液体发酵蛹虫草中虫草素含量分布的研究

研究蛹虫草在5种不同培养基中经液体发酵后菌丝体和发酵液中虫草素占总虫草素含量的分布情况，建立一种高效液相色谱法测定虫草素的含量的方法。色谱柱为Welch Ultimate XB-C18（4.6 mm×250 mm，5 μm）；流动相：水-甲醇（85∶15，V/V）；流速：1 mL/min；检测波长：260 nm；虫草素在0.312 5～20 μg/mL线性关系良好（R=0.999 7），加标回收试验中发酵液和菌丝体中虫草素的平均回收率分别是99.5%、99.2%，相对标准偏差（RSD）分别为1.081%、1.086%，稳定性和精密度试验检测结果的RSD分别为2.68%和1.9%。表明该方法的准确性、精密度及稳定性良好。结果表明，液体发酵培养蛹虫草时，发酵液与菌丝体中虫草素的质量比约为97:3，改变培养基的种类不会影响总虫草素在发酵液与菌丝体中的分配比。

Research on the content distribution of cordycepin in Cordyceps militaris by liquid fermentation

Cordyceps militaris was cultured in five different culture media. After liquid fermentation, the distributed situation of cordycepin in the mycelium and fermented liquid was researched. A determination method of cordycepin content was established by HPLC. The method was conducted with Welch Ultimate XB-C18 (4.6 mm×250 mm, 5 μm) as chromatographic column, mobile phase water-methanol (85∶15, V/V), flow rate 1 ml/min, detection wavelength 260 nm. The cordycepin had a good linear relationship in the range of 0.312 5-20 μg/ml (R=0.999 7). In the standard recovery rate tests, the average recovery rate of cordycepin in the fermented liquid and mycelium were 99.5% and 99.2%, respectively. Relative standard deviation (RSD) was 1.081% and 1.086%, respectively. RSD of stability and precision experiments were 2.68% and 1.9%, respectively, which indicated that the method had good accuracy, precision and stability. The results showed that when the C. militaris was cultured in liquid fermentation medium, the mass ratio of cordycepin in the fermented liquid and mycelium was about 97:3. The changes of culture medium types had no effect on the distribution ratio of total cordycepin in the fermented liquid and mycelium.