anti = S.

The (+) (-) dichotomy can only be determined by putting a single enantiomer in a machine and observing the effect that this has on plane polarized light.

Louis Pasteur I believe was one of the first people to recognize that tartaric acid could be optically resolved.
 
Yup, optical activity has absolutely no correlation to absolute configuration.

Also in continuing with what Bilzor said about different enantiomers having different pharmacological effects, in addition to the effects noted in this thread between the various enantiomers of amphetamine and methamphetamine there is also the case of thalidomide. (R)-Thalidomide controls morning sickness, (S)-Thalidomide gives you flipper babies.
 
Well obviously I don't know know what I'm talking about... you're right smyth....

*sigh*
 
(R)-thalidomide gives you flipper babies too. The compound is "racemized" via an enolate intermediate in vivo.
 
Huh, really? I'm just amazed that the equilibrium constant would be so high under biological conditions as to allow for any large quantity of the R form be transformed into the S form. Though I guess it is pretty damn conjugated system. Learn something new everyday.
 
I also saw on a TV program that this 'horror drug' was very effective in fighting tumors. Conventional cancer drugs such as chemotherapy blast the cancer cells to death but also destroy normal cells. Thalidomide is supposed to work by starving the tumor of a blood supply so it shrivels and well dies. They also discovered that replacement of an oxygen in the molecule with a nitrogen greatly increased the efficiency.
 
Definatly. They still use thalidomide as an anti-angiogenic.
 
BlueMind said:
It should be noted that MDMA hsa the opposite pharmacological profile (I think). The R isomer was more powerful, and usually the S isomer would produce stronger effects from chemicals in the same family. Correct me if I am wrong, its been a while since I discussed such things.

Also, only the racemic MDMA gave the full blown MDMA experience. As if the two isomers were synergistic....
Click to expand...

With most psychedelic phenalkylamines, it is the R isomer that is usually more potent. MDMA is the exception in that the S isomer represents the more potent of the two. Amphetamine and N-methylamphetamine also share this property with MDMA in that it is the S isomers are more potent than racemic and R forms.

I have been lucky enough to try S-MDMA. I guess it wasn't quite the "full blown experience" but it wasn't missing it by much. I found it slightly weaker on a milligram/milligram basis as compared to the racemic form, but some of the "weakness" many have been because S-MDMA did not seem to last near as long, and did not have so much of the "rush." Not near as pushy. Emotionally, I found it very similar to racemic MDMA. Also tried S-MDMA with LSD and it was fantastic. Very similar to a normal LSD/MDMA trip.
 
I too prefer recrystallized, racemic dl-methamphetamine HCl to pure, recrystallized d-methamphetamine HCl "ice" (if greater than 80% pure by legal definition).

Pure, d-methamphetamine is extremely stimulating and jittery. As Rhodium said, stick to the dl form if you value your sex life.
 
FreyGrimrod said:
Has anyone found some studies that might lend some credibility to the rumour I heard that l-amphetamine and to a lesser degree l-methamphetamine seem to actually slightly inhibit the formation of 6-oh-da molecules?
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I heard that too, but can't find any studies to prove it..
 
What? So are you saying that D-meth causes the formation of 6-OHDA? I know it potentiates the formation of 6-OHDA produced by MOA and COMT inhibition (1), but I didn't know it caused its formation by itself.
 
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