T. W. Schultz Presented at the Logan Workshop March 23-24, 2010

Slides:



Advertisements
Similar presentations
Chemistry for Changing Times 12th Edition Hill and Kolb
Advertisements

191 Chapter 21: Ester Enolates 21.1: Ester  Hydrogens and Their pK a ’s. The  -protons of esters are less acidic that ketones and aldehydes. Typical.
ALDEHYDES AND KETONES BY: SALEHA SHAMSUDIN.
275 Chapter 12: Reactions of Arenes: Electrophilic Aromatic Substitution 12.1: Representative Electrophilic Aromatic Substitution Reactions of Benzene.
Chemical Category Formation: Toxicology and REACH Dr Steven Enoch Liverpool John Moores University 14 th May 2009.
ECVAM Key Area Sensitisation: Overview on Activities Silvia Casati, Chantra Eskes.
1 Nucleophilic reactions of carbonyl groups Oxygen is more electronegative than carbon (3.5 vs 2.5) and, therefore, a C=O group is polar.
Chapter 12 Organic Chemistry: The Infinite Variety of Carbon Compounds
Benzene & Aromatic Compounds By: Dr. Shatha alaqeel
Opportunities for Measuring Amine Reactivity Under LINK Mark Cronin Liverpool John Moores University England.
Optimizing Target Interactions
Mike Comber Consulting TIMES-SS Assessment of skin sensitisation hazard Presented on behalf of the TIMES-SS consortia.
CHAPTER 23 ORGANIC CHEMISTRY. The Nature of Organic Molecules Carbon is tetravalent. It has four outer-shell electrons (1s 2 2s 2 2p 2 ) and forms four.
Mike Comber TIMES-SS Application of Reactivity Principles in Screening for Skin Sensitisers Presented on behalf of the TIMES-SS consortia & International.
Chemistry. Organic Compounds Containing Oxygen - III Session.
T. W. Schultz Presented at the Logan Workshop March 23-24, 2010.
Predictive safety study of ticagrelor's degradation combining LC-MS and in silico approach H. SADOU YAYE*, B. DO, N. YAGOUBI * Pharmacist at Pitié-Salpêtrière.
The Adverse Outcome Pathway (AOP) for Skin Sensitisation (SS): How We Got Here and Where We are Going 1 T. W. Schultz Professor Emeritus The University.
The McKim Conferences for the Strategic Use of Testing Gitchee Gumee Conference Center Duluth, Minnesota June 27-29, 2006.
UNDERSTANDING CHEMICAL ALLERGEN POTENCY THROUGH THE MOLECULAR EVENTS THAT TRIGGER IMMUNE CELL ACTIVATION Elena Kummer.
QSAR in CANCER ASSESSMENT PURPOSE and AGENDA Gilman Veith Duluth MN May 19-21, 2010.
ADVERSE OUTCOME PATHWAYS LESSONS FROM SENSITISATION DR DAVID BASKETTER, DABMEB CONSULTANCY LTD, SHARNBROOK, UK.
Black Box Lush Prize 2015: Skin Sensitization Adverse Outcome Pathway G. Frank Gerberick The Procter & Gamble Company.
T. W. Schultz Presented at the McKim Conference September 17, 2008.
OECD’s work on Adverse outcome pathways
Dr. Hayder kh. Q. Ali School of Bioprocess Engineer UniMAP.
McKim Conference on Predictive Toxicology The Inn of Lake Superior Duluth, Minnesota September 25-27, 2007 Narcosis as a Reference Gilman Veith.
Chem 341 Review for Finals Structure Determination NMR –Chemical shifts, splitting patterns, integrations IR –ROH, C=O Formula => # of Rings + Pi-Bonds.
McKim Conference on Predictive Toxicology The Inn of Lake Superior Duluth, Minnesota September 16-18, 2008 Toxicity Pathways as an Organizing Concept Gilman.
McKim Workshop on Strategic Approaches for Reducing Data Redundancy in Cancer Assessment Duluth, MN, USA 19 May, 2010.
Organization for Economic Co-operation and Development QSAR Application Toolbox -filling data gaps using available information- McKim Conference, September.

