Two new sulfur glycosides, bursapastoris A–B (3–4), were extracted and isolated from shepherd’s purse seed, along with two new natural products, 11-(methylsulfinyl)undecanoic acid (2) and 10-(methylsulfinyl)decanoic acid (1). Their structures were determined though infrared spectroscopy, one-dimensional nuclear magnetic resonance (¹H and ¹³C), and electrospray ionization mass spectrometry. Additionally, the structures of 3–4 were further identified by two-dimensional nuclear magnetic resonance (HMBC, HSQC, ¹H-¹H COSY, and NOESY). Compounds 1–4 showed relatively favorable docking to NF-κB. Unfortunately, we only discovered that compound 1–4 had weak anti-radiation activity at present. Therefore, further research regarding the biological activity of these organosulfur compounds is required at a later stage.

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 steroidals (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 the compounds and the 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 extractive fractions and the compounds 1-3, 8-10 and 13 had strong scavenging ability to free radical, and the reduction power of the extractive fractions and compounds 1-3, 8 and 10 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.