Orientin

The analysis of anthocyanins and major flavonoids content in EO was performed using two validated UHPLC-DAD methods, as described elsewhere [29 (link),30 (link)]. Orientin, homoOrientin, taxifolin, cyanidin 3-glucoside and cyanidin 3-rutinoside (Extrasynthèse, Genay, France) were used as standard compounds.

Orientin, isoOrientin, vitexin, and isovitexin (all with ≥99% purity) were purchased from Extrasynthese (Genay, France). Rutin hydrate (≥94%), HPLC-grade formic acid (≥98%), and dimethyl sulfoxide (DMSO) were obtained from Sigma Aldrich Co., LLC (St. Louis, MO, USA). HPLC-grade water, methanol, and acetonitrile were purchased from Thermo Fisher Scientific (Waltham, MA, USA).

Methanol (MeOH) and acetonitrile (ACN) were obtained from Riedel de Haen, Honeywell (LC-MS grade, >99.9% purity, Seelze, Germany). Formic acid (MS grade), NaOH (>98% pure), HCl (MS grade), and ethyl acetate (>99.7% pure) were purchased from Sigma (Sigma Aldrich, Vienna, Austria). Water was purified by ion exchange and ultrafiltration with an ELGA system (PURELAB Ultra, Veolia Water, Vienna, Austria). ¹³C₉-phenylalanine (99% isotopic purity, uniformly labelled) was purchased from Euriso-top (St Aubin, France). The following authentic reference standards were used for metabolite identification: phenylalanine (native, >99% pure, Roth), orientin (>99% pure, Extrasynthese), tricin (>95% pure, PhytoLab), ferulic acid (>99% pure, Fluka), vanillin (99% pure, Sigma-Aldrich), pinoresinol (95% pure, Sigma), chlorogenic acid (>95%, Sigma), and coumaric acid (>98%, Sigma). Coumaroylputrescine was kindly provided by G. Adam, BOKU.