OBJECTIVE: To preliminarily explore the mechanism of baicalin and berberine hydrochloride in inhibiting Acinetobacter baumannii（ A. baumannii） in vitro based on metabonomics

so as to provide new ideas for clinical medication. METHODS: The The metabolites were analyzed by liquid chromatography-mass spectrometry

and the neutral ion data of the extracellular metabolites of A. baumannii were subjected to principal component analysis（ PCA） with orthogonal partial least squares-discriminant analysis（ OPLS-DA）. Metlin database was used to determine the differential metabolites

combined with the literature and MetaboAnalyst online software

the metabolic pathway enrichment analysis of the differential metabolites was performed. RESULTS: Differential metabolites such as Lcysteine（ baicalin group） and uridine triphosphate（ berberine hydrochloride group） were preliminarily screened out.Compared with the control group

the content of L-cysteine in the baicalin group and the content of uridine triphosphate in the berberine hydrochloride group had significant changes

and the differences were statistically significant（ P <0. 05）. Metabolic pathway enrichment analysis showed that glutamate metabolism pathway and cysteine metabolism pathway were related to the mechanism of baicalin; pyrimidine metabolism pathway and amino sugar metabolism pathway were related to the mechanism of berberine hydrochloride. CONCLUSIONS: Baicalin may inhibit A.baumannii by regulating metabolic pathways such as glutamate and cysteine

while berberine hydrochloride may inhibit A. baumannii by regulating pathways such as pyrimidine metabolism and amino sugar metabolism.