About Molecule of the WeekMolecule of the Week has been a popular feature on this site since 2001. Many molecules are suggested by chemists and chemistry enthusiasts. Every structure is reviewed by a scientist and displayed in 3-D and flat images with brief a description.

Each week’s molecule also links to a sample record from the CAS Registry, which is searched using SciFinder. Each record displays the registry number, index name and synonyms, bibliographic information, and more.

Molecule of the Week

May 19, 2008

Cadaverine(H2N-(CH2)5-NH2)

Yes, it’s what you think it is: a foul-smelling compound found in putrefying animal tissue. Cadaverine, or 1,5-pentanediamine, is formed by the decarboxylation of the amino acid lysine. It and its companion decomposition product putrescine (1,4-butanediamine) also contribute to odors associated with bad breath, urine, semen, and bacterial vaginosis.

参考译文：是的，它和你想的一样：一种存在于腐烂的动物器官里的难闻化合物。尸胺，或者说是1，5-2氨基戊烷，是由于赖氨酸的脱羧作用产生的。他和他的同系列分解物 1，4-丁二胺都与呼吸、尿、精液、细菌性阴道炎等产生的难闻气味有关。

Note:

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Have a favorite molecule? Please send us your suggestions. Be sure to note if you would like us to name you as the contributor.

The structure of the amino acid lysine:

The structure of the amino acid ornithine:

The structure of the amino acid arginine (Arg)

May 26, 2008

Cycloguanil

Cycloguanil was first observed in 1951 as a metabolite of the antimalarial drug chlorguanide; it also has shown activity against malaria. Because traditional antimalarials are becoming ineffective against new strains of the malarial protozoan Plasmodium falciparum, renewed efforts are underway to develop cycloguanil into a commercial drug.

参考译文：1951年 Cycloguanil（环氯胍）作为一种抗疟疾药物——氯胍，一种同样显示出抗疟疾活性的药物——的代谢物第一次被发现。因为传统的抗疟疾药物已经不能有效对抗新的疟原虫变种——恶性疟，人们把更新药物的努力放在了把环氯胍发展成为一种商用（抗疟疾）药物上。

Molecule of the Week

April 9, 2007

Fluoroantimonic acid

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Fluoroantimonic acid (HSbF6), the strongest known superacid, is made by combining hydrofluoric acid with antimony pentafluoride. It can be as much as 2 × 10 19 times stronger than 100% sulfuric acid. However, super acids are all as strong as one another in aqueous solution; other solvents need to be used to see their effect.

June 11, 2007

Gallic Acid

Gallic Acid, or 3,4,5-trihydroxybenzoic acid, is produced by plants such as sumac, tea leaves, oak bark, and witch hazel; it provides the astringent property and antihemorrhoid activity of witch hazel. Derivatives are used in the production of azo dyes and photographic developers. It gets its name from gall nuts, which are the swelling of plant tissue in response to parasitic infection.

参考译文：五倍子酸（没食子酸），或者称为 3，4，5—三羟基苯甲酸，存在于漆树、茶叶、橡树皮和山榆等植物中，它使山榆具有收敛性和治疗痔疮的作用。五倍子酸的名字来源于五倍子——植物组织由于受到感染而产生的膨大部分。

April 23, 2007

Polyvinyl alcohol

Polyvinyl alcohol, made by removing acetate groups from polyvinyl acentate, is a polymer used in a tremendous

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variety of products: as a vapor barrier in 2 L soda bottles, a thickening agent in shampoos, and the polymer that kids slime.

参考译文：

聚乙烯醇

聚乙烯醇通过脱去聚醋酸乙烯酯上的醋酸基团制备，是一种广泛应用于各类的

产品的聚合物：用作 2L汽水瓶的蒸气密封剂，作为洗发剂的增稠剂，还是一种

可以粘附于粘土的聚合物（这句总感觉不妥）。

Molecule of the Week

October 27, 2008

#Squalamine

Squalamine is a broad-spectrum antibiotic found in the dogfish shark

(Squalus acanthias). It was first reported by researchers at the University of Pennsylvania School of Medicine in 1993. The website http://www.squalamine.com makes somewhat extravagant claims about the benefits of taking a squalamine-containing supplement.

参考翻译：角鲨胺是在角鲨鱼身上发现的一种广谱抗生素。

关 于 角 鲨 胺 最 早 的 报 导 由 Pennsylvania 大 学 医 学 院 发 布 。 以 下 网 站 ： http://www.squalamine.com 对摄入含角鲨胺物质的好处的说法有点过分。（该网站的网页底部有说明： *

These statements have not been evaluated by the Food and Drug Administration（简称 FDA,(美国)食品和药品管理

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局）. This product is not intended to diagnose, treat, cure or prevent any disease.）

August 7, 2006

Benzocaine

Benzocaine, a common ingredient in sunburn remedies and first aid creams, is a topical anesthetic—it numbs the nerve endings near the surface of the skin where it is applied. This ethyl ester of p-aminobenzoic acid (PABA, a common sunscreen ingredient) can react with compounds in sunscreens and hair dyes or

produce an allergic reaction.

