Studies On The Chemical Constituents And Activities Of Diaphragma Juglandis Fructus

Diaphragma juglandis Fructus, the wooden diaphragma of the kernel of Juglans regia L., has long been used to strengthen the kidney to stop nocturnal emission. D. juglandis Fructus are widely distributed in China. The chemical constituents of it include flavonoids, phenolic acid, quinones, et al. Pharmacological activities study showed that D. juglandis Fructus has antibacterial and antioxidant activity. Up to now, there are few reports on D. juglandis Fructus. This research aims to study the chemical components of D. juglandis Fructus and the pharmacological activities of the isolated compounds, which provided useful information for the development and utilization of this plant in the future.Objectives To study the chemical constituents of D. juglandis Fructus and pharmacological activities of the isolated compounds.Methods The chemical constituents were isolated from D. juglandis Fructus by silica gel column chromatography(CC), sephadex LH-20 CC, ODS CC, re-crystallization and pre-HPLC. Their structures were identified on the basis of physical properties, chemical evidences and spectroscopic analyses including MS, NMR, UV and IR. DPPH radical scavenging capacity and xanthine oxidase inhibitory activity were evaluated for the isolated compounds.Results A phytochemical investigation on the ethanol extract of D. juglandis Fructus resulted in the isolation of seventeen compounds. Their structures were established as taxifolin-3-O-?-D-arabinofuranoside(1), taxifolin-3-O-?-L-arabinofuranoside(2), quercitrin(3), quercetin-3-O-(6??-O-galloyl)-?-D-galactopyranoside(4), quercetin-3-O-(4??-O-acetyl)-?-L-rhamnopyranoside(5), naringenin(6), taxifolin(7), catechin(8), protocatechuic acid(9), vanillin(10), gallic acid(11), progallin A(12), juglanin A(13), dihydrovomifoliol-O-β-D-glucopyranoside(14), juglanin D(15), β-sitosterol(16) and daucosterol(17). Pharmacological experiments showed that compounds 3, 5-9, 11 and 12 had DPPH free radical clearing activity and compounds 3-6, 11 and 12 exhibited xanthine oxidase inhibitory activity.Conclusion Seventeen compounds were isolated from D. juglandis Fructus. Among them, compounds 1 was a new compounds, compounds 2-6, 9-10, 13, 14 and 17 were isolated from the plant for the first time. Among them, some compounds exhibited antioxidant activity and xanthine oxidase inhibitory activity.