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不同取代2',4'-二羟基查尔酮的合成
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作者 赵莹 张建平 +3 位作者 李彤 梁力曼 王月辉 赵永光 《河北科技师范学院学报》 CAS 2014年第2期27-30,共4页
以间苯二酚和苯甲醛为起始原料,经两步加热回流合成法合成了几种2',4'-二羟基查尔酮。结果表明,以对甲苯磺酸为催化剂,其用量为反应物总质量的15%,冰醋酸为溶剂,温度为90℃,合成的取代查尔酮化合物,产率为61.51%-74.96%。
关键词 查尔酮 2' 4'-二羟基查尔酮 合成
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2',5,6',7-四羟基二氢黄酮醇对内毒素诱导巨噬细胞活化的影响
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作者 葛迪 史清海 +2 位作者 伏建峰 刘正祥 郑江 《解放军药学学报》 CAS 2011年第5期427-430,共4页
目的检测2',5,6',7-四羟基二氢黄酮醇对细菌内毒素诱导的巨噬细胞RAW264.7释放TNF-α、IL-6及TNF-αmRNA表达的影响。方法 RAW264.7细胞经不同浓度(0、10、20、40、80、160 mg/L)2',5,6',7-四羟基二氢黄酮醇预处理后,EL... 目的检测2',5,6',7-四羟基二氢黄酮醇对细菌内毒素诱导的巨噬细胞RAW264.7释放TNF-α、IL-6及TNF-αmRNA表达的影响。方法 RAW264.7细胞经不同浓度(0、10、20、40、80、160 mg/L)2',5,6',7-四羟基二氢黄酮醇预处理后,ELISA法分别检测LPS(100μg/L)刺激的RAW264.7细胞释放TNF-α和IL-6的水平,Real-Time PCR法检测TNF-αmRNA的表达水平。MTT法检测2',5,6',7-四羟基二氢黄酮醇对RAW264.7细胞活力的影响,以排除实验用量2',5,6',7-四羟基二氢黄酮醇的细胞毒性作用。结果不同浓度的2',5,6',7-四羟基二氢黄酮醇预处理后,可显著抑制LPS诱导RAW264.7细胞释放TNF-α和IL-6,显著抑制TNF-αmRNA的表达,并都具有量效关系。MTT实验结果显示,低于320 mg/L浓度的2',5,6',7-四羟基二氢黄酮醇对RAW264.7细胞无明显的毒性作用。结论 2',5,6',7-四羟基二氢黄酮醇能够拮抗LPS对炎症反应细胞的刺激效应,有望成为脓毒症防治药物的候选药物前体。 展开更多
关键词 2' 5 6' 7-四羟基二氢黄酮醇 内毒素 巨噬细胞 TNF-Α IL-6
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2′羟基在酵母丙氨酸tRNA与合成酶识别中的作用 被引量:2
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作者 包俊茹 龚佩娟 +1 位作者 金由辛 王德宝 《自然科学进展(国家重点实验室通讯)》 1994年第2期232-235,共4页
70年代末和80年代初Cech和Altman分别发现了具有酶活性的RNA。由此,人们相信生物进化的初期曾有一个RNA世界。当时的生命仅仅由RNA单分子所组成。在进化过程中,蛋白质、DNA等其它分子逐渐进入生命体。DNA逐渐代替RNA成为遗传信息的主要... 70年代末和80年代初Cech和Altman分别发现了具有酶活性的RNA。由此,人们相信生物进化的初期曾有一个RNA世界。当时的生命仅仅由RNA单分子所组成。在进化过程中,蛋白质、DNA等其它分子逐渐进入生命体。DNA逐渐代替RNA成为遗传信息的主要携带分子。蛋白质逐渐代替RNA成为主要的生物催化剂——酶。但是RNA并没有被淘汰,它们仍是一种主要的生物高分子化合物。它最主要的生物功能是参与蛋白质的生物合成。因此,一个问题产生了,即现代RNA所具有的生物功能为什么不能被其它高分子化合物(如DNA或蛋白质)所取代。Cedergren发现锤头状Ribozyme的催化功能既决定于特殊的高级结构(蛋白质也可以形成具有催化活力的高级结构) 展开更多
关键词 2'羟基 TRNA 合成酶 识别 酵母
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血清25-羟基维生素D和骨钙素水平对2型糖尿病患者病程转归的预警价值 被引量:10
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作者 姜文娟 张进安 黎丹凤 《中国临床医学》 2017年第3期382-386,共5页
目的:探讨血清25-羟基维生素D(25-hydroxyvitaminD,25-OH-VD)和骨钙素(osteocalcin,OC)水平对2型糖尿病(type 2diabetes mellitus,T2DM)病程转归的预警价值。方法:选取2013年1月至12月在复旦大学附属金山医院内分泌科住院治疗的T2DM患者... 目的:探讨血清25-羟基维生素D(25-hydroxyvitaminD,25-OH-VD)和骨钙素(osteocalcin,OC)水平对2型糖尿病(type 2diabetes mellitus,T2DM)病程转归的预警价值。方法:选取2013年1月至12月在复旦大学附属金山医院内分泌科住院治疗的T2DM患者116例作为病例组,对照组为2013年在我院门诊体检的健康体检者50例,比较两组的年龄、体质指数(body mass index,BMI)、空腹血糖(fasting blood glucose,FBG)、血脂、血压、25-OH-VD及OC等生理指标。分析病例组25-OH-VD和OC与糖尿病肾病的相关性,进一步采用多元逐步回归分析25-OH-VD和OC水平与血脂、血压、BMI、FBG、糖化血红蛋白(glycosylated hemoglobin,HbA1c)、空腹胰岛素(fast insulin,FINS)、胰岛素抵抗指数(homeostasis model assessment for insulin resistance index,HOMA-IR)、肌酐(creatinine,CR)、尿酸(uric acid,UA)和颈动脉内膜中层厚度(carotid artery intimal medial thickness,CA-IMT)之间的相关性。结果:病例组与对照组在年龄、血压、BMI和血脂间的差异无统计学意义,但病例组25-OH-VD水平低于正常对照组[(13.91±7.13)ng/mL vs(30.35±19.7)ng/mL,P=0.000],病例组OC也低于对照组[(4.02±1.66)ng/mL vs(6.62±1.68)ng/mL,P=0.000]。病例组中,肾病患者的25-OH-VD水平明显低于尿微量白蛋白(urine microalbumin,U-MA)正常者[(10.33±3.46)ng/mL vs(16.45±7.95)ng/mL,P=0.000],而两者之间OC水平差异无统计学意义[(3.91±1.67)ng/mL vs(4.09±1.67)ng/mL,P=0.558]。T2DM患者的25-OH-VD水平与BMI、血脂、血压、FBG、HbA1c、FINS、HOMA-IR、CR、UA和CA-IMT均无明显相关性。T2DM患者的OC水平与FBG、HbA1c和HOMAIR负相关,而与FINS、CR和CA-IMF正相关,HbA1c和FBG是OC的独立影响因素。结论:血清25-OH-VD和OC可作为T2DM病情进展的预警信号,25-OH-VD与糖尿病肾脏并发症的发生发展相关,OC则与糖尿病微血管病变的进展相关。 展开更多
