The following is a report of the American Medical Association Chemical Laboratory. Paul Nicholas Leech, Director.
Examination of Synthetic Thyroxine, RocheThe story of the discovery and isolation of thyroxine is legend to the medical profession. It will be recalled that, following a series of diligent researches, Kendall isolated the preparation from the thyroid gland; he had considered it to be 4,5,6 trihydro, 4,5,6 tri iodo-alpha-oxy-beta indole propionic acid. Such was the status of the preparation when the U. S. Pharmacopeia was revised and thyroxine was included. It is interesting to note the definition in the U. S. Pharmacopeia X: "Thyroxin [(C8H5ONI2).C2H4COOH] is an active principle obtained from the thyroid gland and contains not less than 63 per cent of iodine."1About three years ago, Harington and his co-workers at Cambridge, England, retraced the steps so well