41 research outputs found

    Copper-Catalyzed Arylstannylation of Arynes in Sequence

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    Copper-catalyzed arylstannylation of arynes has been developed. This transformation enables variously substituted ortho-stannylbiaryls and teraryls to be constructed straightforwardly. An electron-deficient tin center is the key, and thus the single or dual insertion of arynes into arylstannanes is precisely controllable by simply changing the equivalence of aryne precursors.This work was financially supported by JSPS KAKENHI Grant Number JP17K05864

    Nickel-catalyzed [4 + 2] Cycloaddition of Styrenes with Arynes via 1:1 Cross-coupling : Synthesis of 9,10-Dihydrophenanthrenes

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    The [4 + 2] cycloaddition of styrenes with arynes was achieved via 1:1 cross-coupling by a nickel catalyst. This protocol applies to a variety of styrenes and arynes generated in situ from o-(trimethylsilyl)aryl triflates to afford 9,10-dihydrophenanthrenes involving substituted aromatic rings. By using this method, a naturally occurring stilbenoid is easily synthesized

    Germline pathogenic variants of 11 breast cancer genes in 7,051 Japanese patients and 11,241 controls

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    Pathogenic variants in highly penetrant genes are useful for the diagnosis, therapy, and surveillance for hereditary breast cancer. Large-scale studies are needed to inform future testing and variant classification processes in Japanese. We performed a case-control association study for variants in coding regions of 11 hereditary breast cancer genes in 7051 unselected breast cancer patients and 11,241 female controls of Japanese ancestry. Here, we identify 244 germline pathogenic variants. Pathogenic variants are found in 5.7% of patients, ranging from 15% in women diagnosed <40 years to 3.2% in patients ≥80 years, with BRCA1/2, explaining two-thirds of pathogenic variants identified at all ages. BRCA1/2, PALB2, and TP53 are significant causative genes. Patients with pathogenic variants in BRCA1/2 or PTEN have significantly younger age at diagnosis. In conclusion, BRCA1/2, PALB2, and TP53 are the major hereditary breast cancer genes, irrespective of age at diagnosis, in Japanese women

    Association of variations in HLA class II and other loci with susceptibility to EGFR-mutated lung adenocarcinoma

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    Lung adenocarcinoma driven by somatic EGFR mutations is more prevalent in East Asians (30-50%) than in European/Americans (10-20%). Here we investigate genetic factors underlying the risk of this disease by conducting a genome-wide association study, followed by two validation studies, in 3,173 Japanese patients with EGFR mutation-positive lung adenocarcinoma and 15,158 controls. Four loci, 5p15.33 (TERT), 6p21.3 (BTNL2), 3q28 (TP63) and 17q24.2 (BPTF), previously shown to be strongly associated with overall lung adenocarcinoma risk in East Asians, were re-discovered as loci associated with a higher susceptibility to EGFR mutation-positive lung adenocarcinoma. In addition, two additional loci, HLA class II at 6p21.32 (rs2179920; P =5.1 × 10(-17), per-allele OR=1.36) and 6p21.1 (FOXP4) (rs2495239; P=3.9 × 10(-9), per-allele OR=1.19) were newly identified as loci associated with EGFR mutation-positive lung adenocarcinoma. This study indicates that multiple genetic factors underlie the risk of lung adenocarcinomas with EGFR mutations

    Dicumyl Peroxide as a Methylating Reagent in the Ni-Catalyzed Methylation of Ortho C–H Bonds in Aromatic Amides

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    The direct methylation of ortho C–H bonds in aromatic amides with dicumyl peroxide (DCP) using a nickel complex as the catalyst is reported. The reaction shows a high functional group tolerance and is inhibited by radical scavengers. In reactions of meta-substituted aromatic amides, the reaction proceeds in a highly selective manner at the less hindered C–H bonds

    Effects of Quercetin on Mushroom Tyrosinase and B16-F10 Melanoma Cells

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    In searching for tyrosinase inhibitors from plants using L-3,4-dihydroxyphenylalanine (L-DOPA) as a substrate, quercetin was found to be partially oxidized to the corresponding o-quinone under catalysis by mushroom tyrosinase (EC 1.14.18.1). Simultaneously, L-DOPA was also oxidized to dopaquinone and both o-quinones were further oxidized, respectively. The remaining quercetin partially formed adducts with dopaquinone through a Michael type addition. In general, flavonols form adducts with dopaquinone as long as their 3-hydroxyl group is free. Quercetin enhanced melanin production per cell in cultured murine B16-F10 melanoma cells, but this effect may be due in part to melanocytotoxicity. The concentration leading to 50% viable cells lost was established as 20 μM and almost complete lethality was observed at 80 μM

    チリーにおける地殻熱流量測定

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    Results of terrestrial heat flow measurements in Chile, conducted in 1969, are presented. Data from eight metal mines and one oil-field were used. It was found that the sites in the Pacific coastal zone have lower than normal heat flow, whereas moderately high heat flow values were obtained at inland sites and in Isla Tierra del Fuego. Since the coverage of sites (Table I, and Fig. 1) is still poor, it is not possible to determine whether or not the heat flow distribution in Chile is similar to that often found in trench-arc-back arc areas such as Japan

    Genome-wide association study of pancreatic cancer in Japanese population.

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    Pancreatic cancer shows very poor prognosis and is the fifth leading cause of cancer death in Japan. Previous studies indicated some genetic factors contributing to the development and progression of pancreatic cancer; however, there are limited reports for common genetic variants to be associated with this disease, especially in the Asian population. We have conducted a genome-wide association study (GWAS) using 991 invasive pancreatic ductal adenocarcinoma cases and 5,209 controls, and identified three loci showing significant association (P-value<5x10(-7)) with susceptibility to pancreatic cancer. The SNPs that showed significant association carried estimated odds ratios of 1.29, 1.32, and 3.73 with 95% confidence intervals of 1.17-1.43, 1.19-1.47, and 2.24-6.21; P-value of 3.30x10(-7), 3.30x10(-7), and 4.41x10(-7); located on chromosomes 6p25.3, 12p11.21 and 7q36.2, respectively. These associated SNPs are located within linkage disequilibrium blocks containing genes that have been implicated some roles in the oncogenesis of pancreatic cancer
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