Unidade Acadêmica Especial de Química, Universidade Federal de Goiás, Regional Catalão, 75704-020, Catalão, GO, Brazil.
Unidade Acadêmica Especial de Química, Universidade Federal de Goiás, Regional Catalão, 75704-020, Catalão, GO, Brazil; Laboratório de Ressonância Magnética Nuclear, Instituto de Química, Universidade Federal de Goiás, Campus Samambaia, 74001-970, Goiânia, GO, Brazil.
Carbohydr Polym. 2018 Dec 1;201:532-538. doi: 10.1016/j.carbpol.2018.08.109. Epub 2018 Aug 27.
The inhibition of arginase from Leishmania spp. is considered a promising approach to the leishmaniasis treatment. In this study, the potential of a fucogalactan isolated from the medicinal mushroom Agrocybe aegerita was evaluated against arginase (ARG) from Leishmania amazonensis. The polysaccharide was obtained via aqueous extraction, and purified by freeze thawing and precipitation with Fehling solution. Its chemical structure was established by monosaccharide composition, methylation analysis, partial acid hydrolysis, and NMR spectroscopy. The data indicated that it is a fucogalactan (FG-Aa; M = 13.8 kDa), having a (1→6)-linked α-D-Galp main-chain partially substituted in O-2 by non-reducing end-units of α-L-Fucp. FG-Aa showed significant inhibitory activity on ARG with ICpotency of 5.82 ± 0.57 μM. The mechanism of ARG inhibition by the heterogalactan was the competitive type, with Kof 1.54 ± 0.15 μM. This is the first report of an inhibitory activity of arginase from L. amazonensis by biopolymers, which encourages us to investigate further polysaccharides as a new class of ARG inhibitors.
从 Leishmania spp.中抑制精氨酸酶被认为是治疗利什曼病的一种有前途的方法。在这项研究中，评估了从药用蘑菇 Agrocybe aegerita 中分离出的褐藻胶半乳聚糖对 Leishmania amazonensis 精氨酸酶 (ARG) 的潜在抑制作用。多糖通过水提取获得，并通过冷冻解冻和 Fehling 溶液沉淀进行纯化。通过单糖组成、甲基化分析、部分酸水解和 NMR 光谱确定其化学结构。数据表明，它是一种褐藻胶半乳聚糖 (FG-Aa；M = 13.8 kDa)，具有 (1→6)-连接的α-D-Galp 主链，部分在 O-2 位被非还原端单元的α-L-Fucp 取代。FG-Aa 对 ARG 表现出显著的抑制活性，ICpotency 为 5.82 ± 0.57 μM。杂半乳聚糖对 ARG 的抑制机制为竞争型，Kof 为 1.54 ± 0.15 μM。这是首次报道 L. amazonensis 的 ARG 被生物聚合物抑制，这鼓励我们进一步研究多糖作为一种新型 ARG 抑制剂。
