Formula of Fugu

The poisonous puffer fish, which inflates itself into a small balloon when caught, lives in most of the world's oceans. But only in Japan, where it is called fugu, has it become a national tradition. There, though its poison kills 200 victims per year, its flesh sends gourmets into philosophical ecstasies. They get a particular kick from knowing they are playing a kind of gustatory Russian roulette.

The fugu has drawn additional attention by its long-defiant challenge to the chemists' skill. Its poison, tetrodotoxin, has proved almost impossible to isolate or identify. But Japanese science has finally turned the trick. For establishing the molecular structure of tetrodotoxin, Professors Kyosuke Tsuda of Tokyo University, Yoshimasa Hirata of Nagoya University, Isamu Nitta of Kwansei Gakuin University, and Akira Yokoo of Okayama University have just won the prestigious Asahi prize.

No Antidote. Cases of tetrodotoxin poisoning do not occur every day, but only too often the chopsticks drop from a victim's fingers. His breathing becomes difficult; his heart action falters.

No antidote is known, and the fatality rate of fugu poisoning has remained nearly 60%.

The peak of fugu gastronomy is sashimi made from the rare tiger fugu: paper-thin slices of raw fish flesh arranged artistically on platters in flower or bird patterns. Japanese, who pay $8 for two ounces of tiger fugu sashimi, eat it with almost religious ceremony and little or no risk. The sashimi is cut from the back flesh of the fugu, which is nonpoisonous* unless it has been carelessly contaminated with poison from other parts.

Perilous Aphrodisiac. The peril and excitement come from other fugu dishes. Most risky is a milky-white preparation of fugu testes that is mixed with hot sake and drunk by eager virility seekers. The testes are nontoxic, but the ovaries and liver are so deadly that small bits of them can kill a man, and it takes an experienced chef to distinguish a deadly liver from an aphrodisiac testis.

Fugu chefs pass strict examinations before they are licensed to practice their risky art, but no Japanese politician would dare prohibit fugu, or even its dangerous entrails. Many of them, including Premier Eisaku Sato, are passionate fugu lovers.

For all its power, the poison exists in very small amounts, and its molecule is so delicate that it falls to pieces when chemically molested. Generations of chemists managed to make stronger and stronger concentrations of tetrodotoxin, and in 1949 Professor Akira Yokoo isolated the poison in pure crystalline form. But still the molecular formula defied investigation.

Practical Chore. The chemists used every kind of modern apparatus as soon as it became available, but progress was slow. Then some of them turned to X-ray diffractions and called on an IBM 7090 computer to interpret their results. Finally, they found the long-sought formula which is unlike that of any other known poison. Then a group of chemists at Stanford University led by Professor Harry S. Mosher found the same poison in egg clusters of California newts. Both U.S. and Japanese chemists are now trying to figure out why such distantly related animals as fish and newts should have the same rare poison.

Japanese chemists are also hard at work on a more practical chore: finding an antidote for tetrodotoxin poisoning. But success may not be applauded by risk-loving gourmets. When a bottle of antitoxin is standing in every restaurant, the dangerous fugu will have become just another fish; fugu roulette will have lost its excitement, and something unique will have vanished from Japanese culture.

*American puffer fish, which are also poisonous, are sold as "sea squab" or under some other euphemistic name. Only the back flesh is cut free; the dangerous remainder of the fish is discarded at sea.

This file is automatically generated by a robot program, so reader's discretion is required.