Biomaterial Database

Hydrolysis of saturated soybean phosphatidylcholine in aqueous liposome dispersions. 1993

M Grit, and W J Underberg, and D J Crommelin

Department of Pharmaceutics, Faculty of Pharmacy, University of Utrecht, The Netherlands.

Hydrolysis kinetics of saturated soybean phosphatidylcholine (PC) were investigated as a function of pH, temperature, buffer concentration, buffer species, and ionic strength in aqueous liposome dispersions. A high-performance liquid chromatography method was used to separate PC and the hydrolysis products. Hydrolysis of PC followed pseudo first-order kinetics. Hydrolysis of fatty acid esters at sn-1 and sn-2 positions initially resulted in the formation of 2-acyl lyso-phosphatidylcholine and 1-acyl lyso-phosphatidylcholine; because of acyl migration, the most stable isomer of lyso-phosphatidylcholine, 1-acyl lyso-phosphatidylcholine, was formed predominantly. General acid-base catalysis was observed for acetate and Tris ions. The pH profiles at 40 and 70 degrees C for a buffer concentration of 0.05 M showed a minimum hydrolysis rate at about pH 6.5. The relationship between the observed rate constant and temperature could be described adequately by the Arrhenius equation below and above the phase transition temperature of saturated soybean PC (52 degrees C).

UI	MeSH Term	Description	Entries
D008081	Liposomes	Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.	Niosomes,Transferosomes,Ultradeformable Liposomes,Liposomes, Ultra-deformable,Liposome,Liposome, Ultra-deformable,Liposome, Ultradeformable,Liposomes, Ultra deformable,Liposomes, Ultradeformable,Niosome,Transferosome,Ultra-deformable Liposome,Ultra-deformable Liposomes,Ultradeformable Liposome
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D010713	Phosphatidylcholines	Derivatives of PHOSPHATIDIC ACIDS in which the phosphoric acid is bound in ester linkage to a CHOLINE moiety.	Choline Phosphoglycerides,Choline Glycerophospholipids,Phosphatidyl Choline,Phosphatidyl Cholines,Phosphatidylcholine,Choline, Phosphatidyl,Cholines, Phosphatidyl,Glycerophospholipids, Choline,Phosphoglycerides, Choline
D002021	Buffers	A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.	Buffer
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D013025	Glycine max	An annual legume. The SEEDS of this plant are edible and used to produce a variety of SOY FOODS.	Soy Beans,Soybeans,Bean, Soy,Beans, Soy,Soy Bean,Soybean
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures