Phytochemical Constituents from the Seeds of Capsella bursa-pastoris and Their Antioxidant Activities.

Phytochemical investigation of 70% EtOH extract of the seeds of Capsella bursa-pastoris led to the isolation of a new cyclobutane organic acid (1), and fourteen known compounds, including two organosulfur compounds (2, 3), two quinonoids (4, 5), five flavonoids (6-10), three sterols (11-13) and two other types (14, 15). The structures of the compounds were elucidated by extensive spectroscopic analyses as well as comparison of their spectroscopic data with those reported in the literature. The antioxidant capacities of all compounds and extractive fractions were evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging test and ferric reducing antioxidant power (FRAP) assay. Then the antioxidative substances were evaluated for their neuroprotective effects against H2O2-induced HT22 cell injury. The results indicated the strong scavenging ability to free radical of the extractive fractions and compounds 1-3, 8-10 and 13, and the ferric reducing antioxidant power of the extractive fractions and compounds 1-3, 8 and 10, which were close to or higher than that of the positive control trolox. The EtOAc fraction, n-BuOH fraction, and compounds 1, 3 and 8 can protect HT-22 cells from oxidative damage.

Alkaloids with neuroprotective effects from the leaves of Isatis indigotica collected in the Anhui Province, China.

Six undescribed alkaloids, indiforine A-F, together with four known ones, were isolated from the leaves of Isatis indigotica Fortune. Their structures were elucidated on the basis of extensive spectroscopic analyses. The absolute configurations of indiforine A and B were determined by comparison of the experimental and calculated electronic circular dichroism spectra, as well as experimental and calculated optical rotations. The isolated alkaloids were evaluated for their neuroprotective activities against H2O2-induced cell injury in human neuroblastoma SH-SY5Y cells. The results showed that in H2O2-induced SH-SY5Y cell injury models, indiforine A and B exhibited potent neuroprotective activities. Further investigation of the most potent indiforine A by Hoechst 33258 staining and Annexin V/PI analysis demonstrated that it could protect SH-SY5Y cells from oxidative damage through inhibiting cell apoptosis.

Antioxidant and anti-inflammatory neolignans from the seeds of hawthorn.

Seven new neolignans (1-2, 7-11) and five known compounds (3-6, 12) were isolated from the 70% EtOH extract of hawthorn seeds. Their structures were determined by spectroscopic analyses. The antioxidant and anti-inflammatory activities of all the isolates were investigated. Most of the isolates showed moderate radical scavenging activity in the DPPH assay and significant activities in the ABTS and FRAP assays. Furthermore, compounds 7-12 exhibited marked nitric oxide (NO) inhibition and compounds 1-4 had a potent necrosis factor-α (TNF-α) inhibitory effect. The results we obtained showed that hawthorn seeds can be regarded as a potential new and cheap source of antioxidants and inflammation inhibitors.