Quite an eventful week, with the lowest recorded maximum temperatures in over a decade (those Europeans do not know what cold is), and some ‘building issues’ that prevented me from getting to the lab. But what would life be without challenges.
So I’ve analysed the Artemisia afra tea and compared it to Artemisia annua. The phenolic profile looks quite stable (figure 1) but there are differences between the profiles of the two species (figure 2).
This is fully expected. Chemical differences between species is well known but also within species (depending on where, how, when etc samples were collected). We have a number of A. annua and A. afra samples and will be conducting a test to see how much the chemical intra-and interspecies variation will be.
The main bioactive compound in A. annua is artemisinin. I’ve set up a very sensitive MRM method on our new MS equipment to quantify artemisinin in these samples. The A. annua material that I used for a first test did yield significant amounts of artemisinin – no surprise there. But the interesting thing is that I could not find any trace of artemisinin in the A. afra sample. I’ve tested a number of A. afra samples in the past mainly to see if I could find any artemisinin but I’ve always came up empty handed (I’ve even published a paper on this way back in 2009). The first report that a specific A. afra sample contains artemisinin was published in the clinical trial paper a couple of years ago and I’ve actually managed to get some of that material. This material is currently being analysed on our LCMS and it will be very interesting to see if we can confirm those published results.
So there is a lot of things that needs to happen this week. I need to test the chemical variation of all the samples. I need to quantify artemisinin in all these samples and I need to fractionate selected samples to be tested against the corona virus (if all goes well, the antiviral testing will be done at Basel university within a couple of weeks).