We reported here an interesting source of Alpinia zerumbet Polysaccharides (named AZPs) from the residues after extracting essential oil by steam distillation from Alpinia zerumbet fructus. After a series of purifications, a homogeneous polysaccharide (AZP-2) of molecular weight 1.25 × 10 5 Da was obtained. Structure, anti-inflammatory activity, and anti-inflammatory mechanism were investigated. AZP-2 was mainly composed of galactose, arabinose, xylopyranose, glucose, and galacturonic acid. The main linkage structure of AZP-2 was determined after integrating the nuclear magnetic resonance (NMR) and methylation analysis, and the structure was comparatively complex. The results indicated that AZP-2 significantly decreased the production of NO and ROS in the inflammatory model established by lipopolysaccharide (LPS) stimulated RAW264.7, particularly at the concentration of 200 μg/mL. Furthermore, AZP-2 significantly modulated the secretion of both pro-inflammatory and anti-inflammatory cytokines. Notably, the mechanism of AZP-2 exhibiting inhibitory effects was related to regulating the NF-κB signaling pathway. Overall, AZP-2 could be used as a potential anti-inflammatory agent for further in-depth studies.
In this study, silver nanowires (AgNWs) were successfully synthesized by using a polyvinylpyrrolidone (PVP)-free hydrothermal method with an Alpinia zerumbet leaf chunk as a reducing agent and template. Meanwhile, the mechanism of biomass synthesis of AgNWs is also explored. The AgNWs have a diameter of ∼77 nm and a length of ∼10 μm. During the hydrothermal process, the biomass initially serves as a reducing agent to reduce silver ions. As the reaction proceeds, the biomass will form a pipe-shaped soft template by hydrothermal carbonization. Silver ions are adsorbed and reduced along the pipe-shaped soft templates to form silver nanorods, and adjacent nanorods are merged to AgNWs. Thus, AgNWs are grown along the pipeline soft template based on the oriented attachment mechanism. Inspired by this, the mechanism of the polyol method was further investigated. In the initial growth stage, AgNWs synthesized by the polyol method have a V-shaped notch. Therefore, AgNWs synthesized by the polyol method may also grow on the basis of the oriented attachment mechanism with PVP as a template.