A new research framework is proposed to incorporate machine learning techniques into the field of experimental chemistry to facilitate chromatographic enantioseparation. A documentary dataset of chiral molecular retention times (CMRT dataset) in high-performance liquid chromatography is established to handle the challenge of data acquisition. Based on the CMRT dataset, a quantile geometry-enhanced graph neural network is proposed to learn the molecular structure-retention time relationship, which shows a satisfactory predictive ability for enantiomers. The domain knowledge of chromatography is incorporated into the machine learning model to achieve multi-column prediction, which paves the way for chromatographic enantioseparation prediction by calculating the separation probability. Experiments confirm that the proposed research framework works well in retention time prediction and chromatographic enantioseparation facilitation, which sheds light on the application of machine learning techniques to the experimental scene and improves the efficiency of experimenters to speed up scientific discovery.

The accurate prediction of physicochemical properties of chemical compounds in mixtures (such as the activity coefficient at infinite dilution $\gamma_{ij}^\infty$) is essential for developing novel and more sustainable chemical processes. In this work, we analyze the performance of previously-proposed GNN-based models for the prediction of $\gamma_{ij}^\infty$, and compare them with several mechanistic models in a series of 9 isothermal studies. Moreover, we develop the Gibbs-Helmholtz Graph Neural Network (GH-GNN) model for predicting $\ln \gamma_{ij}^\infty$ of molecular systems at different temperatures. Our method combines the simplicity of a Gibbs-Helmholtz-derived expression with a series of graph neural networks that incorporate explicit molecular and intermolecular descriptors for capturing dispersion and hydrogen bonding effects. We have trained this model using experimentally determined $\ln \gamma_{ij}^\infty$ data of 40,219 binary-systems involving 1032 solutes and 866 solvents, overall showing superior performance compared to the popular UNIFAC-Dortmund model. We analyze the performance of GH-GNN for continuous and discrete inter/extrapolation and give indications for the model's applicability domain and expected accuracy. In general, GH-GNN is able to produce accurate predictions for extrapolated binary-systems if at least 25 systems with the same combination of solute-solvent chemical classes are contained in the training set and a similarity indicator above 0.35 is also present. This model and its applicability domain recommendations have been made open-source at https://github.com/edgarsmdn/GH-GNN.

Deep learning models that leverage large datasets are often the state of the art for modelling molecular properties. When the datasets are smaller (< 2000 molecules), it is not clear that deep learning approaches are the right modelling tool. In this work we perform an extensive study of the calibration and generalizability of probabilistic machine learning models on small chemical datasets. Using different molecular representations and models, we analyse the quality of their predictions and uncertainties in a variety of tasks (binary, regression) and datasets. We also introduce two simulated experiments that evaluate their performance: (1) Bayesian optimization guided molecular design, (2) inference on out-of-distribution data via ablated cluster splits. We offer practical insights into model and feature choice for modelling small chemical datasets, a common scenario in new chemical experiments. We have packaged our analysis into the DIONYSUS repository, which is open sourced to aid in reproducibility and extension to new datasets.

阐明并准确预测分子的吸毒性和生物活性在药物设计和发现中起关键作用，并且仍然是一个开放的挑战。最近，图神经网络（GNN）在基于图的分子属性预测方面取得了显着进步。但是，当前基于图的深度学习方法忽略了分子的分层信息以及特征通道之间的关系。在这项研究中，我们提出了一个精心设计的分层信息图神经网络框架（称为hignn），用于通过利用分子图和化学合成的可见的无限元素片段来预测分子特性。此外，首先在Hignn体系结构中设计了一个插件功能的注意块，以适应消息传递阶段后自适应重新校准原子特征。广泛的实验表明，Hignn在许多具有挑战性的药物发现相关基准数据集上实现了最先进的预测性能。此外，我们设计了一种分子碎片的相似性机制，以全面研究Hignn模型在子图水平上的解释性，表明Hignn作为强大的深度学习工具可以帮助化学家和药剂师识别出设计更好分子的关键分子，以设计更好的分子，以设计出所需的更好分子。属性或功能。源代码可在https://github.com/idruglab/hignn上公开获得。

