My Early Years in Chemistry

My father was a mechanical engineer but had a special passion for chemistry. He conveyed this interest to me with such enthusiasm that, by the age of 13, when I had my first chemistry lessons at school, I knew that I wanted to be a chemist. On completion of my first degree in chemical engineering at the University of Technology in Lund, Sweden, in 1969, I therefore continued my studies there as a graduate student in the Organic Chemistry Department. I still regard my thesis work on the toxic principle of the mushroom Coprinus atramentarius, supervised by Professor Borje Wickberg, as my most important piece of work, which set the tone for the rest of my career.

8.17.1.1 My Thesis Work

The goal of my thesis work was to isolate and identify the toxic principle of the gray inky cap mushroom C. atramentarius. It had been known for some time that this mushroom was edible and palatable, but if eaten along with alcohol it caused flushing, nausea, vomiting, palpitation, and increased blood pressure. Numerous scientific publications had appeared in the literature going back to the beginning of the twentieth century, describing attempts to isolate the active principle, but without success. Borje Wickberg therefore made it clear at the outset that this project might present a challenge for a graduate student. He was right. It took a year of hard work before I had any breakthrough on how to monitor the isolation work, which we believed to be a prerequisite for future success.

As it was thought that the reaction with the mushroom and concomitant alcohol was caused by inhibition of the liver aldehyde dehydrogenase, I began by testing mushroom extracts for their ability to inhibit the partially purified enzyme from bovine liver, but with no success. After fruitless attempts to establish an efficient collaboration with pharmacologists at the local university, I also introduced my own animal testing (in the chemistry laboratory) and started working with mice, again without success. In my thesis1 you can find the following footnote: ''In a more-or-less desperate experimental situation during present attempts to find the toxic principle, the author ate 300 g of boiled

C. atramentarius and then, on the following day, took 20 cL of ethanol (40%), but no uncomfortable effects were experienced." Luckily, however, I finally developed a test method in rats, in which per oral administration of mushroom extracts dissolved in water was followed by a large dose of alcohol 6h later. If the extract contained the active compound, the rats developed a tremendous facial edema some 12 h later. Using this test method to monitor the success of extraction and separation techniques, I was able to isolate the active compound in a couple of months.1'2 Elucidation of the structure of the active compound was performed in the classical way, and various degradation reactions finally revealed N5-(1-hydroxycyclopropyl)-glutamine (coprine; 1), the first (and probably still the only) natural product to be isolated that contains a cyclopropanone equivalent. After initial synthesis of the important fragment, 1-hydroxycyclopropylammonium chloride (2) (the free base being unstable), from cyclopropanone, concentrated ammonia and concentrated hydrochloric acid, I was able to synthesize the compound via an efficient photolysis reaction. By acylation of 1-hydroxycyclopropylamine by means of N1-phthaloyl-glutamic acid anhydride, coprine could be synthesized in good yield.1,2

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Dealing With Back Pain

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