立体异构的

For lactic acid has one asymmetric carbon atom, the mechanical, physical and biological properties of PLA are related to the stereochemistry of lactic acids.

合成聚乳酸的初始物质―乳酸是有手性的分子，使得聚乳酸的机械和物理性能以及生物学性质与乳酸单体的立体异构性有关。

Serum levels of ADMA and its stereoisomer, symmetrical dimethylarginine, were determined using high-performance liquid chromatography.

使用高效液相色谱法测定ADMA及其立体异构体对称二甲基精氨酸的血清浓度。

Uses: Lutein, and its naturally occurring stereoisomer zeaxanthin, is used as part of a general carotenoid defense against oxidative stress, whether solar or metabolic.

用途： 叶黄素和其立体异构体玉米黄质，作为常规类胡萝卜素的一部分，用于防止来自日光的或者来自新陈代谢的氧化压力。

The optical activity of a stereoisomer is expressed quantitatively by its optical rotation, The specific rotation 〖α〗D25C of an optically active compound is defined thus

立体异构体的光学活性是以旋光度定量表示的，光学活性物质的比旋光度〖α〗D25C是这样定义的

B (1R,3S)-1-ethyl-3-bromocyclopentane,andan optically active stereoisomer of 1,3-diethylcyclohexane.

答：指出1-甲基萘的所有手性中心，它存在多少个立体异构体

Accordingly, in the original reaction (formation of B from cyclopentadiene and benzoquinone) Diels and Alder found only one of the following six conceivable stereoisomers of B.

因此，在该原始反应中(即通过P-苯醌和过量的环戊二烯生成B)，Diels and Alder发现在他们推测的六个立体异构中，只有一个出现。

The present invention concerns the compounds having the formula N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs, esters and metabolites thereof, wherein R1 and R8 each are H, optionally substituted C1-6alkyl, C2-6alkenyl, C3-7cycloalkyl, aryl, Het1, Het2; R1 may also be a radical of formula (R11aR11b)NC(R10aR10b)CR9-; t is 0, 1 or 2; R2 is H or C1-6alkyl; L is -C-,-O-C-,-NR8-C-,-O-C1-6alkanediyl-C-,-NR8-C1-6alkanediyl-C-,-S2-,-O-S2-,-NR8-S2 ; R3 is C1-6alkyl, aryl, C3-7cycloalkyl, C3-7cycloalkylC1-4alkyl, or arylC1-4alkyl; R4 is H, C1-4alkylOC, carboxyl, aminoC, mono- or di(C1-4alkyl)aminoC, C3-7cycloalkyl, C2-6alkenyl, C2-6alkynyl or optionally substituted C1-6alkyl; R5 and R6 are H or C1-6alkyl.

本发明涉及右式化合物其N-氧化物、盐、立体异构形式、外消旋混合物、前药、酯及代谢物，其中R 1 及R 8 各是氢、C 1-6 烷基、C 2-6 烯基、C 3-7 环烷基、芳基、Het 1 、Het 2 ；R 1 也可以是式(R 11a R 11b )NC(R 10A R 10b )CR 9 -之基；t是0、1或2；R 2 是氢或C 1-6 烷基；L是-C-、-O-C-、-NR 8 -C-、-O-C 1-6 烷二基-C-、-NR 8 -C 1-6 烷二基-C-、-S 2 -，-O-S 2 -、-NR 8 -S 2 -；R 3 是C 1-6 烷基、芳基、C 3-7 环烷基、C 3-7 环烷基C 1-4 烷基或芳基C 1-4 烷基；R 4 是氢、C 1-4 烷基OC、羧基、氨基C、一-或二(C 1-4 烷基)氨基C、C 3-7 环烷基、C 2-6 烯基、C 2-6 炔基或任选被取代的C 1-6 烷基；R 5 及R 6 是氢或C 1-6 烷基。

This requirement may be satisfied by the submission of information such as the following: name (generic name, chemical name, code number); Chemical Abstracts Service number if available; description (e.g., appearance, color, physical state); molecular formula and molecular weight; structural formula (including ionic state if applicable); stereochemistry identifying chiral centers, cis-trans isomerism, etc.

该要求可以通过提供下述信息来满足：名称（通用名、化学名、编码等）、化学摘要服务编码、性状描述（如：外观、颜色、物理状态）、分子式和分子重量、结构式、立体化学（找出手性中心、顺式反式异性等）、对映结构体比率（如：外消旋物、规定的异构体、对映异构物和固态形式的混合物）、溶解度概况、分配系数、溶液 pH 值、解离常数、熔点或沸点、折射率、比重。

This requirement may be satisfied by the submission of information such as the following: name (generic name, chemical name, code number ); Chemical Abstracts Service number if available; description (e.g., appearance, color, physical state ); molecular formula and molecular weight; structural formula (including ionic state if applicable ); stereochemistry identifying chiral centers, cis-trans isomerism, etc.

有的话、描述（如：外观、颜色、物理状态）、分子式和分子重量、结构式、立体化学（找出手性中心、顺式贯穿异性等）、对映结构体或固态形式比率（如：外消旋物、规定的异构体、对映异构物和固态形式的混合物）、溶解性档案、分隔系数、溶液pH值、解离常数、熔点和沸点、拆射率、精确重力。

Enantiomer or solid-state form ratios (e.g., for racemates, and for defined admixtures of isomers or enantiomers or solid-state forms); solubility profile (aqueous and nonaqueous as applicable); partition coefficients; solution pH; dissociation constant; melting or boiling point; refractive index; specific gravity.

该要求可以通过提供下述信息来满足：名称（通用名、化学名、编码等）、化学摘要服务编码、性状描述（如：外观、颜色、物理状态）、分子式和分子重量、结构式、立体化学（找出手性中心、顺式反式异性等）、对映结构体比率（如：外消旋物、规定的异构体、对映异构物和固态形式的混合物）、溶解度概况、分配系数、溶液pH值、解离常数、熔点或沸点、折射率、比重。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失