关键词 2型糖尿病 25-羟基维生素D 骨钙素
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2,2,′4,4′-四羟基二苯甲酮的极谱行为研究 被引量:1
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作者 徐绍炳 夏新泉 张盈艳 《日用化学工业》 CAS CSCD 北大核心 2007年第3期203-205,共3页
用线性扫描极谱法系统研究了2,2,′4,4′-四羟基二苯甲酮(BP-2)在不同缓冲体系中的极谱行为。实验表明,在2.5 mol/L的H2SO4溶液中BP-2的二阶导数峰电位为-1.06 V,其峰电流与浓度在5.0×10-6mol/L^3.0×10-5mol/L的对数值有良好... 用线性扫描极谱法系统研究了2,2,′4,4′-四羟基二苯甲酮(BP-2)在不同缓冲体系中的极谱行为。实验表明,在2.5 mol/L的H2SO4溶液中BP-2的二阶导数峰电位为-1.06 V,其峰电流与浓度在5.0×10-6mol/L^3.0×10-5mol/L的对数值有良好的线性关系,线性方程ip″(nA/s2)=19 096.79+745.75×lgc(mol/L),相关系数为0.993 6。BP-2的微分循环伏安曲线表明,该极谱波为不可逆还原波。 展开更多
关键词 防晒剂 2 2 '4 4'-四羟基二苯甲酮(BP-2) 线性扫描极谱法 极谱波
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Is三七中 2-(1′,2′ ,3′,4′-四羟基丁基 )-6-(2″,3″,4″-三羟基丁基 )吡嗪的分离、纯化和结构鉴定(英文)
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作者 李琦 阎爱新 +1 位作者 叶蕴华 邢其毅 《北京大学学报(自然科学版)》 CAS CSCD 北大核心 2001年第2期286-288,共3页
从三七水溶性成分中首次分离得到一个多羟基吡嗪衍生物。该化合物经MS ,NMR ,1H 1HCOSY ,13C 1HCOSY ,HMBC等鉴定其结构为 2 (1′ ,2′,3′,4′ 四羟基丁基 ) 6 (2″ ,3″ ,4″ 三羟基丁基 ) 吡嗪。将分离样品与化学合成的化合物进... 从三七水溶性成分中首次分离得到一个多羟基吡嗪衍生物。该化合物经MS ,NMR ,1H 1HCOSY ,13C 1HCOSY ,HMBC等鉴定其结构为 2 (1′ ,2′,3′,4′ 四羟基丁基 ) 6 (2″ ,3″ ,4″ 三羟基丁基 ) 吡嗪。将分离样品与化学合成的化合物进行了对照 。 展开更多
关键词 三七 羟基吡嗪化合物 水溶性组分 分离 纯化 结构鉴定 2-(1' 2 3' 4’-四羟基丁基)-6-(2^〃 3^〃 4^〃-三羟基丁基)吡嗪
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纺织品中的2-(2’羟基-3’,5’-二叔丁基苯基)-苯并三唑含量的气相色谱测定 被引量:14
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作者 薛建平 朱峰 涂貌贞 《质量技术监督研究》 2012年第4期18-20,48,共4页
通过对萃取方式和色谱条件的优化,建立了纺织品中的2-(2'-羟基-3',5'-二叔丁基苯基)-苯并三唑的气相色谱-氢离子火焰检测器的测定方法。结果表明该方法的回收率在90%~110%,相对标准偏差小于10%,方法检测限可达0.3mg/kg。... 通过对萃取方式和色谱条件的优化,建立了纺织品中的2-(2'-羟基-3',5'-二叔丁基苯基)-苯并三唑的气相色谱-氢离子火焰检测器的测定方法。结果表明该方法的回收率在90%~110%,相对标准偏差小于10%,方法检测限可达0.3mg/kg。本方法操作简单、快速,准确度和灵敏度高,重现性好,适用于纺织品中2-(2'-羟基-3',5'-二叔丁基苯基)-苯并三唑含量的日常检测。 展开更多
关键词 2-(2'-羟基-3' 5'-二叔丁基苯基)-苯并三唑 纺织品 气相色谱 测定
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Enhanced Photocatalytic Performance of Anatase TiO_(2) by Deposition-Precipitation Treatment
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作者 Mengqi Wan Qian Wen +2 位作者 Mengyi Ci Wangyang Li Zhen Zhang 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第4期531-538,I0094,共9页
Deposition-precipitation(DP)method is commonly used to prepare the supported metal catalysts.In this study,the modification effect of the mild DP method on the photocatalytic performance of TiO_(2)was investigated.The... Deposition-precipitation(DP)method is commonly used to prepare the supported metal catalysts.In this study,the modification effect of the mild DP method on the photocatalytic performance of TiO_(2)was investigated.The TiO_(2)samples with DP treatment,as well as Au/TiO_(2)prepared under the same conditions,showed enhanced photocatalytic performance of the degradation of methylene blue(MB).