Abstract:

In an effort to provide experimental evidences for quality control of bio-products from medicinal Cordyceps, a highthroughput method for the quantitative determination of mycelial mannitol and polysaccharide in Cordyceps mycelia using ultraviolet/visible spectrophotometry coupled with universal microplate reader was presented. In addition, the optimal extraction process of mannitol from dried Cordyceps mycelia was determined using orthogonal array design. Results showed that the analytical method developed had a good linearity and reproducibility with relative standard deviations (RSD) of 3.82% and 1.01% for detecting mannitol and polysaccharide, respectively. The spike recovery ratios of mannitol and polysaccharide were 99.03% and 100.99%, respectively. The optimal design for mannitol extraction from Cordyceps mycelia was that this material was extracted with 60-fold weight of ultrapure water at 40 ℃ twice for 1 h each time. A significant increase in detectable level of mannitol in fermented mycelia of Paecilomyces gunnii Liang, Metarhizium taii Liang et Liu and Penicillium jiangxiense Kong et Liang was obtained using the optimal extraction process, in which mannitol contents of 4.73%, 8.72% and 11.81% and polysaccharide contents of 11.29%, 11.61% and 11.52% were determined, respectively. These results demonstrate the advantage of the analytical method as a rapid and effective tool for high-throughput determination of mycelial mannitol and polysaccharide in medicinal Cordyceps and the promising potential of Penicillium jiangxiense Kong et Liang mycelia as a source of fungusderived mannitol.

Key words: Cordyceps, mannitol, polysaccharide, detection, extraction process