Search

In this work, cellulose nanoparticles regenerated by water, methanol, ethanol and n-propanol as the anti-solvents from ionic liquid solution were studied systematically. Crystallinity and enthalpy in cellulose degradation of the regenerated cellulose decreased in the order water > methanol > ethanol > n-propanol. Nevertheless, the thermal stability of the regenerated cellulose showed an opposite trend. In addition, morphology of regenerated cellulose changed sharply with the variation of anti-solvents. Moreover, we introduced Kamlet-Taft parameters of anti-solvents to analyze the crystallinity, enthalpy in cellulose degradation and thermal stability variation of regenerated cellulose. Hydrogen bond acidity and basicity of anti-solvent definitely drove the property variation of regenerated cellulose nanoparticles to opposite directions. Furtherly, we proposed two competitive cellulose regeneration routes, providing a reasonable explanation to the crystallinity, enthalpy in cellulose degradation and thermal stability variation of regenerated cellulose nanoparticles. Our work successfully demonstrate that H-bond acidity/basicity of anti-solvent could tune the property of regenerated cellulose nanoparticles, unveiling the competitive routes of cellulose regeneration. [ABSTRACT FROM AUTHOR]

A formula granule is a traditional Chinese medicine preparation made from the decoction of a single herbal medicinal. Because of the flexibility for combination and the convenience for utilization, formula granules are becoming popular in clinical applications. However, the efficacy and safety of commercial formula granules often suffer from the improper addition of carbohydrate excipients. Therefore, the detection of carbohydrate excipients is indispensable for the quality control of formula granules. FTIR spectroscopy has been used for the detection of carbohydrate excipients in formula granules. But the overlapped absorption signals limit the sensitivity and specificity of detection. Besides, a large number of multivariate calibration models are needed for quantitative determination. To overcome the above disadvantages, this research utilizes FTIR microspectroscopy for the model-free and universal detection of carbohydrate excipients in formula granules. Using ATR-FTIR imaging, excipient particles and herbal extract particles in formula granules can be measured individually, which resolves the absorption signals of excipients and herbal extract spatially and thus improves the sensitivity and specificity of detection. The content of excipients can be estimated directly from the number of excipient particles, which is robust to the variations of herb extracts and free of calibration models. The case study of Gardeniae Fructus formula granules shows the potential of FTIR microspectroscopy in the direct and rapid detection of carbohydrate excipients in formula granules. [ABSTRACT FROM AUTHOR]

Fourier transform infrared microspectroscopy is a powerful tool to obtain knowledge about the spatial and/or temporal distributions of the chemical compositions of plants for better understanding of their biological properties. However, the chemical morphologies of plant leaves in the plane of the blade are barely studied, because sections in this plane for mid-infrared transmission measurements are difficult to obtain. Besides, native compositions may be changed by chemical reagents used when plant samples are microtomed. To improve methods for direct infrared microspectroscopic imaging of plant leaves in the plane of the blade, the bulk and surface chemical morphologies of nonmicrotomed Ginkgo biloba leaves were characterized by near-infrared transmission and mid-infrared attenuated total reflection microspectroscopic imaging. A new self-modeling curve resolution procedure was proposed to extract the spectral and concentration information of pure compounds. Primary and secondary metabolites of secretory cavities, veins, and mesophylls of Ginkgo biloba leaf blades were analyzed, and the distributions of cuticle, protein, calcium oxalate, cellulose, and ginkgolic acids on the adaxial surface were determined. By the integration of multiple infrared microspectroscopic imaging and chemometrics methods, it is possible to analyze nonmicrotomed leaves and other plant samples directly to understand their native chemical morphologies in detail. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

With the traditional Chinese medicine herbs angelicae dahuricae radix (ADR or Baizhi) and salviae miltiorrhizae radix (SMR or Danshen) as two examples, this work studies the automatic discrimination of the geographic origins of the herbs using near infrared (NIR) reflectance spectroscopy. Multi-class support vector machine (SVM) is utilized for the purpose, and recursive SVM is utilized to select the feature spectral segments that are decisive for the discrimination. With only S and S short spectral segments, discriminative accuracies of 92% are achieved on independent test sample sets. This work not only provides a prototype of accurate rapid discriminating systems for quality control of herbal medicines, but also opens new possibilities in studying subtle differences in the chemical compositions of herbs from different cultivation conditions and investigating their associations with the effectiveness of the herbs. [ABSTRACT FROM AUTHOR]