新型长效植物调节剂2-O-β-L-glucopyranoside-4-O-methyl phloracetophenone的全合成

以β-L-(-)葡萄糖、无水醋酐及吡啶为原料,通过五步反应进行全合成,制备一种新型植物生长调节剂;β-D-葡萄糖水解酶催化下进行水解反应,研究其水解曲线。全合成产物经1H NMR鉴定为2-O-β-L-glucopyranoside-4-O-methyl phloracetophenone(1),总得率17.4%;水解实验表明domesticoside(2)可被β-D-葡萄糖水解酶水解为苷元,而化合物(1)不被水解。本法可作为一种新型长效生长调节剂的制备方法,也为体内快速被β-D-葡萄糖水解酶水解失活药物的结构修饰提供了新的思路。

Hydrothermal Synthesis of H_3PW_(12)O_(40)/TiO_2 Nanometer Photocatalyst and Its Catalytic Performance for Methyl Orange

H3PW12O40/TiO2 nanometer photocatalyst was prepared by one step hydrothermal synthesis from H3PW12O40·nH20 and Ti（OBu）4, simultaneously realizing the load and modification of H3PW12O40. The catalyst was characterized by Fourier transform infrared spectroscopy（FTIR）, powder X-ray diffraction（XRD）, nitrogen adsorp- tion-desorption analysis and scanning electron microscopy（SEM）. The results show that the catalyst is Keggin struc- ture and crystallized in anatase structure, the diameter and specific area of the prepared catalyst are 3.8 nm and 177.9 m^2/g, respectively, and its dispersity is better. The photocatalytic properties were compared for TiO2H3PW12O40/TiO2 prepared by impregnation and H3PW12O40/TiO2 prepared by hydrothermal method with methyl orange as a probe. The effects of H3PW12O40 loadings, crystallization method, initial pH and concentration of dye solution on the degradation of methyl orange were investigated.

O6-methylguanine DNA methyltransferase is upregulated in malignant transformation of gastric epithelial cells via its gene promoter DNA hypomethylation

BACKGROUND O_(6)-methylguanine-DNA methyltransferase(MGMT)is a suicide enzyme that repairs the mispairing base O_(6)-methyl-guanine induced by environmental and experimental carcinogens.It can transfer the alkyl group to a cysteine residue in its active site and became inactive.The chemical carcinogen N-nitroso compounds(NOCs)can directly bind to the DNA and induce the O_(6)-methylguanine adducts,which is an important cause of gene mutation and tumorigenesis.However,the underlying regulatory mechanism of MGMT involved in NOCs-induced tumorigenesis,especially in the initiation phase,remains largely unclear.AIM To investigate the molecular regulatory mechanism of MGMT in NOCs-induced gastric cell malignant transformation and tumorigenesis.METHODS We established a gastric epithelial cell malignant transformation model induced by N-methyl-N’-nitro-N-nitrosoguanidine(MNNG)or N-methyl-N-nitroso-urea(MNU)treatment.Cell proliferation,colony formation,soft agar,cell migration,and xenograft assays were used to verify the malignant phenotype.By using quantitative real-time polymerase chain reaction(qPCR)and Western blot analysis,we detected the MGMT expression in malignant transformed cells.We also confirmed the MGMT expression in early stage gastric tumor tissues by qPCR and immunohistochemistry.MGMT gene promoter DNA methylation level was analyzed by methylation-specific PCR and bisulfite sequencing PCR.The role of MGMT in cell malignant transformation was analyzed by colony formation and soft agar assays.RESULTS We observed a constant increase in MGMT mRNA and protein expression in gastric epithelial cell malignant transformation induced by MNNG or MNU treatment.Moreover,we found a reduction of MGMT gene promoter methylation level by methylation-specific PCR and bisulfite sequencing PCR in MNNG/MNU-treated cells.Inhibition of the MGMT expression by O_(6)-benzylguanine promoted the MNNG/MNU-induced malignant phenotypes.Overexpression of MGMT partially reversed the cell malignant transformation process induced by MNNG/MNU.Clinical gastric tissue analysis showed that MGMT was upregulated in the precancerous lesions and metaplasia tissues,but downregulated in the gastric cancer tissues.CONCLUSION Our finding indicated that MGMT upregulation is induced via its DNA promoter hypomethylation.The highly expressed MGMT prevents the NOCs-induced cell malignant transformation and tumorigenesis,which suggests a potential novel approach for chemical carcinogenesis intervention by regulating aberrant epigenetic mechanisms.

