Abstract
Determination of ergosterol in Lentinus edodes was studied. After extraction of the fungus (ca. 1g) with petroleum ether and separation by TLC, ergosterol was colorimetrically determined as described below:
(1) A Kieselgel G (Merck) TLC using benzene/acetone/chloroform (10: 1: 1) as a developing system promoted fine separation of free and ester forms of ergosterol from other lipids. Their recoveries were 99.4±6.2% and 96.6±4.8%, respectively (Table 1).
(2) The colorimetry of ergosterol using a color reagent of sulfuric and acetic acid mixture (3: 1) was quite satisfactorily made in the range of 1 to 300μg. This reaction colored mixture was proved to be stable during 20 to 120minutes, and showed an absorption maximum at 472mμ (Fig. 1 and 2).
(3) In onder to clear the distribution of ergosterol in fungus, three main parts (pileus, stipe, and gills) were taken up and then the contents of ergosterol in them were individually determined. The results indicated that the free fonm was dominat than the ester form in all of these 3 parts. The contents of ergosterol in these 3 parts were 433, 524, and 633μg per 1g of fresh sample, respectively (Table 2 and 3).
