ACS 2012 Flashtalk

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A talk I gave on August 19, 2012 at the 2012 ACS 244th national meeting held in Philadelphia, PA. This talk was given as a part of a series of 8 minutes long "lightening talks" on a variety of topics in chemistry and cheminfomatics. This talk looked at errors and missing information from literature in the field of chemistry.

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ACS 2012 Flashtalk

  1. 1. Examining the Literature toDemonstrate the Need for the Careful Checking of Reported Measurements CINF Flash ACS Symposia #244 Philadelphia, PA Matthew McBride Undergraduate Chemistry Major Drexel University Bradley Research Group August 19, 2012
  2. 2. Main Points1. Published results need to be compared for consistency with the rest of literature2. Missing information in a published article decreases the reliability of the reported results
  3. 3. Preparing a SynthesisDesire to synthesize: (http://www.chemspider.com/4523376)(1E,4E)-1,5-Di(2-naphthyl)-1,4-pentadien-3-oneAldol condensation between two molecules of2-naphthaldehyde and one molecule ofacetone
  4. 4. Search the LiteratureUsing a database such as Reaxys©
  5. 5. InconsistencyConflicting reported melting points
  6. 6. Identify CompoundAlways need to confirm that the listed meltingpoint corresponds to the desired compoundAlways need to confirm that Reaxys© hascorrectly listed the melting point (doi: 10.1139/v90-351)
  7. 7. ONS Webservices (http://onswebservices.wikispaces.com/meltingpoint)Conclusion: The melting point value of114°C is an outlier [Andrew Lang]
  8. 8. Synthesis ProcedureHow to make the compound (doi: 10.1016/0040-4020(96)00788-0)Reference to Organic Syntheses procedure (http://www.orgsyn.org/orgsyn/orgsyn/prepcontent.asp?prep=cv2p0167)
  9. 9. ConcentrationClaim that 1 mole of aldehyde can bedissolved to make an approximately 0.5Msolution in 1:1 ethanol/water mixturePicture: 0.16M solution2-naphthaldehyde visiblePaper lacking details (http://onschallenge.wikispaces.com/EXP337)
  10. 10. Drug DiscoveryIf interested in the compound as a potentialdrug, check the bioactivity results
  11. 11. CytotoxicityCompound identifiedToxicity results listed against tumor cell lines (doi:10.1016/j.bmc.2008.10.044)
  12. 12. Problem?Check the characterization of the compound(B46) (doi:10.1016/j.bmc.2008.10.044)There is none! No melting point, percentyield, NMR..etc.No scientific evidence to support the claimthat the listed compound was tested.Reduces the reliability of the reported results
  13. 13. CharacterizationHNMR spectrum should have a singlet (2H)All peaks represent an even number ofhydrogen atoms
  14. 14. CharacterizationCompare HNMR spectral data from literature (US Patent 20100152493) (doi: 10.1139/v90-351) (doi: 10.1016/0040-4020(96)00788-0)Need to check spectral data for consistency
  15. 15. SummaryReported measurements, such asmelting points, listed in databases mustbe considered in context with allpublished values to identify outliersMissing data and characterizationinformation reduces the impact andreliability of published work

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