Green Synthesis of Urethane-Linked Tamarind Seed Xyloglucan: Thermal Stability, Antibacterial Properties, and DFT Study

Biopolymers. 2025 Jan;116(1):e23648. doi: 10.1002/bip.23648.

Abstract

This study presents a feasible, one-pot synthesis approach for the preparation of a composite biopolymer material derived from tamarind seed xyloglucan (XG) by utilizing isocyanate chemistry. Through a facile reaction process, urethane bonds are formed in XG, resulting in the formation of a crosslinked network. FTIR spectra confirm the successful urethane link formation in XG via the OH-NCO reaction, and CHN analysis provides insights into the elemental composition. The synthesized XG-urethane composite (U-XG) exhibits enhanced thermal stability compared to native XG, with an enhanced degradation temperature (T5%) of 276°C (XG marked T5% at a lower temperature of 163°C). The optimized geometric structure, hydrogen bond types, and hydrogen bond strength of the synthesized U-XG are computationally studied by density functional theory (DFT) at the B3LYP/6-31G(d,p) level. This study also investigates the antibacterial efficacy of both XG and U-XG against a panel of pathogenic bacteria, including gram-positive bacteria such as S. aureus and S. epidermidis, as well as gram-negative E. coli. The U-XG demonstrates superior antibacterial activity against S. epidermidis compared to pristine XG. This research showcases the feasibility of a one-pot synthesis approach for preparing urethane-linked XG with enhanced thermal properties and superior antibacterial activity, offering promising prospects for biomedical and antimicrobial applications.

Keywords: antibacterial efficiency; isocyanate; urethane link; xyloglucan.

MeSH terms

  • Anti-Bacterial Agents* / chemical synthesis
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Density Functional Theory*
  • Escherichia coli / drug effects
  • Glucans* / chemistry
  • Green Chemistry Technology* / methods
  • Hydrogen Bonding
  • Microbial Sensitivity Tests
  • Seeds* / chemistry
  • Spectroscopy, Fourier Transform Infrared
  • Staphylococcus aureus / drug effects
  • Tamarindus* / chemistry
  • Temperature
  • Urethane* / chemistry
  • Xylans* / chemistry

Substances

  • Xylans
  • xyloglucan
  • Urethane
  • Glucans
  • Anti-Bacterial Agents

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