Maidong, the root tuber of Ophiopogon japonicus (Thunb.) Ker Gawl., is a commonly used herbal medicine in China. There are three quality grades of Maidong according to traditional opinion and modern research studies: superior quality (Zhe-Maidong), medium quality (Chuan-Maidong), and poorest quality (Chuan-Maidong with paclobutrazol, which is a kind of plant growth regulator). However, no efficient way to distinguish the three quality grades of Maidong exists; thus, the herbal markets and botanical pharmacies are flooded with Chuan-Maidong with paclobutrazol. To ensure the safety and quality of Maidong, a comparative microscopic study was performed on three quality grades of Maidong. The result was to establish a microscopic quantification method based on the area ratio between xylem and pith to distinguish the three quality grades of Maidong. Subsequently, Maidong from regional markets was evaluated by this method. In this study, we developed a novel quantification method to identify the three quality grades of Maidong, which could in turn make efforts on the quality improvement of Maidong. Our study is the first to demonstrate that microscopic technology could be used to distinguish different quality grades of a specific herbal medicine.
The eco-benign water-absorbent gel was obtained by modification of tartaric acid (TA) onto parenchyma cellulose from corn stalk pith (CSP) in N, N-dimethylacetamide (DMAc)/LiCl system. The water affinity of the gel was aided with TA as both grafting agent and cross-linker via esterification. The degree of swelling was strongly influenced by TA amount, reaction temperature and duration, and the absorbency of TA-esterified product reached up to about 417 g H 2 O/g dry gel. The three-dimensional macro-porous structures of the bio-absorbent led to fast penetration and diffusion of water into gel. Studies of absorption behavior in deionized water showed that the initial water uptake followed the non-Fickian mechanism, the Schott second-order equation governed the swelling kinetics, and the later part of swelling was relaxation of polymer chains. FTIR and X-ray diffraction analyses confirmed successful modification of TA molecules onto cellulose chains through the formation of ester bonds and transition of crystalline forms from cellulose Ⅰ to cellulose Ⅱ. Moreover, thermogravimetric outcomes illustrated the thermal resistance of the TA-esterified gel with a loose structure was lower than SCP cellulose. This work designed a green water-absorbent that could be potentially utilized as favorable water retention material in agriculture and horticulture.
Parenchyma cellulose, isolated from bagasse pith BP, was utilized as an alternative resource for preparation of soluble cellouronic acid sodium salt (SCA) by selective oxidation with the catalytic amounts of 4-acetamide-TEMPO and NaClO, in which NaClO 2 was used as a primary oxidant in an aqueous condition. The yield and carboxyl content of SCA were measured as a function of NaClO 2 content, 4-acetamide-TEMPO loading, oxidation temperature, initial pH, and reaction time, and optimized by an orthogonal test with the objective of achieving a maximum yield with high carboxyl content. An optimal SCA yield of 71.0 % with 32.92 % carboxyl content was found under the conditions of NaClO 2 dosage of 16 mmol/g, 4-acetamide-TEMPO loading of 0.20 mmol/g, and oxidation temperature of 50 °C in acetate buffer at pH 5.5 for 72 h. The structure and morphology of both parenchyma cellulose and its oxidized product were further characterized by means of Fourier transform infrared spectroscopy (FTIR), X-ray photoelectronic spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). These techniques confirmed that parenchyma cellulose from bagasse pith was successively modified by an effective TEMPO-derivative-catalyzed oxidation process. The finding of this study might provide guidance in maximizing the yield of SCA from parenchyma cells utilizing the 4-acetamide-TEMPO/NaClO/NaClO 2 system. Considering the simple preparation process and favorable SCA property, this BP parenchyma cellulose showed unique characteristics with a great promise for high-valued modification and application in the areas of advanced and functional materials.
危险品化学品经营许可证（带存储）