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Metallopolymers with precise structures and particular properties have emerged as promising functional materials. The applications of metallopolymers depend on the unique characteristics of the metal centers (such as electronic, optical, magnetic, redox, etc.) and the superior mechanical and processing performances of classical polymers. Access to accurately design metallopolymers with well-defined structures and chemical compositions has enabled researchers to detailedly investigate their performances and a series of advanced applications. Along with the rapid development of modern synthetic chemistry and polymerization techniques, various functional metallopolymers have been synthesized largely and have shown many potential applications. Especially, controlled polymerizations, including ATRP, RAFT, ROMP, living anionic polymerization, and so on, are currently attracting considerable attention for the synthesis of well-defined metallopolymers. These polymerizations have become versatile and powerful synthetic tools, which enable the synthesis of new metallopolymers with accurately controlled molecular weight, relatively narrow molecular weight distribution, composition (block, graft, alternating gradient copolymers), and various functionalities. In this review, we highlight the most recent progress on the controlled synthesis of various well-defined metallopolymers. The review summarizes the recent progress on controlled polymerizations (such as ATRP, RAFT, ROMP, living anionic polymerization, etc.) for various well-defined metallopolymers, and these polymerizations enable the synthesis of novel metallopolymers with accurately controlled molecular weight, relatively narrow molecular weight distribution, composition (block, graft, alternating gradient copolymers), and diverse functionalities. [ABSTRACT FROM AUTHOR]

Irritable bowel syndrome (IBS) is a very common refractory disease. Its exact pathophysiological mechanism is still unclear. Despite the availability of plentiful drugs to control IBS, most patients do not respond well. Ginsenoside Rd is one of the major active components of Panax ginseng, which has been verified to produce various pharmacological actions. However, the role of ginsenoside Rd in modulating smooth muscle contractility is still undefined. The aim of this study is to investigate the effects of ginsenoside Rd on intestinal contractility and related mechanisms in IBS. [ABSTRACT FROM AUTHOR]

Due to their unique physical and chemical features, dendronized polymers (DPs) have received increasing attention in various fields such as hierarchically structured materials, stimuli-responsive materials, catalysis, biosciences, optoelectronic devices, and so on. A large number of synthetic strategies also have been reported to prepare various functionalized DPs. Among these strategies, ring-opening metathesis polymerization (ROMP) and metathesis cyclopolymerization (MCP) using highly active and group-tolerant Ru-based catalysts as initiators were used as living and controlled techniques to fabricate well-defined DPs. The two efficient techniques present a promising prospect in the design and preparation of functional DPs. In this review, we focus on the synthesis of various classes of DPs by ROMP and MCP of dendritic macromonomers, and describe their characteristic structures and properties, as well as various functional applications. [ABSTRACT FROM AUTHOR]

Context: Ginsenosides are primary active ingredients of ginseng, which are believed to have various health benefits. It is found that the biotransformation of ginsenosides mainly takes place in the gastrointestinal tract and the information about ginsenosides-exerted effects on intestinal contractility is not sufficient. Aims: The present study proposed that ginsenosides could exert stimulatory or inhibitory effects on intestinal motility depending on the assay condition-related intestinal contractile states and was to characterize the effects of ginsenosides on intestinal motility. Methods: Jejunal contractility determination, Western blotting analysis, and real-time polymerase chain reaction were performed to test the effects of total ginsenosides isolated from Panax ginseng C. A. Mey (Araliaceae) root. Results: The results showed that ginsenosides at the fixed concentration of 20 mg/L exerted bidirectional regulation (BR) on the contractility of isolated jejunal segment (IJS), depending on the contractile states. The contractility of IJS was increased by ginsenosides in low contractile states, which were correlated to the cholinergic activation, and the contractility of IJS was decreased by ginsenosides in high contractile states, which were correlated to the adrenergic activation and nitric oxide related mechanisms. Ginsenosides-induced BR was abolished in the absence of Ca2+ or by using tetrodotoxin, implicating the requirement of Ca2+ and the enteric nervous system. Effects of ginsenosides on myosin light chain phosphorylation and the mRNA expression of myosin light chain kinase were also bidirectional. Discussion and conclusion: Results suggest that ginsenosides may have the potential clinical implication for reliving the symptoms of alternative hypo- and hyper-intestinal motility. [ABSTRACT FROM AUTHOR]