Kaempferol 3 o glucoside

Acetonitrile (hypergrade for LC–MS), formic acid (for LC-MS) and methanol (analytical grade) were purchased from Merck (Merck, Bulgaria). The authentic standards used for compound identification were obtained from Extrasynthese (Genay, France) for protocatechuic, syringic, vanillic gentisic, p-coumaric, m-coumaric, o-coumaric acid, quercetin, apigenin, luteolin, apigenin 7-O-glucoside, kaempferol 3-O-glucoside, isorhamnetin 3-O-glucoside, luteolin 7-O-glucoside and rutin, and kaempferol 3-O-rutinoside, homoorientin, isoquercitrin, hyperoside, nepetin. Caffeic acid, neoChlorogenic acid, 3,4-dicaffeoylquinic acid, 1,5-dicaffeoylquinic acid, jaceosidin and hispidulin were supplied from Phytolab (Vestenbergsgreuth, Germany). Chlorogenic acid, isorhamnetin and cirsimaritin were purchased from Sigma-Aldrich (St. Louis, MO, USA).

Apigenin, luteolin, kaempferol, kaempferol-3-O-glucoside, myricetin, daidzein, genistein, daidzin and genistin (all purity ≥95%) were purchased from Extrasynthese (Lyon, France). Quercetin, Quercetin-3-O-glucoside and rutin (all purity ≥95%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Tricin (purity ≥95%) was chemically synthesized according to our previous publication53 (link). Acrylamide, L-asparagine monohydrate, D-(+)-glucose monohydrate, DPPH, ABTS, potassium persulfate and 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ) and 6-hydroxy-2,5,7,8-tetra- methylchromane-2-carboxylic acid (trolox) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Acrylamide-d₃ (isotopic purity ≥99%) was obtained from Cambridge Isotope Laboratories (Andover, MA, USA). Acetonitrile and methanol (HPLC-grade) were purchased from Merck (Kenilworth, NJ, USA) while formic acid (≥96%) was obtained from Tedia (Fairfield, OH, USA). Potato powder (Atlantis variety) was obtained from Sanjiang (Group) Potato Products Co., Ltd. (Lintao, Gansu, China). Water was purified with a Milli-Q system (Millipore, Bedford, USA) and used throughout the sample treatment and instrumental analysis.

Gallic (3), ellagic (38), protocatechuic (45), neochlorogenic (48), caffeic (49), chlorogenic (50), syringic acids (53), myricitrin (59), isoquercitrin (60), hyperoside (64), kaempferol 3-O-glucoside (67), quercitrin (68), isorhamnetin 3-O-glucoside (72), quercetin (77), myricetin (78), kaempferol (80), (+)-catechin (82), and prunin (87) were obtained from Extrasynthese (Genay, France). All reagents and solvents were of analytical grade.

The presence of polyphenolic compounds was identified by the LC-PDA-MS method using the Acquity Ultraperformance LC system (Waters Corp., Milford, USA; [9 (link)]). The polyphenol extracts were prepared according to the procedure described by Wojdyło et al. [9 (link)]. The results were evaluated using the MassLynx 4.0 ChromaLynx Application Manager software (Waters Corp., Milford, CT, USA). The quantification of polyphenolic compounds in plum pomace powders was performed by ultra-performance liquid chromatography (UPLC-PDA) (Waters Corp., Milford, USA). Calibration curves (0.05–5 mg∙mL⁻¹; R² = 0.9998) were made from procyanidins B2 and C1, neochlorogenic and chlorogenic acid, quercetin, isorhamnetin and kaempferol-3-O-glucoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, and peonidin-3-O-glucoside as standards (Extrasynthese, Genay, France). Quercetin and kaempferol derivatives were expressed as quercetin-3-O-glucoside and kaempferol-3-O-glucoside, and coumaroylquinic and caffeoylshikimic acid derivatives as chlorogenic acid. Anthocyanins, flavonol glycosides, phenolic acids and flavan-3-ols were detected at wavelengths of 360, 320, and 280 nm, respectively. The analysis was carried out in duplicate and the results were expressed in mg∙100 g⁻¹ dm.

All reagents and organic solvents were of analytical grade. Authentic standards of loganic acid, cyanidin 3-O-glucoside, p-coumaric acid, gallic acid, quercetin 3-O-glucoside, and kaempferol 3-O-glucoside were purchased from Extrasynthese (Genay Cedex, France). Trans-caftaric acid was purchased from the Cayman Chemical Company (Michigan, EUA, Ann Arbor, MI, USA). Trans-Coutaric acid was purchased from Merck (Darmstadt, Germany). Methanol, acetonitrile, and formic acid were obtained from POCh (Gliwice, Poland).

Acetonitrile (hypergrade for LC-MS), formic acid (for LC-MS) and methanol (analytical grade) were purchased from Merck, Sofia, Bulgaria. The authentic standards used for compound identification were obtained from Extrasynthese (Genay, France) for protocatechuic, p-hydroxyphenylacetic, vanillic, gentisic, ferulic, p-coumaric, o-coumaric acid, rutin, hyperoside, luteolin 7-O-rutinoside, luteolin 7-O-glucoside, isoquercitrin, kaempferol 3-O-rutinoside, isorhamnetin 3-O-rutinoside, kaempferol 3-O-glucoside, isorhamnetin 3-O-glucoside, apigenin 7-O-glucoside, quercetin, apigenin, luteolin, chrysoeriolq eupatilin and genkwanin. Caffeic, 3,4-dicaffeoylquinic, 3,5-dicaffeoylquinic 1,5-dicaffeoylquinic, 4,5-dicaffeoylquinic and 3,4,5- tricaffeoylquinic acids were supplied by Phytolab (Vestenbergsgreuth, Germany). Chlorogenic acid and isorhamnetin were purchased from Sigma-Aldrich (St. Louis, MO, USA). Diclofenac, silymarin, collagenase, 1-chloro-2,4-dinitrobenzene, beta-nicotinamide adenine dinucleotide 2′-phosphate reduced tetrasodium salt (NADPH), ethylenediaminetetraacetic acid (EDTA), bovine serum albumin (fraction V) and 2,2′-dinitro-5,5′dithiodibenzoic acid (DTNB) were obtained from Merck (Darmstadt, Germany). Reduced glutathione (GSH), oxidized glutathione (GSSG), glutathionereductase (GR) and cumene hydroperoxide were purchased from Sigma Chemical Co. (Taufkirchen, Germany).

All reagents and organic solvents were of analytical grade. Authentic standards of loganic acid, cyanidin 3-O-glucoside, p-coumaric acid, gallic acid, quercetin 3-O-glucoside, kaempferol 3-O-glucoside were purchased from Extrasynthese (Genay, France). Trans-caftaric acid was purchased from Cayman Chemical Company (Michigan, EUA, Ann Arbor, MI, USA). Trans-coutaric acid was purchased from Merck (Darmstadt, Germany). Methanol, acetonitrile and formic acid were obtained from POCh (Gliwice, Poland).