Norsesquiterpenoids and triterpenoids from strawberry cv. Falandi.

Falandi is a common strawberry (Fragaria × ananassa Duch.) cultivar in southern China. Further study of the chemical constituents in Falandi fruit led to the isolation of nine norsesquiterpenoids and three triterpenoids. Falandioside D (1) and falandins A (2) and B (3) were new norsesquiterpenoids, and the others excluding tormentic acid (11) were found in strawberry for the first time. Compounds 1 and 11 exhibited potent α-glucosidase inhibitory activity with the half maximal inhibitory concentration (IC50) values of 565.0 and 27.4 μM in comparison to acarbose (619.9 μM). Compounds 3, 7 (blumenol C glucoside), and 11 showed cytotoxicity against human nasopharyngeal carcinoma cell line CNE1 with the IC50 values of 57.6, 56.4, and 36.0 μM, respectively. Among new compounds, 1 showed 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation scavenging capacity (IC50=36.2 μM). These results suggested that non-phenolic constituents were also involved in the antidiabetic, antitumour, and antioxidant effects of strawberry fruit.