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In order to realize the resource utilization of the Pinus koraiensis pine cone, the polysaccharides were obtained by a traditional hot water extraction process, and the optimal extraction process was confirmed. The effects of a traditional hot water, alkali, and ultrasound assisted extraction on the yield and properties of polysaccharides were studied. The structure, monosaccharide composition, and content of polysaccharides obtained by different extraction methods were analyzed by means of Fourier infrared chromatography and liquid chromatography. Effects of polysaccharides extracted by different methods on the antimicrobial activity of Staphylococcus aureus and Escherichia coli were studied. The scavenging effect of DPPH free radicals were also examined. The optimum condition of the hot water extraction was identified as an extraction temperature of 100 °C, a ratio of material to water at 1:16 (w/v), an extraction time of 4 h, and a yield of polysaccharide at 10.2%. In comparison, the yield of the pine cone polysaccharide was improved significantly to 29.1% by using NaOH solution extraction method. The FTIR spectra of polysaccharides showed that the samples possessed the typical chemical structure of a polysaccharide.

Hemicellulosic fractions isolated from agricultural wastes (rice straw and rice husk) were investigated using expansion pretreatment and subsequent alkali extraction, which is a method that combines the advantages of extrusion and milder steam explosion. The structure of the obtained hemicellulosic samples was determined by high-performance anion-exchange chromatography (HPAEC), Fourier transform infrared spectroscopy (FT-IR), 2D heteronuclear single quantum coherence nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). The expansion pretreatment resulted in a remarkable increase in the hemicellulose extraction efficiency from the rice straw compared with that of the controlled sample, while that from the rice husk was relatively unnoticeable. It was concluded from the FT-IR, molecular weight, sugar analysis, and NMR spectra results that the molecular weights of the hemicellulosic fractions extracted with this process significantly decreased and then rose, which was probably due to the prominent degradation and then generation of condensation substances. Moreover, the obtained hemicelluloses of the rice husk had a relatively more linear polymer structure than the rice straw. Considering the extraction efficiency and composition of each component, the expansion pretreatment was confirmed to be a promising method for the comprehensive separation and utilization of agricultural wastes.

Due to their biocompatible and eco-friendly properties, natural polymers have attracted significant attention as controlled drug delivery carriers. In this paper, a facile method is presented for preparing pH-sensitive microspheres via acidic esterification between sodium alginate (SA) and hydroxypropyl methylcellulose (HPMC). The resulting microspheres were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). To evaluate the potential applications of microspheres as a drug carrier, the controlled release of a model drug—diclofenac—was examined. The SEM analysis revealed that the microbeads were spherical with a relatively smooth outer surface and porous inner network structure. The drug release experiments indicated that the cumulative release of diclofenac was less than 1% in an acidic medium, whereas it was close to 100% within 3 h in a pH 6.8 phosphate buffer saline solution. These results demonstrated that the SA/HPMC microspheres are promising candidates as pH-sensitive drug delivery system.