·OH generated by photoexcited holes is identified as the main intermediate reactive species during the degradation reaction.X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectroscopy(FTIR)show that TiO_(2)(A)-17 after DP treatment has the most amount of surface OH^(-)_(ad)species.The presence of surface OH^(-)_(ad)species not only changes the surface zeta potential,favoring the attraction of cationic MB;but also depresses the electron-hole recombination,favoring photodegradation of MB by hole-produced·OH.An implication of these findings is that the modification of support properties should be taken into account while preparing supported metal catalysts using DP methods. 展开更多
关键词 TiO_(2) PHOTOCATALYSIS ·OH Deposition-precipitation method
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以2-(8’-羟基喹啉-5’-磺酸-7’-偶氮)-变色酸特定波长法测定血清镁
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作者 陈力平 黄雅娟 任孔建 《医学研究生学报》 CAS 2001年第z1期20-23,共4页
目的 :建立一种以不被钙离子干扰、2 - (8 -羟基喹啉 - 5 -磺酸 - 7 -偶氮 ) -变色酸 (8Q5 SAC)显色、特定波长比色的血清镁测定法。 方法 :用 8Q5 SAC作显色剂 ,在 p H10 .8、含聚乙烯吡咯烷酮 (PVP)的甘氨酸 - Na OH缓冲介质中 ,以 ... 目的 :建立一种以不被钙离子干扰、2 - (8 -羟基喹啉 - 5 -磺酸 - 7 -偶氮 ) -变色酸 (8Q5 SAC)显色、特定波长比色的血清镁测定法。 方法 :用 8Q5 SAC作显色剂 ,在 p H10 .8、含聚乙烯吡咯烷酮 (PVP)的甘氨酸 - Na OH缓冲介质中 ,以 5 70 nm特定波长比色测定血清镁 ,并对反应条件、方法性能进行系统研究。 结果 :该法线性 0~ 2 m mol/L ,平均回收率为 99.2 % ,CV 2 .0 2 %~ 3.16 %。与 Calm agite法对照 ,r=0 .995 ,P>0 .5 ;与二甲苯基氮紫 (キシリルアゾバイオレツト I)法对照 ,r=0 .992 ,P>0 .5 ;测试灵敏度是 Calm agite法的 2倍 ,与二甲苯基偶氮紫法基本一致。 结论 :该法利用 8Q5 SAC-镁的特异吸收波长测定血清镁 ,不受钙离子干扰 ,方法简便快速 ,灵敏度高 ,适用于血清镁的常规手工或自动化分析。 展开更多
关键词 2-(8'-羟基喹啉-5'磺酸-7'-偶氮)-变色酸 分光光度法
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Flotation behavior and adsorption mechanism of(1-hydroxy-2-methyl-2-octenyl) phosphonic acid to cassiterite 被引量:16
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作者 谭鑫 何发钰 +1 位作者 尚衍波 印万忠 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第9期2469-2478,共10页
The flotation behavior and adsorption mechanism of novel(1-hydroxy-2-methyl-2-octenyl) phosphonic acid(HEPA) to cassiterite were investigated by micro-flotation tests, zeta potential measurements, FTIR determinati... The flotation behavior and adsorption mechanism of novel(1-hydroxy-2-methyl-2-octenyl) phosphonic acid(HEPA) to cassiterite were investigated by micro-flotation tests, zeta potential measurements, FTIR determination and density functional theory(DFT) calculation. The flotation results demonstrated that HEPA exhibited superior collecting performance compared with styrene phosphonic acid(SPA). The cassiterite recovery maintained above 90% over a wide pH range of 2-9 with 50 mg/L HEPA. The results of zeta potential measurement and FTIR detection indicated that the adsorption of HEPA onto cassiterite was mainly attributed to the chemisorption between HEPA monoanions and Sn species on mineral surfaces. The DFT calculation results demonstrated that HEPA monoanions owned higher HOMO energy and exhibited a better affinity to cassiterite than SPA, which provided very clear evidence for the stronger collecting power of HEPA presented in floatation test and zeta potential measurement. 展开更多
