Chem. J. Chinese Universities ›› 2025, Vol. 46 ›› Issue (2): 20240424.doi: 10.7503/cjcu20240424

• Analytical Chemistry • Previous Articles     Next Articles

Understanding the Water Structures in Antifreezing of DMSO Derivatives by Near-infrared Spectroscopy

LIANG Fanfan, HAN Li, CAI Wensheng, SHAO Xueguang()   

  1. Research Center for Analytical Sciences,College of Chemistry,Tianjin Key Laboratory of Biosensing and Molecular Recognition,State Key Laboratory of Medicinal Chemical Biology,Nankai University,Tianjin 300071,China
  • Received:2024-09-13 Online:2025-02-10 Published:2024-11-19
  • Contact: SHAO Xueguang E-mail:xshao@nankai.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22174075)

Abstract:

The molecular mechanism of L-methionine sulfoxide[L-Met(O)-OH], a derivative of dimethyl sulfoxide (DMSO), in inhibiting ice crystal growth was studied using near-infrared spectroscopy combined with chemometrics. High-resolution spectra were obtained through wavelet packet transform, allowing for a detailed analysis of the NIR spectra of L-Met(O)-OH solutions at various concentrations during the freezing process at -5 ℃. Spectral information regarding the interaction between the S=O group and ice was extracted. The results indicate that the primary reason for the effective inhibition of ice growth by L-Met(O)-OH is the formation of hydrogen bonds between the S=O group and ice. Further analysis of solutions at 0 ℃ revealed spectral features of interactions between water molecules and the S=O and C=O groups in L-Met(O)-OH. During the freezing process, the intensity of the spectral peaks associated with these interactions gradually decreased, indicating that the interactions between the S=O and C=O groups and water molecules weakened, and this weakening effect became more pronounced at higher concentrations. Finally, the role of the NH group in the inhibition of ice crystal growth was investigated. It was found that during freezing, the binding of NH groups to water molecules increased, forming a stable hydrogen-bonded network. The result indicates that the NH group consistently interacts with water throughout the freezing process and does not significantly interact with ice.

Key words: Near-infrared spectroscopy, L-Methionine sulfoxide, Ice crystal growth inhibition, Hydrogen bond

CLC Number: 

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