Macromolecular and thermokinetic properties of a galactomannan from Sophora alopecuroides L. seeds: A study of molecular aggregation

Rui Guo; Xujiao Li; Xianda Ma; Xianbao Sun; Yuxing Kou; Jun'ai Zhang; Deshun Li; Yanfang Liu; Hui Zhang; Yan Wu

doi:10.1016/j.carbpol.2021.117890

Macromolecular and thermokinetic properties of a galactomannan from Sophora alopecuroides L. seeds: A study of molecular aggregation

Carbohydr Polym. 2021 Jun 15:262:117890. doi: 10.1016/j.carbpol.2021.117890. Epub 2021 Mar 8.

Authors

Rui Guo¹, Xujiao Li², Xianda Ma³, Xianbao Sun⁴, Yuxing Kou⁵, Jun'ai Zhang⁶, Deshun Li⁷, Yanfang Liu⁸, Hui Zhang⁹, Yan Wu¹⁰

Affiliations

¹ Shanghai Engineering Research Center of Food Safety, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: jackal123@163.com.
² Shanghai Engineering Research Center of Food Safety, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: lixujiao1990@163.com.
³ Shanghai Engineering Research Center of Food Safety, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: 779837463@qq.com.
⁴ Shanghai Engineering Research Center of Food Safety, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: sunxianbao@hotmail.com.
⁵ Shanghai Engineering Research Center of Food Safety, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: kouyuxing123@163.com.
⁶ Shanghai Engineering Research Center of Food Safety, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: january23@sjtu.edu.cn.
⁷ Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, National Engineering Research Center of Edible Fungi, National R&D Center for Edible Fungi Processing, Shanghai 201403, China. Electronic address: 392041082@qq.com.
⁸ Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, National Engineering Research Center of Edible Fungi, National R&D Center for Edible Fungi Processing, Shanghai 201403, China. Electronic address: aliu-1980@163.com.
⁹ School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address: zhh8672@126.com.
¹⁰ Shanghai Engineering Research Center of Food Safety, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: wuy@sjtu.edu.cn.

PMID: 33838792
DOI: 10.1016/j.carbpol.2021.117890

Abstract

The molecular aggregation of a galactomannan (NSAP-25) from Sophora alopecuroides L. seeds was investigated, where three polydisperse systems were confirmed during particle size analysis, indicating existence of different aggregates composed of random coil chains revealed by circular dichroism. Morphologically, NSAP-25 aggregate of various sizes (200-1200 nm) was possibly multi-stranded and formed by ellipsoid-like particles (20-60 nm) composed of compact coil chain, exhibiting extended amorphous structure with chain-like branches intertwined. Hence, NSAP-25 aggregation was inevitable, which exerted an unignorable effect on augmenting flexibility (β↓, γ↓, α↓ and L_p/M_L↓) and compactness (ρ↓, d_f↑ and C_∞↓) of branched random coil chain based on macromolecular analysis, especially when concentration increased. Moreover, it could be relevant to thermokinetic behavior of random nucleation and subsequent growth (A² model and negative ΔS*) as well as good thermal stability (IPDT, ITS, t_0.05, T_m and T_p), thus conferring potential applications for NSAP-25 in food and pharmaceutical industries.

Keywords: Circular dichroism; Conformational behavior; Molecular aggregate; Morphologic properties; Particle size distribution; Thermal analysis.

MeSH terms

Carbohydrate Conformation
Circular Dichroism / methods
Galactose / analogs & derivatives
Kinetics
Macromolecular Substances
Mannans / chemistry*
Microscopy, Electron, Transmission / methods
Particle Size
Seeds / chemistry*
Sophora / chemistry*
Temperature
Thermogravimetry / methods

Substances

Macromolecular Substances
Mannans
galactomannan
Galactose