• Blog Stats

    • 74,442 hits
  • Archives

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 156 other followers

  • Copyright notice

    This blog entry and all other text on this blog is copyrighted, you are free to read it, discuss it with friends, co-workers and anyone else who will pay attention.

    If you want to cite this blog article or quote from it in a not for profit website or blog then please feel free to do so as long as you provide a link back to this blog article.

    If as a school teacher or university teacher you wish to use content from my blog for the education of students then you may do so as long as the teaching materials produced from my blogged writings are not distributed for profit to others. Also at University level I ask that you provide a link to my blog to the students.

    If you want to quote from this blog in an academic paper published in an academic journal then please contact me before you submit your paper to enable us to discuss the matter.

    If you wish to reuse my text in a way where you will be making a profit (however small) please contact me before you do so, and we can discuss the licensing of the content.

    If you want to contact me then please do so by e-mailing me at Chalmers University of Technology, I am quite easy to find there as I am the only person with the surname “foreman” working at Chalmers. An alternative method of contacting me is to leave a comment on a blog article. If you do not know which one to comment on then just pick one at random, please include your email in the comment so I can contact you.

Milk thistle

Dear Reader,

When I was reading a recent copy of a magazine from Aldrich (The Reporter) which in some ways is a series of adverts by Aldrich telling me about the latest analytical gadgets, gizmos, GC columns and other things I saw something interesting. It was on page 6 of the April edition of volume 50.

It was all about C-18 HPLC columns, now in common with many articles in the Reporter the writers show a application. In their case they choose the complex mixture of secondary metabolites from a plant called milk thistle. These include the the silybins and isosilybins. The herb is thought to be good for the liver and has some other medical applications.

When I looked at them I noticed something about the silybins and isosilybins. Here for your information is isosilybin A. I have highlighted in red the part which stood out to me.

Isosilybin A

I have put in red the part of the molecule which looks like it is very similar to eugenol, I looked in the chemical literature and I found that a biomimetic synthesis of a mixture of isosilybins and the silybins. L. Merlini, A. Zanarotti, A. Pelter, M.P. Rochefort and R. Hänsel, Perkin Transactions I, 1980, pages 775-778.

This is a synthesis which used taxifolin and coniferyl alcohol. The synthesis is an oxidation of a mixture of the two compounds in a mixture of benzene and acetone with silver(I) oxide. The first step is the production of some resonance stablised free radicals, these will be much less reactive and more stable than a typical alkyl free radical. As right now I can not be bothered to draw out the whole of the molecule and to make it more clear for you and to keep with the best traditions of organic chemistry I have represented the taxifolin part of the molecule with a simple 1,2-dihydroxybenzene.

The formation of the radicals by the one electron oxidations

Now the next step is the radical-radical coupling which forms the first C-O bond.

Radical radical coupling step

The next step is a nucleophilic attack by the phenol oxygen on the conjugated system in the right hand part of the molecule. This gives us the final product.

The final step of the reaction

I will discuss the synthesis of taxifolin in another post, I saw a paper by Yang, et. al. in Journal of Medicinal Chemistry,  2009 ,  volume 52,  issue 23, pages 7732 to 7752. This is a synthesis of this compound from small molecules. It was done using a combination of aldol and epoxide chemistry. I will write about it soon.

Advertisements

One Response

  1. illions of compounds are detoxified within each liver cell, or hepatocyte. Inevitably, this wear and tear compromises liver cells and surrounding connective tissue. Hepatotoxicity is fast becoming a major health issue. In fact, many practitioners believe poor liver function caused by toxin accumulation or by liver-function decline may contribute to other seemingly unrelated illnesses, such as rheumatoid arthritis, eczema, migraine headaches and premenstrual syndrome, and may manifest symptoms of its own. As a result, milk thistle (Silybum marianum) is widely prescribed by herbalists throughout Europe and the Americas for liver protection. ..

    Check out our own online site as well
    <'http://www.healthmedicinecentral.com/inflamed-pancreas/

Go on, Have your say !

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: