Chemoenzymatic Epoxidation of Limonene Using a Novel Surface-Functionalized Silica Catalyst Derived from Agricultural Waste

Abstract

Limonene is one of the most important terpenes having wide applications in food and fragrance industries. The epoxide of limonene, limonene oxide, finds important applications as a versatile synthetic intermediate in the chemical industry. Therefore, attempts have been made to synthesize limonene oxide using eco-friendly processes because of stringent regulations on its production. In this regard, we have attempted to synthesize it using a cost-effective and eco-friendly process. Chemoenzymatic epoxidation of limonene to limonene oxide was carried out using in situ generation of peroxy octanoic acid from octanoic acid and H 2 O 2 . In this study, agricultural-waste rice husk ash (RHA)-derived silica was surface-functionalized using (3-aminopropyl) triethoxysilane (APTS), which was cross-linked using glutaraldehyde for immobilization of Candida antarctica lipase B. Furthermore, the immobilized enzyme was entrapped in calcium alginate beads to avoid enzyme leaching. Thus, limonene oxide was prepared using this catalyst under conventional and microwave heating. The microwave irradiation intensifies the process, reducing the reaction time under the same conditions. Maximum conversion of limonene to limonene oxide of 75.35 ± 0.98% was obtained in 2 h at 50 °C using a microwave power of 50 W. In the absence of microwave irradiation, the conventional heating gave 44.6 ± 1.14% conversion in 12 h. The reaction mechanism was studied using the Lineweaver–Burk plot, which follows a ternary complex mechanism with inhibition due to peroxyoctanoic acid (in other words H 2 O 2 ). The prepared catalyst shows high reusability and operational stability up to four cycles.

Modelling of green biocatalytic (R)-(+)-limonene oxidation using the mycelium of psychrophilic Cladosporium cladosporioides 01

“…The maximum conversion efficiency (75.3%) was obtained after 2.5 h at 50 °C at 25 mM limonene, 50 mM octanoic acid, and 50 mM H 2 O 2 concentrations, and 1 g of enzyme in toluene and an agitation speed of 300 rpm. 27 Limonene 1,2-epoxide was synthesized via epoxidation of R -(+)-limonene catalyzed by CALB immobilized on hydrophobic polymer resin (NS 88011), and its best yield was 74.92% at 40 min (at 40 mM limonene, 70 mM octanoic acid and 250 mM H 2 O 2 at 50 °C). 10 The product of the ( R )-(+)-limonene oxidation by Candida antarctica lipase B was a mixture of cis and trans isomers of limonene 1,2-epoxide.…”

“…Full conversion was achieved within 6 hours. 9 Optimization of the parameters of the limonene epoxidation reaction was also carried out by Salvi and Yadav (2020). Amorphous silica was obtained from rice husks and then subjected to surface functionalization with 3-aminopropyltriethoxysilane cross-linked with glutaraldehyde.…”

R-(+)-limonene diastereoselective epoxidation: A minireview about of the synthesis methods

“…1 Universidad Pedagógica y Tecnológica de Colombia, Grupo de Catálisis de la Universidad Pedagógica y Tecnológica de Colombia (GC-UPTC), Tunja, Boyacá, Colombia. * PhD in Chemistry: jairo.cubillos@uptc.edu.co Ganapati et al [57], employed a similar system shown in Figure 10, but in this work, they immobilized the enzyme in a silica derived from the rice husk ash for a cross-linked method using 3aminopropyl triethoxysilane (APTS) as silanization agent and glutaraldehyde as an cross-linking agent. Also, they obtained the limonene oxide using microwave radiation to improve the process yield, where the best conditions were 2 hours of reaction time, temperature of 50 • C, and a power of 50 W, to achieve a 75.35% of limonene conversion to 1,2-limonene oxide.…”

Synthesis of Biorenewable Terpene Monomers Using Enzymatic Epoxidation under Heterogeneous Batch and Continuous Flow Conditions

“…We considered Candida antarctica Lipase B (CALB) immobilized onto poly­(methyl methacrylate) cross-linked with a divinyl-benzene macroporous support (known as Novozym 435) as a promising candidate. Commercial CALB is an attractive epoxidation catalyst in the presence of an externally added or in situ generated carboxylic acid and allows to prepare various types of terpene oxides as originally and individually reported by Björkling, Skouridou, Moreira/Nascimento, and Sieber. − …”