lemon juice

[skwiff]

does any one know why caspicin (think that is the right spelling) is deactivated by lemon? i found this to be better than milk to rid you of the burning of chillies, does the lemon juice act as a buffer or does the citric acid bind with the spicy alkoid?

[rktpro]

does any one know why caspicin (think that is the right spelling) is deactivated by lemon? i found this to be better than milk to rid you of the burning of chillies, does the lemon juice act as a buffer or does the citric acid bind with the spicy alkoid?

 

I thought oil was the best thing to get rid of chillies sensation.

[skwiff]

I thought oil was the best thing to get rid of chillies sensation.

 

would you drink oil?

[Greg Boyles]

does any one know why caspicin (think that is the right spelling) is deactivated by lemon? i found this to be better than milk to rid you of the burning of chillies, does the lemon juice act as a buffer or does the citric acid bind with the spicy alkoid?

 

 

The substance that causes the burning sensation is oil soluble, hence oil will make it worse. Yoghurt or milk are supposed to be best at disipating the substance that burns due to their high protein content that absorbs it.

[hypervalent_iodine]

After eating a whole jalapeno, I found the only thing that actually worked to a significant degree and for more than 1 second was bananas. I ate about 5 of them over the course of half an hour.

 

As for lemon juice, I am not entirely sure on the mechanism. I read a few things saying that it neutralised the alkaline nature of capsaicin, which I think is more or less true. Looking at the structure of capsaicin, I would guess that the citric acid could hydrolyse the amide present in its structure to give the corresponding benzyl amine and carboxylic acid, which would then take away the associated burn. But that's little more than a guess.

[skwiff]

After eating a whole jalapeno, I found the only thing that actually worked to a significant degree and for more than 1 second was bananas. I ate about 5 of them over the course of half an hour.

 

As for lemon juice, I am not entirely sure on the mechanism. I read a few things saying that it neutralised the alkaline nature of capsaicin, which I think is more or less true. Looking at the structure of capsaicin, I would guess that the citric acid could hydrolyse the amide present in its structure to give the corresponding benzyl amine and carboxylic acid, which would then take away the associated burn. But that's little more than a guess.

 

i ate a dorest naga (one of the hottest peppers) and lemon worked better and milk! (dont drink the two together, it will make you vomit) but the neutralation of the capsaicin does sound pluasable

[rktpro]

would you drink oil?

 

This is not what exactly I meant. I mean you can have fried things or even bread.

[mississippichem]

After eating a whole jalapeno, I found the only thing that actually worked to a significant degree and for more than 1 second was bananas. I ate about 5 of them over the course of half an hour.

 

As for lemon juice, I am not entirely sure on the mechanism. I read a few things saying that it neutralised the alkaline nature of capsaicin, which I think is more or less true. Looking at the structure of capsaicin, I would guess that the citric acid could hydrolyse the amide present in its structure to give the corresponding benzyl amine and carboxylic acid, which would then take away the associated burn. But that's little more than a guess.

 

So is the amide the active site? I would assume so, as I can't see that orthomethoxy-phenol group having good docking properties anywhere due to steric bulk and rigidity.

 

Maybe lemon juice is a competitive inhibitor for TRPV1, capascin's receptor. Or maybe the acidity of lemon juice has some allosteric effect on that enzyme. These may not be the case, I'm just throwing stuff out there, (which is how all good chemistry starts ).

[John Cuthber]

I think the phenoxy bit is the handle that binds to the receptor.

 

From

http://en.wikipedia.org/wiki/Vanillyl

 

"A number of vanilloids, most notably capsaicin, bind to the Transient receptor potential vanilloid type 1 (TRPV1) receptor, an ion channel which naturally responds to noxious stimuli such as high temperatures and acidic pH.[1] This action is responsible for the burning sensation experienced after eating spicy peppers."

 

This

http://en.wikipedia.org/wiki/Resiniferatoxin

is a spectacularly potent one, but has no amide group.

What the lemon offers I don't know.

Could be a specific antagonist; they do exist.

[skwiff]

I think the phenoxy bit is the handle that binds to the receptor.

 

From

http://en.wikipedia.org/wiki/Vanillyl

 

"A number of vanilloids, most notably capsaicin, bind to the Transient receptor potential vanilloid type 1 (TRPV1) receptor, an ion channel which naturally responds to noxious stimuli such as high temperatures and acidic pH.[1] This action is responsible for the burning sensation experienced after eating spicy peppers."

