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Operationally simple and generally applicable arene nitration with cheap and easily accessible chemicals has been a long-sought transformation in the synthetic organic community. In this work, we realized this goal with nontoxic and inexpensive Fe(NO3)3·9H2O as the nitro source and easily recyclable solvent hexafluoroisopropanol as the promotor via a network of hydrogen-bonding interactions. As a result of the relative mildness and high reliability of this protocol, late-stage nitration of various highly functionalized natural products and commercially available drugs was realized.
RESUMEN
Spider mites belonging to the genus Tetranychus infest many important agricultural crops in both fields and greenhouses worldwide and are diversified in their host plant range. How spider mites perceive their suitable host plants remains not completely clear. Here, through two-host-choice designs (bean vs. tomato, and bean vs. eggplant), we tested the efficacies of the olfactory and gustatory systems of five spider mite species (T. urticae, T. truncatus, T. pueraricola, T. piercei, and T. evansi), which differ in host plant range in sensing their suitable host plant, by Y-tube olfactometer and two-choice disc experiments. We found that spider mites cannot locate their suitable host plants by volatile odours from a long distance, but they can use olfactory sensation in combination with gustatory sensation to select suitable host plants at a short distance. Highly polyphagous species displayed strong sensitivity in sensing suitable host plants rather than the lowered sensitivity we expected. Intriguingly, our principal component analyses (PCAs) showed that the similarity among five spider mite species in the performance of perceiving suitable host plants was highly correlated with their relative phylogenetic relationships, suggesting a close relationship between the chemosensing system and the speciation of spider mites. Our results highlight the necessity of further work on the chemosensing system in relation to host plant range and speciation of spider mites.
RESUMEN
The plant root is an important storage organ that stores indole-3-acetic acid (IAA) from the apical meristem, as well as nitrogen, which is obtained from the external environment. IAA and nitrogen act as signaling molecules that promote root growth to obtain further resources. Fluctuations in the distribution of nitrogen in the soil environment induce plants to develop a set of strategies that effectively improve nitrogen use efficiency. Auxin integrates the information regarding the nitrate status inside and outside the plant body to reasonably distribute resources and sustainably construct the plant root system. In this review, we focus on the main factors involved in the process of nitrate- and auxin-mediated regulation of root structure to better understand how the root system integrates the internal and external information and how this information is utilized to modify the root system architecture.
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An efficient iodine-imine synergistic promoted Povarov-type multicomponent reaction was reported for the synthesis of a practical 2,2'-biquinoline scaffold. The tandem annulation has reconciled iodination, Kornblum oxidation, and Povarov aromatization, where the methyl group of the methyl azaarenes represents uniquely reactive input in the Povarov reaction. This method has broad substrate scope and mild conditions. Furthermore, these 2,2'-biquinoline derivatives had been directly used as bidentate ligands in metal-catalyzed reactions.
RESUMEN
Background and Purpose:Polygonum orientale L. (family: Polygonaceae), named Hongcao in China, is a Traditional Chinese Medicinal and has long been used for rheumatic arthralgia and rheumatoid arthritis. However, no pharmacological and mechanism study to confirm these clinic effects have been published. In this investigation, the anti-inflammatory, analgesic effects and representative active ingredient compounds of P. orientale have been studied. Methods: Dried small pieces of the stems and leaves of P. orientale were decocted with water and partitioned successively to obtain ethyl acetate and ethyl ether extract of P. orientale (POEa and POEe). Chemical compositions of them were analyzed by UPLC-Q-Exactive HRMS. Anti-inflammatory and analgesic effects of POEa and POEe were evaluated using xylene induced ear edema, carrageenan induced paw edema, Freunds' complete adjuvant induced arthritis, and formaldehyde induced pain in rat. Their mechanisms of anti-inflammatory and analgesic effects were also studied via assays of TNF-α, IL-1ß, IL-6, and PGE2 in serum. Results: UPLC-Q-Exactive HRMS analysis showed that POEa and POEe mainly contained flavonoids including orientin, isoorientin, vitexin, luteolin, and quercetin. Furthermore, anti-inflammatory effects of POEa and POEe were evident in xylene induced ear edema. The paw edema in Freund's complete adjuvant and carrageenan were significantly (P < 0.05, 0.01) inhibited by POEa (5, 7.5 g/kg). POEe (7.5 g/kg) was significantly (P < 0.05, 0.01) inhibited Freunds' complete adjuvant induced paw edema and cotton pellet induced granuloma formation. Similarly, POEe significantly (P < 0.05, 0.01) inhibited the pain sensation in acetic acid induced writhing test. POEa (5, 7.5 g/kg) significantly (P < 0.05, 0.01) inhibited formaldehyde induced pain in both phases. POEa (7.5 g/kg) markedly (P < 0.05) prolonged the latency period of hot plate test after 30 and 60 min. The concentrations of TNF-α, IL-1ß, IL-6, and PGE2 were significantly (P < 0.01) decreased by POEa (3.75, 5 g/kg). Conclusion: POEa and POEe have anti-inflammatory and analgesic effects, which was mainly relevant to the presence of flavonoids, including orientin, isoorientin, vitexin, luteolin, and quercetin. The mechanism of anti-inflammatory and analgesic effects of POEa may be to decrease the concentrations of TNF-α, IL-1ß, IL-6, and PGE2 in serum.