Vapour-phase O-methylation of Catechol with Methanol on Ti-containing Phosphate Catalysts

Ti-containing phosphate（ Ti-P-O ） catalysts with different molar ratios of P to Ti （0--2. 0 ） were synthesized and characterized by XRD, N2-adsorption/desorption, IR and temperature-programmed desorption （TPD） methods. The catalytic properties of Ti-P-O samples in the vapor-phase O-methylation of catechol with methanol were also studied. The catechol conversion increases with the increase of the molar ratio of P to Ti in a range of 0-0. 33, while a further increase in the P content leads to a decrease of the catalytic activity. Meanwhile, the selectivities of the catalysts to the main product（guaiacol） increase gradually with the increase of the molar ratio of P to Ti. The presence of relatively strong Lewis acidic and/or basic sites in the P-free catalyst should be responsible for the formation of C-alkylation products. The weak acid-base characteristics of the catalysts are favourable for the mono-O-methylation of catechol. In comparison with the Lewis acidic sites, the Bronsted acidic sites on the catalysts are more active for the title reaction.

MGMT is down-regulated independently of promoter DNA methylation in rats with all-trans retinoic acidinduced spina bifida aperta

O6-methylguanine DNA methyltransferase(MGMT), a DNA repair enzyme, has been reported in some congenital malformations, but it is less frequently reported in neural tube defects. This study investigated MGMT mRNA expression and methylation levels in the early embryo and in different embryonic stages, as well as the relationship between MGMT and neural tube defects. Spina bifida aperta was induced in rats by a single intragastric administration of all-trans retinoic acid on embryonic day(E) 10, whereas normal control rats received the same amount of olive oil on the same embryonic day. DNA damage was assessed by detecting γ-H2 A.X in spina bifida aperta rats. Real time-polymerase chain reaction was used to examine mRNA expression of MGMT in normal control and spina bifida aperta rats. In normal controls, the MGMT mRNA expression decreased with increasing embryonic days, and was remarkably reduced from E11 to E14, reaching a minimum at E18. In the spina bifida aperta model, γ-H2 A.X protein expression was increased, and mRNA expression of MGMT was markedly decreased on E14, E16, and E18. Bisulfite sequencing polymerase chain reaction for MGMT promoter methylation demonstrated that almost all CpG sites in the MGMT promoter remained unmethylated in both spina bifida aperta rats and normal controls, and there was no significant difference in methylation level between the two groups on either E14 or E18. Our results show that DNA damage occurs in spina bifida aperta rats. The mRNA expression of MGMT is downregulated, and this downregulation is independent of promoter DNA methylation.

Promoter methylation status of hMLH1,MGMT,and CDKN2A/p16 in colorectal adenomas

AIM:To investigate aberrant DNA methylation of CpG islands and subsequent low-or high-level DNA microsatellite instability(MSI)which is assumed to drive colon carcinogenesis. METHODS:DNA of healthy individuals,adenoma(tu-bular or villous/tubulovillous)patients,and colorectal carcinoma patients who underwent colonoscopy was used for assessing the prevalence of aberrant DNA methylation of human DNA mismatch repair gene mutator L homologue 1(hMLH1),Cyclin-dependent kinase inhibitor 2A(CDKN2A/p16),and O-6-methylguanine DNA methyltransferase(MGMT),as well as their rela- tion to MSI. RESULTS:The frequency of promoter methylation for each locus increased in the sequence healthy tissue/adenoma/carcinoma.MGMT showed the highest frequency in each group.MGMT and CDKN2A/p16 presented a statistically significant increase in promoter methylation between the less and more tumorigenic forms of colorectal adenomas(tubular vs tubullovillous and villous adenomas).All patients with tubulovillous/villous adenomas,as well as all colorectal cancer patients,showed promoter methylation in at least one of the examined loci.These findings suggest a potentially crucial role for methylation in the polyp/adenoma to cancer progres- sion in colorectal carcinogenesis.MSI and methylation seem to be interdependent,as simultaneous hMLH1, CDKN2A/p16,and MGMT promoter methylation was present in 8/9 colorectal cancer patients showing the MSI phenotype. CONCLUSION:Methylation analysis of hMLH1,CD- KN2A/p16,and MGMT revealed specific methylation profiles for tubular adenomas,tubulovillous/villous adenomas,and colorectal cancers,supporting the use of these alterations in assessment of colorectal tumorigenesis.

