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A new palladium-catalyzed three-component coupling involving acylation/alkenylation of aryl iodide is reported. The reaction was carried out with readily available starting materials and gave the ortho-acylated styrene in moderate to good yields. Compared with previous Catellani–Lautens reactions, this reaction is the first example of introducing an acyl group at the ortho position of aryl iodides. The proposed PdIV complex, generated via oxidative addition of the carboxylic anhydrides, is a key intermediate for this transformation.

The proteins in the food are the source of common allergic components to certain patients. Current lists of plant endogenous allergens were based on the medical/clinical reports as well as laboratory results. Plant genome sequences made it possible to predict and characterize the genome-wide of putative endogenous allergens in rice (Oryza sativa L.). In this work, we identified and characterized 122 candidate rice allergens including the 22 allergens in present databases. Conserved domain analysis also revealed 37 domains among rice allergens including one novel domain (histidine kinase-, DNA gyrase B-, and HSP90-like ATPase, PF13589) adding to the allergen protein database. Phylogenetic analysis of the allergens revealed the diversity among the Prolamin superfamily and DnaK protein family, respectively. Additionally, some allergens proteins clustered on the rice chromosome might suggest the molecular function during the evolution.

Without extra addition of sulfinate salt, allylic sulfones were synthesized by palladium-catalyzed cross-coupling of aryl iodide with N-tosylhydrazone. In this transformation, not only the diazo compound but also the sulfinate salt, which were both generated in situ from base-mediated decomposition of the N-tosylhydrazone, was used as nucleophilic partner.

Beet armyworm, Spodoptera exigua, is a major pest of cotton around the world. With the increase of resistance to Bacillus thuringiensis (Bt) toxin in transgenic cotton plants, there is a need to develop an alternative control approach that can be used in combination with Bt transgenic crops as part of resistance management strategies. MicroRNAs (miRNAs), a non-coding small RNA family (18-25 nt), play crucial roles in various biological processes and over-expression of miRNAs has been shown to interfere with the normal development of insects. In this study, we identified 127 conserved miRNAs in S. exigua by using small RNA deep sequencing technology. From this, we tested the effects of 11 miRNAs on larval development. We found three miRNAs, Sex-miR-10-1a, Sex-miR-4924, and Sex-miR-9, to be differentially expressed during larval stages of S. exigua. Oral feeding experiments using synthetic miRNA mimics of Sex-miR-10-1a, Sex-miR-4924, and Sex-miR-9 resulted in suppressed growth of S. exigua and mortality. Over-expression of Sex-miR-4924 caused a significant reduction in the expression level of chitinase 1 and caused abortive molting in the insects. Therefore, we demonstrated a novel approach of using miRNA mimics to control S. exigua development.

BACKGROUND: MicroRNAs (miRNAs) are considered to be very important in regulating the growth, development, behavior and stress response in animals and plants in post-transcriptional gene regulation. Pinewood nematode, Bursaphelenchus xylophilus, is an important invasive plant parasitic nematode in Asia. To have a comprehensive knowledge about miRNAs of the nematode is necessary for further in-depth study on roles of miRNAs in the ecological adaptation of the invasive species. METHODS AND FINDINGS: Five small RNA libraries were constructed and sequenced by Illumina/Solexa deep-sequencing technology. A total of 810 miRNA candidates (49 conserved and 761 novel) were predicted by a computational pipeline, of which 57 miRNAs (20 conserved and 37 novel) encoded by 53 miRNA precursors were identified by experimental methods. Ten novel miRNAs were considered to be species-specific miRNAs of B. xylophilus. Comparison of expression profiles of miRNAs in the five small RNA libraries showed that many miRNAs exhibited obviously different expression levels in the third-stage dispersal juvenile and at a cold-stressed status. Most of the miRNAs exhibited obviously down-regulated expression in the dispersal stage. But differences among the three geographic libraries were not prominent. A total of 979 genes were predicted to be targets of these authentic miRNAs. Among them, seven heat shock protein genes were targeted by 14 miRNAs, and six FMRFamide-like neuropeptides genes were targeted by 17 miRNAs. A real-time quantitative polymerase chain reaction was used to quantify the mRNA expression levels of target genes. CONCLUSIONS: Basing on the fact that a negative correlation existed between the expression profiles of miRNAs and the mRNA expression profiles of their target genes (hsp, flp) by comparing those of the nematodes at a cold stressed status and a normal status, we suggested that miRNAs might participate in ecological adaptation and behavior regulation of the nematode. This is the first description of miRNAs in plant parasitic nematodes. The results provide a useful resource for further in-depth study on molecular regulation and evolution of miRNAs in plant parasitic nematodes.