Chemical Forums

Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: scarletthj on April 28, 2009, 06:23:05 AM

Title: 2-hydroxypropanenitrile
Post by: scarletthj on April 28, 2009, 06:23:05 AM

Hello,

I am having trouble with an assignment.

There are 2 questions i am stuck on which are ~

1. Explain why one isomer of 2-hydroxypropanenitrile is likely to be more toxic than the other

2. Inorganic cyanide in the form of K+ CN- is much more toxic than 2-hydroxypropanenitrile. The cyanide bonds with haemoglobin in blood replacing bonded oxygen and causing death.
Explain the difference in toxicity between the 2 substances.

If anyone can help i would be most grateful!

Thank you.

Title: Re: 2-hydroxypropanenitrile
Post by: sjb on April 28, 2009, 08:35:41 AM

Why is one isomer of any compound likely to have a different effect in vivo than another?

What are the main differences between the cyanide group in KCN and in 2-hydroxypropanenitrile?

Title: Re: 2-hydroxypropanenitrile
Post by: scarletthj on April 28, 2009, 01:31:46 PM

I think the answer is something to do with the 3D shape connecting to the enzyme molecules?

I'm really struggling on this one.

Title: Re: 2-hydroxypropanenitrile
Post by: Mitch on April 28, 2009, 02:36:42 PM

1.) Think R and S stereochemistry.

Title: Re: 2-hydroxypropanenitrile
Post by: scarletthj on April 28, 2009, 04:46:15 PM

ok, so i think that the arrangement of the atoms differ in the isomers - one is an R configuration and one is an S.

But how does this affect it's toxicity? and which one is the toxic one?

How do i find this information?

Thanks for helping.

Title: Re: 2-hydroxypropanenitrile
Post by: Mitch on April 28, 2009, 05:03:58 PM

It would be odd if you had to know which one is more toxic. I think the question was asking in general terms why a given enantiomer would be more toxic.

http://en.wikipedia.org/wiki/Chirality_(chemistry)#In_biology

Title: Re: 2-hydroxypropanenitrile
Post by: sjb on April 29, 2009, 03:30:59 AM

Quote from: Mitch on April 28, 2009, 05:03:58 PM

It would be odd if you had to know which one is more toxic.

Agreed to that, perhaps at a higher level you might need to know which enantiomer. Anyway I think you have the essence of the answer, a nuance though - what are the breakdown products, are any of them toxic / involved anywhere in vivo? (You may not need to know this, so feel free to ignore ;) )

Title: Re: 2-hydroxypropanenitrile
Post by: scarletthj on April 29, 2009, 05:51:01 AM

Thanks to those who helped me, i think i have got the answer sorted now!

I appreciate your help.