Enantioselective Synthesis of 2,3,3a,8a-Tetrahydrofuro[2,3-b]benzofuran Scaffolds Enabled by Cu(II)/SPDO-Catalyzed [3+2] Cycloaddition of 2,3-Dihydrofuran and Quinone Esters.

An asymmetric [3+2] cycloaddition of quinone esters with 2,3-dihydrofuran has been realized via a newly developed Cu(II)/SPDO complex. It provides straightforward access to 2,3,3a,8a-tetrahydrofuro[2,3-b]benzofurans (TFB) with high enantioselectivity (up to 97.5:2.5 er) and diastereoselectivity (all >20:1 dr). The resulting adducts contain two adjacent stereocenters and a continuously functionalized benzene ring. Additionally, this transformation could be easily performed on a gram scale, allowing for expedient synthesis of natural dihydroaflatoxin D2 and aflatoxin B2.

[Retraction Note: Association of Gene Polymorphisms in Wnt Signal Pathway with Tuberculosis in Chinese Tibetan Population.2016,47(6):920-925.]

This corrects the article DOI: 10.13464/j.scuxbyxb.2016.06.021.

[Methylation Chip Screening and Verification of Differential Genes Related to Tuberculosis Infection].

OBJECTIVE: To screen the genes with significant changes in DNA methylation level in active tuberculosis patients, we used the methylation chips and expanded the sample size to verify candidate genes. METHODS: ① This study enrolled 9 cases of active tuberculosis patients, 3 cases of latent tuberculosis patients and 3 cases of healthy controls whose age and gender were all matched. Genome DNA was extracted from peripheral blood mononuclear cell in blood samples collected from these candidates, and bisulfite conversion treatment was then conducted. After hybridization with the Illumina HD 450K Infinium Mehtylation BeadChip, the results were compared between patients group and control group, and GO and KEGG pathway analyses were performed to evaluate the function of differentially expressed genes. ② We further enrolled 60 cases of active tuberculosis patients and 60 cases of health controls (age-and gender-matched), DNA was extracted from their peripheral blood and also followed bisulfite conversion treatment. Pyrosequencing method was used to detect the methylation levels of candidate genes (IFNGR2, PTPN6, CRK1, ATP6V0B, WIF1, DKK1 and SFRP1) screened by gene chip. RESULTS: Compared with healthy controls, the fragments in the patients that showed low methylation change accounted for the vast majority. Most of the methylation differential fragments (DMRs) were located in the main body region, followed by the upstream region of transcription initiation site, and the lowest DMRs distribution area was 3´UTR area. GO and Pathway analysis showed that the functions of the differentially methylated regions related genes are mainly enriched in the biological processes of the regulation of leukocyte differentiation, apoptosis, cytokine regulation and inflammatory response which are closely related to tuberculosis. There were 32 CpG sites involved in the verified 7 tuberculosis related genes, and 16 CpG locus showed significant difference (P<0.05), they were distributed in 6 genes: PTPN6, WIF1, CRK1, SFRP1, DKK1 and IFNGR2.Of these genes with significant difference, PTPN6 genes showed hypermethylation status and WIF1, CRK1, SFRP1, DKK1 and IFNGR2 genes exhibited demethylation status in the patients group compared to the health controls. SFRP1 and CRK-1 mRNA up-regulated in the patients group compared with health controls. CONCLUSION: In the course of MTB infection, the methylation status of genomic DNA is altered, and most of the differentially methylated regions (DMRs) are showed status of demethylation. The expressions ofSFRP1and CRK-1gene up-regulate in tuberculosis infection.

[Methylation Analysis and Validation of Whole Genome DNA in Active Tuberculosis].

OBJECTIVE: To screen and identify the gene of DNA methylation in patients with active tuberculosis. METHODS: ① This study enrolled 9 cases of active tuberculosis patients (including 3 newly diagnosed tuberculosis patients and 6 cases of retreatment of active tuberculosis patients), 3 cases of latent tuberculosis patients and 3 cases of healthy controls. Genome DNA was extracted from Peripheral Blood Mononuclear Cell and following bisulfite conversion treatment. After hybridization with the Illumina HD 450K Infinium Mehtylation BeadChip, the results were compared between patients group and control group, GO and Pathway analysis were performed to evaluate the function of differentially expressed genes; ② We further enrolled 60 cases of active tuberculosis patients and 60 cases of health controls (their age and gender were matched). By using pyrosequencing method to detect the methylation levels of candidate genes (TLR1, TLR2, TLR4) screened by gene chip. RESULTS: ① Compared with healthy controls, we found that most of them were showed demethylation status. GO and Pathway analysis showed that the functions of the differentially methylated regions related genes were mainly enriched in the biological processes of the regulation of leukocyte apoptosis, cytokine regulation and inflammatory response which were closely related to tuberculosis. ②There were 10 CpG sites involved in the verified tuberculosis related genes (TLR1, TLR2, TLR4), the CpG sites of TLR1 gene showed the hypermethylation status (P<0.001), the CpG sites of TLR4 gene showed demethylation status (P=0.012). CONCLUSION: The present study demonstrated that in the course of MTB infection, the methylation status of genomic DNA was altered, and most of the Differentially Methylated Regions (DMRs) were showed status of demethylation. TLR1 gene and TLR4 gene may play an important role in the occurrence and development of tuberculosis.

[Gene Mutation Spectrum Analysis of 170 Patients with Duchenne/Bayesian Muscular Dystrophy in Southwest of China].