McKim Conference on Predictive Toxicology The Inn of Lake Superior Duluth, Minnesota September 25-27, 2007 Toxicity Pathways as an Organizing Concept Gilman.
QSAR in CANCER ASSESSMENT PURPOSE and AGENDA Gilman Veith Duluth MN May 19-21, 2010.
Organic Chemistry Review Part II. Functional Groups 1. Hydrocarbons 2. Derivatives of Hydrocarbons.
Aromaticity: Reactions of Benzene and Substituted Benzenes
+ Chem 350 Delmis Hernandez. + What are the main topics of Organic Chemistry 2? Chemistry of benzenes Reactions of alcohols Carbonyl chemistry.
QSAR Application Toolbox: First Steps - Data Gap Filling (Read-Across by Analogue Approach)
Chapter 2 Families of Carbon Compounds. Basic Definitions Hydrocarbons- Compounds containing only carbon and hydrogen. Alkanes- hydrocarbons that contain.
Aromatic compounds
Laboratory of Mathematical Chemistry,
Skimune™ Technologies for sensitization and potency assessment   Unique tools for the Cosmetic and Chemical Industries.  
DRUG DESIGN: OPTIMIZING TARGET INTERACTIONS
QSAR Application Toolbox: Step 12: Building a QSAR model
Cl H H C Electrophiles and Nucleophiles
General Concepts in QSAR for Using the QSAR Application Toolbox
Aromatic compounds
1.3 AROMATIC HYDROCARBONS
Status of the Glutathione Reactivity Database for Skin Sensitization
Decision Contexts in a Changing Toxicology Paradigm
Outlook Background Objectives Specific Aims
Properties Nomenclature Preparation Reactions Synthesis
Benzene & Aromatic Compounds
Aromatic Compounds.
Skin Sensitisation – Chemical Applicability Domain of the LLNA
Quantitative modelling of human potency
Dr. Pandit Khakre Asst. Prof Mrs. K.S.K. College, Beed.
Evaluating alert performance accounting for a metabolism
Fundamentals of Organic Chemistry
Ovanes Mekenyan, Milen Todorov, Ksenia Gerova
Chapter 23 Carbonyl Condensation Reactions
Fundamentals of Organic Chemistry
Aromatic Compounds.
Fundamentals of Organic Chemistry
Fundamentals of Organic Chemistry
Reaction Mechanism in Aromatic hydrocarbons Batch: 2nd Semester Prof
Isolated and Conjugated Dienes
Fundamentals of Organic Chemistry
Chapter 22 Carbonyl Alpha-Substitution Reactions
Presentation transcript:

T. W. Schultz Presented at the Logan Workshop March 23-24, 2010 Estimating Reactivity From Structure Using the OECD (Q)SAR Application Toolbox T. W. Schultz Presented at the Logan Workshop March 23-24, 2010

Topics Background & The Problem Michael Acceptors: An Example  Toolbox Applications Pathways Application Summary

Coding Reactivity From Structure Currently no universal QSAR model Local models for simple congeneric groups 2D structure Qualitatively easy Main drawback false positives Quantitatively more difficult Iso-reactive groups (lumping vs. splitting) Sub-grouping and sub-sub-grouping

2D Coding Michael Acceptors Qualitatively Predicted as any Polarized a,b-Unsaturated Compound for example, C=CC(=O)

2D Coding Michael Acceptors Quantitative Predictions Impacted By Substitution at C1=C2(Pg)C3 Reactivity is extended fragment -based

Structural Variation in Reactive Potency of Esters TYPE STRUCTURE RC50(mM) Acetylene dicarboxylates ROC(=O)C#CC(=O)OR 0.025 Propiolates C#CC(=O)OR 0.1 Vinylene dicarboxylates ROC(=O)C=CC(=O)OR 0.2 Acrylates C=CC(=O)OR 0.8 Alkyl 2-alkynoates RC#CC(=O)OR 1.5 Crotonates CC=CC(=O)OR 15.0 Methacrylates C=C(C)C(=O)COR >30.0