关键词 (1-hydroxy-2-methyl-2-octenyl) phosphonic acid CASSITERITE adsorption FLOTATION density functional theory
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Metabolites of Marine-derived Mangrove Endophytic Fungus #2492 from the South China Sea
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作者 朱峰 林永成 +2 位作者 王军 周世宁 Vrijmoed L L P 《Marine Science Bulletin》 CAS 2006年第2期92-96,共5页
Two metabolites (A and B) were isolated from the mycelium of mangrove endophytic fungus Stysanus like sp. (#2492) from the South China Sea. Their structures were identified by spectral data as N-(2-hydroxytetraco... Two metabolites (A and B) were isolated from the mycelium of mangrove endophytic fungus Stysanus like sp. (#2492) from the South China Sea. Their structures were identified by spectral data as N-(2-hydroxytetracosyl)-2-amino-1,3,4-trihydroxyoctadecane (A) and γ -stearolactone (B). It is the first report that γ -stearolactone (B) is isolated from marine fungus as natural product. 展开更多
关键词 marine fungus METABOLITES N-(2-hydroxytetracosyl)-2-amino-1 3 4-tfihydroxy -octadecane γ -stearolactone
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Synthesis and Crystal Structure of 4-Salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole JI Bao-Minga 被引量:4
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作者 JI Bao-Ming DU Chen-Xia +1 位作者 ZHU Yu WANG Yang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2002年第3期252-255,共4页
The title compound, 4-salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole, was obtained by the condensation reaction of 4-amino-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole with salicylaldehyde in methanol. The crys... The title compound, 4-salicylimine-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole, was obtained by the condensation reaction of 4-amino-3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazole with salicylaldehyde in methanol. The crystal structure (C21H16N4O3, Mr = 372.38) belongs to monoclinic system, space group P21/n with a = 10.507(2), b = 16.878(3), c = 11.199(2) ? = 110.86(3), V = 1855.9(6) ?, Z = 4, Dc = 1.333 g/cm3, F(000) = 776, (MoK? = 0.092 mm-1, R = 0.0552 and wR = 0.1095 for 1920 reflections ( I > 2.0(I) ). The analytical results of crystal structure show that there are two different non-covalent interactions in the compound. One is hydrogen bond, and the other p-p stacking interaction. These two types of non-covalent interactions play an important role in the packing of crystal. 展开更多
关键词 TRIAZOLE hydrogen bond crystal structure stacking interaction
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Cyclosporine A, FK-506, 40-0-[2-hydroxyethyl]rapamycin and mycophenolate mofetil inhibit proliferation of human intrahepatic biliary epithelial cells in vitro 被引量:7
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作者 Chao Liu Thomas Schreiter +4 位作者 Andrea Frilling Uta Dahmen Christoph E Broelsch Guido Gerken Ulrich Treichel 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第48期7602-7606,共5页