April 7, 2008

Aluminum chloride

At first glance, aluminum chloride appears to be an inorganic salt with the empirical formula AlCl3; however, aluminum, like other group III elements, tends to form covalent bonds with halides. The energetically preferred coordination number of four causes AlCl3 to form the dimer Al2Cl6 shown, even in the vapor phase. AlCl3 is perhaps the quintessential Lewis acid; it reacts violently with water to form strongly acidic solutions. It has been used for decades in industry, most notably as a catalyst in Friedel–Crafts alkylation and acylation reactions, as well as in dozens of other processes. Its hexahydrate is the active ingredient in many antiperspirants.

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参考译文：

乍一看，氯化铝好像是一种经验分子式为AlCl3的无机盐，然而，与其他第三

纵行的元素一样，铝与卤族元素倾向于形成共价键。

November 11, 2006

Caffeine

Ah, caffeine. For many people, productivity at school, work, and home would slip without a morning dose of this alkaloid found in tea leaves, coffee beans, cocoa beans, and kola nuts. Caffeine acts as a central nervous system and respiratory stimulant and is also a diuretic.

参考译文：

此文太难忠实于原文翻译

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December 1, 2008

Triptycene

Triptycene, or 9,10-dihydro-9,10[1’,2’]-benzenoanthracene, is a C14 hydrocarbon with D3h symmetry. Paul D. Bartlett and co-workers reported its synthesis in 1942; they named it after “the triptych of antiquity, which was a book with three leaves hinged on a common axis.” Its rigid framework has been incorporated in molecular motors and certain catalyst ligands.

参考译文：

三蝶烯又名。。。。，是一种具有D3h 的 c14烃(这点我很有疑问)。Paul D.

Bartlett和他的合作者于 1942年报告了这种化合物的合成，由于它的结构类

似与古代的三联图画——一本通过一条共同的轴连在一起的有三张纸的书，所

以他们给它取了这样一个名字。三蝶烯的刚性结构已经用于组装分子马达和向心

配合价体催化剂。

April 18, 2005

Carbon Monoxide,

Carbon Monoxide, produced by the incomplete combustion of organic materials, comes from automobile exhaust, tobacco smoke, and

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malfunctioning gas heaters. It has a greater affinity for hemoglobin in the bloodstream than does oxygen, and several hundred parts per million in the air can cause symptoms of oxygen deprivation.

September 12, 2005

Lithium bromide,

Lithium bromide is an extremely hygroscopic chemical commonly used in absorption chillers, where water is the refrigerant. Because of its high affinity to water, LiBr can easily absorb excess vapor, making the system an environmentally friendly non-CFC alternative.

参考译文：

溴化锂

溴化锂是一种吸湿性极强的化学品，广泛应用于冷却器里水被冷却时的吸收过

程。因为他对水的高亲和力，溴化锂很容易吸收过量的水蒸气，使（冷却）系

统成为环境友好的不使用氟氯化碳类物质的替代产品。

附：溴化锂制冷剂的原理：

April 25, 2005

Niacin,

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Niacin (also known as vitamin B-3), helps the digestive system, skin, and nerves to work properly; and it assists in converting food to energy. Niacin-rich foods include dairy products, poultry, fish, lean meats, nuts, and eggs. Legumes and enriched breads and cereals also supply some niacin.

参考译文：

烟酸

烟酸（又称为维生素B-3），

June 30, 2008

Sodium Hypochlorite

If you weren’t a chemist, you’d know sodium hypochlorite (NaClO) as bleach, or possibly as the “chlorine” you put in your swimming pool or spa. NaClO solution is a convenient way to handle chlorine in an aqueous solution; it is prepared by absorbing chlorine gas in sodium hydroxide solution. Industrially, NaClO solution is produced directly by electrolyzing sodium chloride solution.

Notes: hypo——1、海波(大苏打)；2、“下等、次等”

March 12, 2007

#Abacavir

Abacavir, is an antiretroviral drug. When a virus (such as HIV) tries to manufacture DNA from the viral RNA, it unknowingly incorporates abacavir instead of a natural component of DNA, guanosine, which stops the virus from reproducing.Suggested by Mamoun Abacavir.

