Molecular holograms

Hurst, T. and Heritage, T. (1997) HQSAR—A highly predictive QSAR technique based on molecular holograms. 213th ACS Natl. Meeting, San Francisco, CA, CINF 019. 

In addition to binary descriptors, molecular holograms are also useful for similarity searches. Similar to fingerprint, hologram is a vector that contains numerical... 

Molecular holograms are an extended form of fingerprints based on the 2D structures. An HQSAR model was derived for 250 compounds (r2 = 0.93, q2 = 0.70) and tested with 52 compounds (r2 = 0.85) [37], which is a good result. The authors correctly point out some limitations of the model. Training is based on drugs, most compliant to the rule-of-5, and has no real solubility issues. The question therefore arises whether such model would be predictive for and pick out nondrug-like compounds. 

Molecular holograms are thus very similar to hashed fingerprints, but rather than using a binary bit string containing either 0 or 1 in each bin, the bins of molecular holograms contain information about the number of fragments hashed to each bin. 

Wang, X., Tang, S., Liu, S., Cui, S. and Wang, L.-S. (2003) Molecular hologram derived quantitative structure-property relationships to predict physico-chemical properties of polychlorinated biphenyls. Chemosphere, 51, 617—632. 

Heritage TW, Lowis DR. Molecular hologram QSAR. Rational Drug Design, ACS Symposium Series, Vol. 719. Washington, DC 1999. p 212-225. 

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