25 Matching Annotations
  1. May 2017
  2. Apr 2017
  3. Mar 2017
    1. An Entrez "node" is a collection of data that is grouped together and indexed together

      As an example for searching on Entrez AIDS so like Literature, Health, Genomes, etc are considered as a "node" and little section above that are link within nodes?- Phuc

    1. This “legacy” designation applies to project/contributors that appear to no longer be active, as well as to their individual records.  This designation will help PubChem users quickly identify records that may have out-of-date information and/or hyperlinks.

      This might sound a bit dumb. But, if it's out of date or not really validated, why not just remove it? Phuc

    1. As of February 2017, PubChem’s data are from more than 500 organizations, including government agencies, university labs, pharmaceutical companies, substance vendors, and other databases

      How would Pubchem curate and check the validity of those data coming from different sources? Phuc

  4. Feb 2017
    1. <request string="arsinic acid" representation="names">   <data id="1" resolver="name_by_opsin" notation="arsinic acid">     <item id="1" classification="pubchem_iupac_name">arsinic acid</item>     <item id="2" classification="pubchem_substance_synonym">CHEBI:29840</item>     <item id="3" classification="pubchem_substance_synonym">HAsH2O2</item>     <item id="4" classification="pubchem_substance_synonym">[AsH2O(OH)]</item>     <item id="5" classification="pubchem_substance_synonym">arsinic acid</item>     <item id="6" classification="pubchem_substance_synonym">dihydridohydroxidooxidoarsenic</item>   </data> </request>

      How can you pull this string of data? is it from inspection option on the browser? what type of file is this?

    1. The first block of 14 (out of total 27) characters for anInChIKey encodes core molecular constitution, as de-scribed by formula, connectivity, hydrogen positions andcharge sublayers of the InChI main laye

      Can you search the web with the first block of the InchI key and find all isomer of the compound?

    1. Generic structures are commonly used in chemistry texts as well as in chemical patents in which the inventor claims a whole class of related compounds.  Generic structures are more often called “Markush” structures after Dr. Eugene A. Markush, who involved in a legal case which set a precedent in the USA for generic chemical structure patent filing.

      This might sound a bit dumb! Can Inchi be generate from a Markush structure? I know generic structure and Inchi are quite contradicted from each other. Markush can be quite proprietary and InCHI is open science.

    1. MOL files do indicate chirality. However, they can do so in two ways. A “1” or “6” in the fourth field of the bonds table indicates wedged and dashed bonds, respectively. A “1” or “2” in the stereochemistry field of the atom table represents the chirality of a stereocenter.

      Is there any clue on the Mol File that if the structure has more than one chirality center?

    2. As an example, take isopropyl alcohol. SCT I is a connection table representing this compound – or, more specifically, representing this structural formula. Connection tables are not necessarily unique We could draw up other tables of atoms and bonds that represent this compound as well: for example, SCT II and SCT III

      I'm just wonder how this connection table is form? Is it from Morgan algorithm or just randomly assign number for atom?

    1. The Morgan algorithm identifies atoms basedon an extended connectivity value. The atom withthe highest value becomes the first atom in the name,and its neighbors are then listed in descending or-der. Ties are resolved based on additional parame-ters, for example, bond order and atomic number.The original Morgan algorithm did not handle stere-ochemistry; the stereochemically unique naming algo-rithm [stereochemical extension of Morgan algorithm(SEMA)] was developed to handle stereoisomers

      If figure 3 connection table is created based on Morgan algorithm, how would the carbon from the far left is put as the 1st atom not the nitrogen?

    1. Fortunately, this can be done with the Morgan Algorithm18.In this algorithm, each atom is given a "connectivity value" reflecting how many atoms it is connecte

      So you can create as many connection table as possible like the exercise in OLCC website, the correct or "canonical" table is the one that is generated with Morgan algorithm. Is it sound right?