Da Silva Davi Vieira Teixeira, Baião Diego Dos Santos, Magalhães Alviclér, Almeida Nathan Farias, Conte Carlos Adam, Paschoalin Vania Margaret Flosi
Instituto de Química, Programa de Pós-Graduação em Ciência de Alimentos e Programa de Pós-Graduação em Química, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, Cidade Universitária, Rio de Janeiro 21941-909, RJ, Brazil.
Antioxidants (Basel). 2023 Oct 2;12(10):1823. doi: 10.3390/antiox12101823.
Red beetroot extract (E162) is a natural colorant that owes its color to betanin, its major red pigment. Betanin displays remarkable antioxidant, anti-inflammatory, and chemoprotective properties mediated by its structure and influence on gene expression. However, the betanin employed in most preclinical assays is a beetroot extract diluted in dextrin, not pure betanin, as no isolated compound is commercially available. This makes its use inaccurate concerning product content estimates and biological effect assessments. Herein, a combination of conventional extraction under orbital shaking and ultrasound-assisted extraction (UAE) to purify betanin by semi-preparative HPLC was performed. The employed methodology extracts betalains at over a 90% yield, achieving 1.74 ± 0.01 mg of pure betanin/g beetroot, a 41% yield from beetroot contents increasing to 50 %, considering the betalains pool. The purified betanin exhibited an 85% purity degree against 32 or 72% of a commercial standard evaluated by LC-MS or HPLC methods, respectively. The identity of purified betanin was confirmed by UV-Vis, LC-MS, and H NMR. The combination of a conventional extraction, UAE, and semi-preparative HPLC allowed for betanin purification with a high yield, superior purity, and almost three times more antioxidant power compared to commercial betanin, being, therefore, more suitable for clinical purposes.
红甜菜根提取物（E162）是一种天然色素，其颜色归因于其主要红色色素甜菜红素。甜菜红素通过其结构和对基因表达的影响表现出显著的抗氧化、抗炎和化学保护特性。然而，大多数临床前试验中使用的甜菜红素是稀释在糊精中的甜菜根提取物，而非纯甜菜红素，因为没有分离的化合物可供商业使用。这使得在产品含量估计和生物学效应评估方面其使用不准确。在此，采用了在振荡条件下的常规提取与超声辅助提取（UAE）相结合的方法，通过半制备高效液相色谱法（HPLC）纯化甜菜红素。所采用的方法提取甜菜色素的产率超过90%，从甜菜根中获得1.74±0.01毫克纯甜菜红素/克甜菜根，考虑到甜菜色素总量，产率从41%提高到50%。通过液相色谱-质谱联用（LC-MS）或高效液相色谱（HPLC）方法评估，纯化后的甜菜红素纯度分别为85%，而商业标准品的纯度分别为32%或72%。通过紫外-可见光谱（UV-Vis）、液相色谱-质谱联用（LC-MS）和核磁共振氢谱（H NMR）确认了纯化甜菜红素的身份。常规提取、超声辅助提取和半制备高效液相色谱相结合的方法能够以高产率、更高的纯度纯化甜菜红素，并且与商业甜菜红素相比，抗氧化能力几乎高出三倍，因此更适合临床应用。
