Wikipedia:WikiProject Chemicals/Chembox validation

The WikiProject Chemicals, in cooperation with the WikiProject Pharmacology, is validating the content in the infoboxes {{chembox}} and {{drugbox}}. Values in the infobox are compared with values that are reported in li

• 5001-end

Problems found when validating the Excel file

Please note any "to be checked" entries here.

201-300

• Kanamycin One chiral center seems to not match CAS. Are there multiple forms of this? Structure says Kanamycin A.
  • Yes, there are multiple forms (A, B, C, D, X) and several derivatives, but the difference is in the side chains. Fvasconcellos (t·c) 11:48, 10 February 2009 (UTC)
• Tocopherol One chiral center seems not to match, multiple forms? a-tocopherol, CAS just says tocopherol.

There are multiple isomers. File:RRR alpha-tocopherol.png shows the most common isomer. Tim Vickers (talk) 04:28, 10 September 2009 (UTC)

• Acetylcholine Parent ion, infobox not chembox.
• Linoleic_acid WP says cis, cis, CAS says trans trans 'linoelaidic acid', the whole world says linoleic acid is 60-33-3 including the spreadsheet and sigma.
  • 60-33-3 appears to refer to all-cis. Fvasconcellos (t·c) 11:52, 10 February 2009 (UTC)
    • This is very strange, it is trans,trans in the union file and cis,cis in the wikichem file (I have been using the union file to verify CAS numbers). I need to look into this. Ambix (talk) 12:47, 12 February 2009 (UTC)
• Glucose_1-phosphate One chiral center is not specified (should be up to match CAS). (probably a result of copying glucose skeleton, in which this atom is not chiral?).
  • See anomer. It is likely that both forms (alpha and beta-glucopyranoside) are described by this CAS number. --Tweenk (talk) 21:41, 15 November 2009 (UTC)
• Streptomycin 57-92-1 Seems to be mirror image of WP structure.
• Tubocurarine 57-94-3 and 57-95-4 Structure is messed up in union file. I can't make sense of it.

301-400

• Cephalosporin No chembox and other issues.
  • This is a class article, I don't think there should be a chembox. Fvasconcellos (t·c) 19:54, 24 January 2009 (UTC)
  • The CASRN refers to Cephalosporin C, for which we don't seem to have an article. Physchim62 (talk) 20:19, 25 January 2009 (UTC)
• Lactose CAS is for open chain aldehyde form, is this significant?
  • I don't think so, but we're checking. Physchim62 (talk) 22:35, 23 January 2009 (UTC)
• Methionine Chiral issues.
  • as per talk page Physchim62 (talk) 22:35, 23 January 2009 (UTC)

401-500

• Cholecalciferol: The structure diagram has one carbon atom with two wedge bonds attached, making verification difficult (the stereochemistry should be R here, and I think it is)
• Vitamin B12: The structure diagram does not adequately specify the stereochemistry of the Corrin ring
• Ellman's reagent: no chembox, and needs text cleanup
  • I added a chembox. -- Ed (Edgar181) 19:12, 11 February 2009 (UTC)
• Sanger's reagent: no chembox
• Asparagine: The structure diagram has one carbon atom with two wedge bonds attached, making verification difficult (the stereochemistry should be S here, and is)
• Histidine: Structure needs to show stereochemistry
• Medroxyprogesterone acetate: Redirects to Medroxyprogesterone
• Veratridine: still to be verified, the structure displays badly in ChemFileBrowser
• Sodium lactate: old-style chembox; note that CASRN is for unspecified stereochemistry
• Valine: The structure diagram has one carbon atom with two wedge bonds attached, making verification difficult (the stereochemistry should be S here, and is)
• Threonine: The structure diagram does not specify the stereochemistry at the two chiral centres (should be 2S,3R)
• Endrin: The structure diagram appears to show the endo-isomer whereas the CASRN is for the exo-isomer (or vice versa, I never was very good at this particular bit of nomenclature! in any case, it's not the same compound!) We should recheck with Dieldrin (CASRN [60-57-1]) as well. Neither compound has the stereochemistry correctly specified.
  • I've rechecked Dieldrin, adding the implicit hydrogens to the WP structure and drawing in chemsketch, I also copied the CAS structure exactly and had the program assign stereo labels. They match, which leads me to think my initial verify is OK. It maybe should be noted that while the carbon skeletons look to be the same projection, WP is from above and CAS (turns out to be) from below. If you are still unhappy could you describe your assignment in more detail? I'll try the chemsketch method with Endrin and hopefully we can compare notes Ambix (talk) 23:27, 6 February 2009 (UTC)
  • I have checked Endrin with the same process and it does not match. There is an older version of this image Endrin.png and this does match. Given the difficulties of transposing a 3D structure to more conventional form it would probably be better to have a more conventional structure as well for compounds like this but I would suggest we avoid removing 3D structures providing it is possible to validate them. I will investigate furthur.
    • I suggest that for our validated structure on such compounds, we should explicitly show the stereochemistry of each chiral centre, which is not the case at present on Endrin and Dieldrin (even if a knowledgeable chemist can figure out what it must be from the diagram). That doesn't necessarily mean changing the structures in the chemboxes (our images for inorganics don't always give a clear idea of the structure), but we should insist on the chembox information being correct and not-misleading, and that the full details be available in the article (maybe in a separate image). Physchim62 (talk) 23:23, 9 February 2009 (UTC)
• Dichlorodiphenyldichloroethylene: short-form chembox
• Trypan blue: Structure diagram shows free acid whereas CASRN is for tetrasodium salt
• Isoleucine: The structure diagram does not specify the stereochemistry at the two chiral centres (should be 2S,3S)
• Ethambutol: The structure diagram does not specify the stereochemistry at the two chiral centres (should be 2S,2'S)
  • Done. Fvasconcellos (t·c) 23:42, 9 February 2009 (UTC)
• Arginine: Structure needs to show stereochemistry
• Ethylene: old-style chembox
• Missing articles: 3,5-Dimethylpyrazole, O-Methylhydroxylamine, Tetraethylammonium iodide, Ethyl 3-bromopyruvate, 1-Methyl-3-nitro-1-nitrosoguanidine, Mercaptosuccinic acid, p-Toluenesulfonamide, 4-Chlorobenzoic acid, N,N'-Diphenyl-1,4-phenylenediamine
• Ions: Acetate, Bicarbonate

501-600

• Trimethylaluminium is dimer, CAS is monomer. Is this significant, will CAS have a dimer listed?
• Camphor Both the WP page and the CAS are for unspecified stereoisomers however if we follow the naturally occuring rule, should the WP page be changed for the natural isomer and the unspecified CAS be relegated to an 'other'?

601-700

• Aprobarbital CAS 77-02-1 is unspecified.
• 2,3-Dimethylbutane redirects to Dimethylbutane only 2,2 has an article. Generic name is now DAB, both 2,2 and 2,3 have articles.

Inorganics

The 677 "inorganics" (neutral compounds without C–C or C–H bonds) have now all been checked. 496 entries gave a perfect match, 74 entries had some sort of problem in the article (often minor and already fixed) and 100 entries had no appropriate corresponding article on Wikipedia. A full report will be available in due course.

Elements and ions

These will require special treatment: please contact Physchim62 for more details.