Phytochemical investigation of Aesculus chinensis Bge. var. chekiangensis (Hu et Fang) Fang obtained 33 triterpenoid saponins, including 14 new ones, aesculiside C-P (1-14). The structure elucidations were performed through comprehensive MS, 1D and 2D-NMR analysis, and their absolute configuration was unambiguously determined by X-ray diffraction analysis as well as Mo 2 (OAc) 4-induced ECD method for the first time. All the substances were examined for their cytotoxic activities against three tumor cell lines, Hep G2, HCT-116, and MGC-803. Of these, compounds 8, 9, 14-16, 18, and 22 exhibited potent cytotoxicities against all cell lines with IC 50 of 2-21 µM, while compounds 3, 6, 7, 17-19, 20, 24, and 28 depicted moderate activity (IC 50 13 to >40 µM). On these bases, the preliminary structure-activity correlations were also discussed. Meanwhile the neuroprotective properties of triterpenoid saponins from Aesculus genus were evaluated for the first time. Among them, compounds 1, 4, 12, 20, 22, 25, 29, and 31 exhibited moderate activities against C O Cl 2-induced PC12 cell injury.

Three new phenylethanol glycosides (1-3) and one known analogue (4) were isolated from the seeds of Aesculus chinensis Bge. var. chekiangensis. To the best of our knowledge, this represents the first isolation of phenylethanol glycosides from the genus of Aesculus, which enriched its chemical composition. Structure elucidations were performed via extensive NMR and HRESIMS data together with comparison with literature data. Thereafter, the isolated compounds were assayed for their neuroprotective activities against CoCl 2 -induced cytotoxicity in PC12 cells and compound 3 exhibited moderate activity.