The fruit of Hippophae rhamnoides L. has been used for centuries in Europe and Asia as a food with high nutritional and medicinal values. In this study, a bioactivity-guided phytochemical investigation of H. rhamnoides L. has resulted in four new dimethylallylated flavonolignans (1–4), four new isopropylpentenone–flavonolignan heterodimers (5–8), two new geranylated flavonolignans (9 and 10), and 14 known flavonolignan derivatives (11–24); they were elucidated by their spectrometric and spectroscopic methods, including HR-ESI-MS, NMR, IR, and UV from the fruit of H. rhamnoides L. for the first time. Among them, compounds 2, 5, 6, 20, and 21 showed potent immunosuppressive activities with IC50 values from 19.42 ± 3.91 to 48.05 ± 12.56 μM. Meanwhile, compounds 1, 4, 11, 12, and 13 showed moderate neuroprotective activities, which increased the cell survival rate from 50.30 ± 4.24% for the model group to 71.63 ± 3.04%, 70.02 ± 4.13%, 61.53 ± 5.93%, 61.08 ± 3.58%, and 65.68 ± 4.88% at 10 μM, respectively. The hypothetical biogenetic pathway and preliminary structure–activity relationship were found and discussed scientifically.

Three new phenylpropanoid glycosides 1-3, along with nine known phenylpropanoid glycosides 4-12, were isolated from the aerial parts of Cirsium japonicum. The structures of isolated compounds were elucidated by chemical and spectroscopic methods. Compounds 1, 3, 6, 8, and 11 showed moderate cytotoxicities against MCF-7, U87, HCT116, and A549 cell lines with IC values in the range of 1.35-11.32 μM. The known compounds 4-12 were obtained from this plant for the first time.

In this work, nanomaterial was introduced into titrimetric analysis. Firstly, gold nanoparticles (AuNPs) with negative charges were prepared by reducing chloroauric acid with sodium citrate. Then, based on localized surface plasmon resonance of AuNPs, a novel Fajans method was designed to detect chloride ion using gold nanoparticles as the adsorption indicator to indicate the titration endpoint. The results showed that the method could accurately determine millimole chloride ion. Moreover, the gold and silver in waste liquid can be recycled through complexation reaction, precipitation reaction and redox reaction, which can reduce the cost and pollution. Through the practice of this experiment, students will study the frontier of the nanomaterial, and their interest in scientific research will be stimulated. Furthermore, the scientific research ability will be cultivated. Finally, the application of green chemistry is promoted in teaching.