Corosolic acid

All solvents, reagents, and standards were of analytical reagent grade. Acetone, methanol, acetonitrile, hydrochloric acid, 4-(Dimethylamino) cinnamaldehyde and reference standarts for β-Amyrin, maslinic acid, oleanolic acid, corosolic acid, ursolic acid, α-Amyrin, quercetin-3-rhamnoside, myricetin, quercetin-3-α-L-arabinopyranoside and quercetin-3-α-L-arabinofuranoside were purchased from Sigma-Aldrich (Steinheim, Germany). Ethanol 96% (v/v) was purchased from AB Stumbras (Kaunas, Lithuania), formic acid was bought from Merck (Darmstadt, Germany), and Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) was purchased from Scharlau (Sentmenat, Spain). Reference standards for myricetin-3-galactoside, cyanidin chloride, peonidin chloride, malvidin-3-galactoside, malvidin-3-arabinoside, malvidin chloride, peonidin-3-arabinoside, cyaniding-3-galactoside, delphinidin-3-galactoside, peonidin-3-glucoside, peonidin-3-galactoside, cyaniding-3-glucoside and cyaniding-3-arabinoside were purchased from Extrasynthese (Genay, France). Standards for quercetin and quercetin-3-galactoside were purchased from Carl Roth (Karlsruhe, Germany). The standard for quercetin-3-O-glucoside was bought from Biochemistry (Buchs, Switzerland). Purified deionized water was provided using a water purification system (Milli-Q^®, Millipore, Bedford, MA, USA).

The specific compounds, were: Caffeic acid, CAPE, chrysin, luteolin, daidzein, suberic acid, apigenin, (Alfa Aesar), pinocembrin, isorhamnetin, isosakuranetin, vitexin, orientin, rosmarinic acid, myricetin, vanillin, ursolic acid, hydroxytyrosol, tangeretin, chrysoeriol, betulinic acid, eriodictyol, sakuranetin, naringenin, t-cinnamic acid, genistein, diosmetin, resveratrol, galangin, pinocembrin 7-methyl ether, techtochrysin, (Extrasynthese) rutin, isoferulic acid, ellagic acid, kaempferol, quercetin, corosolic acid, acacetin, diosmin, protocatechuic acid ethyl ester, hesperetin, phloridzin, chlorogenic acid, p-coumaric acid, (±)catechin, maslinic acid, (Sigma Aldrich), rhamnetin, syringic acid, protocatechuic acid, ferulic acid, kaempferide, adipic acid, pinostrobin, gallic acid, pinobanksin (Fluka), naringin, hesperidin, (Acros Organics) pinobanksin-3O-acetate (Interchim Inc), cinnamylidenacetic acid, artepillin C (Wako Chemicals). o-Orselllinaldehyde was purchased from Santa Cruz Biotechnology (USA).
Water, acetonitrile, mEthanol and formic acid were purchased from Fisher Scientific, UK and they were of LC-MS grade. Ethanol was purchased from Merck, Germany. PTFE filters (0.45 μm) were obtained from Macherey-Nagel, Germany.

The standards: asiatic acid (2α,23-dihydroxyursolic acid, 97% purity), arjunolic acid (2α,3β,4α)-2,3,23-trihydroxyolean-12-en-28-oic acid, ≥95 purity), corosolic acid (2α,3β-dihydroxyurs-12-en-28-oic acid, ≥98% purity), maslinic acid (2α,3β-dihydroxyolean-12-en-28-oic acid, ≥98% purity), and (4α)-23-hydroxybetulinic acid ((3β,4α)-3,23-dihydroxylup-20(29)-en-28-oic acid, ≥98% purity) were purchased from Sigma-Aldrich (Spain, Madrid). The standards: madecassic acid (≥90% purity), caulophyllogenin ((3β, 4α, 16α)-3,16,23-trihydroxyolean-12-en-28-oic acid, ≥98.5% purity), and hederagenin ((3β, 4α)-3,23-dihydroxyolean-12-en-28-oic acid, ≥98.5% purity) were purchased from Extrasynthese (France, Paris). The derivatization reagents (pyridine and N,O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA)) and dichloromethane were acquired from Sigma-Aldrich (Spain).

