Two new dihydroflavonol triglycosides from the seeds of Camellia petelotii and their α-glucosidase inhibitory and anti-inflammatory activities

Two previously undescribed dihydroflavonol triglycosides, petelotiiosides A and B (1–2), together with two known flavonoid glycosides (3–4) and six known triterpenoid saponins (5–10), were isolated from the seeds of Camellia petelotii (Merr.) Sealy var. petelotii. Their structures were elucidated by HRMS, 1D and 2D NMR, and acid hydrolysis followed by HPLC analysis. Comparison of experimental and calculated electronic circular dichroism spectra established the absolute configurations of 1 and 2 as (2S,3R) and (2S,3S), respectively. Both compounds inhibited lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages, with IC50 values of 13.81 ± 1.73 and 13.48 ± 1.78 μM, respectively, without significant cytotoxicity over the tested concentration range. They also exhibited weak α-glucosidase inhibitory activity, with respective IC50 values of 7.0 ± 0.4 and 16.5 ± 0.7 mM, compared with 0.31 ± 0.08 mM for acarbose. These findings expand the phytochemical profile of C. petelotii seeds and identify two dihydroflavonol triglycosides with inhibitory effects on nitric oxide production in vitro.