学习表达性分子表示对于促进分子特性的准确预测至关重要。尽管图形神经网络（GNNS）在分子表示学习中取得了显着进步，但它们通常面临诸如邻居探索，不足，过度光滑和过度阵列之类的局限性。同样，由于参数数量大，GNN通常具有较高的计算复杂性。通常，当面对相对大尺寸的图形或使用更深的GNN模型体系结构时，这种限制会出现或增加。克服这些问题的一个想法是将分子图简化为小型，丰富且有益的信息，这更有效，更具挑战性的培训GNN。为此，我们提出了一个新颖的分子图粗化框架，名为FUNQG利用函数组，作为分子的有影响力的构件来确定其性质，基于称为商图的图理论概念。通过实验，我们表明所产生的信息图比分子图小得多，因此是训练GNN的良好候选者。我们将FUNQG应用于流行的分子属性预测基准，然后比较所获得的数据集上的GNN体系结构的性能与原始数据集上的几个最先进的基线。通过实验，除了其参数数量和低计算复杂性的急剧减少之外，该方法除了其急剧减少之外，在各种数据集上的表现显着优于先前的基准。因此，FUNQG可以用作解决分子表示学习问题的简单，成本效益且可靠的方法。

自我监督学习（SSL）是一种通过利用数据中固有的监督来学习数据表示的方法。这种学习方法是药物领域的焦点，由于耗时且昂贵的实验，缺乏带注释的数据。使用巨大未标记数据的SSL显示出在分子属性预测方面表现出色的性能，但存在一些问题。 （1）现有的SSL模型是大规模的；在计算资源不足的情况下实现SSL有限制。 （2）在大多数情况下，它们不利用3D结构信息进行分子表示学习。药物的活性与药物分子的结构密切相关。但是，大多数当前模型不使用3D信息或部分使用它。 （3）以前对分子进行对比学习的模型使用置换原子和键的增强。因此，具有不同特征的分子可以在相同的阳性样品中。我们提出了一个新颖的对比学习框架，用于分子属性预测的小规模3D图对比度学习（3DGCL），以解决上述问题。 3DGCL通过不改变药物语义的预训练过程来反映分子的结构来学习分子表示。仅使用1,128个样本用于预训练数据和100万个模型参数，我们在四个回归基准数据集中实现了最先进或可比性的性能。广泛的实验表明，基于化学知识的3D结构信息对于用于财产预测的分子表示学习至关重要。

深度生成模型吸引了具有所需特性的分子设计的极大关注。大多数现有模型通过顺序添加原子来产生分子。这通常会使产生的分子与目标性能和低合成可接近性较少。诸如官能团的分子片段与分子性质和合成可接近的比原子更密切相关。在此，我们提出了一种基于片段的分子发生模型，其通过顺序向任何给定的起始分子依次向任何给定的起始分子添加分子片段来设计具有靶性质的新分子。我们模型的一个关键特征是属性控制和片段类型方面的高概括能力。通过以自动回归方式学习各个片段对目标属性的贡献来实现前者。对于后者，我们使用深神经网络，其从两个分子的嵌入载体中预测两个分子的键合概率作为输入。在用金砖石分解方法制备片段文库的同时隐式考虑所生成的分子的高合成可用性。我们表明该模型可以以高成功率同时控制多个目标性质的分子。即使在培训数据很少的财产范围内，它也与看不见的片段同样很好地工作，验证高概括能力。作为一种实际应用，我们证明，在对接得分方面，该模型可以产生具有高结合亲和力的潜在抑制剂，其抗对接得分的3CL-COV-2。

