• Journal of the Korean Applied Science and Technology
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• v.25 no.1
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• pp.48-51
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• 2008

Dipalmitoyl phosphatidyl choline and p-nitrophenyl palmitate were directly sonicated in acidic water for 6 minutes to give clear stock solutions. The catalytic hydrolysis of p-nitrophenyl palmitate was studied at $30-50^{\circ}C$ in the presence of unilamellar vesicle and mixture of unilamellar and multilamellar aggregates. The difference of reaction rate between unilamellar and multilamellar was observed. The rate of unilamellar reaction compared to the rate of mixture reaction showed more catalytic effect. The phase transition temperature of vesicle was measured at $37-44^{\circ}C$.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.348-354
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• 2019

Dipalmitoyl phosphatidyl choline(DPPC), Polyphenol Derivatives, and Hematoxylin-Eosin were directly sonicated in acidic condition for 6 minutes to give clear stock solutions. Absorbtion properties of Polyphenol Derivatives in lecithin vesicle of Diphalmitoyl phosphatidyl choline system at $25^{\circ}C$ have been studied by absorbtion spectroscopy. The equilibrium of Polyphenol Derivatives between monomer and dimer in lecithin vesicles have been existed at low concentration of Polyphenol Derivatives, but oligomer has been formed in vesicle at high concentration of lecithin vesicles. By adding Bacteriorhodopsin(BR) to constant concentration of Polyphenol Derivatives decreased the absorbtion ratio(${\alpha}/{\beta}$) of Polyphenol Derivatives was increased during phase transition of dipalmitoyl phosphatidyl choline. In the presence of column eluted lamella vesicle and mixture of uni- and multilamella aggregates. The differences of rate between column eluted- and mixture were observed, therefore column eluted lamella reaction was represented more catalytic effect. The phase transition temperature of hydrolysis on Dipalmitoyl phosphatidyl choline and Polyphenol Derivatives were measured higher than it of Dipalmitoyl phosphatidyl choline and no Polyphenol Derivatives.

• Preventive Nutrition and Food Science
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• v.8 no.3
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• pp.235-238
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• 2003

We investigated the effect of the phase transition temperature (T$_{c}$) of phospholipid in liposomes on the stability of incorporated retinol. Two kinds of phospholipid which have different T$_{c}$, L- $\alpha$ -dimyristoyl phosphatidyl choline (DMPC, T$_{c}$=22$^{\circ}$C) and D,L- $\alpha$ -dipalmitoyl phosphatidyl choline (DPPC, T$_{c}$=42$^{\circ}$), were used to prepare liposomes. Liposome with retinol was prepared as multilamella vesicles (MLVs) by the dehydration/rehydration method. The incorporation efficiency of retinol into liposomes prepared from DMPC and DPPC were 99.89$\pm$0.08% and 99.97$\pm$0.03, respectively. The average size of liposomes from DPPC were greater than that of DMPC. Two kinds of liposomes in phosphate buffer (10 mM, pH 7.0) were stored at 15, 30, and 5$0^{\circ}C$, and stability of incorporated retinol was analyzed. The stability of retinol in DMPC liposome was decreased, whereas the stability in DPPC liposome was increased as temperature increased, although the overall protection effect of liposome on the incorporated retinol was greater in DMPC liposomes than in DPPC liposomes.posomes.