Wednesday, February 27, 2008
A few more links summarizing where this new development has been already integrated, can be found on
Saturday, February 9, 2008
At the moment approx. 33 millions of organics are known. Chemspider holds approx. 21M, PUBCHEM-Compounds approx. 18M structures, which represents 2/3 of known chemistry. I know that within CHEMSPIDER structure correction is an ongoing process as it is e.g. within my own CSEARCH-project. NMRshiftdb has been severly improved over the last months, etc.
Tuesday, February 5, 2008
Some background information:
- C-NMR spectra have been calculated using CSEARCH-NN-technology
- Spectral search technique is based on SAHO as implemented into CSEARCH
- The main intention of this system is to get some feeling about the compound class for an unknown. It must be clearly stated, that a database of 5M unqiue structures is definitely too small to cover known organic chemistry (approx. 33M at 02/2007). When taking into account the possible structures for a given molecular formula, 5M structures represent a neglictable part of possible organic chemistry !
In the meantime there were massive updates on PUBCHEM - this was the reason for rerunning the predictions and implementing another (much faster) search technique - the principle is still based on Wolfgang Bremsers SAHO-technique - the speed has been increased to allow searching of 1 billion (10**9) of CNMR-spectra within less than 3 seconds on a single CPU. At the moment the system is only partly installed and allows searching of 405,704,611 spectral patterns (usually in 1.2-1.6 seconds).
- PREDICTED CNMR-spectra for approx. 23M unique structures downloaded from PUBCHEM using CSEARCH-NN-technology
- Structures deposited from CHEMSPIDER are already included
- Intention is again to give some flavour of possible compound classes for an unknown
A detailed description of the search-technique will be given soon - stay tuned !
Another nice feature of this system: Whenever an experimental set of NMR-data is available within CSEARCH / SPECINFO / NMRPRedict / NMRShiftDB / CHEMGATE - this information is automatically included into the final resulting table of structures !
Feel free to test it ! The URL is
Your feedback is highly appreciated - use the comment section !