Green and efficient synthesis of pine sterol oleate catalyzed by SO₃H‐functionalized ionic liquid

Abstract

Background Phytosterol esters can be used in the food industry because of their various physiological activities and better physical properties compared to free phytosterols. However, existing synthetic methods for phytosterol esters tend to have the problems of environment unfriendliness, excessive by‐products, and difficulty in product separation and purification. Therefore, it is crucial to develop a green and efficient synthetic process for phytosterol esters. Results The catalytic properties of various SO3H‐functionalized ionic liquids for the synthesis of pine sterol oleate were investigated, and [BSO3HMIm]Ts showed the best catalytic effect and reaction selectivity. Under the optimized reaction conditions: using 7% of [BSO3HMIm]Ts (based on the mass of pine sterols) as the catalyst, the molar ratio of oleic acid to pine sterols 2:1, reaction at 140 °C for 2.5 h, the yield of pine sterol oleate could reach 93.9%, while only 4.2% of dehydrated sterols by‐products could be produced. Furthermore, the esterification yield could still reach 85.0% after the catalyst [BSO3HMIm]Ts was reused six times under the optimal conditions. Conclusion This study demonstrates that SO3H‐functionalized ionic liquid [BSO3HMIm]Ts has higher catalytic activity and selectivity than many reported chemical catalysts in the synthesis of phytosterol esters. A green, efficient, and scalable procedure for the esterification of phytosterols with fatty acids in a solvent‐free system has been developed. © 2022 Society of Chemical Industry (SCI).

Octadecyl and sulfonyl modification of diatomite synergistically improved the immobilization efficiency of lipase and its application in the synthesis of pine sterol esters

“…[16,17] The chemical synthesis of phytosterol esters is industrially feasible, but the high energy consumption, low selectivity of the reaction, and the unavoidable by-products of dehydrated sterols limit its further applications. [18] Enzymatic catalysis which is performed under mild operating conditions, has high selectivity and fewer by-products and is therefore attractive in this field. [19] In recent years, several lipases, including Novozym @ 435, [20,21] Candida rugosa lipase, [22] and others, have demonstrated their ability in the synthesis of phytosterol esters.…”

Study on the synthesis of pine sterol esters in solvent‐free systems catalyzed by Candida rugosa lipase immobilized on hydrophobic macroporous resin

“…Given a lower melting point, higher oil solubility, and similar physiological effects, 13 phytosterol esters are considered ideal substitutes for phytosterols. [14][15][16] At present, there are two types of methods for the synthesis of phytosterol esters, chemical and enzymatic methods, among which the chemical catalytic synthesis of phytosterol esters suffers drawbacks of higher reaction temperature, 14 poor product appearance, 17 and residual chemical catalyst, 18,19 whereas enzymatic synthesis of phytosterol esters has received widespread attention because of its mild reaction conditions, low number of by-products, and high product quality. 20,21 The enzymatic synthesis of pine sterol esters can be performed using esterification 22 (thermodynamically controlled synthesis) and transesterification 23 (kinetically controlled synthesis).…”

Octadecyl and sulfonyl modification of diatomite synergistically improved the immobilization efficiency of lipase and its application in the synthesis of pine sterol esters

“…The chemical synthesis of phytosterol esters is industrially feasible, but the high energy consumption, low selectivity of the reaction, and the unavoidable by-products of dehydrated sterols limit its further applications [18]. Enzymatic catalysis which is performed under mild operating conditions, has high selectivity and fewer by-products and is therefore attractive in this field [19].…”