A new chlorine-containing flavanol and four new phenylpropanoids from Toddalia asiatica

A rare chlorine-containing flavanol, chlorotoddalianone A (1), together with four new phenylpropanoids, toddaliaphenols A–D (2–5) and six known compounds (6–11) were obtained from the foliage and branches of Zanthoxylum asiaticum (L.) Appelhans, Groppo & J.Wen (syn. Toddalia asiatica (L.) Lam.). Their chemical structures and absolute configurations were elucidated through extensive spectroscopic analyses, including 1D and 2D NMR, HRESIMS and ECD calculation. Notably, compound 1 possesses an unusual structural framework, featuring a chlorinated 2,2-dimethylpyran unit linearly fused to the epicatechin A-ring. Biological evaluation of these isolates was conducted utilising an LPS-activated RAW 264.7 macrophage model to assess their impact on NO production. Compound 1 emerged as a moderate anti-inflammatory inhibitor (IC50 value = 20.96 ± 1.84 μM). Given its lack of evident cytotoxicity, chlorotoddalianone A represents a promising candidate for further anti-inflammatory research.