Ferulic acid methyl ester

Red grape marc (Vitis vinifera L.) of the “Merlot” variety was obtained from the Pilot Laboratory of Microvinification at the Technical University of Moldova Chisinau, Republic of Moldova). The Folin–Ciocalteu reagent, tannic acid, acetonitrile and formic acid were purchased from Merck (Darmstadt, Germany); (+)-catechin (98%), quercetin, syringic acid, ferulic acid, gallic acid (98%), protocatechuic acid, parahydroxybenzoic acid, salicylic acid (99.9%), ferulic acid methyl ester, DPPH, tartaric acid, ascorbic acid, citric acid (99.5%) and acetic acid (99.8%) were obtained from Sigma-Aldrich (Darmstadt, Germany; Tokyo, Japan; Shanghai, China). Sinapic acid (98%) was purchased from Alfa Aesar (Kandel, Germany). Procyanidin B1, procyanidin B2 and hyperoside were purchased from Extrasynthese (Genay, France). quercetin (>95%) was obtained from Sigma-Aldrich (Bangalore, India). Cyanidin 3-glucoside chloride (≥98%), peonidin 3-glucoside chloride (≥90%), malvidin 3-glucoside chloride (≥95%) and malvidin 3,5-diglucoside chloride (≥90%) were obtained from PhytoLab, (Vestenbergsgreuth, Germany). All spectrophotometric measurements were performed on the Analytik Jena Specord 200 Plus (Jena, Germany) spectrophotometer.

The ABTS reagent was provided by Alfa Aesar, the Folin–Ciocalteu reagent was purchased from Merck (Darmstadt, Germany), and (+)-catechin 98%, quercetin, caffeic acid, syringic acid, ferulic acid, gallic acid (98%), protocatechuic acid, gentisic acid, parahydroxybenzoic acid, salicylic acid (99.9%), para-coumaric acid, trans-5-O-caffeoylquinic) acid, epicatechin, vanillic acid, cis-resveratrol, ferulic acid methyl ester and DPPH were obtained from Sigma- Aldrich (Darmstadt, Germany, Tokyo, Japan, Shanghai, China). methyl 4-hydroxy-3-methoxycinnamate (99%) and sinapic acid (98%) were purchased from Alfa Aesar (Kandel, Germany). Procyanidin B1, procyanidin B2, polydatin, hyperoside, carotenoid standards, β-carotene, lycopene, β-cryptoxanthin, lutein, and zeaxanthin were purchased from Extrasynthese (Genay, France). Trans-resveratrol was purchased from TCI Europe (Zwijndrecht, Belgium). The acetonitrile and the formic acid were purchased from Merck. quercetin (>95%) was obtained from Sigma-Aldrich (Bangalore, India). All spectrophotometric measurements were performed on the Analytik Jena Specord 200 Plus (Jena, Germany) spectrophotometer.