New and original pKa prediction method using grid molecular interaction fields
New and original pKa prediction method using grid molecular interaction fields
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DOI:
10.1021/ci700018y
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发表时间:
2007-11-01
影响因子:
5.6
通讯作者:
Cruciani, Gabriele
中科院分区:
文献类型:
--
作者:
Milletti, Francesca;Storchi, Loriano;Cruciani, Gabriele
One of the most important physicochemical properties of a molecule is pK(a). It is known that two parameters imperative in ADME profiling, solubility, and lipophilicity are governed by pK(a), and receptor binding can be influenced by pK(a). Because most drugs are ionized in physiological conditions, pK(a) is particularly relevant to medicinal chemistry. Despite the numerous advances in high-throughput measurements, in silico determination is still the fastest and cheapest way of obtaining pK(a). This paper presents a new original computational method for pK(a) prediction of organic compounds. Descriptors were generated using the program GRID, and these descriptors are based on molecular interaction fields precomputed on a set of molecular fragments. The new method was developed, trained, and cross-validated by using a large and diverse data set of 24 617 pK(a) values. This paper presents the results for a class of 421 acidic nitrogen compounds (RMSE = 0.41, r(2) = 0.97, q(2) = 0.87) and for a class of 947 six-membered N-heterocyclic bases (RMSE = 0.60, r(2) = 0.93, q(2) = 0.85). For external validation 28 novel compounds were selected that covered nine different ionizable groups, and 39 pK(a) values could be experimentally determined by spectral gradient analysis (SGA). Comparison of experimental pKa with calculated pK(a) demonstrated that the predictive ability of the method is good (external set, r(2) = 0.85, RMSE = 0.90).