Medicinal Chemistry

The Medicinal Chemistry team is made up of personnel with over 200 years of cumulative experience in medicinal chemistry, of which many were spent in the drug discovery industry – both in drug discovery as well as pre-clinical drug development. Our main focus is to transform small molecule candidates into safe and effective drugs that can be easily manufactured at scale for broad use and work against as many different viruses as possible.

Robert Damoiseaux, PhD

Principal Investigator

Professor, Department of Molecule and Medical Pharmacology

Professor, Bioengineering

University of California, Los Angeles

Received Ph.D. degree in bioorganic chemistry of the University of Lausanne, Switzerland; at the Functional Genomics Institute of Novartis in La Jolla, he developed the first nucleic acid encoded small molecule substrate libraries in 2004 before joining UCLA to build the Molecular Screening Shared Resource where he now resides as professor directing UCLA small molecule drug discovery efforts in the California NanoSystems Institute. He has several candidates drug that originated in his laboratory in ongoing clinical trials.

Over 110 publications with a total of ~8500 citations, H-index of 47.



Target selection and validation, library screening, functional genomics, activity profiling, assay development and validation, screening library selection including PAINS filtering and structure activity analysis for drug optimization and cheminformatics,

Ruben Abagyan, PhD

 Professor, University of California, San Diego, School of Pharmacy and Pharmaceutical Sciences, San Diego Supercomputer Center

Received Ph.D. degree in molecular physics at MPTI and MSU; at EMBL in Heidelberg he developed internal coordinate mechanics and structural docking approach (ICM) for modeling and docking, an expert in computer-aided drug design, screening, properties.  He founded Molsoft LLC, received his tenure at New York University and Courant Institute of Mathematics, continued at Novartis Functional Genomics Institute as a Director of Computational Chemistry, the Scripps Research Institute and UCSD in La Jolla as a professor. Over 330 publications and 37,700 citations, H-index of 93, several awards, including Princess Diana Award. 


Giga libraries design and screens, characterizing libraries for drug-like, adverse effects, and antiviral properties, expertise in both covalent and non-covalent lead candidates.


Patrick Harran, PhD

Donald J. and Jane M. Cram Chair in Organic Chemistry,

University of California, Los Angeles

Harran trained in chemistry at Skidmore College (BA 1990), Yale University (PhD 1995) and Stanford University (NIH-sponsored postdoctoral fellowship). In 1997 he joined the faculty at the University of Texas Southwestern Medical Center. In 2005, he was promoted to Full Professor and named the Mar Nell & F. Andrew Bell Distinguished Chair in Biochemistry. He joined the UCLA faculty in 2008 as the inaugural Cram Chair in Organic Chemistry.



1) Synthesis, Structure and Function of Bioactive Natural Products 2) Creating Small Molecule Mimics of Intracellular Regulatory Proteins and 3) Methods to Systematically Generate Composite Macrocyclic Peptidomimetics

Kendall N Houk, PhD

Distinguished Research Professor in Organic Chemistry,

University of California, Los Angeles

Professor Houk is an authority on theoretical and computational organic chemistry. His group is involved in developments of rules to understand reactivity, computer modeling of complex organic reactions, and experimental tests of the predictions of theory. He collaborates prodigiously with chemists all over the world. Among current interests are the theoretical investigations of mechanisms and design of enzyme-catalyzed reactions, the quantitative modeling of asymmetric reactions used in synthesis, and the dynamics and properties of supramolecular nanomachines, as well as his lifelong interest in the mechanisms and dynamics of pericyclic reactions. He has published over 1400 publications and a physical organic chemistry textbook with Pierre Vogel. He has an h-index of 137.



The Houk group brings to ATTACK the computational tools to explore protein-protein and protein-ligand interactions.  Reactions relevant to the synthesis of diverse compounds to expand the library of potential hits, and reactions of covalent anti-viral drugs in protein binding sites, are studied with quantum mechanics and molecular dynamics.


Varghese John, PhD

Department of Neurology

University of California, Los Angeles

Dr. John is an accomplished medicinal chemist and is PI of the Drug Discovery Laboratory (DDL) in the  Department of Neurology at UCLA.  Dr. John is a member of the Alzheimer’s Disease Program in the Mary S. Easton Center for Alzheimer’s Disease.   Previously Dr. John was with Athena Neurosciences and Elan Pharmaceuticals for ~18 years where he was part of project teams developing drug candidates for CNS disorders. These efforts led to clinical candidates for AD and an approved product for multiple sclerosis.   His work at Elan included development of potent inhibitors for proteases BACE and g-secretase, key enzymes in formation Ab and amyloid plaques.  Dr. John has several key scientific publications and is an inventor on over 100 pending or issued patents on compounds for CNS related targets. 



The John Dr. John and the DDL will be part of the MedChem core and their efforts will focus on structure activity optimization, synthesis of analogs and identification small molecules with brain permeability important to address neurological issues in the context of

long SARS-CoV-2.

Dionicio Siegel, PhD

Professor/Head, Division of Pharmaceutical Chemistry, University of California at San Diego

With an established background in synthetic organic chemistry I am committed to the use state of the art methods in medicinal chemistry to create new preclinical agents functioning on new, validated targets against viruses. Within medicinal chemistry our research group has a long-term interest in chemical reactivity and applying concepts in rates of reaction to the design of new covalent functionality that can be incorporated into new viral inhibitors. Currently I serve as the Head of the Division of Pharmaceutical Chemistry at UCSD, a division in the Skaggs School of Pharmacy and Pharmaceutical Sciences with a focus on increasing chemistry driven, translational science.



Complex molecule synthesis, reaction development, and molecular pharmacology has provided the foundation for my research group’s efforts to discover and develop small molecule regulators of newly discovered biological targets and processes. I will focus on covalent inhibitors, optimization of small molecule structure-activity relationship elaboration and synthesis development.

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Felice C. Lightstone, PhD

Principal Investigator

Lawrence Livermore National Laboratory

Group Leader

Associate Program Lead of Medical Countermeasures

Director of the American Heart Association’s Center for Accelerated Drug Discovery.

 Undergraduate degrees in Electrical Engineering and Honors Biology and a Master’s Degree in Electrical Engineering from the University of Illinois and a Ph.D. in Chemistry from the University of California, Santa Barbara.  Her research uses cutting-edge, multi-scale, in silico simulations to tackle problems in biology. A wide range of computational biology and machine learning methods that employ LLNL’s high-performance computing resources are used to accelerate the design and development of new therapies.  She has ongoing collaborations with industry and academia to computationally optimize compounds and bring Investigational New Drug entities to clinical trials.



Artificial Intelligence approaches towards drug discovery and design, target and off-target prediction, usage of supercomputing resources for the prediction of potency and DMPK optimized analogs during

drug development.

Maurizio Pellecchia, PhD

University of California, Riverside

Professor of Biomedical Sciences

Director, Center for Molecular and Translational Medicine

A central theme of my laboratory is the development of novel methodologies to tackle protein-protein interactions (PPIs) as targets for drug discovery, and to further advance our most promising agents into potential therapeutics.