合成设计程序有赖于人机合作和机器学习

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var xhr=new XMLHttpRequest();var url="/acs/cServe";xhr.open("POST",url,!1);xhr.onreadystatechange=function(){if(xhr.readyState===4&&xhr.status===200){var json=xhr.responseText;digitalData.userInfo=JSON.parse(atob(json))}};xhr.send() </script> <script> aemMode.push("publishMode"); </script> <script> digitalData.pageInfo.primaryTag = htmlEntities('Synthesis'); tagStack.push('synthesis'); nativoStack.push('synthesis'); articleInfo = 'Chinese'; articleInfoArr = articleInfo.split(','); for (var i = 0; i < articleInfoArr.length; i++) { articleInfoArr[i] = articleInfoArr[i].trim(); } articleInfoStack.push(articleInfoArr); </script> <script> if("Synthesis".localeCompare(digitalData.pageInfo.primaryTag)){ digitalData.pageInfo.secondaryTag = htmlEntities('Synthesis'); tagStack.push('synthesis'); nativoStack.push('synthesis'); } </script>  <script> collectionStack.push('chinese'); </script> <script type="application/ld+json"> { "@context": "http://schema.org", "@type": "Article", "mainEntityOfPage": { "@type": "WebPage", "@id":"https://cen.acs.org/synthesis/cn-Synthesis-planning-program-relies-human/97/i47" }, "description": "混合程序结合人类洞察力及机器学习开发出合成路径", "image": { "@type": "ImageObject", "url": "https://cen.acs.org/content/dam/cen/97/47/WEB/09747-scicon40-bimato-cn.jpg" }, "datePublished": "20200122", "author": { "@type": "Person", "name": "Sam Lemonick" }, "wordCount":"", "pageStart":"", "pageEnd":"", "articleSection":"Synthesis,Synthesis,C&EN 中文版", "abstract":"<p>计算机辅助合成路线设计（CASP）程序旨在复制合成化学家们处理合成时所做的工作：由一个目标分子着手，然后逆向追溯合成路径，其中包括一系列高效和可实现的反应及试剂。这一领域的工作可追溯至50年前，但成功的案例仅出现在近几年。这些案例依靠或是人类化学家们编写的化学规则或是从反应数据库中获得合成认知的机器学习算法。科研人员现今宣布结合了人类认知与机器学习的一个CASP程序比仅使用人工智能的程序表现更好，尤其涉及极少使用反应的合成路线 (Angew. Chem., Int. Ed. 2019, DOI: 10.1002/anie.201912083)。该程序为Chematica的升级版本，Chematica是由韩国蔚山国立科学技术研究所和波兰科学院的Bartosz A.Grzybowski研发，由密理博西格玛（MilliporeSigma，默克子公司）以”Synthia”为名销售。Grzybowski介绍称，该程序包含他与同事用时15余年所编写的近100，000条规则。去年，他们论证了Chematica的合成设计和人类化学家在实验室的合成设计同样或更胜一筹。截至目前，对于合成设计软件Grzybowski一度“或许是专家方针最坚定的拥护者”，美国麻省理工学院的ConnorW.Coley说，后者研发了一个基于机器学习的CASP程序。 Grzybowski及其同事如今已将机器学习加入Chematica。在与Chematica的专家编码反应的一个或多个匹配的约140万个产物分子中，他们对名为神经网络（ neural networks）的机器学习算法进行训练。Grzybowsk说，该混合方法可教会算法化学家们实际使用的专家规则。这可帮助Chematica避免有可能但不切实际的合成步骤，或帮助它支持一个文献中鲜见但对若干转化必要的反应。 Grzybowski表示，将人类洞察力加入CASP程序至关重要，因为相比总是击败人类的下象棋或围棋的那些程序，化学合成对机器学习算法提出更大的挑战。举例而言，一个成功的合成路线设计通常涉及同时考虑2或3个步骤。与在那些游戏中前进一步不同，计算某个既定合成转化的效果——例如，电子密度或立体化学—需要大量的计算时间。科研人员比较了他们的混合算法与去年公布的单纯基于神经网络方法的性能(Nature 2018, DOI: 10.1038/nature25978）。当训练数据含有数千个这些反应的案例时，两种方法获得的合成步骤在与公布反应匹配度几乎相同。而当案例数量少于100时，神经网络方法极少可识别已验证的转换，与此同时Chematica的混合版可发现的次数在75%以上。对于合成青光眼药物比马前列素，混合程序给出的个别反应并未出现在其训练数据中，这展示了其采用非常见反应的能力。化学家们认为人机合作显露出希望，尤其是对于不常见的反应。“这非常重要，因为现代逆合成算法偏好选择有良好先例的反应。”Timothy A.Cernak说，他所在的美国密歇根大学的实验室受密理博西格玛公司的支持并使用了Synthia。不过麻省理工学院的Coley提出警戒，很难将混合方法与单独的神经网络进行公平对比，因为人类专家对系统训练和测试的数据产生偏见的潜在可能很大。科研人员还未在实验室中验证生成的合成路径，但Grzybowski表示其团队很快将发布来自该程序的、经实验室测试的天然产物合成。