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Four sesquiterpenoids were isolated from an ethyl acetate-soluble fraction of A. princeps ethanolic extract: seco-tanapartholide B (5-epi-seco-tanapartholide A) (1), 4-epi-seco-tanapartholide A (2), 11,13-dehydrodesacetylmatricarin (3) and desacetylmatricarin (4). Compounds 1 − 3 dose-dependently inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophages. These compounds also decreased mRNA and protein expression levels of inducible NO synthase and cyclooxygenase-2 as well as mRNA levels of pro-inflammatory cytokines (interleukin-1β and tumour necrosis factor-α) in LPS-stimulated RAW 264.7 macrophages. Moreover, compound 3 effectively enhanced the expression of heme oxygenase-1 (HO-1) in macrophages in the presence or absence of LPS. Additionally, the exocyclic methylene of α-methylene-γ-lactone moiety of compound 3 was found to be essential for the activation of the NF erythroid 2-related factor 2 (Nrf2)/HO-1 pathway. Here, we firstly report the isolation of compounds 3 and 4 from A. princeps and the anti-inflammatory activity of compound 3 by up-regulation of Nrf2/HO-1 pathway.

Semiconductor heterostructure is a critical building block for modern semiconductor devices. However, forming semiconductor heterostructures of lattice-mismatch has been a great challenge for several decades. Epitaxial growth is infeasible to form abrupt heterostructures with large lattice-mismatch while mechanical-thermal bonding results in a high density of interface defects and therefore severely limits device applications. Here we show an ultra-thin oxide-interfaced approach for the successful formation of lattice-mismatched semiconductor heterostructures. Following the depiction of a theory on the role of interface oxide in forming the heterostructures, we describe experimental demonstrations of Ge/Si (diamond lattices), Si/GaAs (zinc blende lattice), GaAs/GaN (hexagon lattice), and Si/GaN heterostructures. Extraordinary electrical performances in terms of ideality factor, current on/off ratio, and reverse breakdown voltage are measured from p-n diodes fabricated from the four types of heterostructures, significantly outperforming diodes derived from other methods. Our demonstrations indicate the versatility of the ultra-thin-oxide-interface approach in forming lattice-mismatched heterostructures, open up a much larger possibility for material combinations for heterostructures, and pave the way toward broader applications in electronic and optoelectronic realms., 29 pages, 6 figures, 1 table. Supplementary Information not included