Fernandes-Negreiros Marília Medeiros, Batista Lucas Alighieri Neves Costa, Silva Viana Rony Lucas, Araujo Sabry Diego, Paiva Almino Afonso Oliveira, Paiva Weslley Souza, Machado Raynara Iusk Araujo, Sousa Junior Francimar Lopes de, de Lima Pontes Daniel, Vitoriano Jussier de Oliveira, Alves Junior Clodomiro, Lanzi Sassaki Guilherme, Rocha Hugo Alexandre Oliveira
Department of Biochemistry, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte 59.078-970, Brazil.
Department of Biomedicine, Faculdade Nova Esperança (FACENE), Mossoró 59.628-000, Brazil.
Antioxidants (Basel). 2020 Nov 27;9(12):1192. doi: 10.3390/antiox9121192.
A 12.4 kDa laminarin (LM) composed of β(1→3)-glucan with β(1→6)-branches was extracted from brown seaweed and modified via carboxylation using dielectric barrier discharge (LMC), conjugation with gallic acid (LMG), and sulfation (LMS). Analyses of the chemical composition of LMC, LMG, and LMS yielded 11.7% carboxyl groups, 1.5% gallic acid, and 1.4% sulfate content, respectively. Antioxidant activities of native and modified laminarins were assessed using six different in vitro methods. Sulfation stopped the antioxidant activities of LM. On the other hand, carboxylation improved cooper chelation (1.2 times). LMG was found to be a more efficient antioxidant agent than LM in terms of copper chelation (1.3 times), reducing power (1.3 times), and total antioxidant capacity (80 times). Gallic acid conjugation was further confirmed using Fourier transform infrared spectroscopy (FT-IR) and one- and two-dimensional NMR spectroscopy analyses. LMG also did not induce cell death or affect the cell cycle of Madin-Darby canine kidney (MDCK) cells. On the contrary, LMG protected MDCK cells from HO-induced oxidative damage. Taken together, these results show that LMG has the potent antioxidant capacity, and, therefore, potential applications in pharmacological and functional food products.
从褐藻中提取了一种由具有β(1→6)分支的β(1→3)-葡聚糖组成的12.4 kDa海带多糖（LM），并通过介电阻挡放电羧化（LMC）、与没食子酸共轭（LMG）和硫酸化（LMS）对其进行改性。对LMC、LMG和LMS的化学成分分析分别得到11.7%的羧基、1.5%的没食子酸和1.4%的硫酸盐含量。使用六种不同的体外方法评估了天然和改性海带多糖的抗氧化活性。硫酸化使LM的抗氧化活性丧失。另一方面，羧化提高了铜螯合能力（1.2倍）。就铜螯合能力（1.3倍）、还原能力（1.3倍）和总抗氧化能力（80倍）而言，发现LMG是比LM更有效的抗氧化剂。使用傅里叶变换红外光谱（FT-IR）以及一维和二维核磁共振光谱分析进一步证实了没食子酸共轭。LMG也不会诱导细胞死亡或影响马-达二氏犬肾（MDCK）细胞的细胞周期。相反，LMG保护MDCK细胞免受HO诱导的氧化损伤。综上所述，这些结果表明LMG具有强大的抗氧化能力，因此在药理和功能性食品中具有潜在应用。
