Chemical Composition of the Hazelnut Kernel ( L.) and Its Anti-inflammatory, Antimicrobial, and Antioxidant Activities.

The chemical composition of hazelnut kernels ( L.) and their COX-2 inhibitory, antimicrobial, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activities were investigated. Six previously undescribed indoleacetic acid glycosides, hazelnutins A-F (-), and five known compounds (-) were isolated from the hazelnut kernels. The structures of compounds - were successfully identified by high-resolution-electrospray ionization-mass spectrometry and NMR data, and their absolute configurations were established by electron-capture detector spectroscopy analyses in corporation with quantum chemical calculations. Furthermore, the absolute configurations of compounds and were unambiguously confirmed for the first time. Compounds - were discovered in hazelnut kernels for the first time. Compounds - inhibited COX-2 expression with inhibition rates ranging from 36.10 to 64.08%. Compounds , , and could inhibit the proliferation of . Compound exhibited potent antioxidant activity against ABTS and DPPH with IC values of 11.22 and 13.21 μmol/L, respectively. Compounds and exhibited moderate antioxidant activity against ABTS.