High acyl gellan gums have been widely considered using as gelling biopolymers in colloidal products although their structure and chain conformation characteristics have been poorly understood. Five fractions of high acyl gellan gum (HG) with a molecular weight (M_w) ranging from 4.2 × 10⁵ to 10.1 × 10⁵, obtained by ultrasonic depolymerization from a native gellan, have been used to determine their molecular parameters and conformation characteristics in the good solvent of 50 mM NaNO₃ dimethyl sulphoxide solution by using capillary viscometry and laser light scattering. The influence of ultrasound on the chemical structure and M_w of HG is investigated by GPC, FT-IR and NMR. The chain architectures of HG fractions are confirmed to be very similar to that of the native one without either deacylation or deglycerylation. Mark−Houwink equation and the relationship between radius of gyration (R_g) and M_w are established to be [η] = 1.16 × 10⁻³M_w^0.67 (dl/g) and R_g = 2.06 × 10⁻²M_w^0.61 (nm) for HG with a ratio of geometric to hydrodynamic radius (R_h) of 1.67 that is independent of the M_w of HG. In term of Zimm model, a relationship among these molecular parameters is founded as [η]≈4N_AR_g²R_h/M_w. On the basis of unperturbed chain models, the conformation parameters of HG are also calculated and compared. The results indicate that HG macromolecules with an estimate of about 9 nm for persistence length L_p take the conformation of relatively extended semi-flexible chains in solution.

高酰基结冷胶被广泛认为在胶体产品中用作胶凝生物聚合物，尽管对其结构和链构象特征了解甚少。高酰基结冷胶的五个级分（HG），其分子量（中号_瓦特）为4.2×10 ⁵至10.1×10 ⁵，从天然绞兰通过超声解聚获得的，已被用于确定它们的分子参数和构象特征在50 mM NaNO ₃二甲基亚砜溶液的良溶剂中，采用毛细管粘度法和激光散射法。超声波对化学结构和M _w的影响通过GPC，FT-IR和NMR研究了HG的峰。HG馏分的链结构被证实与天然的非常相似，没有脱酰基或去甘油基化。建立Mark-Houwink方程以及回转半径（R _g）与M _w之间的关系，使其为[ η ] = 1.16×10 ^-3 M _w ^0.67（dl / g）和R _g  = 2.06×10 ^-2 M _w HG的几何半径与流体力学半径之比（R _h）为1.67的^0.61（nm），独立于M _wHG。在齐姆模型的术语，这些分子参数之间的关系是建立为[ η ]≈4 Ñ_甲ř_克² - [R _ħ /中号_瓦特。在无干扰链模型的基础上，还计算并比较了HG的构象参数。结果表明，对于持久性长度L _p估计约为9 nm的HG大分子在溶液中具有相对延伸的半柔性链的构象。