他同时也表示无计划将混合系统加入 Synthia。请访问cenm.ag/chinese或关注ACS微信订阅号获取更多《化学与化工新闻》的中文内容由YanYan为C&EN翻译为中文。原文（英文）点击此处。</p>", "dateModified": "2020-01-22 13:17:27.733+0000", "keywords": "Chinese", "copyrightHolder": "Chemical & Engineering News", "publication": "Chemical & Engineering News", "copyrightYear": "2019", "alternativeHeadline": "", "headline": "https://cen.acs.org/physical-chemistry/computational-chemistry/cn-Synthesis-planning-program-relies-human/97/i47", "publisher": { "@type": "Organization", "name": "American Chemical Society", "logo": { "@type": "ImageObject", "url": "https://cen.acs.org/apps/cen-cloud/clientlibs/misc/cen/images/favicon.ico" } } } </script> <script type="application/ld+json"> { "@context": "http://schema.org", "@type": "Periodical", "issn": "0009-2347", "hasPart": { "@id": 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Chem., Int. Ed.</i> 2019, DOI: <a href="http://dx.doi.org/10.1002/anie.201912083" shape="rect" title="Read the article here: DOI: 10.1002/anie.201912083">10.1002/anie.201912083</a>)。</p> </div> <div class="text-left article-content"> <p>该程序为Chematica的升级版本，Chematica是由韩国蔚山国立科学技术研究所和波兰科学院的Bartosz A.Grzybowski研发，由密理博西格玛（MilliporeSigma，默克子公司）以”Synthia”为名销售。Grzybowski介绍称，该程序包含他与同事用时15余年所编写的近100，000条规则。去年，他们论证了Chematica的合成设计和人类化学家在实验室的合成设计同样或更胜一筹。截至目前，对于合成设计软件Grzybowski一度“或许是专家方针最坚定的拥护者”，美国麻省理工学院的ConnorW.Coley说，后者研发了一个基于机器学习的CASP程序。</p> </div> <div class="text-left article-content"> <p>Grzybowski及其同事如今已将机器学习加入Chematica。在与Chematica的专家编码反应的一个或多个匹配的约140万个产物分子中，他们对名为神经网络（ neural networks）的机器学习算法进行训练。Grzybowsk说，该混合方法可教会算法化学家们实际使用的专家规则。这可帮助Chematica避免有可能但不切实际的合成步骤，或帮助它支持一个文献中鲜见但对若干转化必要的反应。</p> </div> <div class="text-left article-content"> <p>Grzybowski表示，将人类洞察力加入CASP程序至关重要，因为相比总是击败人类的下象棋或围棋的那些程序，化学合成对机器学习算法提出更大的挑战。举例而言，一个成功的合成路线设计通常涉及同时考虑2或3个步骤。与在那些游戏中前进一步不同，计算某个既定合成转化的效果——例如，电子密度或立体化学—需要大量的计算时间。</p> </div> <div class="text-left article-content"> <p>科研人员比较了他们的混合算法与去年公布的单纯基于神经网络方法的性能(<i>Nature</i> 2018, DOI: <a href="http://dx.doi.org/10.1038/nature25978" shape="rect" title="Read the article here: DOI: 10.1038/nature25978">10.1038/nature25978</a>）。当训练数据含有数千个这些反应的案例时，两种方法获得的合成步骤在与公布反应匹配度几乎相同。而当案例数量少于100时，神经网络方法极少可识别已验证的转换，与此同时Chematica的混合版可发现的次数在75%以上。对于合成青光眼药物比马前列素，混合程序给出的个别反应并未出现在其训练数据中，这展示了其采用非常见反应的能力。</p> </div> <div class="text-left article-content"> <p>化学家们认为人机合作显露出希望，尤其是对于不常见的反应。“这非常重要，因为现代逆合成算法偏好选择有良好先例的反应。”Timothy A.Cernak说，他所在的美国密歇根大学的实验室受密理博西格玛公司的支持并使用了Synthia。不过麻省理工学院的Coley提出警戒，很难将混合方法与单独的神经网络进行公平对比，因为人类专家对系统训练和测试的数据产生偏见的潜在可能很大。</p> </div> <div class="text-left article-content"> <p>科研人员还未在实验室中验证生成的合成路径，但Grzybowski表示其团队很快将发布来自该程序的、经实验室测试的天然产物合成。他同时也表示无计划将混合系统加入 Synthia。</p> </div> <div class="long-form-text-par-9 container responsivegrid"> <div id="container-d0c82e3dfa" class="cmp-container"> <div class="articleBox"> <div class="artcle-large-box"> <div class="text-left 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