羟基

It is seen that oxygen group function of additives is very remarkably in tribological characteristics, that is EP property of dihydroxy docosanoic acid without active element is very near to that of SO with active element sulfur.

双羟基廿二酸的极压性与不含氧基团的硫化烯烃十分接近，以液体石蜡为基础油，最大无卡咬负荷P〓值，前者为539N，后者为588N，再者相差49N，可以看出，氧基团的作用是十分显著的，即无活性元素的双羟基廿二酸的极压性可以十分接近于含活性元素的抗磨极压剂硫化烯烃。

The method comprises: utilizing arctiin as the precursor compound, and converting arctiin into 4, 4'-dihydroxy enterolactone by intestinal bacteria in an anaerobic condition. 4, 4'-dihydroxy enterolactone is lignin compound, and can be converted into phytoestrogen in human intestinal canals.

本发明是以牛蒡苷为先导化合物，在厌氧条件下，以肠道细菌将牛蒡苷转化为4，4′-二羟基肠内酯。4，4′-二羟基肠内酯为木脂素类化合物，在人的肠道中能被转化为植物雌激素―肠内酯而发挥药理作用。

Two oleanane type triterpenes were isolated from the crude drug Lu Lu Tong , the fruits of Liquidambar formosana and their structures were elucidated as 2α,3β dihydroxy 23 norolean 4(24), 12(13) dien 28 oic acid(1), 2α,3β,23 trihydroxyolean 12(13) en 28 oic acid(2), based on 13 C NMR, DEPT, 1H NMR, 1H 1H COSY, 13 C 1H COSY, IR, MS and elemental analysis.

从生药路路通分离得到2个齐墩果烷骨架的五环三萜类化合物。通过13CNMR，DEPT，1HNMR，2D1H－13CCOSY，2D1H－1HCOSY，IR，MS和元素分析阐明了它们的结构。（1）为2α，3β－二羟基－23－去甲－齐墩果－4（24），12（13）－二烯－28－羧酸，（2）为2α，3β，23－三羟基齐墩果－12（13）－烯－28－羧酸，（1）未见文献报道，（2）是首次从这一植物中分离得

Result: 5 compounds were identified as eriodictyol (1), 5, 7-dihydroxy-3′, 4′-dimethoxy flavanone (2), oleanolic (3), 5, 7-dihydroxychromone (4) and homeriodictyol (5) by spectral evidences, in which homeriodictyol (5) had acceleration differentiation to PC12 cell.

结果：获得了5个主要化学成分，即北美圣草素(1)， 5，7-二羟基-3′，4′-二甲氧基-二氢黄酮(2)，齐墩果酸(3)， 5，7-二羟基色原酮(4)，高北美圣草素(5)。经活性筛选试验发现，化合物高北美圣草素(5)具有促PC12细胞分化作用。

The new synthetic technology of some important anthraquinone intermediates derived from 1-amino- anthraquinone, l-amino-4-hydroxy-anthraquinone, l-amino-4-bromo- anthraquinone-2-sulfonic acid, 1,5- and 1,8 dinitro- anthraquinone, have been studied.

本文研究了几种重要的由1-氨基蒽醌衍生的蒽醌型中间体：1-氨基-4-羟基蒽醌、1-氨基-4-溴蒽醌-2-磺酸和1，5-及1，8-二硝基蒽醌的合成化学，在此基础上开发了上述中间体的合成新技术。现行1-氨基-4-羟基蒽醌的生产技术是从1-氨基蒽醌出发，经二溴化再水解制得，溴的耗量在1.5mol以上。

The first asymmetric synthesis of trans-β-hydroxy-γ-butyrolactones:-(3R, 4R, 5S)-4-(1-acetoxy-isopropyl)-3-hydroxy-butyrolactone 65a was achieved starting from isobutylaldehyde through nine steps. The key steps involve the construction of three chiral carbon centers by the Sharpless's asymmetric epoxidation and Substrate directable chemical reaction.

以异丁醛为起始原料，经过九步反应首次设计合成了具有三个手性中心的trans-β-羟基-γ-丁内酯：-（3R，4〓，5S）-4-（1-乙酰氧基-异丙基）-3-羟基-丁内酯65a，关键步骤是Sharpless不对称环氧化和底物定向不对称合成反应。

A fully ethoxy-terminated polymethylsilsesquioxane has been prepared via a dehydration ethanolysis reaction between absolute ethanol and an ordered ladder-like HO-Me-T, which improved long-term storage stability of HO-Me-T. Meanwhile, EtO-Me-T can still participate in the cross-linking reaction with hydroxy-terminated PDMS in the presence of catalyst.

利用含端羟基的LPS与无水乙醇之间的催化脱水反应合成了一种乙氧基为末端基团的活性梯形聚甲基倍半硅氧烷，有效地改善该类聚合物的长期稳定性；同时，该乙氧基封端聚合物仍然具有活性，可以代替常用的正硅酸乙酯与羟基硅油进行交联反应。

In the presence of alkalinity and tetraethyl ammonium bromide, 2,4-dihydroxy benzophenone reacts with allyl glycidyl ether to form an ethylenic derivative of benzophenone, 2-hydroxy-4-(β-hydroxy-γ-allyloxy) propyloxy benzophenone, which can further undergo hydrosilylation with polyhydromethylsiloxane.

在相转移催化剂四乙基溴化按作用下，利用2，4-二羟基二苯甲酮与烯丙基缩水甘油醚在碱性水溶液中的开环加成反应，合成了中间体4-丙氧基－2-羟基二苯甲酮，将其进一步与聚甲基氢硅氧烷进行硅氢化加成反应。

In this work , 1,8-octodiol, the starting material, reacted with 40% hydrobromic acid to produce 8-bromooctan-1-ol, with the catalytic action of PPTs, its hydroxyl group was protected by 2,3-dihydropyran. Then it coupled with 1-heptaalkyne, by means of P-2 nickel as catalyst, stereoselectivity catalysis hydrogenated, with the catalytic action of acid to take off extremital 2, 3-dihydropyran which protected hydroxy group, then used PCC to oxidize alcohol into corresponding aldehyde.

以1，8-辛二醇为原料，与40%氢溴酸进行单溴代反应，得到8-溴-1-辛醇，在对甲苯磺酸吡啶盐的催化下与2，3-二氢吡喃反应，保护分子中的羟基，再与1-庚炔进行偶联，以P-2镍为催化剂立体选择性催化加氢，酸性条件下脱末端的2，3-二氢吡喃对羟基的保护，使用氯铬酸吡啶盐将醇氧化成醛。

The main metabolites in each reactor were detected by UV/VIS, infrared and high performance liquid chromatography and mass spectrometry. Probably, the mother dye molecule facultatively hydrolyzed to produce 1-NH2-2-hydroxy anthraquinon, OH-substituted anthraquinon and 3,4-dihydroxy-benzonic acid.

对各反应器中主要的代谢产物分别进行紫外-可见、红外和高效液相色-质联谱仪检测分析后发现，母体染料经兼氧水解首先生成1-氨基-2-羟基蒽醌以及还原态的—OH基取代蒽醌隐色体，进一步水解生成3，4-二羟基苯甲酸。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。