Fresh beetroots (Beta vulgaris subsp. vulgaris var. vulgaris), also known as red beet, were obtained from a local market in Santo André, SP, Brazil (sample A), commercial lyophilised beetroot (food-grade, sample B), and commercial betanin in dextrin (sample C) were purchased in Jena, Germany. Sample A: beetroots (0.5 kg) were peeled, sliced and homogenised in a centrifugal juice extractor (Phillips–Walita, ABT 263 RI1858) at maximum speed. The homogenate was centrifuged (3500 rpm, 30 min, 25 °C) and filtered (Whatman qualitative filter paper, grade 4). The supernatant
was stored at −20 °C and used within 5 days. Samples B and C: lyophilised beetroot and betanin in dextrin were resuspended in water (40–200 mg/mL) and filtered through a PTFE filter membrane (25 mm, pore size 0.45 μm) before purification. Samples A, B and C were submitted to purification by the following methods: gel permeation chromatography (GPC), normal phase column chromatography (NPC), reversed-phase column chromatography (RPC), reversed-phase high-performance liquid chromatography (RP-HPLC), ion-exchange chromatography learn more (IEX) and aqueous
two-phase extraction (ATPE). All experiments were performed in independent triplicates and purification yields are reported as mean ± standard deviation (mg/100 g of fresh (A) or dry (B and C) weight, namely raw weight) across all replicates. After purification, magenta fractions containing betanin were collected, pooled and the solution was concentrated (final volume of 1 mL) under reduced pressure (18 mbar, 25 °C). Afterwards, samples were submitted to UV–Vis spectroscopy and analytical HPLC analysis. Sephadex G-25 (6 g) and Sephadex LH-20 (5 g) were used as the stationary phases in a glass column and packed under deionised water. The elution was performed with deionised water as the mobile phase, flow rates of 2.2 mL/min (GPC-G25) and 0.25 mL/min (GPC-LH20). After Hydroxychloroquine mouse complete elution, the column was regenerated by washing with 5 column volumes of deionised water. Cleaning
and re-equilibration steps were performed between each elution. Silica gel 60 (15 g) was used as the stationary phase in a glass column and packed with the binary solvent mixture of methanol/water 8:2 v/v with 1% v/v glacial acetic acid. The elution was performed with the same binary solvent mixture at a flow rate of 0.7 mL/min. The silica gel 60 column was not regenerated. Silica gel 90 C18 (20 g) was used as stationary phase in a glass column and conditioned with methanol followed by deionised water. The elution was performed with deionised water at a flow rate of 0.3 mL/min. After complete elution, the column was regenerated by washing with 6 column volumes of methanol and re-equilibrated with water. Cleaning (MeOH) and re-equilibration (water) steps were performed between each elution.