S perillic acid

The following chemicals were used as received, unless mentioned otherwise. Pentafluorophenol (Carbolution Chemicals GmbH, Saarbrücken, Germany, 99%), 4-pentenoic acid (Sigma-Aldrich, Steinheim, Germany, 95%), (S)-perillic acid (Sigma-Aldrich, Buchs, Switzerland, 95%), N-phenylmaleimide (Sigma-Aldrich, Steinheim, Germany, 97%), N,N′-dicyclohexylcarbodiimide (Sigma-Aldrich, Steinheim, Germany 99%), 4-dimethylaminopyridine (Sigma-Aldrich, Steinheim, Germany, 99%), 1,2-dichloroethan (Alfa Aesar, ThermoFisher (Kandel) GmbH, Karlsruhe, Germany, 99+%), 1,4-dioxane (Acros Organics, Geel, Belgium, 99.5%), N,N-dimethylformamide (Sigma-Aldrich, Steinheim, Germany, 99.8%), 2,2′-azobis (2-methylpropionitrile) (Acros Organics, Geel, Belgium, 98%), n-hexylamine (Sigma-Aldrich, Steinheim, Germany, 99%), benzylamine (MERCK, Kenilworth, NJ, USA, >99%), CDCl₃ (Deutero GmbH, Kastellaun, Germnay, 99.8%), 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol (abcr, Karlsruhe, Germany, 99%). 2,2′-azobis (2-methylpropionitrile) (AIBN, Acros Organics, Geel, Belgium, 98%) was recrystallized from methanol.

Salvia dorisiana plant tissues were harvested in three biological replicates. The FW/DW ratio was determined by drying at 105 °C for 20 h. To measure metabolites, the plant tissues were frozen in liquid N₂, ground in a mortar and pestle while still frozen, and 1 ml of ethyl acetate, with 3 µg ml^–1 γ-terpinen-4-ol as internal standard, was added to 100 mg of frozen plant powder, vortexed for 20 s, subjected to sonication for 5 min, and centrifuged for 5 min at 3400 rpm. The supernatant was analysed by GC-MS as described below. A standard mix of 3 µg ml^–1 terpinen-4-ol, (R)-(+)-limonene (97%, Sigma Aldrich), perillyl alcohol (96%, Sigma Aldrich), (S)-(–)-perillaldehyde (Sigma Aldrich), and (S)-(–)-perillic acid (95%, Sigma Aldrich) was prepared for identification and semi-quantification. The standard mix was methylated by addition of diazomethane 1:1 and injected as well, to be able to identify and semi-quantify MePA in the samples.

N,N-Diisopropylethylamine (DIPEA) [MACKLIN®], N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC·HCl) [MACKLIN®], dodecylamine [MACKLIN®], 1-hydroxybenzotriazole hydrate (HOBt·xH₂O) [MACKLIN®], 3-(trifluoromethyl)aniline [MACKLIN®], 4,4′-diamino-2,2′-dimethylbibenzyl [TCI], N,N′-dimethylformamide (DMF) [Shanghai Rich joint], sodium chloride (NaCl) [KESHI®], sodium hydroxide (NaOH) [KESHI®], sodium sulfate (Na₂SO₄) [SCR®], dichloromethane [KESHI®], ethanol [KESHI®], ethylacetate (EtOAc) [KESHI®], methanol (MeOH) [KESHI®], hexane [KESHI®], petroleum-ether [KESHI®], chloroform (CHCl₃) [KESHI®], dimethylsulfoxide (DMSO), deuterated chloroform (CDCl₃) [J&K®], deuterated dimethylformamide (DMSO, d6) [J&K®], (S)-perillic acid [Sigma Aldrich], (S)-perillyl alcohol (POH) [Sigma Aldrich, 96%], HepG2 human liver cancer cell lines [cell bank of academy of science, Shanghai, China], H22 murine hepatoma cancer cell lines [Shanghai Sixing Biotechnology], Foetal bovine serum [Invitrogen Co., CA, USA], Dulbecco's modified Eagle's medium (DMEM) [Invitrogen Co., CA, USA], 5-Fluorouracil (5-FU) [Aladdin® 99%], MTT [Beyotime Institute of biotechnology, Jiangsu, China], trypsin MTT [Beyotime Institute of biotechnology, Jiangsu, China], Cremophor EL® [Aladdin®].