Partition Coefficient (LogP)
Partition Coefficient (LogP) — The ratio of a compound's concentration in octanol versus water, predicting peptide hydrophobicity and membrane permeability.
What Is the Partition Coefficient?
The partition coefficient (LogP or LogD) measures how a peptide distributes between an organic phase (octanol) and an aqueous phase, quantifying overall lipophilicity. LogP predicts membrane permeability, oral absorption, and tissue distribution. Most peptides are highly hydrophilic (negative LogP), which is why they cannot cross membranes passively.
Context
- Lipinski's Rule of 5: LogP < 5 for oral drugs. Most peptides violate MW and H-bond rules but can be orally available if LogP and HBD are optimized
- N-methylation: Each N-methyl group increases LogD by ~0.5-1.0 units
- Lipidation: Fatty acid conjugation dramatically increases LogP
Frequently Asked Questions
What is Partition Coefficient (LogP)?
The ratio of a compound's concentration in octanol versus water, predicting peptide hydrophobicity and membrane permeability.
Why is Partition Coefficient (LogP) important in peptide research?
Partition Coefficient (LogP) is a fundamental concept in chemistry as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.
Authority Sources
- Partition Coefficient (LogP) on Wikipedia
- Search Partition Coefficient (LogP) on PubChem (NIH)
- Research articles on ScienceDirect