Artemisia samples arrived at Max-Planck for testing and a chemistry update

Finally. It took a while but the Artemisia samples have arrived in Germany and will hopefully be tested for in-vitro activity against SARS-Covid-2 quite soon. Now in the meantime, I’ve been separating the extract into various fractions. The idea behind this is that in case the original samples, currently in Germany, turn out to be active, then we need to concentrate that active compound(s) into a specific fraction. (To save time I will be sending these fractions early next week as well). So step-by-step we get rid of in-actives (which I always call rubbish) and we start to zoom in on the possible actives. Unfortunately, my semi-prep column died on me (and wasted quite a bit of my time), so I had to revert to some old-school techniques which actually works quite well. I am still drying some of these fractions, but to illustrate how it works, please have a look at Fig 1.

A afra tea Hexane fraction
Fig 1. The top chromatogram illustrates the fresh A. afra tea infusion (data 1) whilst the bottom chromatogram illustrates the non-polar fraction separated from the fresh A. afra tea infusion (data 2) 

Okay, so what are we looking at? One can divide the chromatogram in Fig 1 into roughly three sections.

Section 1: between 2-10 min, containing mainly polar compounds;

Section 2: between 10-15 min, containing your medium polarity compounds and:

Section 3: between 15-25 min, containing your non-polar compounds.

So what I’ve done here is to extract and concentrate the non-polar compounds into one fraction, and I’ve also managed to get rid of all the polar and a lot of the medium polarity compounds (they will be in the other fractions not shown here). So let’s say, for argument sake, that the active compound turns out to be non-polar, then we will expect this fraction to be a lot more active than the original tea infusion and all of the other fractions. The advantage of separating the extract based on polarity is that it also separates both UV-visible and UV-invisible compounds into these fractions – so you don’t loose any of your ‘invisible’ compounds without you knowing about it.

With a semi-prep column (which I’ve ordered) one can do a far better job than with this old-school technique that I’ve used, but it is still not too shabby.

If you find any of this interesting (strongly doubt of many people will do so), please add your email to this blog site for automatic updates, and please have a look at our crowd funding campaign website which is currently funding this work (and thanks to all who have donated – excluding the one troll).

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