In this work, we propose MEDICO, a Multi-viEw Deep generative model for molecule generation, structural optimization, and the SARS-CoV-2 Inhibitor disCOvery. To the best of our knowledge, MEDICO is the first-of-this-kind graph generative model that can generate molecular graphs similar to the structure of targeted molecules, with a multi-view representation learning framework to sufficiently and adaptively learn comprehensive structural semantics from targeted molecular topology and geometry. We show that our MEDICO significantly outperforms the state-of-the-art methods in generating valid, unique, and novel molecules under benchmarking comparisons. In particular, we showcase the multi-view deep learning model enables us to generate not only the molecules structurally similar to the targeted molecules but also the molecules with desired chemical properties, demonstrating the strong capability of our model in exploring the chemical space deeply. Moreover, case study results on targeted molecule generation for the SARS-CoV-2 main protease (Mpro) show that by integrating molecule docking into our model as chemical priori, we successfully generate new small molecules with desired drug-like properties for the Mpro, potentially accelerating the de novo design of Covid-19 drugs. Further, we apply MEDICO to the structural optimization of three well-known Mpro inhibitors (N3, 11a, and GC376) and achieve ~88% improvement in their binding affinity to Mpro, demonstrating the application value of our model for the development of therapeutics for SARS-CoV-2 infection.

Ionic Liquids (ILs) provide a promising solution for CO$_2$ capture and storage to mitigate global warming. However, identifying and designing the high-capacity IL from the giant chemical space requires expensive, and exhaustive simulations and experiments. Machine learning (ML) can accelerate the process of searching for desirable ionic molecules through accurate and efficient property predictions in a data-driven manner. But existing descriptors and ML models for the ionic molecule suffer from the inefficient adaptation of molecular graph structure. Besides, few works have investigated the explainability of ML models to help understand the learned features that can guide the design of efficient ionic molecules. In this work, we develop both fingerprint-based ML models and Graph Neural Networks (GNNs) to predict the CO$_2$ absorption in ILs. Fingerprint works on graph structure at the feature extraction stage, while GNNs directly handle molecule structure in both the feature extraction and model prediction stage. We show that our method outperforms previous ML models by reaching a high accuracy (MAE of 0.0137, $R^2$ of 0.9884). Furthermore, we take the advantage of GNNs feature representation and develop a substructure-based explanation method that provides insight into how each chemical fragments within IL molecules contribute to the CO$_2$ absorption prediction of ML models. We also show that our explanation result agrees with some ground truth from the theoretical reaction mechanism of CO$_2$ absorption in ILs, which can advise on the design of novel and efficient functional ILs in the future.

在药物发现中，具有所需生物活性的新分子的合理设计是一项至关重要但具有挑战性的任务，尤其是在治疗新的靶家庭或研究靶标时。在这里，我们提出了PGMG，这是一种用于生物活化分子产生的药效团的深度学习方法。PGMG通过药理的指导提供了一种灵活的策略，以使用训练有素的变异自动编码器在各种情况下生成具有结构多样性的生物活性分子。我们表明，PGMG可以在给定药效团模型的情况下生成匹配的分子，同时保持高度的有效性，独特性和新颖性。在案例研究中，我们证明了PGMG在基于配体和基于结构的药物从头设计以及铅优化方案中生成生物活性分子的应用。总体而言，PGMG的灵活性和有效性使其成为加速药物发现过程的有用工具。

预测化合物的化学性质在发现具有具体所需特征的新型材料和药物方面至关重要。最近机器学习技术的显着进展使得能够从文献中报告的过去的实验数据启用自动预测建模。然而，这些数据集通常被偏置，因为各种原因，例如实验计划和出版物决策，并且使用这种偏置数据集训练的预测模型经常遭受对偏置分布的过度拟合，并且在随后的用途时执行不良。因此，本研究专注于减轻实验数据集中的偏差。我们采用了两种来自因果推断和域适应的技术与图形神经网络相结合，可以代表分子结构。在四种可能的偏置方案中的实验结果表明，基于逆倾向评分的方法使得稳定的改进，但是域不变的表示学习方法失败。

