Scavenging and reclaiming phosphines associated with group 10 metal-mediated couplings

[reaction: see text] Exposure of any of several mono- or bidentate phosphines to CuCl leads to quick removal of unwanted ligands from solution. Most phosphines, if desired, can be easily recovered.     

A promotor polymorphism in the Interleukin 11 gene is associated with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a multifactorial disorder characterized by irreversible airflow obstruction due to chronic inflammation. Hence, the gene encoding the anti-inflammatory cytokine IL 11 is a good candidate for being involved in the genetic predisposition to COPD. In order to evaluate the role of the Interleukin 11 (IL 11) gene in the genetic predisposition for COPD, a dinucleotide microsatellite polymorphism in the promoter region has been genotyped in 153 patients with COPD (including 25 non-smokers) and 463 healthy controls. Frequencies of the IL 11.A2 microsatellite allele and of IL 11.A2 homozygous individuals were significantly decreased among the patients with COPD (p < 0.012 and p < 0.022, respectively) as compared to controls. Both frequencies were even more drastically reduced among the nonsmoking patients. Tight linkage of this microsatellite allele with another polymorphism in the promotor region was established. Altered expression of IL 11 may be involved in the genetic predisposition to COPD.     

13C NMR investigation of solid-state polymorphism in 10-deacetyl baccatin III

To investigate the origins of solid-state NMR shift differences in polymorphs, carbon NMR chemical shift tensors are measured for two forms of solid 10-deacetyl baccatin III: a dimethyl sulfoxide (DMSO) solvate and an unsolvated form. A comparison of ab initio computed tensors that includes and omits the DMSO molecules demonstrates that lattice interactions cannot fully account for the shift differences in the two forms. Instead, conformational differences in the cyclohexenyl, benzoyl, and acetyl moieties are postulated to create the differences observed. X-ray analysis of six baccatin III analogues supports the suggested changes in the cyclohexenyl and benzoyl systems. The close statistical match of the (13)C chemical shifts of both polymorphic forms with those calculated using the X-ray geometry of 10-deacetyl baccatin III supports the contention that the B, C, and D rings are fairly rigid. Therefore, the observed tensor differences appear to arise primarily from conformational variations in ring substituents and the cyclohexenyl ring.     

薄层荧光扫描法测定喜树果中喜树碱及10-羟基喜树碱

建立了薄层荧光扫描法测定中药喜树果中喜树碱和10-羟基喜树碱的方法.以无水甲醇为溶剂从喜树果样品中提取喜树碱和10-羟基喜树碱.在硅胶H板上以氯仿∶丙酮(7∶3)为展开剂可使喜树碱与10-羟基喜树碱很好地分离.以荧光激发波长350 nm线性扫描进行定量分析.在0.010 5～0.063 0μg范围内,喜树碱的积分荧光强度A与其质量m呈线性,相关系数为0.998,加标回收率为99％.在0.003 3 ～0.033 0 μg范围内,10-羟基喜树碱的积分荧光强度与质量呈线性,相关系数为0.999,加标回收率为96％.该方法简便,重复性好.以此方法测得喜树果样品中喜树碱和10-羟基喜树碱的含量分别为0.122％和0.013％.     

Common variants at the promoter region of the APOM confer a risk of rheumatoid arthritis

Although the genetic component in the etiology of rheumatoid arthritis (RA) has been consistently suggested, many novel genetic loci remain to uncover. To identify RA risk loci, we performed a genome-wide association study (GWAS) with 100 RA cases and 600 controls using Affymetrix SNP array 5.0. The candidate risk locus (APOM gene) was re-sequenced to discover novel promoter and coding variants in a group of the subjects. Replication was performed with the independent case-control set comprising of 578 RAs and 711 controls. Through GWAS, we identified a novel SNP associated with RA at the APOM gene in the MHC class III region on 6p21.33 (rs805297, odds ratio (OR) = 2.28, P = 5.20 × 10-7). Three more polymorphisms were identified at the promoter region of the APOM by the re-sequencing. For the replication, we genotyped the four SNP loci in the independent case-control set. The association of rs805297 identified by GWAS was successfully replicated (OR = 1.40, P = 6.65 × 10-5). The association became more significant in the combined analysis of discovery and replication sets (OR = 1.56, P = 2.73 × 10-10). The individuals with the rs805297 risk allele (A) at the promoter region showed a significantly lower level of APOM expression compared with those with the protective allele (C) homozygote. In the logistic regressions by the phenotype status, the homozygote risk genotype (A/A) consistently showed higher ORs than the heterozygote one (A/C) for the phenotype-positive RAs. These results indicate that APOM promoter polymorphisms are significantly associated with the susceptibility to RA.     