AIM: To investigate the effect of cyclosporine A (CsA), FK-506, and mycophenolate mofetil (MMF) and 40-0-[2- hydroxyethyl]rapamycin (RAD) on proliferation of human intrahepatic biliary epithelial cells (BECs)... AIM: To investigate the effect of cyclosporine A (CsA), FK-506, and mycophenolate mofetil (MMF) and 40-0-[2- hydroxyethyl]rapamycin (RAD) on proliferation of human intrahepatic biliary epithelial cells (BECs) in vitro.METHODS: BECs were isolated from six human liver tissuespecimens with the immunomagnetic separation method and treated with different concentrations of CsA, FK-S06, RAD, and MMF in vitro. Proliferation of the cells was measured by MTT assay at 24 and 48 h after treatment, respectively. One-way analysis of variance was used to analyze the results. Expression of CK 19 in BECs was monitored by flow cytometry and Western blot.RESULTS: Six lines of BECs were established. They survived for 4-18 wk in vitro. Flow cytometry analysis showed that these cells always expressed CK19. CsA, FK-506, RAD, and MMF inhibited proliferation of BECs in a dose-dependent manner. The lowest concentration of CsA, FK-506, RAD, and MMF to inhibit proliferation of BECs (P〈0.05) was 500, 100, 0.25, and 100 pg/L, respectively. However, the expression of CK19 by BECs was not changed.CONCLUSION: CsA, FK-506, RAD, and MMF have an antiproliferative effect on human intrahepatic BECs in vitro, while RAD has the strongest growth-inhibitory effect. Their possible effects on liver regeneration and bile duct injury in transplant patients should be further investigated. 展开更多
关键词 Cyclosporine A FK-506 Rapamycin Mycophenolate mofetil Biliary epithelial cells
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Synthesis and Crystal Structure of an Ion- pair Compound: [HL]_2[Ni(CN)_4]·4H_2O (L = 4-(2- Hydroxyphenyl)-1,5, 9-triazacyclododecan-2-one) 被引量:1
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作者 李建荣 谢亚勃 +3 位作者 蔡丽珍 郭国聪 卜显和 黄锦顺 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第4期361-365,共5页
An ion-pair compound, [HL]2[Ni(CN)4]4H2O 1 has been obtained as an unexpected product when we attempt to prepare a heterometallic cyano-bridged complex by the reaction of GdCl3nH2O, K2Ni(CN)4 and L (L=4-(2-hydroxyphen... An ion-pair compound, [HL]2[Ni(CN)4]4H2O 1 has been obtained as an unexpected product when we attempt to prepare a heterometallic cyano-bridged complex by the reaction of GdCl3nH2O, K2Ni(CN)4 and L (L=4-(2-hydroxyphenyl)-1,5,9-triazacyclododecan-2-one) in aqueous solution, and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/n with a = 12.380(1), b = 9.9637(8), c = 17.087(1) ? ?= 105.947(2)? V = 2026.6(3) ?, Rint = 0.0509, Z = 2, Dc = 1.297 g/cm3, C34H56O8N10Ni, Mr = 791.60, F(000) = 844, m(MoKa) = 0.538 mm1, S = 1.030, the final R = 0.0644 and wR = 0.1299 for 2023 observed reflections with I ≥ 2(I). The title compound 1 contains one anion of [Ni(CN)4]2, two cations of [HL]+ and four packing water molecules, which are held together by the NH···O and OH···O hydrogen bonds to form a three- dimensional framework. 展开更多
关键词 tetracyanonickelate anion macrocyclic triamine cation crystal structure