定量探索了量子化学参考数据的训练神经网络（NNS）预测的不确定性量化的价值。为此，适当地修改了Physnet NN的体系结构，并使用不同的指标评估所得模型，以量化校准，预测质量以及预测误差和预测的不确定性是否可以相关。 QM9数据库培训的结果以及分布内外的测试集的数据表明，错误和不确定性与线性无关。结果阐明了噪声和冗余使分子的性质预测复杂化，即使在发生变化的情况下，例如在两个原本相同的分子中的双键迁移 - 很小。然后将模型应用于互变异反应的真实数据库。分析特征空间中的成员之间的距离与其他参数结合在一起表明，训练数据集中的冗余信息会导致较大的差异和小错误，而存在相似但非特定的信息的存在会返回大错误，但差异很小。例如，这是对含硝基的脂肪族链的观察到的，尽管训练集包含了与芳香族分子结合的硝基组的几个示例，但这些预测很困难。这强调了训练数据组成的重要性，并提供了化学洞察力，以了解这如何影响ML模型的预测能力。最后，提出的方法可用于通过主动学习优化基于信息的化学数据库改进目标应用程序。

在药物发现中，分子优化是在所需药物性质方面将药物候选改变为更好的阶梯。随着近期人工智能的进展，传统上的体外过程越来越促进了Silico方法。我们以硅方法提出了一种创新的，以通过深生成模型制定分子并制定问题，以便产生优化的分子图。我们的生成模型遵循基于片段的药物设计的关键思想，并通过修改其小碎片来优化分子。我们的模型了解如何识别待优化的碎片以及如何通过学习具有良好和不良性质的分子的差异来修改此类碎片。在优化新分子时，我们的模型将学习信号应用于在片段的预测位置解码优化的片段。我们还将多个这样的模型构造成管道，使得管道中的每个模型能够优化一个片段，因此整个流水线能够在需要时改变多个分子片段。我们将我们的模型与基准数据集的其他最先进的方法进行比较，并证明我们的方法在中等分子相似度约束下具有超过80％的性质改善，在高分子相似度约束下具有超过80％的财产改善。 。

蛋白质 - 配体相互作用（PLIS）是生化研究的基础，其鉴定对于估计合理治疗设计的生物物理和生化特性至关重要。目前，这些特性的实验表征是最准确的方法，然而，这是非常耗时和劳动密集型的。在这种情况下已经开发了许多计算方法，但大多数现有PLI预测大量取决于2D蛋白质序列数据。在这里，我们提出了一种新颖的并行图形神经网络（GNN），以集成PLI预测的知识表示和推理，以便通过专家知识引导的深度学习，并通过3D结构数据通知。我们开发了两个不同的GNN架构，GNNF是采用不同特种的基础实现，以增强域名认识，而GNNP是一种新颖的实现，可以预测未经分子间相互作用的先验知识。综合评价证明，GNN可以成功地捕获配体和蛋白质3D结构之间的二元相互作用，对于GNNF的测试精度和0.958，用于预测蛋白质 - 配体络合物的活性。这些模型进一步适用于回归任务以预测实验结合亲和力，PIC50对于药物效力和功效至关重要。我们在实验亲和力上达到0.66和0.65的Pearson相关系数，分别在PIC50和GNNP上进行0.50和0.51，优于基于2D序列的模型。我们的方法可以作为可解释和解释的人工智能（AI）工具，用于预测活动，效力和铅候选的生物物理性质。为此，我们通过筛选大型复合库并将我们的预测与实验测量数据进行比较来展示GNNP对SARS-COV-2蛋白靶标的实用性。

Here, we demonstrate how machine learning enables the prediction of comonomers reactivity ratios based on the molecular structure of monomers. We combined multi-task learning, multi-inputs, and Graph Attention Network to build a model capable of predicting reactivity ratios based on the monomers chemical structures.