Simply air:Vanadium-catalyzed oxidative kinetic resolution of methyl o-chloromandelate by ambient air

Vanadium-catalyzed oxidative kinetic resolution（OKR） of methyl o-chloromandelate 2a,key intermediate of the well-known oral antiplatelet agent（S）-clopidogrel,was achieved by ambient air for the first time.The air oxidation system,which was composed of vanadium and tridentate Schiff base ligands derived from amino alcohols and salicylaldehyde derivatives,afforded an efficient and economic approach to the target intermediate with high enantioselectivities（99%ee）.

Promoter Hypermethylation of DNA Repair Gene MGMT in Laryngeal Squamous Cell Carcinoma

The relationship between hypermethylation of CpG islands in the promoter regions of O^6- methylguanine DNA methyhransferase （MGMT） genes and laryngeal squamous cell carcinoma was explored. Methylation-specific PCR and semi-quantitative RT-PCR were used to study the promoter methylation and mRNA expression of the MGMT gene in laryngeal carcinoma tissues, tissues adjacent to the tumor and normal laryngeal tissues. Hypermethylation of MGMT gene was detected in 16 samples of 46 （34.8 %） laryngeal squamous cell carcinoma samples. However, the MGMT hypermethylation was not detected in all tissues adjacent to the tumors and normal tissues. No significant difference in MGMT gene hypermethylation was found in samples with different histological grades （χ^2= 3. 130, P=0. 077） or in samples from patients with different TNM status （χ^2= 3. 957, P=0. 138）. No expression of MGMT mRNA was detected in all hypermethylated laryngeal carcinoma tissues. The expression of MGMT mRNA was detected in all unmethylated laryngeal carcinoma tissues, tissues adjacent to the tumors and normal tissues. It suggests that MGMT gene promoter hypermethylation is associated with MGMT gene transcription loss in laryngeal carcinoma tissues and possibly plays an important role in carcinogenesis of laryngeal tissues.

C-H…O Hydrogen Bonds and π…π Interaction and the Crystal and Molecular Structures of 3-Nitro-benzylideneaniline-methyl-2’

The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = 0.93 cm-1 and F(000) = 504.00. The final R and wR are 0.0440 and 0.1370 for 2153 observed reflections (I > 2s(I)), respectively. The dihedral angle between the two phenyl rings is 52.9 and that between the NO2 group and its attached ring is 3.0. In the crystal, molecules are stacked along [100] through p…p interactions. The CH…O hydrogen bond (3.403 ? 120.4? laterally connects the stacks along [010] to form networks (001) which are further anti- parallelly connected by CH…O (3.382 ? 142.9) and p…p interactions extending along [001]. Also presented here is a brief study on the CH…O hydrogen bonds in nitro-substituted benzyl-ideneanilines which can be classified into five types, namely, )5(12R, )4(21R, )8(22R, )6(12R and )7(22R, with the first three occurring more often.

Ultrasonic Degradation of Methyl Orange in Presence of Y2O3 Doping Anatase TiO2 Catalyst

Various affecting factors and degradation mechanism were studied on ultrasonic degradation of methyl orange adopting Y2O3 doping anatase TiO2 catalyst prepared in laboratory.In the experiment, the UV-VIS spectrophotometer was used to follow and inspect the degradation process of methyl orange.The results indicate that the ultrasonic degradation ratios of methyl orange in the presence of anatase TiO2 catalyst are much better than those without catalyst.Moreover, the catalytic performance of Y2O3 doping anatase TiO2 catalyst is obviously higher than that of anatase TiO2 catalyst without doping.The optimal conditions were adopted in this work and the degradation and COD elimination ratio of methyl orange got to98% and 99.0% in 90 min, respectively.

Catalytic Hydrogenation Performance of Methyl Isobutyl Ketone over Ni/γ-Al_2O_3 Catalysts

Supported nickel-based catalysts were prepared by the incipient wetness impregnation method for the selective hydrogenation of methyl isobutyl ketone to methyl isobutyl carbinol in a fixed-bed reactor. The effects of the nickel source,Ni loading, calcination time, and calcination temperature on the hydrogenation performance were studied. The experimental results showed that the Ni/γ-Al_2O_3 catalyst demonstrated the highest catalytic performance under the preparation conditions by using nickel nitrate as the nickel source with a NiO loading of 20%, followed by calcination at 440°C for 5h. In addition,this catalyst showed the largest specific surface area, best crystal structure, highest active component content, smallest particle size, and uniform distribution of NiO on the surface of the carrier. The nickel-based catalyst prepared using the optimized conditions exhibited a 96.1% conversion of methyl isobutyl ketone, with a methyl isobutyl carbinol selectivity of 99.6%. The described procedure is very effective for the preparation of methyl isobutyl carbinol using methyl isobutyl ketone as the feedstock.

