Figure 3.

Optimization of derivatization reagents and the reaction conditions. A, Representative reaction formula of 24-epiBL with DMAPBA. B, Chemical formulae of derivatization reagent candidates and their derivatization efficiency under different reaction conditions. Py, Pyridine. The time durations for all derivatization conditions were 1 h. The efficiency was measured on UPLC-ESI-QTOF MS in positive MS mode. The target m/z was extracted with the window of 0.02 Da, and the peak area was acquired to monitor the product yields. C, The effect of molar ratio of DMAPBA to 24-epiBL on the derivatization product yields. The reactions were performed in ACN at 40°C for 1 h. Error bars represent the sd (n = 3).