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RNA interference (RNAi) is a powerful tool that post‐transcriptionally silences target genes in eukaryotic cells. However, silencing efficacy varies greatly among different insect species. Recently, we met with little success when attempting to knock down genes in the mirid bug Apolygus lucorum via dsRNA injection. The disappearance of double‐stranded RNA (dsRNA) could be a potential factor that restricts RNAi efficiency. Here, we found that dsRNA can be degraded in midgut fluids, and a dsRNase of A. lucorum (AldsRNase) was identified and characterized. Sequence alignment indicated that its 6 key amino acid residues and the Mg2+‐binding site were similar to those of other insects' dsRNases. The signal peptide and endonuclease non‐specific domain shared high sequence identity with the brown‐winged green stinkbug Plautia stali dsRNase. AldsRNase showed high salivary gland and midgut expression and was continuously expressed through the whole life cycle, with peaks at the 4th instar ecdysis in the whole body. The purified AldsRNase protein obtained by heterologously expressed can rapidly degrade dsRNA. When comparing the substrate specificity of AldsRNase, 3 specific substrates (dsRNA, small interfering RNA, and dsDNA) were all degraded, and the most efficient degradation is dsRNA. Subsequently, immunofluorescence revealed that AldsRNase was expressed in the cytoplasm of midgut cells. Through cloning and functional study of AldsRNase, the enzyme activity and substrate specificity of the recombinant protein, as well as the subcellular localization of nuclease, the reason for the disappearance of dsRNA was explained, which was useful in improving RNAi efficiency in A. lucorum and related species. [ABSTRACT FROM AUTHOR]

Xanthohumol, a natural isoflavone from Humulus lupulus L., possesses biological activities. However, the biological fate of xanthohumol in vivo remains unclear. The aim of this study was to investigate the absorption and metabolism of xanthohumol in rats through UPLC‐MS/MS. The plasma, urine and fecal samples were collected after oral administration of xanthohumol (25, 50, 100 mg/kg) in SD rats. The contents of xanthohumol and its metabolites were determined by UPLC‐MS/MS. A total of 6 metabolites of xanthohumol were identified in rats, including methylated, glucuronidated, acid‐catalyzed cyclization and oxidation, indicating xanthohumol underwent phase I and II metabolism. Besides, isoxanthohumol was the major metabolites of xanthohumol. Xanthohumol was rapidly absorbed, metabolized, and eliminated in rats. The pharmacokinetics results showed the Tmax of xanthohumol and isoxanthohumol were 3 and 2.33 h, respectively. The AUC0−t of xanthohumol and isoxanthohumol were 138.83 ± 6.03 and 38.77 ± 4.46 ng/ml·h, respectively. Furthermore, xanthohumol was mainly excreted in the form of prototype through feces and a small amount of xanthohumol was excreted through urine. These results illustrated the absorption, metabolism, and pharmacokinetics process of xanthohumol in rats, and provided a reference for the further rational applications. [ABSTRACT FROM AUTHOR]

Our study aims to ascertain the antiinflammatory activity of Veronicastrum axillare and characterize the bioactive constituents. Antiinflammatory activity of the total extract and different fractions from V. axillare was investigated by employing the xylene-induced mouse ear edema model. As a result, the ethyl acetate (EtOAc) fraction showed the highest antiinflammatory activity in vivo. From the EtOAc fraction and the inactive dichloromethane fraction, a total of five new compounds, axillasides A-C and axillactones A and B, together with four known compounds, procumboside A, buergeriside C1, indole-3-carboxylic acid and apigenin, were isolated and identified. Their structures were elucidated on the basis of spectroscopic analysis and by comparison of their nuclear magnetic resonance data with those reported in the literature. Procumboside A, a major constituent in EtOAc fraction, showed significant antiinflammatory activity in vivo. Further studies revealed that procumboside A was a potent COX-2 inhibitor, significantly reducing the COX-2 protein level in lipopolysaccharide-stimulated RAW 264.7 macrophages. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the title compound, C14H26ClN5, the triazine ring is almost planar and both pendant alkyl chains are disordered; the site occupancy ratios are 0.5:0.5 for the tert-butyl chain and approximately 0.6:0.4 for the n-propyl chain. The crystal packing is consolidated by N—H...N hydrogen bonds, resulting in infinite chains propagating along [001]. [ABSTRACT FROM AUTHOR]

The title compound, C15H26ClN5O, was synthesized by the reaction of 2,4,6-trichloro-1,3,5-triazine with 2,4,4-trimethylpentan-2-amine and morpholine. The triazine ring is planar and the morpholine ring displays a typical chair conformation. Intermolecular N—H...O hydrogen bonding is present in the crystal structure. [ABSTRACT FROM AUTHOR]