N-Acetyl-L-Cysteine (NAC) vs. L-Cysteine. What would the difference be?
I mean, N-Acetyl L-cysteine has an acetyl group attached to the cysteine, right? For what purpose? What would be the advantages, disadvantages as supplements?
Posted 29 October 2014 - 03:40 PM
N-Acetyl-L-Cysteine (NAC) vs. L-Cysteine. What would the difference be?
I mean, N-Acetyl L-cysteine has an acetyl group attached to the cysteine, right? For what purpose? What would be the advantages, disadvantages as supplements?
Posted 29 October 2014 - 09:21 PM
For the same reason why Aspirin has an acetyl group attached salicylic acid: to improve pharmacokinetics and to enable the molecule to cross the blood-brain barrier.
Edited by timar, 29 October 2014 - 09:25 PM.
Posted 29 October 2014 - 10:38 PM
For the same reason why Aspirin has an acetyl group attached salicylic acid: to improve pharmacokinetics and to enable the molecule to cross the blood-brain barrier.
Do you have any links for this?
I suppose I'm asking what would you not get from L-cysteine that you get from NAC? Would you have to take more L-cysteine to get an effect, for example?
Edited by Skyguy2005, 29 October 2014 - 10:39 PM.
Posted 30 October 2014 - 01:08 AM
Felix Hoffmann was a pioneer in acetylating all sorts of stuff: Aspirin, Heroin...
The acetyl group increases fat solubilty, which increases intestinal absorption for some compounds but more importantly diminishes first-pass metabolism. Moreover, it allows the acetylated compound to cross the blood-brain barrier and reach much higher concentrations in the brain. This is why acetylated morphine (Heroin) has a very different effect from morphine which is mostly sedative and only mildly euphoriant.
Some compounds are considerably more stable when acetylated. Because of its thiol group, which easily becomes oxidized, cysteine is a highly unstable amino acid with limited bioavailability, so that despite its abundance in the diet most of it is synthesized endogenously.
Posted 30 October 2014 - 01:08 PM
Felix Hoffmann was a pioneer in acetylating all sorts of stuff: Aspirin, Heroin...
The acetyl group increases fat solubilty, which increases intestinal absorption for some compounds but more importantly diminishes first-pass metabolism. Moreover, it allows the acetylated compound to cross the blood-brain barrier and reach much higher concentrations in the brain. This is why acetylated morphine (Heroin) has a very different effect from morphine which is mostly sedative and only mildly euphoriant.
Some compounds are considerably more stable when acetylated. Because of its thiol group, which easily becomes oxidized, cysteine is a highly unstable amino acid with limited bioavailability, so that despite its abundance in the diet most of it is synthesized endogenously.
OK. I read something saying that they recommended L-cysteine with vitamin C, to avoid the cysteine becoming oxidised to cystine.
So does N-acetyl-L-Cysteine actually exist in nature?
Posted 30 October 2014 - 01:17 PM
OK. I read something saying that they recommended L-cysteine with vitamin C, to avoid the cysteine becoming oxidised to cystine.
That's what happens with pure Cystein, but much less so with NAC. Recommendations to ingest NAC with ascorbic acid in a 1:1 ratio are probably based on some studies done with cystein, not with NAC. There is no need to take NAC together with vitamin C, but it may improve the bioavailability somewhat. Pharmaceutical NAC preperations here in Germany usually come in a 8:1 ratio (600 mg NAC with 80 mg of vitamin C). I think pharma companies have based this on some reliable evidence and not on internet hearsay
So does N-acetyl-L-Cysteine actually exist in nature?
Most acetylated compounds from the lab don't exist in nature, or only in almost indetectable traces. Neither NAC nor Aspirin do.
Posted 03 November 2014 - 02:55 AM
One more thing: I hear NAC is supposed to boost glutathione. Has this claim been made for L-cysteine as well?
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