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It's a wrap

It's a wrap

作者:郜妹栓  时间:2019-03-07 04:13:00  人气:

By Jens Thomas ONE piece of string and a couple of ceramic tubes may be all that’s needed to make and test potential drugs, according to chemists in Wisconsin. Chemists would love to eschew the laborious approach of making and testing one molecule at a time, in favour of reacting thousands of chemicals to make large libraries of new compounds (New Scientist, 13 July 1996, p 22). Until now, though, this has been limited by difficulties in tracking and testing solutions of the chemicals under scrutiny. So Alan Schwabacher, a chemist from the University of Wisconsin in Milwaukee, has developed a novel approach that overcomes the tracking problem. Schwabacher’s answer is to use a long thread that has a number of different compounds attached to it at regular intervals. The string is wrapped around a cylinder (see Diagram) of known diameter. The cylinder is then marked out lengthways into sections, and each section is reacted with a different chemical building block. This can be done in a number of ways, but for his prototype Schwabacher draws a pair of lines with wax—which acts as a barrier to aqueous solutions—along the cylinder and runs a chemical between the two lines.FIG-22042201.jpg The thread is then wrapped around another cylinder of a different diameter and split into sections again, but as the new cylinder is a different size, the previous sections are mixed into the new sections. Each of these is then reacted with a different chemical, ensuring that many permutations of reaction occur. This process can be repeated as many times as is necessary to generate the required structural diversity. At the end of the process the thread can be unwrapped and analysed—the position of a molecule along the thread determining which particular chemical building blocks have been used to make that compound. “It’s a totally novel technique and really quite clever,” said Nick Terrett,