铁碳微电解-A/O工艺处理丁酮肟生产废水试验研究

为了解决丁酮肟生产废水难以生化降解、常规处理工艺无法达到出水水质要求等问题,利用铁碳在酸性条件下会发生氧化还原作用的原理对丁酮肟生产废水进行预处理,主要对比了生产废料铁刨花和工业铁碳2种铁碳材料对丁酮肟生产废水的处理效果。结果表明:铁刨花和工业铁碳均可显著提高废水可生化性,ρ(BOD5)/ρ(COD)从0.17提高至0.46~0.51;预处理采用工业铁碳处理2 h后加入H2O2,组合A/O生化工艺的处理效果最好,COD的质量浓度从1881 mg/L下降为346.15 mg/L,去除率为81.6%;氨氮的质量浓度从72.88 mg/L降至31.12 mg/L,去除率为57.3%,满足园区污水处理站进水要求。

THEORETICAL INVESTIGATION OF COLLISION ENERGY EFFECT ON REACTION O(?) BARIUM WITH METHYL BROMIDE

The reac dynamics on Ba+BrCH_3→BaBr+CH_3 has been investigated in the first proposed potential energy surface of the generalized LEPS type,using the quasiclassical trajectory method.In simulation of the conditions in molecular beam experiments,the results of the present study show significant effect of the reagent collision energy on the dynamics of the reaction,and are in good agreement with the experimental ones.

Synthesis of 2-Methyl-4-methoxyaniline from o-Nitrotoluene Using Pt/C and Acidic Ionic Liquid as Catalyst System

2-Methyl-4-methoxyaniline (MMA ) 被一个壶方法作为催化剂系统用酸的离子的液体和 3% Pt/C 在甲醇通过加氢和 o 硝基甲苯的 Bamberger 重新整理综合。o 硝基甲苯变换和 MMA 选择上的离子的液体类型，离子的液体的剂量和 3% Pt/C，反应温度和反应压力的效果被调查。结果比在这使用的另外的酸的离子的液体工作的显示包含 SO3H-functionalized 阳离子的基于 imidazolium 的酸的离子的液体显示出更高的选择到 MMA。使用的 1-(propyl-3-sulfonate )-3-methylimidazolium hydrosulfate ([HSO3-pmim ][HSO4 ]) 作为酸催化剂，到 MMA 的选择在 97.8%o 硝基甲苯象 67.6% 一样高变换。当 3% Pt/C 从 0.01 g 增加了到 0.025 g，到 MMA 的选择从 73.4% ～ 62.5% 减少了，因为到变得更主导的 o-toluidine 的中间的 o-methyl-phenylhydroxylamine 的加氢。氢压力的增加也在降低 MMA 选择有显然戏剧的效果。在从产品的容易的分离以后，催化剂系统能被再使用至少 3 次。

Theoretical Study on the Reaction Mechanism of o-Aminophenol, Acetic Acid and Phosphorus Oxytrichloride One-pot to Form 2-Methyl Benzoxazole

The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol;and the reaction heat being 10.06 kJ·mol;. The dominant product predicted theoretically is in agreement with the experiment results.

Cooperative C–H…O H-bonds in ‘Bay Area’and Crystal Structure of 1-(4-Methylphenyl)-3-(4-methoxyphenyl)-2-propene-1-one

The title compound (C17H16O2, Mr = 252.30) crystallizes in the monoclinic system, space group P21/c with a = 11.5763(14), b = 11.0321(11), c = 11.5094(13) ?, β = 114.581(3)o, V = 1336.7(3) ?3 , Z = 4, Dc = 1.254 g/cm3, μ(MoKa) = 0.081 cm-1 and F(000) = 536.00. The final R and wR are 0.0527 and 0.1285, respectively for 3058 observed reflections (I > 2σ(I)). In the title molecule, two phenyl rings are rotated oppositely with respect to the central part C(1)–C(2)=C(3)– C(4) (plane 3) and the dihedral angle between them is 14.8o. The phenone O(1) atom deviates from plane 3 by 0.291 ?. In the crystal the molecules form H-bond chains of R2 (6) and R2 (5) types 1 1 along [001]. The molecule chains interacted through three cooperative C–H…O H-bonds (R3 (11)) 1 in the ‘bay area’ (Fig. 3), extending along [010] and forming layer (100). Between the layers, there exist C–H/π interactions along [101]. Studies on the cooperative C–H…O H-bonds R3 (11) in the 1 similar crystals are also presented.

