脂肪酸1,1,3,3-四甲基胍離子液體的合成與抗菌性能研究

Synthesis and Antimicrobial Activity of 1,1,3,3-Tetramethylguanidinium Aliphatate Ionic Liquid

脂肪酸是由脂肪族烴類基團連結羧基所構成的羧酸化合物，也是化粧品中重要的原料之一。部分脂肪酸對細菌或真菌等微生物具有抗菌效能，但因水中溶解度不佳的問題，導致使用上的不方便。本研究利用不同碳鏈長度的脂肪酸與1,1,3,3-四甲基胍反應，合成高產率之9種不同脂肪酸胍離子液體，進而探討其溶解度及抗菌的活性。由實驗結果顯示，本研究中的脂肪酸1,1,3,3-四甲基胍，對水具有良好的溶解性；而在抗菌性能的探討上，由紙錠擴散試驗結果顯示，十二酸1,1,3,3-四甲基胍在濃度20 mg/mL時，對枯草桿菌（Bacillus subtilis）與金黃色葡萄球菌（Staphylococcus aureus）的抑菌圈可達22 mm以上，抗菌效能較相同碳鏈長度的十二酸為佳。

Fatty acid is composed of the carboxylic acid with a long saturated or unsaturated aliphatic chain. In general, it was used in cosmetic products as the main ingredient of emollient agents. Part of fatty acids displayed the antimicrobial efficacy in bacteria or fungi, but the problem of solubility led fatty acids into the inconvenient using. This study utilized the 1,1,3,3-tetramethylguanidine to react with the different carbon chain length of fatty acids, and produced nine of 1,1,3,3-tetramethylguanidium aliphatates （TGAs）. Antimicrobial activity of the TGAs was evaluated by the disc diffusion method to detect the inhibitory zones. Our experimental results revealed that the different types of TGA could be easily dissolved in water. Furthermore, the 1,1,3,3-tetramethylguanidium dodecanoate （20 mg/mL） was able to inhibit the growth of Staphylococcus aureus and Bacillus subtilis, and the sizes of inhibitory zones were above 22 mm. In addition, the antimicrobial efficacy of the 1,1,3,3-tetramethylguanidium dodecanoate was better than the dodecanoic acid.