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参考译文：

阿巴卡韦

阿巴卡韦是一种抗逆转录病毒药物。当病毒（譬如HIV病毒）试图通过病毒RNA合成DNA时，会

不知不觉地结合阿巴卡韦，而不是DNA的正常组成部分——鸟嘌呤核苷酸，这个过程会阻止病毒的复制。

Lophine

December 15, 2008

Lophine (2,4,5-triphenyl-1H-imidazole) exhibits lemon yellow chemiluminescence in solution and is one of the few long-lasting chemiluminescent molecules. It forms dimers that have piezochromic and photochromic properties. It has been proposed as an analytical reagent for trace metal ion detection. Lophine’s chemiluminescence was discovered by B. Radziszewski in 1877.

参考译文：

洛粉碱

洛粉碱（2，4，5—3苯基—1h—咪唑）在溶液中会发出柠檬黄色的化学发光，

是为数很少的长余辉化学发光分子之一。它形成的二聚体具有压致变色和光致

变色的性质。洛粉碱应经是一种应用于检测痕量金属离子的分析试剂。它的化

学发光性质由Radziszewski于 1877年发现。

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Ascorbic acid

Ascorbic acid (vitamin C) is a potent water-soluble antioxidant. Fruits, vegetables, and even some meats (beef, pork) are good sources.

参考译文：

抗坏血酸

抗坏血酸（维他命 C）是一种强效的水溶性抗氧化剂。水果，蔬菜，甚至是某

些肉类（牛肉，猪肉）都是很好的获取来源。

January 21, 2008

Barium sulfate

Barium sulfate (BaSO4), also known as barite, is a dense (4.48 g/cm3), insoluble salt that has many uses. Almost all barite (98%) is used as a densifying additive to oil well drilling fluids, or “muds”, which are used to seal the space around the drill bit. The mud also flushes out chippings and cools and lubricates the bit. High-density muds are necessary for drilling into deep formations to counteract high gas pressures. BaSO4 also has multiple uses in X-ray imaging, paint pigments, fireworks, and brake linings.

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October 6, 2008

Calcium Chloride

Calcium chloride (CaCl2) dissolves exothermally in water and is highly hygroscopic. These properties make it useful for applications such as removing water from gases and liquids, melting ice on roadways, maintaining a liquid layer on road surfaces for dust control, and preparing aqueous solutions with low freezing temperatures.

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March 7, 2005

Curcumin

Curcumin, the bright yellow pigment in turmeric, protects the stomach from tainted foods. It inhibits the growth of Helicobacter pylori, which has been implicated in gastric and colon cancers, but it can also reduce the effectiveness of chemotherapy.

参考译文：

姜黄素

姜黄素，在姜黄中显亮黄色的色素，可以保护胃部免受被污染食物的损害。他

可以抑制可能导致胃癌、直肠癌的细菌幽门螺杆菌的生长，但它同时也会降低

化学疗法的效果。（事实上，幽门螺杆菌是胃癌的主要致病因素，翻译为“可

能导致”未必合适）

February 5, 2007

Carminic acid

Carminic acid is a natural red dye used in everything from cosmetics to food to ink; it is commonly called carmine or crimson lake. But did you know it is extracted from the remains of dead cochineal insects?

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参考译文：

胭脂红是一种广泛应用在化妆品、食品和墨水等产品的天然红色色素，通常被

称为洋红或绯红色淀（carmine or crimson lake）。但你是否知道，它是从

死去的胭脂虫残骸中提取而来的呢？

November 24, 2008

β-Carotene

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β-Carotene, one of several naturally occurring carotene isomers, is the most important of the A provitamins. It is widely distributed in the animal and plant kingdoms and is most abundant in yellow and orange fruits and vegetables such as mangoes, papayas, yams, and carrots. In biological systems, it is cleaved at the central C=C bond to form vitamin A by the enzyme β-carotene dioxygenase.

参考译文：

β-胡萝卜素

β-胡萝卜素是几种自然存在的胡萝卜素同分异构体之一，是最重要的维生素A

原。它广泛分布于动物界和植物界，以芒果、木瓜、番薯和胡萝卜等黄色和橙

色的水果和蔬菜中的含量最丰富。在生物系统内，它在胡萝卜素双加氧酶的作

用下，在中心位的碳碳双键处断键，形成维生素A.

（像 β-胡萝卜素这样，分子内双键交替出现并达到一定长度的结构，是有色有

机物产生颜色的本质结构）

September 22, 2008

N,N-Diethyl-m-toluamide (DEET)

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This summer, you may well have used DEET-containing products to ward off mosquitoes, ticks, and other arthropod pests. The synthesis of DEET was first reported in Romanian and German journals in 1929. The U.S. Army formulated it as a repellent after World War II, and it was commercialized in 1957. Its odor is unpleasant to pests and counteracts body odors that attract them.

February 12, 2007

Docosahexaenoic acid

Docosahexaenoic acid (DHA) is an omega-3 fatty acid found in cold-water fish and linked with reducing the risks of heart and other diseases in humans. It’s even being added to infant formula.