OBJECTIVE: To determine gene variations and genotype-phenotype correlations in Duchenne/Bayesian muscular mystrophy (DMD/BMD) patients, and the association between dystrophin gene polymorphisms and clinical phenotype. METHODS: Multiplex ligation-dependent probe amplification (MLPA) was adopted to detect dystrophin gene variations in 170 patients. Sanger sequencing was performed in 3 cases with decreased peaks in MLPA results. RESULTS: The MLPA detected 72.94% mutations in dystrophin gene, including 62.35% (106/170) deletions, 8.82% (15/170) duplications, and 1.76% (3/170) point mutations. 64 different types of mutations were found. 75.47% of deletions occurred in the range from exon 44 to 55. Most 5' breakpoints of exonic variations were located in 2 hotspots (major hotspot: intron 43-55; minor hotspot: intron 1-20), which is different from findings of other studies. Genotype-phenotype analysis showed that the severity of DMD/BMD was associated with frame shift mutation (r = 0.640, P < 0.001) but not with deletions or duplications. CONCLUSION: Deletions and duplications of exon compose the main type of dystrophin gene mutations. DMD/BMD is associated with frame shift mutation.

[Association of Gene Polymorphisms in Wnt Signal Pathway with Tuberculosis in Chinese Tibetan Population.]

OBJECTIVES: To determine the correlation between gene polymorphisms in Wnt signal pathway and susceptibility of Chinese Tibetan people to tuberculosis. METHODS: A total of 488 active tuberculosis patients and 454 healthy subjects(control) were enrolled in this case-control study.Five single nucleotide polymorphisms (SNPs) in Wnt signal pathway (rs4135385 in CTNNB1 gene,rs11001553 in DKK1 gene,rs56900803 in WIF1 gene,rs7832767 in SFRP1 gene and rs11079571 in AXIN2 gene) were genotyped using MassARRAY method.The genotype and allele distributions of these loci were determined using SPSS19.0 and SNP stats software.Significant SNPs were measured in the co-dominant,dominant and recessive genetic models.The polymorphism distributions of Chinese Tibetans were compared with those of Chinese Han populations. RESULTS: The genotype distributions of all SNPs coincided with the Hardy-Weinberg equilibrium in the 2 groups.The frequencies of genotype and allele of rs7832767 in SFRP1 gene were significantly different (P=0.004,0.002,respectively) between the Tibetan patients with tuberculosis and the Tibetan healthy controls.Compared with C allele carriers,those carrying T allele of rs7832767 showed increased risk of tuberculosis [odds ratio (OR)=1.260,95% confidence interval (CI):1.086-1.471,P=0.002].The co-dominant,dominant and recessive models of this locus were also associated with higher risk of tuberculosis.No significant differences in genotype and allele distributions were observed for the other four SNP loci (P all>0.05).The distribution of rs4135385 in CTNNB1 gene in the Chinese Tibetan population differed from the Han population (P=0.035 for genotype,0.021 for allele).There were no obvious differences in genotype and allele distributions for the other four SNPs between the Tibetan and Han populations (P all >0.05). CONCLUSIONS: SFRP1 gene polymorphism in Wnt signal pathway is associated with tuberculosis susceptibility in Chinese Tibetan population.The distribution of CTNNB1 gene polymorphism differs between Chinese Tibetan and Han populations.

[Microwave In-situ Regeneration of Cu-Mn-Ce/ZSM Catalyst Adsorbed Toluene and Distribution of Bed Temperature].

Microwave in-situ regeneration of Cu-Mn-Ce/ZSM catalyst adsorbed toluene, distribution of fixed bed temperature, adsorption breakthrough curves of the catalyst after several regenerations and characterizations of the catalyst by BET and SEM were investigated in this study. The research indicated that regeneration effect of the catalyst adsorbed was excellent under conditions of microwave power 117 W, air flow 0.5 m3 x h(-1) and catalyst dosage of 800 g. Toluene desorbed was oxidized onto the surface of the catalyst, and the adsorption capacity of the catalyst was recovered simultaneously. Under microwave irradiation, bed temperature decreased slowly from inside to outside in horizontal level, and increased gradually from down to up in vertical level so that the highest temperature reached 250-350 degrees C at the upper sites of the bed. Sintering and agglomeration occurred on the surface of the catalyst in the course of regeneration so that the special surface area and micropore volume of the catalyst were reduced and breakthrough time was shortened, which was verified by six adsorption breakthrough curves and related characteristics of the catalyst. However, the structure of the catalyst was steady after two regenerations, and adsorption breakthrough time was kept at 70 min. The result showed that the changes of surface morphology and pore structure were positively correlated with the distribution of bed temperature.

[Catalytic oxidation of two-component VOCs and kinetic analysis ].

Catalytic oxidations of two-component volatile organic compounds (VOCs) toluene and chlorobenzene were investigated under microwave heating and tube furnace heating, respectively, and reaction kinetics were analyzed in this paper. The research indicated that competitive adsorption between toluene and chlorobenzene reduced their removal efficiencies by 3% -12% as compared to single component. 'Hot spot effect' and 'non-thermal effect' under microwave irradiation obviously enhanced conversion efficiencies of VOCs, especially, the chlorobenzene removal was increased by 31% -38%. Moreover, reaction temperature and energy consumption were both reduced under microwave heating. The dynamic calculations showed that microwave heating decreased the activation energies by 2 146 J. mol-1 and 1 450 J mol-1 for toluene and chlorobenzene, respectively, as compared with tube furnace heating. Meanwhile, microwave heating enhanced the reaction rate constants of chlorobenzene and toluene to about 35 times and 6 times of that of tube furnace heating.