Chirality decision tree

The purpose of this study is only intended to illustrate and evaluate the decision tree approach for CSP prediction using as attributes the 166 molecular keys publicly available in ISIS. This assay was carried out a CHIRBASE file of 3000 molecular structures corresponding to a list of samples resolved with an a value superior to 1.8. For each solute, we have picked in CHIRBASE the traded CSP providing the highest enantioselectivity. This procedure leads to a total selection of 18 CSPs commercially available under the following names Chiralpak AD [28], Chiral-AGP [40], Chiralpak AS [28], Resolvosil BSA-7 [41], Chiral-CBH [40], CTA-I (microcrystalline cellulose triacetate) [42], Chirobiotic T [43], Crownpak CR(-i-) [28], Cyclobond I [43], DNB-Leucine covalent [29], DNB-Phenylglycine covalent [29], Chiralcel OB [28], Chiralcel OD [28], Chiralcel OJ [28], Chiralpak OT(-i-) [28], Ultron-ES-OVM [44], Whelk-0 1 [29], (/ ,/ )-(3-Gem 1 [29]. 

Tests for New Drug Substances That Are Optically Active. Chiral impurities had been excluded from ICH guidelines on impurities because of the practical difficulties of measuring them. However, in Q6A, a decision tree describes if, and when, chiral identity tests, impurity tests, and assays may be needed for both new drug substances and products, according to criteria such as the following ... 

Scheme 2 Decision tree for chiral compound resolution. Source Courtesy of Pharmquest Corporation, Mountain View, Caiifornia, U.S.A.

Roussel C, Pierrot-Sanders J, Heitmann I, Piras P. CHIRBASE database current stams and derived research applications using molecular similarity, decision tree and 3D enantiophore search. In Subramanian G, editor. Chiral Separation Techniques. A practical Approach. 2nd edition. Weinheim Wiley-VCH 2001. p 95-125. 

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