All reagents, standards, and solvents were of analytical reagent grade. Ethanol 96% (v/v) was bought from AB Stumbras (Kaunas, Lithuania). Solvents (acetone, methanol, and acetonitrile), reagents (hydrochloric acid and 4-(dimethylamino) cinnamaldehyde), and reference standards (myricetin, quercetin-3-rhamnoside, quercetin-3-α-L-arabinofuranoside, quercetin-3-α-L-arabinopyranoside, oleanolic acid, β-amyrin, corosolic acid, maslinic acid, α-amyrin, and ursolic acid) were bought from Sigma-Aldrich (Steinheim, Germany). Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) was purchased from Scharlau (Sentmenat, Spain). Formic acid was purchased from Merck (Darmstadt, Germany). The standard for quercetin-3-glucoside was purchased from Biochemistry (Buchs, Switzerland). Standards for quercetin-3-galactoside and quercetin were bought from Carl Roth (Karlsruhe, Germany). Reference standards for peonidin chloride, cyanidin chloride, myricetin-3-galactoside, malvidin-3-galactoside, malvidin chloride, malvidin-3-arabinoside, cyaniding-3-galactoside, peonidin-3-arabinoside, peonidin-3-glucoside, delphinidin-3-galactoside, cyaniding-3-glucoside peonidin-3-galactoside, and cyaniding-3-arabinoside were bought from Extrasynthese (Genay, France).

All solvents, reagents, and standards used were of analytical grade. Standards used in HPLC analysis: ursolic acid (UA), oleanolic acid (OA), corosolic acid (CA), and betulinic acid (BA), were purchased from Sigma-Aldrich GmbH (Buchs, Switzerland). Solvents used in the study: 99.9% acetonitrile and 99.9% acetone, were acquired from Sigma-Aldrich GmbH (Buchs, Switzerland), and 99.5% dimethyl sulfoxide (DMSO) was purchased from Scharlab S.L. (Barcelona, Spain). In this study, we used deionized water prepared by a Milli-Q (Millipore, Bedford, MA, USA) water purification system. Doxorubicin (DOX) hydrochloride was bought from Abcam (Cambridge, UK), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (97.0%, MTT) was purchased from Buchs GmbH, Switzerland. The plasticware for cell cultures was obtained from Techno Plastic Products (Trasadingen, Switzerland), Corning (Corning, NY, USA), and Thermo Fisher Scientific (Waltham, MA, USA). Dulbecco’s modified Eagle high-glucose medium (DMEM Glutamax), TrypLETM Express reagent, fetal bovine serum (FBS), penicillin/streptomycin solution (100×), and phosphate-buffered saline (PBS) were obtained from Gibco (Thermo Fisher Scientific Inc., Waltham, MA, USA). NanoShuttle magnetic nanoparticles were purchased from Nano3D Biosciences Inc. (Houston, TX, USA).

Acetone (manufacturer: Sigma-Aldrich, Steinheim, Germany), methanol (manufacturer: Sigma-Aldrich, Steinheim, Germany), formic acid (manufacturer: Merck, Darmstadt, Germany), acetonitrile (manufacturer: Sigma-Aldrich, Steinheim, Germany), reference standards for maslinic acid, corosolic acid, oleanolic acid, ursolic acid, β-Amyrin, campesterol, α-Amyrin, and β-Sitosterol were obtained from Sigma-Aldrich (Steinheim, Germany), and reference standards for squalene were obtained from Carl Roth (Karlsruhe, Germany). The purified deionized water used in the experiments was prepared using a Milli-Q^® (Millipore, Bedford, MA, USA) water purification system.

All solvents, reagents, and standards used were of analytical grade. Acetonitrile, acetone, ursolic acid, oleanolic acid, betulinic acid, and corosolic acid were obtained from Sigma-Aldrich GmbH (Bethesda, MD, USA). Purified deionized water used in the tests was prepared with the Milli-Q^® (Millipore, Bedford, USA) water purification system. Reagents used in the antioxidant activity assay—6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and sodium acetate—were obtained from Scharlau (Barcelona, Spain), 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ) was obtained from Carl Roth (Karlsruhe, Germany), and iron (III)) chloride hexahydrate (FeCl₃ × 6H₂O) from Vaseline-Fabrik Rhenania (Bonn, Germany).