Variations in RC50 Values for Substituted Acrylates, C=CC(=O)OR Derivative RC50 (mM) _______________________________________ Ethyl 0.48, 0.55 Vinyl 0.11, 0.11 2-Hydroxyethyl 0.25, 0.29 n-Propyl 0.80, 0.92 Propargyl 0.19, 0.24 n-Hexyl 0.88, 0.76 Phenyl 0.016, 0.015

To Quantitatively Predict Reactivity: Must Be Able to Separate C#CC(=O) C=CC(=O) CC=CC(=O) C=C(C)C(=O)

To Quantitatively Predict Reactivity: Must Also be Able To Separate C=CNO2 C=CC#N C=CC(=O)C C=CC(O)OC C=CC(=O)NH2

Toolbox Application Use reactive to group chemicals into categories and to facilitate the selection of chemical analogues, which allows the integrates of the mechanism of reaction in defining the best category or sub-category Then do read-across

Read Across with GSH & LLNA Data EC3 = 0.01 RC50 = 0.03 RC50 = 0.05 RC50 = 0.05 RC50 = 0.09 RC50 = 0.02

Protein Binding in Toxicity Mechanisms of Protein Binding In Vitro Measurements In Chemico Measurement Hazard Assessment Endpoints In vitro effects Michael addition SN2 SNAr Reactive Potency In vivo effects In silico modeling

Application Reactivity to Catgorizing an Inventory ≈ 1500 substances on the List of Flavor and Fragrance Related Substances ≈1300 discrete substances of which: 79 Fast- to moderate-reacting Michael-acceptors; 19 Slow-reacting Michael-acceptors; 57 Schiff-base aldehydes; 29 Acetals; 15 Disulfide formers; 11 Cyclic addition diones; 9 Disulfide exchangers; 3 O-heterocyclic ring openers. >40 pro-electrophiles

Pathway Applications Screening Tool Many be used in isolation Risk Assessment Must be used as part of an ITS Represents the molecular initiating event of an adverse outcome pathway

Pathway for Allergic Contact Dermatitis 1. Haptenation; 2. Epidermal inflammation & LC activation; 3. LC migration; 4. DC: T cell interaction; 5. T cell proliferation; 6. Increase in hapten-specific T cells; 7. Hapten re-exposure; 8. Acute inflammation; 9. T cell-mediated inflammation Karlberg et al. Chem. Res. Toxicol. 2008, 21, 53-69.

LLNA-tested Michael Acceptor SUBSTRUCTURE MESSAGE C=CC=O Vinyl or vinylene with a carbonyl [CH2]=C(C)C=O -C-atom alkyl-substituted with a carbonyl O=CC=CC=O -C-atom substituted with a second carbonyl [CH]=C(C(=O))C=O -C-atom substituted with a second carbonyl C=[CH]c1ccncc1 Para-vinyl azaarene O=C1[CH]=CC(=O)C=C1 Para-quinone 18

Michael Acceptor Not Tested in LLNA SUBSTRUCTURE MESSAGE C#CC=O Ethylnylene or acetylenic with a carbonyl C=CN(=O)=O Olefinic nitro C#CS(=O) Ethylnylene or acetylenic with a S=O C=CS=O Vinyl or vinylene with a S=O C=CC#N Olefinic cyano C#Cc1ncccc1 Ortho-ethylnylene azaarene C=[CH]c1ncccc1 Ortho-vinyl azaarene C#Cc1ccncc1 Para-ethylnylene azaarene C=[CH]C(=O)[OX1] Vinylene carboxylic acid O=C1C=C[CH]=CC1=O Ortho-quinone [CH2]=[CH][CH]=O Acrolein

Subcategorization of Michael Acceptors by Reactivity Extremely fast: quinones, propiolates , 1-alken-3-ones Fast: acrylates, 2-alkenals, 3-alken-2-ones Moderately Fast: alkyl 2-alkynoates Slow: crotonates Very Slow: methacryates, tiglates Non-Reactive: non-,-unsaturated

Summary We have a 2D modeling strategy Quantitative reactivity data is available for QSAR development We have an application scheme

Thank you