THE PAROTID SECRETION OF B. BUFO GARGARIZANS AS THE SOURCE OF CH'AN SU

¹ From the Lilly Research Laboratories, Eli Lilly and Company, Indianapolis

From the parotid secretion of the common Chinese toad (B. bufo gargarizans), cholesterol, a bufagin, a bufotoxin, and a bufotenine as a flavianate have been isolated in crystalline form. The cholesterol contains 1.3 parts of ergosterol per thousand, slightly less than that found in the cholesterol separated from Ch'an Su (2 parts per thousand). The bufagin and the bufotenine prove to be, both by chemical analyses and physiological assay in cats, identical with the cino-bufagin and cino-bufotenine of Ch'an Su. The bufotoxin has the same chemical composition and the same minimal emetic dose in cats as cino-bufotoxin, but it has a slightly lower toxicity, which may be due to a trace of impurity persistently adhering to the compound. Evidence for the occurrence of epinephrine in the secretion has been obtained; the amount present has been determined in pithed cats to be approximately the same as that in Ch'an Su.

It appears obvious that Ch'an Su is made of the parotid secretion of the common Chinese toad, B. bufo gargarizans.