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Synthesis and characterization of 2-hydroxy-N-methyl-N-phenyl-acetamide
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作者 周忠诚 舒万艮 《Journal of Central South University of Technology》 2002年第1期25-29,共5页
2-hydroxy N methyl N phenyl acetamide was synthesized by using N methylaniline, chloracetyl chloride, anhydrous sodium acetate and methanol through the acetylation, esterfication and ester interchange steps. The acety... 2-hydroxy N methyl N phenyl acetamide was synthesized by using N methylaniline, chloracetyl chloride, anhydrous sodium acetate and methanol through the acetylation, esterfication and ester interchange steps. The acetylation of N methylaniline with chloracetyl chloride, catalyzed by triethylamide with mole ratio n (C 6H 5NHCH 3)∶ n (ClCH 2C(O)Cl)∶ n (N(C 2H 5) 3)=1∶1.05∶1, the yield of 2 chloro N methyl N phenyl acetamide(Ⅰ) was 93.8%; Then the esterification of Ⅰ with anhydrous sodium acetate in the presence of phase transfer catalyst tetrabutyl ammonia bromide gave 97.3% yield of 2 acetoxyl N methyl N phenyl acetamide (Ⅱ); The ester interchange of with methanol catalyzed by potassium hydroxide gave 2 hydroxy N methyl N phenyl acetamide (Ⅲ) in 96.4% yield. And the total yield was 88.0%. IR and MS spectroscopy of products were analyzed and their characteristic peaks were assigned. Combining the results of elemental analysis, the molecular structure of Ⅰ, Ⅱ and Ⅲ was identified. 展开更多
关键词 -N-methyl N phenyl acetamide synthesis ACETYLATION esterfication ester interchange characterization
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Reaction Characteristics of Asymmetric Synthesis of (2S,5S)-2,5-Hexanediol Catalyzed with Baker’s Yeast Number 6 被引量:2
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作者 肖美添 叶静 +1 位作者 张亚武 黄雅燕 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第3期493-499,共7页
Baker’s yeast number 6 was selected by screening. It showed good catalytic activity and enantioselec-tivity for asymmetric reduction of 2,5-hexanedione to produce (2S,5S)-2,5-hexanediol. Gas chromatography-mass spect... Baker’s yeast number 6 was selected by screening. It showed good catalytic activity and enantioselec-tivity for asymmetric reduction of 2,5-hexanedione to produce (2S,5S)-2,5-hexanediol. Gas chromatography-mass spectrometry (GC-MS) revealed that the intermediate was (S)-5-hydroxyhexane-2-one. Reduction of 2,5-hexanedione proceeded in a two-step reaction. The hydroxyketone was initially formed, and this intermediate was further re-duced to the diol. Factors influencing the product yield and the enantiomeric excess of the reduction of 2,5-hexandione catalyzed by baker’s yeast number 6 were investigated. Higher concentration (≤100 mmol·L-1) of 2,5-hexandione did not influence 5-hydroxyhexane-2-one production, but 2,5-hexanediol production was inhibited by excess accumulation (>30 mmol·L-1) of intermediate. The optimal conditions were glucose as the co-substrate at an initial glucose concentration of 20 g·L-1, 34°C, pH 7.0 and cell concentration 60 g·L-1 (cell dry mass). Under the optimal condition and an initial substrate concentration of 30 mmol·L-1, the yield of 2,5-hexandiol was 78.7% and the enantiomeric excess of (2S,5S)-2,5-hexandiol was 94.4% for 24-h reduction. 展开更多
