When I was doing my undergraduate and masters degrees at University of Natal (Durban), medicinal plants were definitely the hot thing to be researching. My honours project was looking at Warburgia salutaris, a tree whose bark is harvested for all sorts of medicinal purposes from stomach ulcers to malaria. We thought that it would be a good idea to look at what methods were best to treated to damaged trees to help the bark to regenerate as quickly as possible. To achieve this, strips of barks were removed and the damaged areas were either left untreated, covered with lanolin, or either CEPA (releases ethylene) or IAA (auxin) dissolved in lanolin. The bottom line was that lanolin on its own seemed to be the best.
The two active components are warburganal and polygodial and these aldehydes reacted with vanillin to make coloured compounds. I thought that it would be a good idea to stain the bark tissue slides (prepared by slicing the regenerated bark using a vibratome) with vanillin and I got quite a nice effect.
As mentioned in my introductory post, I found some old slides from a talk I gave at a conference in Stellenbosch (January 1996?), but this is really all I have left from this project and I don’t remember any of the finer details. I have made a powerpoint presentation using the images and have uploaded them into google.docs.
The first half
The second half
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