New Convenient Synthesis of 8-C-Methylated Homoisoflavones and Analysis of Their Structure by NMR and Tandem Mass Spectrometry

Homoisoflavonoids are in the subclass of the larger family of flavonoids having one more alkyl carbon than flavonoids. Among them, 8-C-Methylated homoisoflavones have not been extensively studied for synthesis and biological evaluation. Author’s current objective is to synthesize 8-C-Methylated homoisoflavones by the reaction of 3-C-methylated dihydrochalcones with N,N’-dimethyl (chloromethylene) ammonium chloride generated in situ from DMF and PCl5 for one carbon extension at about room temperature. The 3-C-methylated dihydrochalcones were synthesized by the reduction of 3-C-methylated chalcones, which were prepared from 3-C-methylated acetophenones and aromatic aldehydes in the presence of base. All the synthesized novel homoisoflavones’s structures were characterized by NMR and Tandem Mass Spectrometry.

Effect of Postharvest Methyl Jasmonate Treatment on Early-Matured “Hass” Avocado Fruit Exocarp Colour Development during Ripening

Poor exocarp colour development is a common postharvest problem for early harvested “Hass” avocado fruit during ripening, which affects fruit quality and consumer preference. Therefore, measures to improve “Hass” avocado fruit colour developments are of great importance in the industry. This study investigated the effectiveness of postharvest methyl jasmonate treatment to improve early matured “Hass” avocado fruit exocarp colour during ripening. The results showed that T1 (10 μmol∙L−1) and T2 (100 μmol∙L−1) MeJA treatment increased visual colour, and decreased objective colour parameters (L*, C* and h˚) during ripening when compared with control fruit. Moreover, MeJA treated “Hass” avocado fruits had lower total chlorophyll content and higher total anthocyanin and cyanidin-3-O-glucoside concentration during ripening. In conclusion, “Hass” avocado fruit post-harvest treated with either T1 (10 μmol∙L−1) or T2 (100 μmol∙L−1) MeJA concentration improved exocarp quality attributes such as colour parameters (L*, C* h˚ and visual colour) and pigments (total anthocyanin and cyanidin-3-O-glucoside) during ripening, therefore, can be recommended for avocado fruit.

Association of adverse effects with monoamine oxidase type B inhibitor and catechol-o-methyl transferase inhibitor combination therapy in Parkinson’s disease patients

Currently, levodopa is the most effective and commonly used medication to control motor symptoms in Parkinson’s disease (PD). However, its long-term use is associated with adverse effects (AEs). Combination therapy of a monoamine oxidase type B inhibitor (MAOBI) with levodopa or a catechol-O-methyl transferase inhibitor (COMTI) with levodopa provides benefits to PD patients. Direct comparison of efficacy and side effect profiles is complex. The aim of this study is to investigate the different AE profiles of MAOBI and COMTI combination therapies. Data used to analyze the AEs of different PD medications were retrieved from “The Boston University Medical Center’s Parkinson’s Disease and Movement Disorder Database”. Ten categories of AEs were compared between patients receiving MAOBI and COMTI combination treatment. In total, 87 subjects were included in the analysis. Out of ten AEs, the presence of dementia was signifi- cantly different between the MAOBI and COMTI groups with an OR of 6.9 (COMTI vs MAOBI, 95% CI 1.3 - 37.0). Motor fluctuations were also found to be differently distributed in the two medication groups with an OR of 3.1 (COMTI vs MAOBI, 95% CI 1.0 - 9.8). In this retrospective database analysis of patients treated with combination treatment for PD, combination therapy of a COMTI with levodopa was more likely to be associated with dementia and motor fluctuations than a MAOBI with levodopa.

独一味化学成分和药理作用的研究进展及其质量标志物预测分析

独一味Lamiophlomis rotata(Benth.)Kudo为藏族习用药材,药用部位为干燥地上部分。现代研究表明,独一味主要含有环烯醚萜苷类、苯乙醇苷类、黄酮类、挥发油类等化学成分,具有镇痛、止血、抗菌、抗炎、免疫调节、抗肿瘤等药理作用。在对独一味化学成分及药理作用总结的基础上,结合其质量研究现状,从药性、功效、成分可测性、药动学等方面对其质量标志物(Q-marker)进行预测,槲皮素、芹菜素、山栀苷甲酯、8-O-乙酰山栀苷甲酯、胡麻属苷、连翘酯苷B、木犀草苷、马钱苷等成分可作为独一味的主要Q-marker,以期为独一味产品开发研究及质量标准的合理建立提供参考。