Recombination and amino acid point mutations in VP3 exhibit a synergistic effect on increased virulence of rMDPV.

Recombinant Muscovy duck parvovirus (rMDPV) is a product of genetic recombination between classical Muscovy duck parvovirus (MDPV) and goose parvovirus (GPV). The recombination event took place within a 1.1-kb DNA segment located in the middle of the VP3 gene, and a 187-bp sequence extending from the P9 promoter to the 5' initiation region of the Rep1 ORF. This resulted in the alteration of five amino acids within VP3. Despite these genetic changes, the precise influence of recombination and amino acid mutations on the pathogenicity of rMDPV remains ambiguous. In this study, based on the rMDPV strain ZW and the classical MDPV strain YY, three chimeric viruses (rZW-mP9, rZW-mPR187, and rYY-rVP3) and the five amino acid mutations-introduced mutants (rZW-g5aa and rYY-5aa(ZW)) were generated using reverse genetic technology. When compared to the parental virus rZW, rZW-g5aa exhibited a prolonged mean death time (MDT) and a decreased median lethal dose (ELD50) in embryonated duck eggs. In contrast, rYY-5aa(ZW) did not display significant differences in MDT and ELD50 compared to rYY. In 2-day-old Muscovy ducklings, infection with rZW-g5aa and rYY-5aa(ZW) resulted in mortality rates of only 20% and 10%, respectively, while infections with the three chimeric viruses (rZW-mP9, rZW-mPR187, rYY-rVP3) and rZW still led to 100% mortality. Notably, rYY-rVP3, containing the VP3 region from strain ZW, exhibited 50% mortality in 6-day-old Muscovy ducklings and demonstrated significant horizontal transmission. Collectively, our findings indicate that recombination and consequent amino acid changes in VP3 have a synergistic impact on the heightened virulence of rMDPV in Muscovy ducklings.

Highly Diastereo- and Enantioselective Synthesis of Chiral Cyclohexylphosphines by Cu-Catalyzed Phosphination-Aldol Cyclization of Ketone-Enamides.

A highly diastereo- and enantioselective phosphinative cyclization of ketone-enamides with secondary diarylphosphines enabled by copper catalysis is reported, providing a range of chiral tertiary cyclohexylphosphines bearing three contiguous stereogenic centers in high yields. This asymmetric phosphination-aldol cyclization protocol can also be extended to desymmetrization of dione-enamides to create four contiguous stereogenic centers in a highly selective manner.

α-Amino Radical-Mediated Difunctionalization of Alkenes with Polyhaloalkanes and N-Heteroarenes.

Herein, we report a mild and practical protocol for the α-perchloroalkyl ß-heteroarylation of alkenes using available chloroform as the dichloromethyl source via α-amino radical-mediated halogen-atom transfer. Various substrates are compatible under mild reaction conditions, providing the corresponding products in moderate to good yields. This strategy gives an efficient and convenient method for the introduction of chloroalkyl motifs into N-heteroarenes. The control experiment demonstrates that the α-amino radical generated in situ is a key intermediate in the transformation.

A Traceless Heterocyclic Amine Mediator in Regioselectivity-Switchable Formal [1 + 2 + 2] Cycloaddition Reaction to 1,3,4- and 1,4,5-Trisubstituted Pyrazoles.

Switchable multicomponent reactions have been attractive tools for the construction of compound libraries with skeleton diversity and complexity by slightly changing the reaction conditions. Described herein is a regioselectivity-switchable formal [1 + 2 + 2] cycloaddition reaction from difluoroalkyl compounds, enaminones, and RNHNH2, ultimately using 1-methylindazol-3-amine as a traceless mediator to switch the inherent regioselectivity of 1,3,4-trisubstituted pyrazole formation to 1,4,5-trisubstituted pyrazoles. Remarkable features of this work include mild conditions, simple operation, and broad scopes.

Organic acid catalysed Minisci-type arylation of heterocycles with aryl acyl peroxides.

A metal-free method for the Minisci-type arylation of heterocycles with aryl acyl peroxides has been reported. This strategy enables the rapid and simple synthesis of a series of Minisci-type adducts from commercially available starting materials without metal catalysts. A free-radical-pathway mechanism is suggested for this transformation.

Determination of glucosinolates in rapeseed meal and their degradation by myrosinase from rapeseed sprouts.

The utilization of rapeseed meal in food is limited due to its abundant glucosinolates (GLs). In this study, an LC-MS/MS method for GLs determination in rapeseed meal was developed. Then, the degradation of GLs using rapeseed sprouts derived myrosinase (MYR) was investigated. Results showed that 11 kinds of GLs were identified in rapeseed meal. The LC-MS/MS method had a high linearity (R2 greater than 0.9999), repeatability (RSD < 5%) and recovery rate (92%-102%). The optimum condition for hydrolyzing GLs in rapeseed meal was reacting for 4 h with the addition of 2236.35 U/g MYR, 9.63 µg/g ascorbic acid and 26.68 µg/g EDTA. Under this condition, more than 80% of GLs were degraded and the yields of isothiocyanates and oxazolidinone-2-thione were 859.30 µg/g and 685.59 µg/g, respectively. To conclude, this study reported a reliable method for GLs determination and an effective way to degrade GLs in rapeseed meal.