关键词 baker's yeast asymmetric reduetion 2S 5S)-2 5-hexanediol ENANTIOSELECTIVITY (S)-5-hydroxyhexane-2-one
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Synthesis and Crystal Structure of 3-(2-Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-thoxycarbonyl-cyclohexen-2-one
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作者 刘胜利 戴静芳 +1 位作者 陈勇 刘汉文 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第3期324-328,共5页
Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-ethoxycarbonyl-cyclohexen-2-one has been synthesized and characterized by elemental analysis, IR, UV, H NMR and MS, and its crystal 1 structure was determined by X-ray single-crys... Hydroxy-phenyl)-5-(2-methyl-phenyl)-6-ethoxycarbonyl-cyclohexen-2-one has been synthesized and characterized by elemental analysis, IR, UV, H NMR and MS, and its crystal 1 structure was determined by X-ray single-crystal diffraction method. The crystal belongs to the monoclinic system, space group P21/c with a = 14.6298(13), b = 5.8623(5), c = 22.255(2) ?, β = 105.855(2)o, V = 1836.0(3) ?3, Mr = 350.40, Z = 4, Dc = 1.268 g/cm3, F(000) = 744, μ(MoKα) = 0.086 mm-1, R = 0.0680 and wR = 0.1498. The crystal analysis results show that the cyclohexene unit of the title compound has a quasi-chair conformation, and a centrosymmetric dimer with a 16-membered ring is produced by the intermolecular hydrogen bonds. 展开更多
关键词 hydroxy-phenyl)-5-phenyl-6-ethoxycarbonyl-cyclohex-2-enone crystal structure hydrogen bond synthesis UV spectrum
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Synthesis and Crystal Structure of 1,4-Bis(2-hydroxymethylphenyl)-1,4-dioxabutane
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作者 许兴友 刘清亮 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2002年第5期473-476,共4页
A new ligand 1,4-bis(2-hydroxymethylphenyl)-1,4-dioxabutane was synthesized by reducing 1,4-bis(2-formylphenyl)-1,4-dioxabutane with NaBH4 in absolute methanol solution. The crystal structure of the title compound C16... A new ligand 1,4-bis(2-hydroxymethylphenyl)-1,4-dioxabutane was synthesized by reducing 1,4-bis(2-formylphenyl)-1,4-dioxabutane with NaBH4 in absolute methanol solution. The crystal structure of the title compound C16H18O4 has been determined by single-crystal X-ray diffraction. The ligand crystallizes in the orthorhombic system, space group Pbcn with a = 13.777(1), b = 11.731(1), c = 9.076(8) ? V = 1466.8(2) ?, Mr = 274.30, Z = 4, F(000) = 548, Dc = 1.24 g/cm3, T = 293 K, m = 8.9 cm-1 and l = 0.71073 ? The structure was refined to R = 0.0324 and wR = 0.1025 for 1112 observed reflections with I > 2s(I). The two benzene rings are not on the same plane, and the dihedral angle between them is 60.6? The ligand has C2 symmetry axis which passes through the center of C(8)C(8a). The molecules are linked to each other by hydrogen bonding network to form supramolecular chain. The ligands connect to each other through the hydrogen bonds to form one-dimensional chains which further connect through the hydrogen bonds to form two- and three-dimensional structures. 展开更多
