Chinese Oak Tasar Silkworm Antheraea pernyi Silk Proteins: Current Strategies and Future Perspectives for Biomedical Applications

Chinese nonmulberry temperate oak tasar/tussah, Antheraea pernyi (Ap) silk is a natural biopolymer that has attracted considerable attention as a biomaterial. The proteinaceous components of Ap silk proteins, namely fibroin and sericin may represent an alternative over mulberry Bombyx mori silk proteins. In fact, the silk fibroin (SF) of Ap is rich in Arginyl‐Glycyl‐Aspartic acid (RGD) peptides, which facilitate the adhesion and proliferation of various cell types. The possibility of processing Ap silk proteins into different distinct 2D‐ and 3D‐based matrices is described in earlier studies, such as membranes, nanofibers, scaffolds, and micro/nanoparticles, contributing to a different rate of degradation, mechanical properties, and biological performance useful for various biomedical applications. This review summarizes the current advances and developments on nonmulberry Chinese oak tasar silk protein (fibroin and sericin)‐based biomaterials and their potential uses in tissue engineering, regenerative medicine, and therapeutic delivery strategies.     

Analysis of dihydroindole‐type alkaloids in Strychnos nux‐vomica unprocessed and processed seeds by high‐performance liquid chromatography coupled with diode array detection and mass spectrometry

The ripened seeds of Strychnos nux‐vomica L. have been extensively used as herbal medicines in Asian countries. Dihydroindole‐type alkaloids are not only the active constituents but also the toxicants in Strychnos. However, the simultaneous determination of these alkaloids in both crude and processed Semen Strychni is still lacking. The present study represents the first quantitation and relative quantitation assay of 12 dihydroindole‐type alkaloids in Strychnos nux‐vomica unprocessed and sand‐processed seeds using high‐performance liquid chromatography coupled with diode array detection and mass spectrometry. The relative concentration of ten alkaloids was calculated by semi‐quantification using the internal standard and their amounts in unprocessed and detoxified Semen Strychni were compared. We report here for the first time the significant increase of the two alkaloids, 19‐N‐methyl‐strychnine, and 2,3‐dimethoxy‐19‐N‐methyl‐strychnine, during the processing of Semen Strychni. Our study provides new insight into the true complexity of seed processing procedure and valuable information for assessing the efficacy and safety for clinical applications of Semen Strychni‐containing drugs.     

How do we understand mathematical practices in non-mathematical fields? Reflections inspired by cases from 12th and 13th century China

Recent studies of the history of mathematics have shed light on the diversity of mathematical practices in the ancient world. In this article, I address this issue from two perspectives. First, I analyze different mathematical instruments used in different domains in 12^th and 13^th century China. Second, by analyzing how the text is related to the problems written down in the same period, I argue that there existed two categories of mathematical problems. As a result, I suggest that problems, textual procedures, and material operations should be considered together when regarding various mathematical practices in mathematical and non-mathematical fields.     

Comparative analysis of the main active components and hypoglycemic effects after the compatibility of Scutellariae Radix and Coptidis Rhizoma

In this study, a rapid and highly sensitive ultra high performance liquid chromatography with triple quadrupole mass spectrometry method with the mobile phase of acetonitrile and 0.1% aqueous formic acid was established and successfully applied to comparatively analyze main active components after their compatibility. Besides, the effects of Scutellariae Radix, Coptidis Rhizoma and combined extracts on type 2 diabetic rats induced by high‐fat diet along with low dose of streptozocin were investigated. Under the optimized chromatographic conditions, good separation of seven target components was achieved within 12 min. All calibration curves exhibited good linearity (R² ≥ 0.999). The relative standard deviation of precision, repeatability and stability varied from 0.69 to 2.23, 0.98 to 2.56, and 0.92 to 2.57%, respectively. The recovery ranged from 91.11 to 105.35%. The contents of seven active components were notably reduced after compatibility; however, the hypoglycemic effect of combined extracts was stronger than single drug by decreasing the activities of fructose‐1,6‐bisphosphatase, glucose 6‐phosphatase, phosphoenolpyruvate carboxykinase and increasing the activities of glucokinase, phosphofructokinase, pyruvate kinase. Accordingly, the established analytical method was accurate and sensitive enough for quantitative evaluation of seven investigated compounds. Moreover, the combined extract had definite effects on type 2 diabetes through multiple components against multiple targets.     

