Hydrogen bonding number

Burns and Weaver [6] developed an MLR-based BBB permeability model using two experimental measures of BBB penetrability (brain/plasma ratio and the brain-uptake index) and 14 theoretically derived biophysical predictors based on Stein s hydrogen-bonding number and Randic s topological properties of the molecules. The final model accurately predicted the ability of test molecules to cross the BBB. 

Burns and Weaver [6] Stein s hydrogen-bonding number and Randic s topological properties... 

Hydrogen bonding number Number of hydrogen bonding donor sites Number of hydrogen bonding acceptor sites... 

HBN is the hydrogen bond number and is defined by the following equation ... 

Values of rid, rip and tip for a number of solvents determined in this way can be found in Table VI (Part VII). For comparison also values of the dipole moment /i and the hydrogen bonding number 8v are mentioned. Hansen also determined r)d, 8p and dp of the polymers involved, being the coordinates of the centre of the solvents region in his three-dimensional structure. Table 7.8 shows his parameters for some polymers.2 The method of Hansen has the disadvantage that three-dimensional structures are necessary for a... 

Cf SF is responsible for the broad maximum at higher T. Cp captures the enthalpy fluctuations due to the hydrogen bond formation given by the terms proportional to the hydrogen bond number ApB. This term is present also in the SF model . To show that this maximum is due to the fluctuations of hydrogen bond formation, we calculate the locus of maximum fluctuation of Nhb, related to the maximum of dNHB/dT p [Fig. 8(a)], and find that the temperatures of these maxima correlate very well with the locus of maxima of [Fig. 9].We... 

Hydrogen bonding (number of H-bond donors or acceptors, Abraham s oi and 3 descriptors, PSA, etc.)... 

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