High Throughput Method for the Indirect Detection of Intramolecular Hydrogen Bonding

Abstract

A supercritical fluid chromatography method was developed for the detection of intramolecular hydrogen bonds in pharmaceutically relevant molecules. The identification of compounds likely to form intramolecular hydrogen bonds is an important drug design consideration given the correlation of intramolecular hydrogen bonding with increased membrane permeability. The technique described here correlates chromatographic retention with the exposed polarity of a molecule. Molecules that can form an intramolecular hydrogen bond can hide their polarity and therefore exhibit lower retention than similar compounds that cannot. By use of a pairwise analysis strategy, intramolecular hydrogen bonds are identified within a test set of compounds with diverse topologies. The chromatographic results are confirmed by NMR chemical shift and temperature coefficient studies.

An NMR Method for the Quantitative Assessment of Intramolecular Hydrogen Bonding; Application to Physicochemical, Environmental, and Biochemical Properties

“…Neither Shalaeva et al 1 nor Goetz et al 15 addressed the problem of how intraHBs affect physicochemical or biochemical properties. However, this is a crucial step because it is the relationship between structural features such as intraHBs and biochemical and environmental properties that is a driving force in medicinal and environmental chemistry.…”

Improving on Nature: Making a Cyclic Heptapeptide Orally Bioavailable

“…The polarity readout EPSA (experimental polar surface area), [12] derived from supercritical fluid chromatography column retentions determined for 1 (77), 2 (74), 3 (64), and 4 (70), correlated with experimental RRCK [13] cell membrane permeabilities (Papp (cm s À1 ): 0.6 10 À6 , 1; 0.7 10 À6 , 2; 9.6 10 À6 , 3; 1.2 10 À6 , 4) but neither correlated with rank order of oral bioavailability ( Figure 6, Table 2), which is also influenced by factors like solubility, metabolic clearance, and protein binding. The polarity readout EPSA (experimental polar surface area), [12] derived from supercritical fluid chromatography column retentions determined for 1 (77), 2 (74), 3 (64), and 4 (70), correlated with experimental RRCK [13] cell membrane permeabilities (Papp (cm s À1 ): 0.6 10 À6 , 1; 0.7 10 À6 , 2; 9.6 10 À6 , 3; 1.2 10 À6 , 4) but neither correlated with rank order of oral bioavailability ( Figure 6, Table 2), which is also influenced by factors like solubility, metabolic clearance, and protein binding.…”

Leveraging chromatography based physicochemical properties for efficient drug design

“…Utilizing separation sciences expertise, a team of Pfizer scientists developed an assay which outputs a polarity readout termed EPSA (not an acronym) [80]. The main driver behind EPSA was to have access to a fast, robust method capable of identifying the potential for a compound to form intramolecular hydrogen bonds (IMHB) enabling it to hide polarity that might otherwise reduce its passive permeability.…”

“…In the cases that have been studied, using matched molecular pairs with or without IMHBs, compounds with IMHB resulted in a significant reduction in polarity and eluted earlier in the chromatogram. Results are normalized through the use of calibration standards generating a linear relationship between retention times and EPSA values [80]. This is possible to confirm or disprove the presence of an intramolecular hydrogen bond (IMHB) in small molecules or peptides using EPSA and pairwise analysis.…”