Medicine from the Sea

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Bioprospecting the seas

 

Researchers largely overlooked the oceans as a source of pharmaceuticals until scuba technology was first tested in 1943. Among the pioneers of marine bioprospecting was organic chemist Paul Scheuer. In 1950, he began to collect and study an array of underwater organisms—in particular, soft, stationary creatures. Scheuer was intrigued that these thrived, though they lacked obvious defense mechanisms. He assumed the organisms had potent chemical defenses that might prove useful to people. So he began searching for and testing compounds.

 

Discovering a pain reliever

 

Prialt is a marine-derived, chronic painrelieving drug based on venom from a species of Pacific cone snail, whose poisonous harpoonlike stingers can paralyze and kill fish and humans. Biochemist Baldomero Olivera and his colleagues extracted a peptide from the venom of the cone snail, Conus magus (the magician’s cone). “I thought that if these snails were so powerful that they could paralyze the nervous system, smaller doses of the compounds from the venoms might have beneficial effects,” Olivera said. “Cone snails are of exceptional interest because the molecules they make are very small and simple, easily reproducible.”

 

In 2004, the pharmaceutical firm Élan announced that it had completed advanced trials on Prialt. The drug, acting on nerve pathways to block pain more effectively than traditional opiates, appears to be 1,000 times more potent than morphine. Researchers say it lacks morphine’s addictive potential and exhibits a reduced risk of mind-altering side effects.

 

New breed of scientist needed

 

The arduous process of identifying and testing marine compounds will soon accelerate , some scientists say. Automated chemical probes will seek out promising genetic material in a batch of seawater or ground-up sponge; then gene-copying techniques will enable researchers to reproduce the genetic compound. With the field of marine products chemistry showing such promise, a new breed of hybrid scientist has emerged: scuba-diving chemists.

Vocabulary Focus

array (n) [E5rei] a large group of things or people, especially one which causes admiration

stationary (adj) [5steiF(E)nEri] not moving, or not changing

arduous (adj) [5B:djuEs] difficult, tiring and needing a lot of effort

probe (n) [prEub] a device put inside something to test or record information

 

Specialized Terms

pharmaceutical (n) 药剂 a substance used to treat disease; a drug or medicine

peptide (n) 缩氨酸 a chemical compound made by the linking of amino acids; similar in makeup to protein, but smaller

来自海洋的医病良药

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在各海域进行生物勘探

研究人员大多忽略海洋可以成为药品原料的一个来源，直到水肺技术在1943年首次被人试验后，情况才有所改善。有机化学家保罗·邵伊尔是海洋生物勘探的先驱之一，他于1950年开始收集并研究一群海底有机体，尤其是软体、不会移动的生物。这些生物纵然缺乏明显的自我保卫机制，却仍然茂盛地生长，邵伊尔对此深感好奇。他假设这些生物拥有强而有效的化学防卫，对人体可能有所助益，于是开始从中寻找并试验各种化合物。

 

发现一种镇痛剂

Prialt是一种萃取自海洋、用以遣解慢性疼痛的药物，系由太平洋海蜗牛的毒液制造而成。这种海蜗牛鱼叉般的毒刺可令鱼类或人类麻痹或丧命。生物化学家巴度梅罗·奥利维拉与同事从名为Conus magus（直译为：魔术师的锥形筒）的海蜗牛毒液中萃取缩氨酸。奥利维拉说：“我认为若这些海蜗牛的毒素强烈到能令神经系统麻痹的程度，那么减少剂量后毒液中的化合物或许能提供正面功效。海蜗牛之所以备受瞩目，原因是它们产生的毒素分子很小、很简单，因此很容易复制。”

制药公司Élan于2004年宣布已经完成针对Prialt的探索性试验。相比传统的麻醉剂，这种药能在神经元信道阻断疼痛讯息，镇痛效力似乎是吗啡的1000倍。研究人员说，Prialt不像吗啡一样可能令人上瘾，同时大大减少了妨碍神志清醒的不良反应的危险。

 

需要新类型的科学家   

一些科学家认为，辨认与试验海洋化合物的艰苦过程很快就可缩短。自动化的化学探测器将可于一片海域或磨烂的海绵堆里找到基因类物质。之后，研究人员可利用基因复制技术来复制基因化合物。由于海洋产物化学的前景看好，一种新的跨领域科学家因此应运而生：水肺潜水化学家。