Enzymatic Synthesis of Palm-Based Ferulate Ester as Sunscreen Agent
Lim, Sheo Kun (2006) Enzymatic Synthesis of Palm-Based Ferulate Ester as Sunscreen Agent. Masters thesis, Universiti Putra Malaysia.
The invention of modifying palm oils to produce sunscreen agent, ferulate ester (RBD-FE) had been investigated through transesterification reaction of RBD palm olein with ferulic acid (4-hydroxy-3-methoxy-cinnamate, FA) by enzymatic synthesis. Ferulic acid is a natural substance which has free radical scavenging effects and helps to prevent damage to our cells caused by UV light. However, incorporation of ferulic acid into cosmetic compositions is problematic due to its instability in aqueous solution and limited solubility in water in oil emulsions. Besides, currently used sunscreen agent in 90 percent of all sunscreen products throughout the world; octyl methoxycinnamate (OMC) is reported could be toxic to human skin. This process has been studied as one approach in order to overcome these problems to provide a natural cosmetic ingredient with enhanced efficiency and stability. It combines the ultraviolet-absorbing properties of a cinnamate (ferulic acid) with the water-insoluble properties of a lipid (RBDPO) resulting in ultraviolet-absorbing lipids (RBD-FE) made from all natural ingredients under mild, solvent-free conditions to ensure a safe, clean and cosmetically acceptable product. Enzyme screening revealed Novozym 435 to be the most efficient biocatalyst for the reaction and was chosen for optimization studies. The important parameters that may affect the synthesis of RBD-FE had been investigated. The corresponding optimal conditions for the transesterification reaction was time, 96 h; temperature, 40 °C; mole ratio of ferulic acid: RBDPO, 1:3; and amount of enzyme used, 0.10 g resulting in highest percentage of conversion (24.51%) to ultraviolet-absorbing lipids (RBD-FE) that works as a sunscreen agent. Identities of product were verified using TLC, gas chromatography (GC), Fourier transform infrared spectroscopy (FT-IR), High Performance Liquid Chromatography (HPLC), GC-Mass Spectroscopy (GC-MS) and Nuclear Magnetic Resonance (NMR) Spectroscopy analyses. Thermal and oxidative stability of the RBD-FE were also evaluated. Later, palm-based ferulate ester was also formulated into cosmetic formulations to evaluate it as sunscreen agent followed by Sun Protection Factor (SPF) analysi RBD-FE showed higher thermal stability and better oxidative stability. Besides, it became an active ingredient in sunscreen formulation which acted as a broadband sunscreen agent which covers both UVA and UVB rays. It showed a wider light absorption peak between 290 and 400nm.s
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