Steglich esterification of oleic acid with curcumin and toxicity test of its products against Daphnia magna

• Main Authors: Anty, Mentari Zikri, Wukirsari, Tuti, Handayani, Sri, Hudiyono, Sumi
• Format: Conference Proceeding
• Language: English
• Subjects: Absorption; Biocompatibility; Chemical synthesis; Column chromatography; Esterification; Ethyl acetate; Functional groups; Hexanes; Ketones; Oleic acid; Reagents; Silica gel; Toxicity; Toxicity testing
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0204842

Oleic acid is an unsaturated fatty acid that has been known to have therapeutic activities such as antimicrobial, anti-inflammatory, antidiabetic, and anticancer. In this study, the synthesis of oleic acid ester compounds with curcumin was carried out by Steglich esterification using DCC as a coupling reagent and DMAP as a catalyst. Thin layer chromatographic analysis was performed to identify the product and showed that the Rf value of oleic acid was 0.70, dioleic-curcumin ester was 0.92, monooleic-curcumin ester was 0.78, and curcumin was 0.49. The product was then purified using silica gel column chromatography with n-hexane:ethyl acetate (12:1, v/v) as the eluent. Characterization using FT-IR showed that there was a new absorption of the C=O ester functional group at wave numbers 1760 cm−1 – 1735 cm−1. There were also absorption peaks for carboxyl ketone C=O functional group at 1640 cm−1-1620 cm−1, aromatic C=C functional group at 1650 cm−1 – 1566 cm−1, aromatic C-O functional group at 1310 cm−1 – 1250 cm−1, and C-O-C at 1075 cm−1 – 1020 cm−1. The results of the toxicity test against Daphnia magna showed that the LC50 value of the dioleic-curcumin ester compound product was 189.91 mg/L and monooleic-curcumin was 98.68 mg/L. Based on the LC50 value, the monooleic-curcumin ester was categorized as very toxic and had the potential as a bioactive compound.