Correlation of di- and tripeptide distribution coefficients with structure via unitary molecular indices

✍ Scribed by Stephen P. Molnar; James W. King

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 174 KB
• Volume: 69
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1998)69:1<49::aid-qua7>3.0.co;2-x

✦ Synopsis

The unitary molecular structure indices, viz., the integrated molecular Ž . Ž . transform FT , the integrated electronic transform FT , the integrated charge transform m e Ž . Ž . FT , the normalized molecular moment M , and the normalized electronic moment c n Ž . M were used in separate trials to model the reported apparent distribution coefficients e Ž X . log P of 25 dipeptides and 34 tripeptides. Linear regressions indicated that the two series should be considered separately as shown by the correlation coefficients and F statistics. In these cases, the former exceeded 0.75 generally and reached 0.795 for the FT .

e

The correlation coefficients for the FT index were 0.692 and 0.380, respectively, for the c two series and thus indicative of its inadequacy as a descriptor for this model. A bivariant regression of log P X against M and M did not improve on the monovariant n e models. The molecular weight as a structure surrogate gave adequate correlation coefficients but is not recommended as structure parameters are implicit rather than explicit. The M or M correlations may be used to estimate log P X for compounds n e similar to those in the dipeptide series, and FT , likewise in the tripeptide series. The e possible requirement for an amide group descriptor is discussed.