每周分子 | Molecule of the Week

Original ACS 美国化学会 ACS美国化学会 2022-07-01

收录于合集 #每周分子 110个

每周分子: 土臭素

Molecule of the Week: Geosmin

土臭素是一种带有土味的天然双环萜烯。根据默克指数，它是“甜菜精的主要挥发性成分，也是……鱼、豆类、水的强力土味污染物。”人的鼻子可以在低至5ppt的空气中闻到它。

1936年，位于泰丁顿(伦敦)的化学研究实验室的A. C. Thaysen描述了一种由放线菌在钓鱼水流中产生的有味化合物。大约30年后，罗格斯大学(Nutgers University)的Nancy N. Gerber和Hubert A. Lechevalier从数个链霉菌属分离出了这种有气味的化合物。他们没有确定其结构，而是用希腊语“地球”和“气味”将其命名为“土臭素”。生物化学家格柏(Gerber)随后阐明了其结构。

到了2019年，隆德大学(瑞典)的生物学家Marcus C.Stensmyr和博士后Nadia Melo发现黄热蚊(埃及伊蚊)被土臭素吸引。佛罗里达国际大学(公园大学)的同事表明，埃及伊蚊非常喜欢这种气味，以至于将卵产于土臭素诱饵中。

由于甜菜皮富含土臭素，因此Stensmyr聘请了阿拉戈斯联邦大学(巴西马塞约)的一个团队来构建和测试一个用甜菜皮提取物作诱饵的简易捕蚊陷阱。这是一箭双雕的一招，因为果皮是废弃物。Stensmyr打算继续改进陷阱，并观察它是否能让蚊子数量显著减少。

土臭素信息速览

CAS 登记号	19700-21-1
SciFinder命名	4a(2H)-Naphthalenol, octahydro-4,8a-dimethyl-, (4S,4aS,8aR)-
分子式	C₁₂H₂₂O
摩尔质量	182.30 g/mol
外观	无色固体或油
溶点	47 ºC
沸点	270-271 ºC
水溶性	160 mg/L (est.)

土臭素危害信息

危险等级*：严重眼损伤/眼刺激，类别2A
H319——造成严重眼损伤

【关于每周分子】

自2001年以来，“每周分子”已成为广受欢迎的栏目。多数分子由读者推荐。每个结构都经由科学家审查，并以3-D和平面图像的形式显示，同时附有该分子简介。可以通过美国化学文摘社 (CAS) 提供的SciFinder中的CAS REGISTRY获取“每周分子”的更多信息。CAS REGISTRY中的每条物质信息都展示了物质的CAS登记号、索引名、通用名、商品名、书目信息等其他更多信息。发送邮件至motw@acs.org推荐您感兴趣的分子吧。

Geosmin is a natural bicyclic terpene with an earthy odor. According to The Merck Index, it is the “major volatile component of beet essence, also... the potent earthy odor contaminant of fish, beans, [and] water.” The human nose can detect it at concentrations in air as low as 5 ppt.

In 1936, A. C. Thaysen at the Chemical Research Laboratory, Teddington (London) described an odorous compound produced by actinobacteria in fishing streams. About 30 years later, Nancy N. Gerber and Hubert A. Lechevalier at Rutgers University (New Brunswick, NJ) isolated it from several Streptomyces spp. They did not determine its structure but named it geosmin from the Greek words for “earth” and “smell”. Biochemist Gerber later elucidated its structure.

Flash forward to 2019, when biologist Marcus C. Stensmyr and postdoc Nadia Melo at Lund University (Sweden) observed that yellowfever mosquitoes (Aedes aegypti) are attracted to geosmin. Their colleagues at Florida International University (University Park) showed that A. aegypti like the odor so much that they lay their eggs in geosmin baits.

Beet peels are rich in geosmin, so Stensmyr engaged a team at the Federal University of Alagoas (Maceió, Brazil) to construct and test a simple trap baited with beet-peel extract. This is a win–win situation because the peel is a waste product. Stensmyr’s next steps are to optimize the trap and observe whether it significantly decreases mosquito populations.

Geosmin fast facts

CAS Reg. No.	19700-21-1
SciFinder nomenclature	4a(2H)-Naphthalenol, octahydro-4,8a-dimethyl-, (4S,4aS,8aR)-
Empirical formula	C₁₂H₂₂O
Molar mass	182.30 g/mol
Appearance	Colorless solid or oil
Melting point	47 ºC
Boiling point	270-271 ºC
Water solubility	160 mg/L (est.)

Geosmin hazard information

Hazard class*: Serious eye damage/eye irritation, category 2A
H319—Causes serious eye damage

About Molecule of the Week

MOTW has been a popular feature on ACS website since 2001. Many molecules are suggested by our website visitors. Every structure is reviewed by a scientist and displayed in 3-D and flat images with a brief 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. Send us a molecule suggestion at motw@acs.org.

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