UPLC-Q/TOF-MS coupled with multivariate analysis for comparative analysis of metabolomic in Dendrobium nobile from different growth altitudes

Dendrobium nobile alkaloids (DNLA) and glycosides are the main active components extracted from Dendrobium nobile Lindl. (D. nobile) used for thousands of years in China. The pharmacological effects of the above chemical components are significantly different. D. nobile is mainly grown at an altitude ranging from 230 to 800 m in Chishui City, Northwest Guizhou Province. However, it is unclear whether the metabolite in D. nobile is influenced by the planting altitude. Hence, to reveal the different metabolite in D. nobile cultivated at the altitude of 336 m, 528 m, and 692 m, ultra-high performance liquid chromatography with Q/TOF-MS couple with multivariate analysis were developed. Using the orthogonal partial least squares-discriminant analysis, 19 different metabolites were discovered and then tentatively assigned their structures as alkaloids and glycosides by comparing mass spectrometry data with in-house database and literature. Moreover, the result of semiquantitative analysis showed the content of dendrobine that was belonged to alkaloids significantly increased at the altitude of 692 m, whereas the content of glycosides demonstrated an accumulation trend at the altitude of 528 m. The results could provide valuable information for the optimal clinical drug therapeutics and provide a reference for quality control.     

A SERS and HPLC study of traditional dyes from native Chinese plants

Surface-enhanced Raman spectroscopy (SERS) is proposed as analytical method for the characterization of extracts from Chinese plants traditionally used both as medicines and as textile dyes. Spectroscopic results are supported by high-performance liquid chromatography (HPLC) analysis of the extracts. In particular the spectra of extracts obtained from Chinese mulberry (Cudrania tricuspidata), gromwell (Lithospermum erythrorhizon), Chinese rhubarb (Rheum palmatum), tangerine (Citrus reticulata) and Morinda plants are reported here for the first time. A correlation between the SER spectral pattern and the structure of the molecules responsible for color is proposed for each of the examined dyes.     

黄葆同归国始末：1950年代留美学生回国因素探析

黄葆同院士（1921-2005）是我国高分子化学领域的资深专家。早年留学美国,1955年回国后一直在中国科学院长春应用化学研究所工作。在乙丙橡胶合成等研究领域走在全国前列。基于对“老科学家学术成长资料采集工程”所存大量书信和日记等的解读分析,论文还原了黄葆同在美留学期间加入进步组织、争取回国的历史过程以及求学经历。并以此为缩影,探讨当时促使留美学生回国的个体与社会因素,具体而微地揭示了那一代中国留学生在困境之中的家国情怀。     

Separation of three polar compounds from Rheum tanguticum by high‐speed countercurrent chromatography with an ethyl acetate/glacial acetic acid/water system

The separation of polar compounds by high‐speed countercurrent chromatography is still regarded as a challenge. In this study, an efficient strategy for the separation of three polar compounds from Rheum tanguticum has been successfully conducted by using high‐speed countercurrent chromatography. X‐5 macroporous resin chromatography was used for the fast enrichment of the target compounds. Then, the target fraction was directly introduced into high‐speed countercurrent chromatography for separation using ethyl acetate/glacial acetic acid/water (100:1:100, v/v/v) as the solvent system. Consequently, three polar compounds including gallic acid, catechin, and gallic acid 4‐O‐β‐d ‐(6′‐O‐galloyl) glucoside were obtained with purities higher than 98%. The results showed glacial acetic acid could be such an appropriate regulator for the ethyl acetate/water system. This study provides a reference for the separation of polar compounds from natural products by high‐speed countercurrent chromatography.     

Quality evaluation of Eucommiae Cortex processed by different methods and “sweating” conditions based on simultaneous determination of multiple bioactive constituents combined with gray relational analysis

Eucommiae Cortex is a classical traditional Chinese medicine, which needs to be processed by “sweating” methods. To select the suitable processing method and “sweating” processing condition for Eucommiae Cortex, in this study, the quality of Eucommiae Cortex was evaluated based on simultaneous determination of multiple bioactive constituents combined with gray relational analysis. The contents of lignans, iridoids, penylpropanoids, flavonoids, and phenols in samples were simultaneously determined using ultra‐fast performance liquid chromatography coupled with triple quadrupole‐linear ion trap tandem mass spectrometry. The chromatographic separation was performed on a Synergiۛ Hydro‐RP 100 Å column (100 mm × 2.0 mm, 2.5 μm) at 30°C with a gradient elution of acetonitrile with 0.1% formic acid/0.1% aqueous formic acid as the mobile phase. Furthermore, gray relational analysis was performed to evaluate and sort the samples according to the contents of 14 constituents by calculating the relative correlation degree of each sample. The results demonstrated that the quality of Eucommiae Cortex “sweating” at source area was better and the better “sweating” condition was to scrape off the cork layer before “sweating” with straw covering and sun drying. The developed method could provide the foundation and support for “sweating” processing method of Eucommiae Cortex in normalization and standardization.