Page 4 - Science Focus (Issue 017)

The Sweetest Encounter:

Discovery of the First Artificial Sweetener

最甜的巧遇— 首隻人工甜味劑

By Yasine Malki 馬建生 resulted in o-benzosulfimide. Remsen and Fahlberg
published their discovery in 1879, describing the
Artificial sweeteners are commonly found in many compound as “even sweeter than cane sugar.” [1]
“diet” varieties of food and drinks: from soft drinks However, this is where the sweet story took a bitter
to bakery goods, canned fruits and syrups. These turn. After Fahlberg left Remsen’s lab, he started to
sweeteners are synthetic substitutes of sugar, with little realize the commercial potential of o-benzosulfimide
to no caloric content. You might see the common ones, and further optimize its synthesis for large-scale
like sucralose or aspartame among the ingredients of production, even conducting safety tests by feeding
your favourite snack or drink! But did you know that the compound to animals and himself [4]. He realized
the discovery of the first artificial sweetener, saccharin, that the compound was not metabolized by the body
came from experiments with coal tar and an accidental and was eliminated in the urine unchanged — meaning
laboratory spillage? that it could probably be a replacement of sugar for
Ira Remsen was a passionate German chemist who diabetics and dieters, because it did not alter blood
flourished in his work on sulfobenzoic compounds [1] at sugar levels nor provide any calories. Fahlberg filed
1
Johns Hopkins University. Around 1877, a Russian chemist, patents for this substance in several countries under
2
Constantin Fahlberg, had joined his lab and they were the name “saccharin” without Remsen’s knowledge or
working together to oxidize a coal-tar sulfobenzoic permission, and even claimed to be its sole discoverer.
derivative [2], o-toluenesulfonamide [3]. These actions left Remsen feeling betrayed and furious.
One day when Fahlberg went home for dinner and Saccharin quickly gained popularity in the US
took a bite at a piece of bread, he was shocked to find nevertheless, becoming a nation-wide success and
it tasted incredibly sweet! He also detected that both a booming industry. Its increased consumption soon
his hands and arms also tasted sweet, even though he drawn the attention of health experts. After studies
had washed them thoroughly! He concluded that the revealed a link between saccharin consumption to
sweetness came from insoluble remnants of an earlier the development of bladder cancer in male rats [5],
chemical spillage over his hands. Being desperate its use became highly scrutinized. For around 19 years,
for answers, he returned to the lab and tasted all the saccharin had to be sold with a warning label [1] until
glassware on his bench until he found the substance further research showed that those male rats had had
with “eminent sweetening power.” [4] This turned out to unique physiological conditions (high levels of urinary
come from an overboiled mixture of o-toluenesulfonic proteins and calcium phosphate) that triggered their
acid, phosphorus pentachloride and ammonia, which tumor formation by producing microcrystals with