Structural characterization, antioxidant and antitumor properties of an acidic polysaccharide from toad venom

作者：Feng Pan, Xinting Zhu, Nan Yang, Kunmei Li, Gejie Shi, Qinghong Kong, Sanhua Li, Ying Qing, Linjie Meng, Yun Liu · 发表于：Chemical and Biological Technologies in Agriculture · 年份：2025 · DOI：10.1186/s40538-025-00842-7 · 被引用次数：3 · 研究领域：Erythrocyte Function and Pathophysiology、Venomous Animal Envenomation and Studies、Polysaccharides and Plant Cell Walls

As a valuable agricultural product derived primarily from cultivated toads, toad venom has been widely used for its significant antitumor properties in pharmacological formulations. However, the structural and biological characteristics of its major constituents, polysaccharides, remain poorly understood, limiting the development of innovative antitumor drugs. In this study, an extracellular acidic homogeneous polysaccharide (TvPs3-2, average molecular mass: 3.43 × 102 kDa) is isolated from toad venom. Compositional analysis by 1-phenyl-3-methyl-5-pyrazolone (PMP) pre-column derivatization high-performance liquid chromatography (PMP-HPLC) reveals that TvPs3-2 consists of mannose (Man), glucuronic acid (GlcA), glucose (Glc), galactose (Gal), arabinose (Ara), and fucose (Fuc) in a molar ratio of 9.30:26.52:17.26:2.20:8.40:36.31. Comprehensive structural characterization through methylation analysis combined with extensive nuclear magnetic resonance (NMR) spectroscopy indicates a possible backbone: → 4)-β-D-GlcAp-(1 → 3,6)-β-D-Galp-(1 → 3)-α-L-Fucp-(1 → 4)-α-D-Manp-(1 → 2)-β-D-Glcp-(1 → 2,4)-α-D-Glcp-(1 → 4)-β-D-Glcp-(1 → 2)-α-L-Fucp-(1 → 4)-β-D-GlcAp-(1 → , with multiple branched segments. Morphologically, TvPs3-2 exhibits interconnected bulges, undulating surfaces, and square/rhombic crystals while maintaining a triple-helix conformation. Additionally, TvPs3-2 exhibits good antioxidant activity, particularly against 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS, h...