Wednesday, January 2, 2013

Process Wednesday: flow artemisinin?

We've covered the process chemistry of artemisinin here before, but Bethany Halford of Chemical and Engineering News brings us some news from Germany about Peter Seeberger's flow route:
Since its report in January, Seeberger’s group has optimized the process, upping the yield from 39% to 65%, which allows them to purify the product via crystallization rather than chromatography. The ultimate impact of the continuous-flow process remains to be seen. Sanofi has no plan to adopt it for artemisinin production, but Seeberger has set up a company, ArtemiFlow, in Potsdam, Germany, aimed at making the drug. Seeberger and coworkers are in the process of finishing a reactor that will produce more than 1 metric ton of artemisinin per year, he tells C&EN. The company is also developing a 10-ton reactor. (emphasis mine) 
As of June, there didn't seem to be any plans to take this route into the plant, but it looks like things will have changed. It will be interesting to see how far Seeberger gets -- so far, there doesn't seem to be an actual website, as Artemiflow.com diverts to the Seeberger Group page.

[Is anyone else skeptical-ish about those numbers? I suppose "tens or hundreds of kilograms" is not very sexy. I'm terribly curious as to what kind of operation would be required (24-hour-a-day?) to reach a metric ton per year. (Well, not that much, really. 4 kg a day? 20 kg a week?)]

Best wishes to them.

6 comments:

  1. Of course this is happening just as malaria develops resistance.

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  2. The same article points out that Sanofi want to produce 40 metric tons a year of artemisinin.

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    1. My skepticism is about Seeberger's throughput with his reactor.

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    2. Saw a presentation on artemisinin from a Sanofi guy not long ago and they seemed quite close to their target.

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  3. In Seebergers SI (http://onlinelibrary.wiley.com/doi/10.1002/anie.201107446/suppinfo) part 8 he says producitivty is 0.49 mmol/min. The CEN article says he's up to 65% yield from 39%, so that's 0.82 mmol/min, or 431 mol/year, which is 122 kg/year assuming 100% operating time. From a chemistry stand point, he only needs to be 10x more productive, which can come from a better catalyst, more light, higher concentration or temperature, or bigger reactor. One ton/year doesn't seem so far away on paper. Of course, the chemistry might not be the bottle neck in the process. Reactor downtime, purification, sourcing the material, etc. are probably bigger problems. Operating days (or weeks) at a time is a must, since starting the reactor up, waiting for steady state, shutting it down, and cleaning it out can easily take more than a full work day. Kind of defeats the purpose of continuous processing.

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    1. Thanks for looking that up (and shame on me for not doing so!)

      Sounds plausible, at the very least. 10 MT a year might be tough, though.

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