Synthesis of Antimicrobial and Emulsifier Compunds through Hydroxyl Group Esterification of Oxidized Ricinoleic Acid

摘要: In this study, ester synthesis from commercial oxidized ricinoleic acid using various carboxylic acid was conducted. The double bond in ricinoleic acid was oxidized using KMnO4 in alkaline condition to form two hydroxyl groups. Oxidized ricinoleic acid was then esterified chemically using palmitic acid, decanoic acid, and butyric acid by ZnCl2 as catalyst with the molar ratio of oxidized ricinoleic acid to carboxylic acid was 3: 1. Esters produced were characterized using FTIR examined as emulsifier and the antimicrobial activity. The results showed that each ester product gave absorption band C= O ester at the range of 1600 cm-1-1720 cm-1. The highest conversion percentage of esterification was obtained by oxidized ricinoleic acid-palmitic acid esters with the value of 75%. Simple emulsifier test was performed for each ester and the result showed that esters were able to maintain an emulsion form approximately 24 hours with water-in-oil emulsion (w/o) type. The antimicrobial activity test of esters gave positive results in the presence of inhibition zone to the growth of Propionibacterium acnes and Staphylococcus epidermidis. The highest antimicrobial activity against P. acnes and S. epidermidis was produced by oxidized ricinoleic acid-decanoic acid esters.