Choline chloride based natural deep eutectic solvents coupling with ultra-high performance liquid chromatography-tandem mass spectroscopy for effective extraction and rapid detection of adenosine and cordycepin in Cordyceps millitaris

Abstract

In this study, a series of choline chloride-based natural deep eutectic solvents (NADESs) was successfully fabricated and combined with ultra-high performance liquid chromatography-tandem mass spectroscopy (UHPLC-MS/MS) to detect adenosine and cordycepin in Cordyceps militaris. The analysis validation produced precise results with outstanding parameters for analysing extraction samples. In particular, NADESs with a choline chloride to citric acid ratio of 1:2 exhibited exceptional performance under ultrasound-assisted conditions. Using response surface methodology, we optimised the extraction process, obtaining high concentrations of adenosine (2.67 ± 0.05 mg/g) and cordycepin (3.73 ± 0.11 mg/g) from C. militaris. Compared to conventional methods, the NADES-based extraction proved more efficient, delivering elevated levels of target compounds by 36.5-fold for adenosine and 1.5-fold for cordycepin. Additionally, a mechanistic insight was offered by analysing post-extraction samples. The analytical approach was utilised to assess the adenosine and cordycepin content in various C. militaris samples available in the Vietnamese market. The detected values ranged from 1.73 ± 0.07 to 2.78 ± 0.11 mg/g for adenosine and from 2.87 ± 0.04 to 4.52 ± 0.14 mg/g for cordycepin. This analytical method holds promise for accurately evaluating adenosine and cordycepin in C. militaris.