Grapes

In recent years we have all become familiar with the names of grapes commonly used in wine making: cabernet, chardonnay, Pinot, Riesling, Sauvignon, and Shiraz, for instance. Others, less well known, include catawba, haanepoot (or honeypot), Merlot, scuppernong, and zinfandel. So what about some medical grapes?

In Latin a bunch of grapes was racemus. In 1822 Kestner isolated an acid from grapes, and Gay-Lussac called it racemic acid. Racemic acid was in all respects chemically identical to tartaric acid, except that it did not rotate polarised light, a phenomenon described by Jean-Baptiste Biot, who postulated molecular asymmetry. Later Louis Pasteur crystallised racemic acid and saw in his microscope that it contained two types of crystal, left handed and right handed; when he physically teased them apart he …