查询词典 trihydroxy

Dihydroxy-7, 4′-dimethoxy-dihydrflavonol and -3, 5, 7 -trihydroxy-4′-methoxy- dihydrflavonol were synthesized by selective protection, condensation, epoxidation, cyclization and deprotection from 2, 4, 6-trihydroxyacetophone and anisaldehyde.

以2，4，6-三羟基苯乙酮和茴香醛为起始原料，经选择性保护、缩合、环氧化、关环等步骤首次完成了-3，5-二羟基-7，4′-二甲氧基二氢黄酮醇和-3，5，7-三羟基-4′-甲氧基二氢黄酮醇全合成。

Methyl 3,6,8-trihydroxy-7-methoxy-1-methylanthraquinone-2-carboxylate is a new COX-2 selective inhibitor isolated from Gladiolus gandavensis.

1-甲基-2-甲氧羰基-3， 6， 8-三羟基-7-甲氧基蒽醌是从唐菖蒲干球茎中分离到的具有环氧化酶-2选择性抑制活性的多取代蒽醌类化合物。

Result: Seven compounds were obtained and they are identified as luteolin, 5,7,4′-trihydroxy-3′-methoxy flavone, luteolin-7-O-β-D-glucoside, apigenin,β-sitosterol, stigmasterol, ursolic acid.

结果：从乙醇提取物中分离并鉴定了7个化合物，分别为：5 ，7，3′，4′-四羟基黄酮，5 ，7，4′-三羟基- 3′-甲氧基黄酮，5 ，3′，4′-三羟基黄酮- 7- O-β- D-葡萄糖苷，5 ，7，4′-三羟基黄酮，β-谷甾醇，豆甾醇和熊果酸。

A series of crosslinked sulfonated polys were synthesized from 4,4'-difluorodiphenyl sulfone, 4,4'-biphenol, 3,3'-disulfonate-4,4'-difluorodiphenyl sulfone and 1,3,5-trihydroxy benzene by nucleophilic substitution polycondensation reactions. The trifunctional crosslinker of THB was in the mass fraction range of 3%-7%.

以4，4'-二氟二苯砜、4，4'-联苯二酚、3，3'-二磺化－4，4'-二氟二苯砜二钠盐和三羟基苯为原料，经高温溶液缩聚反应，制备了一系列不同磺化度的新型交联磺化聚芳醚砜。

On the basis of spectral analysis, these compounds were identified as Kaempferol , Kaempferol-3-O-β-D-glucopyranoside , Kaempferol-3-O-β-D-galactopyranoside, Quercetin , Quercetin-3-O-β-D-arabinopyranoside, Quercetin-3-O-β-D-galactopyranoside, gallic acid, methyl gallate-4-O-β-D- galactopyranoside, caffeicacid, methyl caffeate, 4-cafeoyl-(3"a, 4"a, 5"β)- trihydroxyquinic acid, 3"-cafeoyl-(3"a, 4"P, 5"P )-trihydroxyquinic acid methyl ester, 5"-cafeoyl-galactonic acid , pumiloside, loganic acid , 5R,6S,7E-megastima-3-on-7-en-9-ol 9-O-β-D-glucopyranoside. 2a, 3β-dihydroxy-oleanoic acid , 2a, 3β, 23-trihydroxy-oleanoic acid, 3a, 6a-dihydroxy-oleanoic acid, 3β-hydroxy-ursoic acid, 2a, 3a, 23-trihydroxy-ursoic acid , 2a, 3β, 23-trihydroxy-ursoic acid, 2β, 3β, 19a -trihydroxy-ursoic acid, 2a , 3β, 19a -trihydroxy-ursoic acid-28-O-β-D-glucopyranoside , 2a. 3a, 19a-trihydroxy-ursoic acid-28-O-β-D-glucopyranoside, 2a, 3a, 19a, 23-tetrahydroxy-ursoic acid, 1a, 3a, 19a, 23-tetrahydroxy-ursoic acid-28-O-β-D-glucopyranoside , 3a, 19a, 23-trihydroxy-ursoic acid.