A delicate balance of energetics. Subtleties associated with alpha-ketol-based bridge migration to afford 9-keto-10beta-p-methoxybenzyloxytaxanes

The feasibility of the title reaction has been pursued for the purpose of advancing a concise total synthesis of Taxol. Of the two closely related series examined, the first featured an exo-methylene group at C4. The second consisted of an alpha-epoxide at that site. Strikingly, the olefinic construct proved inert to attempted alpha-ketol rearrangement. In contrast, the oxiranyl derivative isomerized smoothly. The reaction sequence associated with arrival at taxane 18 is short (15 steps from a D-camphor derivative) and notably efficient. The thermodynamic issues that are raised by this investigation have been clarified by an assessment of molecular mechanics-derived (MM3) steric energy calculations.     

Obesity and genetic polymorphism of ERCC2 and ERCC4 as modifiers of risk of breast cancer

To evaluate the relationship of genetic polymorphisms of ERCC2 and ERCC4 genes, both involved in nucleotide excision repair (NER), and the risk of breast cancer, a hospital-based case-control study was conducted in Korea. Histologically confirmed breast cancer cases (n = 574) and controls (n = 502) with no present or previous history of cancer were recruited from three teaching hospitals in Seoul during 1995-2001. Information on selected characteristics was collected by interviewed questionnaire. ERCC2 Asp(312)Asn (G>A) was genotyped by single-base extension assay and ERCC4 Ser(835)Ser (T>C) by dynamic allele-specific hybridization system. Although no significant association was observed between the genetic polymorphisms and the risk of breast cancer, women with both ERCC2 A allele- and ERCC4 C allele-containing genotypes showed a 2.6-fold risk (95% CI: 1.02-6.48) of breast cancer compared to women concurrently carrying the ERCC2 GG and ERCC4 TT genotypes. The breast cancer risk increased as the number of "at risk" genotypes increased with a borderline significance (P for trend = 0.07). Interactive effect was also observed between ERCC4 genotype and body mass idnex (BMI) for the breast cancer risk; the ERCC4 C allele containing genotypes posed a 1.7-fold (95% CI: 0.96-2.93) breast cancer risk in obese women (BMI>25 kg/m(2)) with a borderline significance. Our finding suggests that the combined effect of ERCC2 Asp(312)Asn and ERCC4 Ser(835)Ser genotypes might be associated with breast cancer risk in Korean women.     

Reaction of a diaryldigermyne with ethylene

Reaction of the stable digermyne BbtGeGeBbt (Bbt = 2,6-[CH(SiMe₃)₂]₂-4-[C(SiMe₃)₃]-C₆H₂) with ethylene initially afforded the corresponding 1,2-digermacyclobutene. Depending on the reaction conditions applied, further reaction of this 1,2-digermacyclobutene with ethylene furnished two different reaction products: a 1,4-digermabicyclo[2.2.0]hexane or a bis(germiranyl)ethane. Combined experimental and theoretical results suggested that the 1,4-digermabicyclo[2.2.0]hexane and the bis(germiranyl)ethane are the thermodynamic and kinetic reaction products, respectively. A reaction mechanism in agreement with these results was proposed.     

Copolymerization of(10-oxo-10-hydro-9-oxa-10λ~5-phospha-phenanthrene-10-yl)-methyl acrylate with styrene

A phosphorus-containing monomer(10-oxo-10-hydro-9-oxa-10λ~5-phosphaphenanthrene-10-yl)-methyl acrylate(M_1) was copolymerized with styrene to give a potential flame retardant copolymer of high thermal stability.The structures of monomer and copolymer were characterized by FT-IR and ~1H NMR measurements.The reactivity ratios for free-radical of the monomer(M_1) and styrene(M_2) were studied.The calculated results are as follows:r_1=0.225,r_2=0.503;Q_1=0.413,e_1= 0.476;azeotropic point = 0.37.TGA and DTG c...     

