Besides, the in-house databases for known and predicted C19- and C20-diterpenoid alkaloids were established by molecular design in Compound Discoverer software for MS data matching and filtering, and two MDF windows were further constructed to screen out more potential diterpenoid alkaloids with novel structures and to obtain the PIL (mass range: even values between 298 and 1020 Da, parent mass width: ±100 mDa) for data acquisition by calculating the m/z values of potential ions using mass range and corresponding mass defect in the MDF windows. 
Compound Discoverer
Besides, the in-house databases for known and predicted C19- and C20-diterpenoid alkaloids were established by molecular design in Compound Discoverer software for MS data matching and filtering, and two MDF windows were further constructed to screen out more potential diterpenoid alkaloids with novel structures and to obtain the PIL (mass range: even values between 298 and 1020 Da, parent mass width: ±100 mDa) for data acquisition by calculating the m/z values of potential ions using mass range and corresponding mass defect in the MDF windows. 
MS data matching and filtering