Investigation into the content change and distribution of active components in Cordyceps sinensis with growth cycle by direct TOF-SIMS detection

Abstract

Analyzing the content of active components in Chinese medicines is crucial to evaluate their medicinal value and further promote the development of pharmaceutical technology. In this work, Cordyceps sinensis, a precious Chinese medicine, was characterized by time-of-flight secondary ion mass spectrometry (TOF-SIMS) to measure the content change of amino acids, nucleosides, mannitol and ergosterol with its growth cycle. Direct and sensitive detection of these active components in Cordyceps sinensis was realized by TOF-SIMS without tedious pretreatment process, such as repeated extraction and purification. Due to complex metabolic regulation, amino acids, nucleosides, mannitol and ergosterol showed different changing trends with growth cycle of Cordyceps sinensis. We found that the changing trend of the same active substance in different parts of Cordyceps sinensis varied dramatically. For instance, with the growth cycle of Cordyceps sinensis, the content of mannitol maintained steady growth in the stroma, while fell first and rose later in the worm body. In some growth stage, the content of mannitol in the worm body was about 10 times higher than that in the stroma. We provided a systematically analytical method and rich data base for further research of the extraction of active components and artificial cultivation of Cordyceps sinensis in this study. Meanwhile, TOF-SIMS is verified to be a sensitive, efficient and convenient method to characterize active components in traditional Chinese medicines.