Copper-catalyzed diamination of unactivated alkenes with hydroxylamines

A copper-catalyzed regio- and stereoselective diamination of unactivated alkenes has been developed with O-acylhydroxylamines as electrophilic nitrogen sources and oxidants. This method provides the first example of metal-catalyzed alkene diamination for directly installing an electron-rich amino group and extends the diamination scope for the synthesis of diverse 1,2-diamines. It offers a rapid and efficient approach to construct a wide range of 1,2-diamines that are an important structural motif in organic synthesis, medicines, catalysts and ligands.     

用左手手势巧学常见单糖的结构式*

分享了一种巧用左手手势,结合一首五言口诀快速判断糖分子结构的方法。口诀为:“罗卓葡古塔,甘露艾半乳。核阿木来苏,酮糖果山古”,包含了常见的12种醛糖和6种酮糖。通过该方法,不仅能快速准确写出各种常见糖的Fischer投影式,而且还可应用于糖分子相应的Haworth透视式及椅式构象,值得在糖类教学中进行推广。     

Interaction of closo-decaborate anion B10H 10 2− with iminium salts

The interaction of closo-decaborate anions with iminium salts, either formed in situ or introduced into the reaction as individual compounds, has been studied. The reaction leads to products with an exopolyhedral boron-nitrogen bond. The formation of compounds with exopolyhedral boron-chlorine and boron-carbon bonds is also possible. The crystal structures of [NMe₂(CH₂Cl)]₂B₁₀H₈ and 3-CH₃-2,8-[NMe₂(CH₂Cl)]₂-7-ClB₁₀H₆ have been studied.     

The association between the CASP5 rs7939842 polymorphism and the risk of rheumatoid arthritis in Chinese Han individuals

BackgroundThe association between inflammatory cysteinyl aspartate protease-5 (CASP5) and the susceptibility to rheumatoid arthritis (RA) remains unclear. This study examined whether the CASP5 rs7939842 polymorphism affects RA risk in Chinese Han individuals.MethodsThis study recruited 805 RA patients and 1095 healthy controls to investigate the association between the CASP5 rs7939842 polymorphism and RA risk. Genotype was examined using the 48-Plex SNPscan? Kit. Plasma CASP5 levels were determined using enzyme-linked immunosorbent assays, and CASP5 gene expression was detected by quantitative polymerase chain reaction in 40 RA patients and 40 healthy controls.ResultThe CASP5 rs7939842 polymorphism G allele is a putative risk factor for RA. After stratified analyses, this polymorphism increased the risk of RA among CRP-, ACPA-, RF-, and ESR-positive individuals, as well as individuals with DAS28 ≥ 3.20 and functional class III + IV. Furthermore, the plasma CASP5 levels and CASP5 mRNA expression were higher in RA patients than in healthy controls.ConclusionThe CASP5 rs7939842 polymorphism appears to be associated with an elevated risk of RA in Chinese Han individuals. Blood CASP5 protein and mRNA levels were significantly higher in RA patients than in healthy controls.     

Reactions of 10-telluroniaanthracene perchlorates with nucleophiles

10-Telluroniaanthracene perchlorates react with nucleophiles (X^–=halide, hydroxide, methoxide) via intermediate free telluroxanthyl radicals. With 9-aryl-10-telluroniaanthracene perchlorates, high yields of 9-aryl-9-X-telluroxanthenes are obtained, but with 10-telluroniaanthracene the principal product is 9,9-bis(telluroxathenyl) as a result of rapid competitive dimerization.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 691–695, May, 1989.     

10-苯基-吖啶酮测定核酸的荧光分析新体系研究

10-苯基-吖啶酮（PACR）是吖啶类强荧光物质,在pH6．5的Tds-HCl的缓冲介质中,在258nm的紫外光激发下,于420nm处有很强的荧光发射。核酸的加入,可以使得体系荧光在峰位基本不变的情况下,发生荧光猝灭。其荧光猝灭程度与小牛胸腺DNA在0．1～3．0mg／L范围内呈良好的线性关系,检出限可达0．044mg／L。本文还用光谱法探讨了10-苯基-吖啶酮与DNA之间的作用机理,认为二者之间可能存在嵌插作用。     

Reaction of 10-vinylphenothiazine with benzoyl peroxide

Conclusions The reaction of 10-vinylphenothiazine with benzoyl peroxide proceeds via the formation of a donor-acceptor complex, and breakdown of the resulting ion-radical pairs into ionic and radical components, thus allowing recombination, neutralization, initiation, and fission of the polymer chain to occur.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2746–2749, December, 1985.