R limonene

R-(+)-limonene (97%) was obtained from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). (+)-Dihydrocarvone was purchased from Beijing Innochem Science and Technology Co. Ltd. (Beijing, China). The carvone and perillyl alcohol were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China). Carveol was obtained from Alfa Aesar (Shanghai, China) Chemical Co. Ltd. (Shanghai, China). The reagents (i.e., NaCl, glucose, FeSO₄·7H₂O, ethanol) were purchased from Sinopharm Chemical Reagent Co., Ltd., Shanghai, China.

(R)-(+)-limonene (>99%) and (S)-(−)-limonene (95%) were obtained from Tokyo Chemical Industries (Tokyo, Japan). Lyophilized enzymatic preparation from oat seed flour was obtained as previously reported [38 (link)] and its activity in the epoxidation of oleic acid was 0.7 μmol/mg/h. TLC (Thin layer chromatography) analyses were performed on aluminium plates coated with silica gel and fluorescent indicator F254, revealing the compounds by UV (Ultraviolet) and cerium sulphate solution. Column chromatography was performed on silica gel (40–63 µm, Merck, Kenilworth, NJ, USA) using the specified eluents. Deactivated silica was prepared by suspending silica (50 g) in n-hexane (100 mL) containing 1% (v/v) triethylamine under stirring for 15 min. Then, the solid was collected by decantation, rinsed with n-hexane, and dried at 40 °C overnight.
¹H- and ¹³C-NMR (Nuclear Magnetic Resonance) spectra were recorded on a Bruker Avance^TM 400 spectrometer (Bruker Milano, Italy) at 400.13 and 100.62 MHz, respectively. Chemical shifts (δ) are given as ppm relative to the residual solvent peak and coupling constants (J) are in Hz.
Optical rotations were measured on DIP-135 polarimeter (Jasco Europe, Lecco, Italy) using a 10 cm length cell.