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参考译文：

二十二碳六烯酸

二十二碳六烯酸（DHA）是一种在冷水鱼体内发现的Omega-3 脂肪酸，与降低

心脏疾病和其他人体疾病有关。它甚至被添加进了婴儿配方食品中。

October 9, 2006

Dopamine

Dopamine is a neurotransmitter, or chemical messenger, that plays a key role in controlling movement, the ability to feel pleasure and pain, and emotional response. Too little dopamine activity leads to the tremors and motor disorders symptomatic of Parkinson’s disease. Excessive dopamine activity has been linked to several medical disorders, including schizophrenia.

参考译文：

多巴胺是一种神经递质，或称为化学信使，它在调控人体活动、感受快乐与痛

苦和情感反应方面起到关键的作用。太少多巴胺的活动会导致帕金森病的颤抖

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和运动混乱症状。过量的多巴胺活动则与一些包括精神分裂在在内的生理混乱

有关。

April 21, 2008

Cyclopentadiene

Cyclopentadiene is a liquid with a low boiling point. It cannot be stored at room temperature because it spontaneously undergoes a Diels–Alder reaction with itself that forms the bridged dimer dicyclopentadiene. This reaction is reversible at elevated temperatures, so the most convenient way to obtain cyclopentadiene is to distill the commercially available dimer. Cyclopentadiene reacts with strong bases to form the cyclopentadienyl anion, which acts as a ligand in ferrocene and other “sandwich” complexes.

参考译文：

戊二烯

Anabasine

December 29, 2008

Anabasine [(±)-3-(2-piperidinyl)pyridine] is a pyridine alkaloid, closely related to nicotine. It has been used historically as an insecticide. Its isolation from the shrub Anabasis aphylla L. was reported by A. P. Orekhov and G. P. Men’shikov in 1931.

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Anabasine is also a nicotinic acetylcholine receptor agonist, and, in high doses, can cause symptoms similar to those of nicotine poisoning.

参考译文：

新烟碱

新烟碱[(±)-3-(2-呱啶基) 吡啶]（思考：哪部分是吡啶、哪部分是呱啶基）是

一种吡啶类生物碱，与尼古丁非常相近。它历史上曾被用作杀虫剂。1931年

A. P. Orekhov and G. P. Men报道了他们从无叶假木贼中提取得到新烟碱。

它同时也是烟碱类乙酰胆碱受体的竞争剂，大剂量时能引起类似于尼古丁中毒

的症状。

Molecule of the Week

Nitrogen triiodide

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June 29, 2009

Nitrogen triiodide is a dark red solid with extreme shock sensitivity. Some chemists may remember playing with it by stepping on small crystals to make it explode with a gunshot-like sound. It is often prepared as a 1:1 adduct with ammonia (NI3NH3). Because it is so sensitive, NI3 has no commercial uses.

参考译文：

三碘化氮

三碘化氮是一种具有极强的冲击敏感度的深红色固体。一些化学家可能还记得

踩踏它的小块晶体使其爆炸，产生射击一样的声音的玩法。他通常会制成与氨

气的比为 1：1的加合物。因为它过于活泼，以致尚未有商业上的应用。

2,2’-Azobis(isobutyronitrile)

February 16, 2009

2,2’-Azobis(isobutyronitrile), or AIBN, is a commonly used initiator for free-radical reactions, including many polymerizations. Its preparation was first reported by Thiele and Heuser in 1896, and it has been used in polymerization since at least the 1940s. Its

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downsides are high toxicity (it decomposes to HCN in vivo), flammability, and the explosivity of its acetone solutions.

Adamantane

July 6, 2009

Adamantane (formally tricyclo[3.3.1.13,7]decane) is an exquisitely symmetrical hydrocarbon that was originally isolated from petroleum in 1933 by the Czech researchers S. Landa and V. Machacek. Its synthesis was first reported by Vladimir Prelog in 1941. It’s the simplest diamondoid compound and is nice to look at, but it has few practical applications.

Paroxetine

September 14, 2009

Paroxetine (trade name Paxil) is an antidepressant drug in the selective serotonin reuptake inhibitor class. It was first marketed in 1992 by the company now known as GlaxoSmithKline. It has some significant side effects, and its sales have dropped off in recent years. A recent report describes a modification of paroxetine to prevent the inactivation of a liver enzyme.

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(Z)-11-Eicosen-1-ol

November 16, 2009

(Z)-11-Eicosen-1-ol is a major component of a honeybee pheromone. German researchers recently found that a species of orchid, Dendrobium sinense, also produces (Z)-11-ecosen-1-ol and uses it to trick hornets, which are honeybee predators, into landing

on its flowers and pollinating them。

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