Radix Asteris (RA), also known as ‘Zi Wan’, is the dried root and rhizome of Aster tataricus L. f., which has been used to treat cough and asthma in many countries such as China, Japan, Korea and Vietnam. This article summarizes the available information on RA in ancient Chinese medicine books and modern research literature: its botanical properties, traditional uses, chemical composition, pharmacological activity, toxicity and quality control. Studies have shown that RA extracts contain terpenes, triterpenoid saponins, organic acids, peptides and flavonoids, and have various pharmacological activities such as anti-inflammatory, anti-tumor, anti-oxidation, and anti-depression. RA is considered to be a promising medicinal plant based on its traditional use, chemical constituents and pharmacological activities. However, there are few studies on its toxicity and the consistency of its components, which indicates the need for further in-depth studies on the toxicity and quality control of RA and its extracts.

Aminopeptidase N (APN) was closely associated with cancer invasion, metastasis, and angiogenesis. Therefore, APN inhibitors have attracted more and more attention of scientists as antitumor agents. In the current study, we designed, synthesized, and evaluated one new series of pyrazoline-based hydroxamate derivatives as APN inhibitors. Moreover, the structure–activity relationships of those were discussed in detail. 2,6-Dichloro substituted compound 14o with R₁ = CH₃, showed the best capacity for inhibiting APN with an IC₅₀ value of 0.0062 ± 0.0004 μM, which was three orders of magnitude better than that of the positive control bestatin. Compound 14o possessed both potent anti-proliferative activities against tumor cells and potent anti-angiogenic activity. At the same concentration of 50 μM, compound 14o exhibited much better capacity for inhibiting the micro-vessel growth relative to bestatin in the rat thoracic aorta ring model. Additionally, the putative interactions of 14o with the active site of APN are also discussed. The hydroxamate moiety chelated the zinc ion and formed four hydrogen bonds with His²⁹⁷, Glu²⁹⁸ and His³⁰¹. Meanwhile, the terminal phenyl group and another phenyl group of 14o interacted with S₂′ and S₁ pockets via hydrophobic effects, respectively.