Antimicrobial resistance is one of the biggest health problem, especially in the current period of COVID-19 pandemic. Due to the unique membrane-destruction bactericidal mechanism, antimicrobial peptide-mimetic copolymers are paid more attention and it is urgent to find more potential candidates with broad-spectrum antibacterial efficacy and low toxicity. Artificial intelligence has shown significant performance on small molecule or biotech drugs, however, the higher-dimension of polymer space and the limited experimental data restrict the application of existing methods on copolymer design. Herein, we develop a universal random copolymer inverse design system via multi-model copolymer representation learning, knowledge distillation and reinforcement learning. Our system realize a high-precision antimicrobial activity prediction with few-shot data by extracting various chemical information from multi-modal copolymer representations. By pre-training a scaffold-decorator generative model via knowledge distillation, copolymer space are greatly contracted to the near space of existing data for exploration. Thus, our reinforcement learning algorithm can be adaptive for customized generation on specific scaffolds and requirements on property or structures. We apply our system on collected antimicrobial peptide-mimetic copolymers data, and we discover candidate copolymers with desired properties.

机器学习（ML）已经证明了用于准确和结晶材料的准确性能预测的承诺。为了化学结构的高度精确的ML型号的化学结构属性预测，需要具有足够样品的数据集。然而，获得昂贵的化学性质的获得和充分数据可以是昂贵的令人昂贵的，这大大限制了ML模型的性能。通过计算机视觉和黑暗语言处理中数据增强的成功，我们开发了奥古里希姆：数据八级化图书馆化学结构。引入了弃头晶系统和分子的增强方法，其可以对基于指纹的ML模型和图形神经网络（GNNS）进行脱颖而出。我们表明，使用我们的增强策略意义地提高了ML模型的性能，特别是在使用GNNS时，我们开发的增强件在训练期间可以用作广告插件模块，并在用不同的GNN实施时证明了有效性。模型通过Theauglichem图书馆。基于Python的封装我们实现了EugliChem：用于化学结构的数据增强库，可公开获取：https：//github.com/baratilab/auglichem.1

We introduce an end-to-end computational framework that enables hyperparameter optimization with the DeepHyper library, accelerated training, and interpretable AI inference with a suite of state-of-the-art AI models, including CGCNN, PhysNet, SchNet, MPNN, MPNN-transformer, and TorchMD-Net. We use these AI models and the benchmark QM9, hMOF, and MD17 datasets to showcase the prediction of user-specified materials properties in modern computing environments, and to demonstrate translational applications for the modeling of small molecules, crystals and metal organic frameworks with a unified, stand-alone framework. We deployed and tested this framework in the ThetaGPU supercomputer at the Argonne Leadership Computing Facility, and the Delta supercomputer at the National Center for Supercomputing Applications to provide researchers with modern tools to conduct accelerated AI-driven discovery in leadership class computing environments.

图形神经网络（GNN）正在化学工程中出现，以基于分子图的物理化学特性端到端学习。 GNNS的一个关键要素是合并函数，将原子矢量结合到分子指纹中。大多数以前的作品都使用标准池功能来预测各种属性。但是，不合适的合并功能会导致概括不佳的非物理GNN。我们根据有关学习特性的物理知识比较并选择有意义的GNN合并方法。通过量子机械计算计算出的分子特性证明了物理池函数的影响。我们还将结果与最近的SET2Set合并方法进行了比较。我们建议使用总和池来预测取决于分子大小的性能并比较分子大小无关的属性的池函数。总体而言，我们表明物理池功能的使用显着增强了概括。

Graph classification is an important area in both modern research and industry. Multiple applications, especially in chemistry and novel drug discovery, encourage rapid development of machine learning models in this area. To keep up with the pace of new research, proper experimental design, fair evaluation, and independent benchmarks are essential. Design of strong baselines is an indispensable element of such works. In this thesis, we explore multiple approaches to graph classification. We focus on Graph Neural Networks (GNNs), which emerged as a de facto standard deep learning technique for graph representation learning. Classical approaches, such as graph descriptors and molecular fingerprints, are also addressed. We design fair evaluation experimental protocol and choose proper datasets collection. This allows us to perform numerous experiments and rigorously analyze modern approaches. We arrive to many conclusions, which shed new light on performance and quality of novel algorithms. We investigate application of Jumping Knowledge GNN architecture to graph classification, which proves to be an efficient tool for improving base graph neural network architectures. Multiple improvements to baseline models are also proposed and experimentally verified, which constitutes an important contribution to the field of fair model comparison.