Rapid identification, isolation, and evaluation on anti-neuroinflammatory activity of limonoids derivatives from the root bark of Dictamnus dasycarpus

•A total of 49 limonoids were rapidly identified by UNIFI software.•A new characteristic fragment ion, m/z 135.0803 ([C9H11O]+), of limonoids from Dictamnus dasycarpus was found.•A new compound, DAS, with a strong anti-neuroinflammatory activity through inhibiting NF-κB signaling pathways was obtained.•The structure-activity relationship between limonoids and their anti-neuroinflammatory was elucidated.