胆烷

Whenpyridine was used as reductive decomposing agent, the expecting cholest-4-en-3,6-dione-22-al was obtained. However, when Zn/HOAc was used to decomposethe ozonide, C-4,5 double bond was further reduced to give cholest-3,6-dione-22-al as main product. 2 For the side-chain construction of compound (1), the solid-liquid phase-transfer Wittig reaction was used. When (3-methyl-2-oxobutyl)-triphenylarsonium bromide was used as reagent, the reaction can be carried out inmild reaction condition and the yield is higher than that when phosphorane wasused.

但使用Zn／HOAc作为分解剂时，却得到其氢化产物胆甾-3， 6-二酮-22-醛；2在甾体支链引入过程中，采用固-液相转移Wittig反应的方法，用(3-甲基)-2-氧丁基三苯基溴化胂作为试剂，反应在非常温和的条件下便可完成，而且产率比传统采用膦烷的方法更高；3在对某些甾酮化合物的选择性还原反应研究时，发现在〓还原体系中，当加入某些金属离子后，反应有更好的区域选择性和立体选择性。

Three days after inoculation, 67.13% grape phylloxera selected 'Kyoho', while only 15.29% and 17.58% phylloxera selected '5BB' and '140Ru', respectively.

对砧木5BB和巨峰根系的挥发性组分进行测定，发现2个品种挥发物独有组分数量均较高，巨峰独有组分为23个，占总成分数的48.94%，5BB的独有组分为32个，占总成分数的57.14%。5BB和巨峰的共有组分为24个，主要成分均为亚油酸甲酯和反油酸甲酯，但含量有所不同，其中，5BB以倍半萜类的丁香醇及脂肪酸甲酯类的亚油酸甲酯，反油酸甲酯，棕榈油酸甲酯含量较高，高于巨峰中相应物质含量的4.23%~6.46%，而巨峰以邻苯二甲酸二丁酯及胆甾烷含量较高，分别高于5BB相应组分含量的6.81%和1.07%。

Cerebrotendinous xanthomatosis is a rare autosomal recessive disorder of bile acid synthesis, caused by impaired hydroxylation of cholesterol side chains due to deficiency of the mitochondrial enzyme sterol 27-hydroxylase （CYP27A1）, leading to accumulation of cholestanol and cholesterol in brain and other tissues.

文章摘要：脑腱黄瘤病是一种罕见的常染色体隐性遗传性胆汁酸合成障碍，由线粒体酶固醇27-羟化酶（CYP27A1）缺陷所致胆固醇侧链羟化受损引起，从而导致胆固烷醇和胆固醇在脑和其他组织贮积。

Two pathways of cleavage and conversion in ring B of ergostane and cholestane are summarized.

第二部分总结了麦角甾烷及胆甾烷B环裂解和转化的两种途径。

Elevated plasma cholestanol serves as a key marker for the clinical diagnosis of CTX.

血浆胆固烷醇水平升高是临床确诊CTX的重要标记物。

This observation lower plasma cholestanol,

上述观察可能暗示激素可降低血浆胆固烷醇水平，该作用可能通过直接诱导残留CYP27A1活性或通过诱导胆固烷醇清除的旁路途径完成。

We use this technology to measure some rock and oil sample taken from Liaohe or Tarim basin. We identified many series of biomarker with dividing-era significance. These series are C26 steranes, C30 methylsteranes; and methly hopanoid alkanes, hexacyclic hopanoid alkanes, which two series were measured first by our laboratory in China.

本论文建立地球化学样品GOMS／MS分析方法；并对辽河盆地和塔里木盆地岩石及原油样品进行GC／MS／MS分析，鉴定出多个系列具有划时代意义的生标组分，这些组分是用GC／MS技术无法检测的极微量的生标组分：C26降胆甾烷系列、C30甲基甾烷系列等：还有高碳数甲基藿烷系列和六环藿烷系列见图1，图2，在国内被我们实验室首次检出。

By means of GC-MS-Ms method, the multiple series of age-related and taxon specific biomarkers are tested in source rocks and oil samples from Liaohe oilfield and Tarim basin, which are hard to be detected by conventional GC-MS method. They are steranes, methylsteranes, Tricyclic and tetracyclic diterpanes, methyl hopanoid alkanes and hexacyclic hopanoid alkanes, etc.

利用色谱－质普－质普方法在辽河与塔里木盆地源岩和原油样品中，检测出了多个系列时代相关及特定种属生物标志物，包括：降胆甾烷系列、甲基甾烷及甲藻甾烷系列、三环二萜烷及四环二萜烷系列、六环蒮烷及甲基藿烷系列等等，这些化合物很难用常规GC-MS形方法检测到。

Comparing with marine oils in the adjacent areas, all crude oils in Hade 4 oil field (except for HD401 well) have following peculiarity: very similar in the composition of light hydrocarbon fraction, and the distribution of of phytane-series isoprenoid alkanes, high concentration in steranes, terpanes and their aromatized compounds, as well as rearranged steranes; low concentration of gammacerane, 24-norcholestanes and 24-rearranged steranes, and low C〓 regular steranes C〓/(C〓+C〓+C〓＜20%; 3-methyl steranes and 27-norcholestane predominated, respectively; very low concentration of dinosterane and 4-methyl steroid.

分析表明，与相邻地区海相原油比较，除最南端的HD401井原油外，其它井区原油均具有下述特点：轻烃馏分组成十分接近、植烷系列类异戊烯烷烃分布较为一致、甾萜类和芳香甾萜类环状化合物浓度较高、重排甾烷丰度较高、伽马蜡烷含量低、规则甾烷组成中C〓丰度低C〓/(C〓+C〓+C〓＜20％、甲基甾烷中以3-甲基甾烷为主、甲藻甾烷和4-甲基甾烷丰度极低、降胆甾烷中以27-降胆甾烷为主、24-降胆甾烷和24-重排降胆甾烷丰度低。

Determination of Tyrosine in Urine Spectrophotometric Method;2. For chemical pre-extraction, MSTFA/TMSL derivatization reaction, GC/MS analysis, it is confirmed that two main metabolites (19-no-randrosterone and 19-noretiocholanolone) were found in nandrolone urine.

本文对合成的19-去甲雄烷醇酮的四个差向异构体混合物进行气相色谱分离，对诺龙和炔诺酮用药后，留取的人尿样通过化学预处理，MSTFA/TMSI衍生化反应，GC/MS分析，确证了尿样中诺龙的两个主要代谢产物为19-去甲雄酮和19-去甲原胆烷醇酮，炔诺酮的两个主要代谢物是四氢炔诺酮的两个形式，可能是3α-OH-5α-THINE和3α-OH-5β-THINE，在炔诺酮代谢前期，还发现有诺龙的上述两个代谢物存在。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。