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Tag: chemistry

Farewell Jeremy Knowles

image I was very sad to discover online the death of Jeremy Knowles, renowned biochemist and former Dean of Harvard’s Faculty of Arts and Sciences. This is especially poignant for me for two reasons.

The first is academic. Throughout college, I was very interested in the study of chemical biology — the chemistry of living processes. Part of this was due to my fascination with Knowles’ work. Professor Knowles was famous for his studies which bridged our early understanding of chemistry with that of natural biological processes. His work in enzymology helped explain how TIM (triose phosphate isomerase, a critical enzyme in one of the chemical reactions which allow cells to turn food into energy) worked and developed a chemical understanding of how antibiotics like penicillin work and how clavulanic acid helps to fight antibiotic-resistant bacteria. When you’re as big a science dork as I am, that is just endlessly fascinating.

The second reason is a more personal one. A few years ago, my roommate Eric and I had the opportunity to dine with Professor Knowles at the Harvard Faculty Club. There we were, face-to-face with a well-respected intellectual luminary and someone who had tangibly shaped the destiny of teaching and student life at the university. I walked away with a sense of wonder at the man — in one short dinner, he was able to imbue in each of us a sense of awe at his sheer brilliance, and all delivered with such charm that you would hardly know he had been the Dean of one of the world’s foremost academic institutions and appointed a Commander of the Order of the British Empire by the Queen of England.

My heart goes out to Mr. Knowles’ family, as well as to the Harvard community he served so well.

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Mr. Hexane

There was a semester where I considered going into organic chemistry. Why not? I had liked the orgo classes I had taken. The subject matter, at least from textbooks, seemed fascinating to me — using the properties of Carbon, Oxygen, Nitrogen, and my other friends from the periodic table to either construct or understand molecules of industrial and biological importance — and it seemed so much more creative than the molecular biology stuff that I was beginning to get tired of. After all, my roommate seemed pretty happy with his Chemistry major.

So, I took Chem135 — Experimental Synthetic Chemistry, a much more advanced and realistic look at synthetic organic chemistry compared with the introductory lab sections I had previously taken. Excited, I dove straight into synthesis — my two projects being the synthesis of Aspartame (better known as NutraSweet) which was, incidentally, discovered by a guy doing random amino acid-like fragment coupling who just happened to lick his unwashed hands (not something I’d recommend) and the Wieland-Miescher Ketone, an interesting chemical structure which is used to synthesize taxol (a potent anti-cancer drug) and other hormones.

Excitement is not the same as skill, however, and, perhaps unsurprisingly, I was a very poor synthetic chemist. An illustrative example of this was during the Aspartame synthesis project. One of the steps of the project entailed azeotroping away acetic acid (what makes vinegar vinegar-y). Acetic acid does not readily boil off or evaporate, but heptane (C7H16) does and because heptane is known to azeotrope well with acetic acid, one can eliminate the acetic acid by adding heptane.

I, the brilliant and attentive budding scholar that I was, made the mistake of adding HEXANE C6H14 (not heptane), and, while in principle, hexane and heptane can sometimes be good replacements for one another, it did not work quite so well — necessitating me to evaporate off an extra four equivalents of heptane. D. Zhao, wonderful friend that he is, hence dubbed me Mr. Hexane — and from that day forth, I labeled all of my tubes and flasks and vials “Mr. Hexane”.

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