Targeted Isolation of Anti-inflammatory Lignans from Justicia aequilabris by Molecular Networking Approach

Herein, the isolation of secondary metabolites from the aerial parts of Justicia aequilabris guided by HPLC-MS and molecular networking analyses is reported. Twenty-two known compounds were dereplicated. Three new lignans (aequilabrines A-C (1-3)) and three known compounds (lariciresinol-4'-O-β-glucose (4), roseoside (5), and allantoin (6)) were obtained. The anti-inflammatory activity of compounds 1-3 was evaluated in vitro by inhibiting the nitric oxide production (NO) and pro-inflammatory activity on the cytokine IL-1β. Compounds 2 and 3 showed significant inhibitory activity against NO production, with IC₅₀ values of 9.1 and 7.3 μM, respectively. The maximum inhibition of IL-1β production was 23.5% (1), 27.3% (2), and 32.5% (3).