甲基化作用

We investigated constituent of triterpenoid saponins ofAlbizzia, two new compounds together with two known compounds were isolated from Albizzia julibrissin Durazz. by using column chromatography (macroreticular resin, silica gel, Sephadex gel, reverse phase silica gel),preparative HPLC methods et al.On the basis of spectroscopic analysis, including IR,ESI-MS,~1H-NMR,~(13)C-NMR,HMBC,HMQC,~1H-~1HCOSY and chemical methods, the structure of two new compounds were identified as 3 - O -[β-D-xylopyranosyl(1→2)-β-D-fucopyranosyl (1→6)-β- D -2- deoxy - 2 - acetoamidoglucopyranosyl] -21-O-[(6S)-2- trans- 2,6-dimethyl - 6 - O-β- D - quinovopyranosyl -2,7- octadienoyl] - acacic acid- 28 - O-β-D-glucopyranosyl(1→3)[α-L-arabinofuranosyl(1→4)]-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside acacic acid 3- O -β- D- glucopyranosy(1→3)-β- D- fucopyranosl(1→6) [β-D- xylopyranosyl (1→2)]-β-D-glucopyranoside ;two known compounds were acacic acid lactone 3- O -β-D- xylopyranosyl-(1→2)-β-D-fucopyranosl (1→6)- 2-deoxy -2 -acetoamido -β-D- glucopyranoside ; acacic acid lactone 3- O-β-D-xylopyranosyl(1→2)-α-L- arabinopyranosl (1→6)- 2- deoxy - 2- acetoamido -β-D-glucopyranoside . The study lays chemical foundation and chemical reference substance for enhancing quality standard of Albizzia julibrissin Durazz.

本研究论文在综述国内外对合欢属Albizzia三萜皂苷化学成分和药理作用研究进展的基础上，利用传统植化分离手段和现代分离技术，包括大孔树脂、硅胶、葡聚糖凝胶、反相硅胶等柱色谱，制备高效液相色谱法等技术从中药合欢皮中分离得到了4个化合物，其中，2个新化合物和2个己知化合物，并进一步通过现代分析技术IR，ESI-MS，~1H-NMR，~(13C-NMR，HMBC，HMQC，~1H-~1HCOSY等和化学方法鉴定了2个新化合物的结构分别是：3-O-[β-D-吡喃木糖基(1→2)-β-D-吡喃夫糖基(1→6)-β-D-2-去氧-2-乙酰氨基吡喃葡萄糖基]-21-O-[(6S)-2-反式-2，6-二甲基-6-O-β-D-吡喃鸡纳糖基-2，7-辛二烯酸基]-金合欢酸-28-O-α-L-呋喃阿拉伯糖基(1→4)[β-D-吡喃葡萄糖基(1→3)]-α-L-吡喃鼠李糖基(1→2)-β-D-吡喃葡萄糖苷，金合欢酸3-O-β-D-吡喃葡萄糖基(1→3)-β-D-吡喃夫糖基(1→6)[β-D-吡喃木糖基(1→2)]-β-D-吡喃葡萄糖苷；2个已知化合物结构分别是：金和欢酸内酯3-O-β-D-吡喃木糖基(1→2)-β-D-吡喃夫糖基(1→6)-β-D-2-去氧-2-乙酰氨基吡喃葡萄糖苷，金和欢酸内酯3-O-β-D-吡喃木糖基(1→2)-α-L-吡喃阿拉伯糖基(1→6)-β-D-2-去氧-2-乙酰氨基吡喃葡萄糖苷。

The absorption bands in visible region are related to photoinduced electron transfer processes, and the dimethylfluorenyl amino benzofuran groups are major chromophore thatcontributed to the sensitization of photo-to-current conversion.

可见区的吸收带都与光诱导电荷转移过程有关，二甲基芴氨基苯并呋喃基团是在光电转换敏化中起主要作用的基团。

In the medium of H_2SO_4 and catalyzed by potassium bromide, iodate can oxidize and decolorize methyl orange very well.

基于硫酸介质中，碘酸根在溴化钾的催化作用下对甲基橙有较好的氧化褪色作用。

This paper reports the sensitizing effect on the fluorescence of Mo morin complex by CTMAB.

研究了十六烷基三甲基溴化铵对钼－桑木色素络合物荧光的增敏作用。

A process for preparingp-fluo-2-(2-methyl-3-propionyl)-4-oxy-N,3-diphenyl-phenylbutylamide includes such steps as Friedle-Craft acylating of newly prepared phenylacetyl chloride and fluorobenzene under catalysis of AlCl3 to obtain 4-fluoro-phenylbenzyl ketone, brominating at carbonyl alpha position under catalysis of less AlCl3 to obtain alpha-bromo-4-fluo-phenylbenzyl ketone, and condensing with isobutyryl acetanilide under action of sodium ethoxide.

本发明涉及一种制备对氟－2－(2－甲基－3－氧丙基)－4－氧－N，3－二苯基－苯丁酰胺(1)的方法，其包括以下步骤：新制的苯乙酰氯与氟苯在AlCl3催化下进行Friedle－Craft酰化反应，得到对4－氟－苯基苄基酮(4)；化合物(4)在少量AlCl3催化下进行羰基α位溴化，得到α－溴－4－氟－苯基苄基酮(5)；然后(3)异丁酰乙酰苯胺在乙醇钠作用下与化合物(5)进行缩合。

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。

Surfactants of Hexadecyl trimethyl ammonium bromide and alkyl polyoxyethylene have a slow dying at a higher temperature and have accelerated dying at a lower temperature while leather dying with the curcuma dye.

而表面活性剂十六烷基三甲基溴化铵及平平加O对姜黄素在皮革的染色在较低温度下有一定的促染作用，在较高温度下有一定的缓染作用。

Dot1 binding to chromatin occurs normally in the absence of H2B-K123 ubiquitylation, suggesting that ubiquitylation does not regulate enzyme recruitment but does regulate the processive activity of the histone methyltransferase.

Dot1结合到染色质通常出现在H2B－K123没有泛素化的状态，暗示泛素化并不调节酶的募集，但调节组蛋白甲基转移酶后续作用的活性。

After superfusing the brain slice with guanylate cyclase inhibitor,MB(3 pmol/L) for 30 min,SDR of 10 units showed significant increase as compared with control. However,MB failed to abolish the effect of L-arg on hippocampal neurons.

3给脑片灌流鸟昔酸环化酶抑制剂亚甲基蓝(3umol/L 30 min后，10个单位的平均放电频率较对照时明显增加，但亚甲基蓝不能消除L-arg对海马神经元的作用。

N-methylmaleimide was prepared by using dimethyl sulfate as methylation reagent.The paper investigated the addition of N-methyl-3,4-dibromomaleimide and indolylmagnesium bromide,and then 2-bromo-3-(1H-indolyl-3-yl)-N-methylmaleimide and 3,4-bis(1H-indolyl-3-yl-)-N-methyl-maleimide were obtained.

对吲哚在溴乙烷和镁作用下生成吲哚溴化镁，而后与3，4－二溴－N－甲基马来酰亚胺的加成反应进行了研究，合成了2－溴－3－(1H－吲哚－3)－N－甲基马来酰亚胺，并对反应条件进行了改进，研究了反应温度和原料配比对反应的影响。

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。