Isolation and Identification of Ergosterol and Mannitol from Aspergillus Fischeri*

Sterols are widely distributed in nature. It has been suggested that they be classified into three groups according to their occurrence : (1) zoosterols, the animal sterols (cholesterol, coprosterol) ; (2) phytosterols, the plant or vegetable sterols (sitosterol, stigmasterol) ; and (3) mycosterols, the sterols found in fungi (ergosterol, fungisterol). Although ergosterol has been detected in small amounts in both animals and higher plants, it is the principal sterol present in fungi. The physical constants reported by various investigators (l-6) for ergosterol isolated from molds are not in agreement. For example, melting points range from 135-161” and specific rotations vary from 117’ to 143.3”. These discrepancies are probably due mainly to the presence of small amounts of impurities (including possibly other sterols) from which it is difficult to separate the ergosterol and some of which may have been actually produced during the attempted purification. Lack of sufficient material has also handicapped the purification. In most cases the quantity of sterol isolated and actually in hand for identification purposes has been small. As a consequence many reports contain insufficient data for a satisfactory characterization of the sterol. Of the six papers recording the presence of ergosterol in molds, only three (2,4,6) give the melting points and optical rotations of both the free sterol and a derivative thereof. In spite of this lack of data, the constants taken as a