Abstract
(1) Distribution of vitamin D_2 and ergosterol in the parts of shiitake (Lentinus edodes), pileus, stipe and gills, were investigated by the determination of the two compounds by HPLC methods. The results showed that the contents of vitamin D_2 (_<IU>/100g) and erogosterol (μg/g) were highest in gills followed by pileus and stipe. (2) Both vitamin D_2 and ergosterol in Shiitake were confirmed to exist mainly as free forms by HPLC methods. The weight ratios of free forms of vitamin D_2 and ergosterol to the respective total amounts were 100% and 98.3%, respectively. (3) In despite of our results mentioned above, Ono et al. (Eiyo to Shokuryo, 26, 547-550, 1973) reported that the weight ratio of ester form of ergosterol to total content in Shiitake was 35-45% by using thin-layer chromatography and Liebermann-Burchard color reaction. Therefore, we performed a supplementary examination according to the method of Ono et al. The results showed that most of ergosterol existed as a free form (98.5% of weight ratio to the total), which agreed with the our results mentioned above.