α-Functionalization of ketones promoted by sunlight and heterogeneous catalysis in the aqueous phase.

Herein, a protocol that combines heterogeneous catalysis and solar photocatalysis for the regioselective α-substitution of asymmetric ketones with quinoxalinones has been reported. The result indicates that the reaction is more likely to occur on the α-carbon. This strategy provides a green and efficient way for the α-functionalization of ketones. A singlet oxygen involved mechanism is suggested for the transformation.

Photoinduced Rapid Multicomponent Cascade Reaction of Aryldiazonium Salts with Unactivated Alkenes and TMSN3.

The first example of a photoinduced rapid multicomponent cascade reaction of aryldiazonium salts with unactivated alkenes and trimethylsilyl azide (TMSN3) under oxidant-free conditions is described. This approach provides the synthetic route for a wide range of unsymmetric azo compounds. The compounds are obtained in good to excellent yields under mild reaction conditions. This transformation is applicable to various aryldiazonium salts and alkenes, providing an alternative route for the synthesis of unsymmetric azo compounds. The control experiment demonstrates that the reaction mechanism follows a radical pathway.

Synthesis of (E)-Quinoxalinone Oximes through a Multicomponent Reaction under Mild Conditions.

Herein, a novel method for the gram-scale synthesis of (E)-quinoxalinone oximes through a multicomponent reaction under mild conditions is described. Such a transformation was performed under transition-metal-free conditions, affording (E)-oximes in a moderate-to-good yield through recrystallization. Our methodology demonstrates a successful combination of a Mannich-type reaction and radical coupling, providing a green and practical approach for the synthesis of potentially bioactive quinoxalinone-containing molecules.

Iron(III)-Mediated Rapid Radical-Type Three-Component Deuteration of Quinoxalinones With Olefins and NaBD4.

Iron(III)-promoted rapid three-component deuteration of quinoxalinones with olefins and NaBD4 is reported for the first time, which provides a novel, economic, and efficient method for the rapid synthesis of deuterated quinoxalinones. In this transformation, a radical pathway is involved according to the results of control experiments.

Synthesis of quinazoin-4-ones through an acid ion exchange resin mediated cascade reaction.

An interesting cascade reaction of N-(2-(4,5-dihydrooxazol-2-yl)phenyl)benzamide in the presence of an acid ion exchange resin is described. In this reaction, a range of substrates bearing various substituent groups are well compatible. This work provides a green and atom-economical alternative approach for the synthesis of quinazolin-4-ones in good yields.

The visible-light-triggered regioselective alkylation of quinoxalin-2(1H)-ones via decarboxylation coupling.

An efficient protocol to synthesize 3-alkylated quinoxalin-2(1H)-ones through photocatalytic decarboxylation coupling reactions of quinoxalin-2(1H)-ones with N-hydroxyphthalimide ester was developed. The control experiment showed that a radical was involved in this transformation. This approach provides an alternative way to obtain various valuable corresponding products in moderate-to-good yields.

Transition-Metal and Solvent-Free Oxidative C-H Fluoroalkoxylation of Quinoxalinones with Fluoroalkyl Alcohols.

The first example of oxidative C-H fluoroalkoxylation of quinoxalinones with fluoroalkyl alcohols under transition-metal and solvent-free conditions is described. This approach provides the synthesis of fluoroalkoxylated quinoxaline derivatives with good to excellent yields under mild reactions conditions. This method can also be extended to the facile and efficient synthesis of histamine-4 receptor.

[The clinical characteristics of primary intracranial germinoma].

OBJECTIVE: To analyse the clinical characteristics of intracranial germinoma. METHODS: Retrospective analysis was applied to study the clinical characteristics of 26 intracranial germ cell tumor patients admitted to our hospital during 1991-2003. The clinical, biochemical and imaging profiles including human chorionic gonadotropin-beta, alphafetoprotein, MRI and CT as well as treatments were analysed. RESULTS: 26 intracranial germ cell tumor patients were admitted to our hospital during 1991-2003, accounting for 0.9% of all intracranial tumors (3020 cases) at the same time. Among these patients 19 cases (73.1%) were primary intracranial germinoma, 9 patients (47.4%) were female and 10 patients (52.6%) were male. 13 patients (68.4%) were younger than 20 years. 14 patients (73.7%) had headache, vomiting and nausea, 8 patients (42.1%) had diabetes insipidus, 5 patients (26.3%) had hypopituitarism. 9 patients' tumors (47.3%) were in pine region, 7 patients' tumors (38.8%) were in sellar region. 14 patients (73.7%) were treated wit radiotherapy and all of them were discharged with good condition. 10 patients were treated with operation (7 patients accepted radiotherapy after operation) and 2 of them died after operation. CONCLUSIONS: Intracranial germinoma mainly affects female children and adolescents, pine and suprasellar regions are the commonly involved regions, the most common manifestations of intracranial germinoma are headache, vomiting, nausea, diabetes insipidus and hypopituitarism. Radiotherapy has good efficacy in the treatment of intracranial germinoma.