Complex formation of p-boronophenylalanine with some monosaccharides

Area of Science:

• Biochemistry
• Medicinal Chemistry
• Analytical Chemistry

Background:

• p-Boronophenylalanine (p-BPA) is crucial for Boron Neutron Capture Therapy (BNCT).
• Enhancing p-BPA solubility at neutral pH is essential for effective administration.
• Monosaccharides are investigated as potential complexing agents to improve solubility.

Purpose of the Study:

• To investigate the complex formation between p-BPA and various monosaccharides.
• To quantify the complex formation constants to determine the most effective monosaccharides for solubility enhancement.
• To describe the in vivo behavior of p-BPA-monosaccharide complexes.

Main Methods:

• 11B-NMR spectroscopy was used to study complex formation.
• UV spectroscopy was employed to determine complex formation constants (log K).
• Solubility of p-BPA in monosaccharide solutions was measured at neutral pH.

Main Results:

• Complex formation constants (log K) varied among monosaccharides: fructose (2.43), mannitol (2.19), galactose (1.28), mannose (1.10), and glucose (0.85).
• Fructose demonstrated the highest complex formation constant, indicating strong interaction with p-BPA.
• 100 mg of p-BPA dissolved in 3 ml of 0.3 M fructose solution at pH 7.98, significantly increasing solubility.

Conclusions:

• Monosaccharide complexation effectively enhances the solubility of p-BPA at neutral pH.
• Fructose is identified as a highly effective agent for increasing p-BPA solubility.
• The findings provide a basis for understanding the in vivo behavior of these complexes for therapeutic applications.