Abstract:The anti-inflammatory active ingredients of rosemary have been reported in many literatures, including carnosic acid, carnosol and ursolic acid. However, the rosemary ethanol extract still showed good anti-inflammatory activity after removal of the above three large-content components, suggesting that there were undiscovered anti-inflammatory ingredients in rosemary in addition to the reported active ingredients. Under the guidance of inhibiting the anti-inflammatory activity of NLRP3 inflammasome in vitro, three flavonoids were isolated and identified from the above-mentioned anti-inflammatory components by various chromatographic techniques and spectroscopy methods including 4′,5-dihydroxy-7-methoxyflavone (1), 5-dydroxy-7, 4′-dimethoxy flavone (2) and 5-hydroxy-7, 8, 4′-trimethoxyflavone (3). The three isolated compounds were confirmed to possess inhibitory effect on NLRP3 inflammasome in vitro. Among them, compound 1 had the strongest inhibitory activity, comparable to the positive control MCC950 (inflammatory inhibitor). Compound 3 was isolated from Rosmarinus for the first time.