关键词 LIGAND SYNTHESIS crystal structure
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Synthesis and Crystal Structure of Copper(II) Complex with Mixed Bipyridine and 2-Hydroxy-1-naphthaldehyde Ligands
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作者 BUPing-Yu YAOXin-Kan 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2002年第1期13-16,共4页
A mononuclear copper(II) complex, [Cu(bipy)(naph)(ClO4)] (where bipy is bipyridine and naph is 2-hydroxy-1-naphthaldehyde), was synthesized and characterized by X-ray single-crystal structure analysis. The crystal is ... A mononuclear copper(II) complex, [Cu(bipy)(naph)(ClO4)] (where bipy is bipyridine and naph is 2-hydroxy-1-naphthaldehyde), was synthesized and characterized by X-ray single-crystal structure analysis. The crystal is triclinic, space group P ?with a = 9.245(4), b = 9.962(4), c = 10.809(7) ? a = 84.83(5), b =82.35(4), g = 81.02(4), V = 972.1 ?, C21H15ClCuN2O6 Mr = 490.36, Z = 2, F(000) = 498, Dx = 1.68 g/cm3, m = 13.05 cm-1, R = 0.078, Rw = 0.081 for 2295 observed reflections with I > 3s(I). The copper(II) ion is coordinated by two nitrogen atoms of bipy and two oxygen atoms of naph in the equatorial plane, with an axial perchlorate oxygen-copper(II) bond to copper(II) ion to form square-pyramidal coordination geometry. The coordination environment of copper(II) is similar to the active site of galactose oxidase and this compound may also be considered as the structural model of galactose oxidase. 展开更多
关键词 copper complex crystal structure galactose oxidase
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Br?nsted acidic ionic liquid catalyzed synthesis of benzo[a]carbazole from renewable acetol and 2-phenylindoles in a biphasic system 被引量:1
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作者 Minghao Li Fengtian Wu Yanlong Gu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第8期1135-1140,共6页
An efficient metal-free strategy for the synthesis of pharmaceutically relevant benzo[α]carbazoles from the derivatives of readily available 2-phenylindole and bio-renewable acetol in an aqueous biphasic system was d... An efficient metal-free strategy for the synthesis of pharmaceutically relevant benzo[α]carbazoles from the derivatives of readily available 2-phenylindole and bio-renewable acetol in an aqueous biphasic system was developed. This protocol employed a sulfone-containing Bronsted acidic ionic liquid as the catalyst, which could be used for five times without a noticeable decrease in its activity and selectivity. Various substituted 2-phenylindoles and α-hydroxyketones participated in the reaction smoothly, with water as the sole byproduct. Mechanistically, the reaction involved the conventional carbon-nucleophile-induced Heyns-type rearrangement and downstream intramolecular olefination. 展开更多
关键词 Benzo[α]carbazole Bronsted acid ionic liquid Bio-renewable acetol 2-Phenylindole
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