The major chemical constituents of <i>Penthorum chinense</i> Pursh and their inhibitory activity against enzymes associated with metabolic dysfunction-associated steatotic liver disease

Penthorum chinense Pursh, a plant of the genus Penthorum Gronov. ex L (Saxifragaceae), is the dried aerial part traditionally used by the Miao ethnic group in China to treat liver diseases. In the present study, an HPLC analytical method was first established to profile the chemical basis of P. chinense. Through targeted isolation and spectroscopic identification, 33 compounds were systematically obtained, including one novel compound (1). Comparison with isolated compounds, ten characteristic peaks were assigned in the HPLC chromatogram. Of these, the two most abundant (compounds 23 and 24) were characterised as tannins bearing hexahydroxydiphenoyl (HHDP) groups. In metabolic dysfunction-associated steatotic liver disease (MASLD)-related enzyme inhibition assays, compounds 1, 22, 23, and 24 demonstrated significant inhibitory effects on pancreatic lipase, yielding respective IC50 values of 13.1 ± 0.9, 11.4 ± 0.4, 17.4 ± 0.6, and 16.7 ± 0.7 μM. Notably, compounds 12, 22, 23, 24, and 27 displayed even stronger inhibition against α-glucosidase, with IC50 values of 14.0 ± 0.9, 16.1 ± 0.6, 0.43 ± 0.03, 0.45 ± 0.03, and 6.80 ± 0.14 μM, respectively. Specifically, the α-glucosidase inhibitory potency of compounds 23 and 24 surpassed that of acarbose, which was used as the positive control. Notably, tannins with HHDP groups possess relatively high content and better activity, which may suggest they are the major chemical constituents of P. chinense.