SYNTHETIC THYROXIN

Wanganui Chronicle, Volume LXXXIII, Issue 19766, 14 February 1927, Page 2

SYNTHETIC THYROXIN

GREAT CHEMICAL EEAT. EQUALS ESSENCE OF GLAND. A feat in organic chemistry classed as among the most remferkable ever made has been accomplished by two British doctors, according to a statement by am expert. They have succeeded in synthesising thyroxin, the the hormone produced by the thyroid gland. Working along the lines followed in 1917 by an Ameriefen, Dr Kendall of the Mayo Clinic at Rochester, Minn., these two British investigators—Dr C. R. Harington of the University College Hospital, London, and Professor George Barger of Edinburgh—have succeeded in obtaining a complete synthesis where organic chemists throughout the world have been vfeinly seeking since 1917. Dr Harington, one of the successful pair, spent several years in fruitless research before success at last crowned his efforts. Commenting on the remarkable discovery the scientific correspondent of the London Observer explains that the thyroid gland, which lies in the neck, is one of several which pour secretions necessary for normal life into the blood. A number of these secretions, including insulin, have been obtained in forms valuable to medicine, but only two, those of the adrenals and thyroid, .so far have been obtained pure. Abrenalinc wfes isolated 25 years ago, and made synthetically in 1904. Feeding with the thyroid gland or its extracts is the only treatment available when the human thyroid is absent or functions badly, and such trefetment has saved many from death and many more from idiocy and stunted growth. But the amount of active principle contained in such extracts vferied greatly, and where a dose of one batch might be correct, the same dose of another was often too strong or too weak. The experiments or Dr Kendall, the American, resulted in isolating from the thyroid a crytfelline substance of immense potency, which he called thyroxin, half an ounce of which would keep a man who had no thyroid gland normal for 75 years. But as the entire human race hfes only about 15 tons of it in their bodies, it was available in extremely small quantities and more precious than diamonds. Dr Harington began experimenting in 1925 and finally devised a method of obtaining the substance in much larger quantities than Dr Kendall. He also threw considerable additional light on its structure. Now, working with Professor Barger, he has accomplished fe complete synthesis, using, it is understood, coal tar products and iodine. A full account of the remarkable discovery, it is announced, will be made soon. The new synthetic thyroxin his been tested on humfen beings and found to be as effective as the product obtained from a gland, it is said. 11 It is not known whether the process of manufacture will be patented, as in the case of insulin,” says the “Observer correspondent, who stfetes that a dose of a quarter grain will double the pulse rate for a week' or more, while prolonged overdosage would be fatal. “Apart from its medical and commercial v'aluc, ’ ’ the ‘ ‘ Observer ’ ’ says, “the discovery marks a great step fori ward in biochemistry, being a successful imitation of the highly complicated process which goes forward in a living cell. It raises hopes of an eventufel synthesis of insulin, a far harder task, but one which would be of-*even greater value if accomplished.” Incidentally, it is pointed out that marketing of the synthetic product will kill one of the sidelines now exploited by the Chiefego meat factories.