Anthony had given some good advice.
In addition, Any organic solvent may be helpful. We often use methanol and chloroform.
================= 2007-7-19 6:12, your message: Re: [ccp4bb] advice for crystallizing hydrophobic small molecules=================
Hi Todd
I have worked in the past with crystallization of dozens of small
molecules, several of them steroids which are hydrophobic. What I did
was, first get the small molecule into the solution. The solvent can
be dimethyl formamide, dimethyl sulfoxide, chloroform or anything
that I can find on my shelf. Also hydrophobic solvents like benzene,
hexane etc.
Leave the compound in the semi-open containers and hope for crystals
to appear. Some times I also used to poison the solution by adding
other solvents that include water.
Here, I should say that steroids crystalize really well, at least
those I synthesized.
People, some times use crystallization techniques similar to protein
like hanging or sitting drops for some small molecules, particularly
those are water soluble.
Good luck
Anthony
________________________________
Anthony Addlagatta, PhD
Institute of Molecular Biology
University of Oregon
Eugene, OR-97403
Phone: (541) 346-5867
Fax: (541)346-5870
Web: http://uoregon.edu/~anthony
On Jul 18, 2007, at 2:56 PM, Green, Todd wrote:
> Hello all,
>
> I am asking this question for a colleague(a chemist not a
> crystallographer) who would like to crystallize a small molecule
> (for clarification this is just the small molecule not a protein
> complex). The compound is quite hydrophobic and is rather "greasy."
> He has a free alcohol which could be a site of modification if this
> would help. I have only worked with proteins and was hoping that
> someone might be knowledgible and could point me in the direction
> of some help(literature, websites, etc) that might aide as a ground
> level tutorial on crystallization of small molecules, and if
> possible more specifically crystallization of hydrophobic/"greasy"
> small molecules.
>
> Thanks in advance-
> Todd Green
> University of Alabama at Birmingham
>
.
============================================================================================
Sincerely yours,
Li Sheng
2007-07-19
__________________________________________
Email:[log in to unmask]
Institute of Biochemistry and Cell Biology
Institutes for Biological Sciences
Chinese Academy of Sciences
320 Yue-Yang Road, Shanghai 200031, China
Tel: +86-21-5492-1217
__________________________________________
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