 

This

http://en.wikipedia....Resiniferatoxin

is a spectacularly potent one, but has no amide group.

What the lemon offers I don't know.

Could be a specific antagonist; they do exist.

 

RTX is nasty! i have been one the wrong end of that chemical to many times!

[hypervalent_iodine]

So is the amide the active site? I would assume so, as I can't see that orthomethoxy-phenol group having good docking properties anywhere due to steric bulk and rigidity.

 

Maybe lemon juice is a competitive inhibitor for TRPV1, capascin's receptor. Or maybe the acidity of lemon juice has some allosteric effect on that enzyme. These may not be the case, I'm just throwing stuff out there, (which is how all good chemistry starts ).

 

I actually thought that something in the lemon juice might be binding in preference to the TRPV1 myself, but I couldn't find anything on it. So my best guess is that the citric acid is hydrolysing the amide. Presumably, cleaving it in half reduces its potency, or perhaps the amide is needed for efficient binding, etc.

 

I did also just find this, from wiki

 

Phenolic hydroxide and amide moieties appear to be vital for inducing capsaicin responses. Removal of the phenolic hydroxide or amide bond in capsaicin analogues leads to reduction of potency.

[mississippichem]

I think the phenoxy bit is the handle that binds to the receptor...

 

It would appear so. That's surprising.

 

I actually thought that something in the lemon juice might be binding in preference to the TRPV1 myself, but I couldn't find anything on it.

 

I guess it is the hydrolysis of the amide then! It would be nice to see kinetics for capsaicin+receptor, lemon juice+capsaicin+receptor, and hydrolyzed capsaicin+receptor.

[hypervalent_iodine]

 

I guess it is the hydrolysis of the amide then! It would be nice to see kinetics for capsaicin+receptor, lemon juice+capsaicin+receptor, and hydrolyzed capsaicin+receptor.

 

You should do your PhD on it an get back to us in a few years

[mississippichem]

You should do your PhD on it an get back to us in a few years

 

And get labeled a biochemist for the rest of my life...yeah right!

 

Take that back. I just got my licensing for the GAMESS computational package. I can include a MD docking simulation and then call it p-chem. Wonderful how journal classification works.

Edited August 3, 2011 by mississippichem

[John Cuthber]

Amides are generally quite difficult to hydrolyse. That's just as well for us since we are made largely of amides and water.

The existence of the (legendary) vindaloo curry shows that the pungent principle present in chillis is stable to acid hydrolysis during cooking for a long time at high temperature.

 

"The name Vindaloo is derived from the Portuguese dish "Carne de Vinha d' Alhos", which is a dish of meat, usually pork, with wine and garlic.[1] The dish was originally modified in Mumbai[citation needed] by the substitution of vinegar for the wine,"

from

http://en.wikipedia.org/wiki/Vindaloo

 

Possibly the strong taste of the lemon juice is responsible

http://en.wikipedia.org/wiki/Counterstimulation

Edited August 3, 2011 by John Cuthber

[skwiff]

Amides are generally quite difficult to hydrolyse. That's just as well for us since we are made largely of amides and water.

The existence of the (legendary) vindaloo curry shows that the pungent principle present in chillis is stable to acid hydrolysis during cooking for a long time at high temperature.

 

"The name Vindaloo is derived from the Portuguese dish "Carne de Vinha d' Alhos", which is a dish of meat, usually pork, with wine and garlic.[1] The dish was originally modified in Mumbai[citation needed] by the substitution of vinegar for the wine,"

from

http://en.wikipedia.org/wiki/Vindaloo

 

Possibly the strong taste of the lemon juice is responsible

http://en.wikipedia....nterstimulation

 

so how comes when you have chilli juice on skin, the best thight to wash it off (imo) is lemon or vinegar?

[John Cuthber]

As you say, that is your opinion. Why do you expect me to justify it?

Incidentally, was that opinion formed on the basis of some sort of controlled experiment?

 

BTW, you say "RTX is nasty! i have been one the wrong end of that chemical to many times! "

What were you doing at the time?

[skwiff]

As you say, that is your opinion. Why do you expect me to justify it?

Incidentally, was that opinion formed on the basis of some sort of controlled experiment?

 

BTW, you say "RTX is nasty! i have been one the wrong end of that chemical to many times! "

What were you doing at the time?

 

i just happen to have a rather large wood spurge in my garden, RTX is in the sap of all Euphorbia species and it burns like hell!