Abstract
In the investigation of Ch'an Su, a commercial preparation of the venom of a Chinese toad, and the poisonous secretions of 10 additional species of toads collected from different parts of the world, the authors found variations in the potency, physical constants, and chemical composition of some of the principles that were isolated from them. The secretion of each species of the toads contains at least from 3 to 5 distinct principles that belong to 5 classes of compounds: cholesterol, epinephrine, bufagin, bufotoxin, and bufotenine.
Cholesterol occurs in all of the secretions. Spectrographs examinations of several different samples showed the presence of ergosterol in various amounts. It has already been proved that after irradiation the sterol from Ch'an Su has an antirachitic action in rats. 1
Epinephrine occurs in B. marinus 2 Ch'an Su, 3 and appears to be present in B. arenarum, B. regularis, B. formosus, and B. bufo gargarisans. The amount varies from 2 to 5% of the dried secretion.
Bufagin is a word used generically, since it was observed that most of the bufagins, although similar in their action and elementary composition, are quantitatively different from each other as shown by their minimal emetic dose in cats and pigeons, respectively, and also by the average fatal do^e in cats (Table I). Besides, their melting points are not the same throughout. The bufagins possess the essential features of the members of the digitalis group. The action of the bufagins is not persistent, for the cat can eliminate completely a minimal emetic dose within one to few hours. The cat unit of each principle is less than 1 mg.
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