taste, inadvertently tasting something that they probably wouldn't
have had they been more careful. Max Delbriick, in another context,
coined the phrase “principle of limited sloppiness” to describe situ-
ations in experimental research where unexpected discoveries are
made because a scientist is a little sloppy, but not so sloppy that he or
she can’t figure out what has happened.
Of these synthetic sweeteners, aspartame has become the most
widely used. It is about two hundred times sweeter than sucrose
and has the molecular form of a dipeptide, a covalently bonded pair
of amino acids, aspartic acid and phenylalanine, with an additional
methyl (-CH3) group on the phenylalanine. Synthetic sweeteners have
given rise to an industry of so-called diet foods—foods that, although
they taste sweet, contain fewer calories than would versions sweet-
ened with sugar.
0
0 wy OCH;
N
H
OH NH, 0
Aspartame
After the commercial success of synthetic sweeteners, some folks
decided that rather than wait for the next accidental discovery to
occur, it should be possible to intentionally seek out newer and even
more potent synthetic sweeteners. One idea was to begin with sucrose
and modify its molecular structure in different ways, hoping to get
something that—because of particular changes in molecular shape—
might bind to and activate the sweet GPCRs even more strongly than