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High Throughput Experimentation: Computational Requirements. John M. Newsam Molecular Simulations Inc. (A Pharmacopeia subsidiary). “Workshop on Combinatorial Methods for Materials Discovery” ATP Fall National Meeting Atlanta, GA Wednesday November 18th 1998. Potential Hindrances?.
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High Throughput Experimentation: Computational Requirements John M. Newsam Molecular Simulations Inc. (A Pharmacopeia subsidiary) “Workshop on Combinatorial Methods for Materials Discovery” ATP Fall National Meeting Atlanta, GA Wednesday November 18th 1998
Potential Hindrances? • Patent profusion • vigilance • Unmet expectations • set reasonably • Infrastructure cost • hindrance for academics • Lack of standards • premature for hardware • Inertia • resistance to change, short-term delivery focus
Synthesis Analytical Characterization of composition, purity, phases, structure QSAR# Lead compounds for resynthesis and secondary testing High-throughput Experimentation Library Design Primary Testing Pooled, parallel or discrete Processing Physical, mechanical etc. processing Performance in specific application Testing requirements drive synthesis format #Quantitative Structure-Activity relationships
Infrastructure Needs • Vertical and horizontal integration • Adaptable • Modular • Geared for huge throughput • Broadly deployable
Engineering Solution New 1536 well HTS Format • 1536 wells, 2 l well volume • Corning Science Products joint design • Automated 961536 reformatter • l-level fluids dispensing • Oxidative and evaporative loss reduced
User Input & Workstation Interfaces Data Base Engines Analysis, Display and Data Access Chemistry & Materials Input Server-based Processing Oracle Molecular Simulation Workstation & Oracle Forms Display Materials Specific Tables Materials Algorithms Statistics Process and Data Management
Luminescence data for a library of mixed metal oxides under 254nm UV irradiation Data from E.Danielson et al., Science 279 (1998) 831
Some Specific Technology Needs • Hits vs misses; improvement criteria • Descriptors • Experiment decision support • Abstracted feature models (AFMs) • Process optimization • Simulation for scale-up • Sensor data (unravelling response of arrays)
Which experiments should be done ? Computation Solution ‘Soft materials’ ‘Hard materials’ R1 R4 M1 + Temp M2 R3 X Scaffold R2 Making it practical: computation • 100 R1, 100 R2, 100 R3, 100 R4108 • 50,000 compounds/week40 years • How do we manage the process ? • What knowledge do the experiments yield ?
Computation Solution Compound library design • Library Specification • Molecular: Product or Reaction-based • Polymers, Heterogeneous catalysts ? • Library Design • Diversity and similarity metrics • Similarity Selection • Array and mixture design • Library Comparison • Library Focussing • Active site model (atomic or abstracted) • QSAR Model World Drug Index of 35,873 compounds in a space of principal components C2.Diversity C2.LibCompare C2.LibSelect
Abstracted Feature Models • Abstraction of key features • Based on activity data • Interesting ‘active’ definition R.C.Willson
Computation Solution Descriptors Descriptor Families Descriptors - calculable molecular attributes that govern particular macroscopic properties Topological Fragments Receptor surface Structural Information-content Spatial Electronic Thermodynamic Conformational Quantum mechanical Products C2.Descriptor+ C2.MFA C2.QSAR+ C2.Synthia Plus Molecular and Quantum Methods
Available, occupiable volume & framework density descriptors (104 zeolite and zeolite-related framework types) Correlative methods in catalyst design: Expert systems, neural networks and structure-activity relationships, in “Advances in Catalyst Design” Catalyst Advance Program (CAP) Report, The Catalyst Group, PA; in press (1998)
Computation Solution Structure-Activity Relationships Properties Descriptors Correlative Methods Statistical Models Linear regression Stepwise & multiple linear regression Principal components analysis Partial least squares Genetic algorithm Genetic function approximation Products C2.QSAR+ C2.GA E.g. K.F. Moschner and A. Cece, “Development of a General QSAR for Predicting Octanol-Water Partition Coefficients and its Application to Surfactants,” ASTM STP 1218 (1995); MSI C2 QSAR manual April 1997.
Organics Oil Field Corrosion Inhibitors • Benzimidazolines function at cathodic sites • Library studied by Kuron et al. (1985) • Key descriptors • Terminal N charge • 3-substituted N charge • Octanol-water logP • Moment of inertia H. Gråfen et al., Werkstoff und Korrosion, Vol. 36, 407 (1985) M.Doyle
Conclusion • Computational infrastructure needs • Specific technology needs • Role of computation • process management system • experiment decision support • data visualization and analysis • knowledge from the experimental data • Integration