Comprehensive chemical and metabolic profiling of anti-hyperglycemic active fraction from Clerodendranthi Spicati Herba.

Extensive pharmacological research has demonstrated that Clerodendranthi Spicati Herba has an obvious anti-hyperglycemic effect via α-glucosidase inhibitory activity. However, the anti-hyperglycemic active fraction and its metabolic behavior in vivo have not been elaborated clearly. In this study, ultra-high-performance liquid chromatography coupled to quadrupole time of flight tandem mass spectrometry with data filtering strategy, including mass defect screening, diagnostic product ions and neutral loss identification, was established for chemical and metabolic profiling of anti-hyperglycemic active fraction from Clerodendranthi Spicati Herba. A total of 28 methoxylated flavonoids and 61 diterpenoids were rapidly identified. Four main known methoxylated flavonoids were purified and unambiguously identified by nuclear magnetic resonance analysis. Thirty-one absorbed diterpenoids, 12 absorbed methoxylated flavonoids, and 56 methoxylated flavonoids metabolites were identified in rat plasma, urine, bile, and feces after oral administration of anti-hyperglycemic active fraction. The methoxylated flavonoids were predominantly metabolized by demethylation, sulfation, and glucuronidation. Glucuronidation metabolites found in bile and urine after demethylation were dominant metabolites. Diterpenoids were absorbed into the blood mainly in the form of prototypes and excreted through bile and urine. These results indicated that methoxylated flavonoids and diterpenoids were responsible for α-glucosidase inhibitory activity, which might provide novel drug candidates for the management of diabetes mellitus.
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