从珙桐中分离鉴定得到了28种化合物，它们分别是：山奈酚，3-O-β-D-吡喃葡萄糖基-山奈酚甙，3-O-β-D-吡喃半乳糖基-山奈酚甙，槲皮素，3-O-β-D-吡喃阿拉伯糖基-槲皮素甙，3-O-β-D-吡喃半乳糖基-槲皮素甙，没食子酸，4-O-β-D-吡喃半乳糖基-没食子酸甲酯，咖啡酸，咖啡酸甲酯，4-咖啡酰基-(3&α，4&α，5&β)-三羟基鸡纳酸，4-咖啡酰基-(3&α，4&β，5&β)-三羟基鸡纳酸甲酯，5'-咖啡酰基-半乳糖酸，pumiloside，loganic acid，5R，6S，7E-megastima-3-on-7-en-9-ol9-O-β-D-glucopyranoside，2α，3β-二羟基齐墩果酸，2α，3β，23-三羟基齐墩果酸，3α，6α-二羟基齐墩果酸，3β-羟基熊果酸，2α，3α，23-三羟基熊果酸，2α，3β，23-三羟基熊果酸，2β，3β，19α-三羟基熊果酸，2β，3β，19α-三羟基熊果酸-28-O-β-D-吡喃葡萄糖甙，2α，3α，19α-三羟基熊果酸-28-O-β-D-吡喃葡萄糖基甙，2α，3α，19α，23-四羟基熊果酸，2α，3α，19α，23-四羟基熊果酸-28-O-β-D-吡喃葡萄糖基甙，3α，19α，23-三羟基熊果酸。

The more the number of hydroxyl substitution in phenyl ring, the better the ability of scavenging DPPH free radical. That is, trihydroxy is better than dihydroxy, and dihydroxy is better than monohydroxy. Moreover, when the polyhydroxy exists in phenyl ring and it is ortho-position or para-position, the ability of scavenging DPPH free radical is better too.

当苯甲醯基的苯环上羟基取代数量越多，其清除DPPH自由基的能力越好，三羟基效果优於双羟基、单羟基，双羟基效果优於单羟基；而苯甲醯基苯环上若为多羟基且羟基的位置为邻位或对位的关系时，其在清除DPPH自由基的能力较佳。

An acid dyeable polyacrylonitrile blend fiber was prepared by blending polyacrylontrile and a copolymer syn-thesized from trihydroxy methyl-aminomethane containing basic groups and acrylonitrile raonomr via wet spinning process.

用含有碱性基团的丙烯酸氨基酯与丙烯腈单体共聚，其共聚物与聚丙烯腈共混，经湿法纺丝制备酸性染料可染PAN共混纤维。

1H-imidazolyl)-1H-imidazolium chloride-4-aminobenzoic acid, 2,2-bi-1H-imidazolium bis(3,4,5-trihydroxy benzoate) tetrahydrate and bis2-(2-1H-imidazolyl-1H-imidazolium 3-carboxy-4-hydroxybenzene-sulfonate monohydrate have been synthesized and characterized by X-ray diffraction methods.

在化合物中，晶体结构中的基本单元是一个通过氢键模式R_2~2(9)和R_2~1(7)构成的氢键三聚体PABA…H_3biim~+…Cl~-，这个三聚体基本单元又通过N-H…Cl氢键相互作用形成了一维带状结构。

The structures were identified by NMR, IRand MS.Results Three compounds were identified from its 80% alcohol extract as: 5,7,3'-trihydroxy- 4'-methoxyflavanone, 4',5, 7- trihydroxyflavanone, stigmaasterol.

结果 从紫茉莉种子的80%乙醇提取物中分离到3 化合物，它们的结构分别被鉴定： 5，7，3'-三羟基-4'-甲氧基黄酮(1)， 4'，5， 7-三羟基黄酮(2)，豆甾醇(3)。

Objective To explore the inhibitive effects of 1, 3, 8-trihydroxy-5-methoxyxanthone on cytochrome P450s (CYP450s) in human liver microsomes.

目的：在人肝微粒体中研究1，3，8-三羚基－5-甲氧基山酮(1，3，8-trihydroxy-5-methoxyx-anthone，TMX)对细胞色素P450酶(CYP450s)的抑制作用。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。