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Abstract

Chemical composition and anticholinesterase activity of the essential oil of Pavetta graciliflora Wall. ex Ridl. (Rubiaceae) was examined for the first time. The essential oil was obtained by hydrodistillation and was fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 20 components were identified in the essential oil, which made up 92.85% of the total oil. The essential oil is composed mainly of β-caryophyllene (42.52%), caryophyllene oxide (25.33%), β-pinene (8.67%), and α-pinene (6.52%). The essential oil showed weak inhibitory activity against acetylcholinesterase (AChE) (I%: 62.5%) and butyrylcholinesterase (BChE) (I%: 65.4%) assays. Our findings were shown to be very useful for the characterization, pharmaceutical, and therapeutic applications of the essential oil from P. graciliflora.

Abstract

This article demonstrates the development of activated carbon fiber electrodes produced from hardwood kraft lignin (HKL) to fabricate electric double layer capacitors (EDLCs) with high energy and power densities using an ionic liquid (IL) electrolyte. A mixture solution of HKL, polyethylene glycol as a sacrificial polymer, and hexamethylenetetramine as a crosslinker in dimethylformamide/acetic acid (6/4) was electrospun, and the obtained fibers were easily thermostabilized, followed by carbonization and steam activation to yield activated carbon fibers (ACFs). The electrochemical performance of EDLCs assembled with the ACFs, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) as an IL electrolyte and a cellulosic separator was insufficient due to the low conductivity of the electrode. The conductivity of the electrode was improved successfully by spraying conductive carbon black (CB) onto the fibers mat during electrospinning. The CB containing electrodes with improved conductivity gave the resulting EDLCs a higher electrochemical performance, with an energy density of 91.5 Wh kg−1 and a power density of 76.2 kW kg−1.

Abstract

In order to improve dimensional stability and durability of wood, furfurylation of poplar and Chinese fir wood using newly developed furfuryl alcohol (FA) formulation combined with a common vacuum and pressure impregnation process was studied. An orthogonal experiment was designed to optimize the furfurylation process for the two wood species. The weight percent gain (WPG), equilibrium moisture content (EMC), anti-swelling efficiency (ASE), modulus of rupture (MOR), modulus of elasticity (MOE), as well as resistance to mold, decay fungi, and termites were evaluated. The results showed that nearly all the properties of the furfurylated wood could be improved to various extents. The average ASE of the furfurylated Chinese fir and poplar could reach as high as 80, 71, 92% and 79, 90, 75% in tangential and radial directions, and by volume, respectively, higher than most previously reported wood modification processes. Furthermore, the modified wood had excellent biological durability, with nearly 100% mold resistance, strong decay and termite resistance. Finally, processing parameters with 50% FA, 105–115 °C curing temperature, and 5–8 h curing time were therefore recommended for pilot-scale production of furfurylated poplar and Chinese fir wood based on range analysis.

Abstract

Potentilla anserina L. is not only a medicinal plant, but also a traditional cuisine. Hence, an acute toxicity study was performed to confirm its safety profile. Forty Kunming mice were randomly divided into two groups: control group and P. anserina L. extract group. Using the maximum dosage method, the P. anserina L. extract group was given the maximum dose within 12 h, equivalent to 345.6 g/kg crude drug. The control group was given distilled water. After administration, toxicity symptoms of mice were observed, body weight and food intake were recorded. After 14 days, blood was collected to measure biochemical parameters, autopsy was carried out to observe the changes of organs, and the vital organs were separated, weighed, and preserved for histopathological examination. The results showed that P. anserina L. extract group had no toxic symptoms. The activity, weight, and diet of mice were normal, and no abnormality was found in organ index, renal function, liver function, anatomical observation, and histopathological examination. Therefore, the maximum oral dosage (345.6 g/kg) of P. anserina L. was good safety. This study indicated that P. anserina L. had a large safety range and the clinical application was safe.

Abstract

The compound α-mangostin (AMG) extracted from Garcinia mangostana L. has potent anticancer properties but its clinical application is limited because of its poor solubility. In this study, AMG-loaded nanoparticles (NMG) were synthesized using a new formula and their apoptosis activity against human cervical carcinoma (HeLa) cells was investigated in comparison with organic solvent-soluble AMG in free form. The NMG was successfully synthesized with a particle size of <50 nm, polydispersity index <0.3, and zeta potential of −35.2 mV. At a concentration of 10 μg/mL, AMG reduced cell survival by 60%, whereas NMG treatment resulted in >90% cell death (p < 0.05). The AMG- or NMG-treated cells also showed changes in the size and shape and exhibited enhanced intensity of blue-stained nuclei, as well as decreased cell density, especially in NMG-treated cells. After 24 h of incubation with AMG or NMG, the cells went through late apoptosis at a rate of approximately 34% in 20 μg/mL AMG treatment and 27% in 10 μg/mL NMG treatment (p < 0.05). Thus, HeLa cells underwent more pronounced cell death through apoptosis induction caused by the NMG treatment compared to that caused by AMG. Clearly, the new NMG improved AMG bioavailability while maintaining the desired activity.

Abstract

With the increasing application of polyvinyl alcohol (PVA) films in the field of food packaging, it is important to improve its mechanical and antibacterial properties. This paper focuses on the preparation of PVA nanocomposite films and how their properties are affected by a silver-loaded nanocellulose solution. Cellulose nanocrystals (CNCs) were used as both the carrier and the dispersant of silver nanoparticles (AgNPs) prepared using glucose as the reducing agent. Ag+ was stabilized by the many hydroxyl groups located in the CNCs, and then the Ag+ was reduced to AgNPs in situ. After addition of silver-loaded nanocellulose, the tensile strength of the CNC-PVA-AgNP films increased from 47 MPa to 73 MPa, and the nanocomposite films displayed reduced moisture absorption and good antibacterial properties.

Abstract

Modification techniques have been widely employed to improve cellulose properties, thus increasing the diversity of industrial applications. While wood pulp cellulose is the most common source for industrial production, little has been studied about the effects of the cellulose source and its purity on modification. Therefore, this article investigates the influence of cellulose source (e.g. wood or cotton) on its modification (acetylation), by estimating the obtained degree of substitution (DS) through Fourier-transform infrared (FT-IR), proton nuclear magnetic resonance (1H NMR) and back titration. The intense reduction in samples’ crystallinity after acetylation was a result of breakage of inter- and intra-molecular hydrogen bonds, thus confirming acetylation. Although Avicel showed the highest cellulose content and was virtually free of hemicellulose and lignin, this did not affect the acetylation degree, as all samples were successfully triacetylated. The techniques used in this study were ideal for detecting acetylation and estimating the DS, which makes them good tools for modification studies of cellulose derivatives.

Abstract

The design of this study was developed to examine the chemical composition, anticholinesterase and anti-inflammatory inhibitory activities of the essential oil of Dipterocarpus cornutus Dyer from Malaysia. Gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS) analysis of the essential oil revealed 20 components, representing 94.6% of the oil. The major components identified were α-gurjunene (50.6%), α-selinene (8.3%), spathulenol (5.7%), and bicyclogermacrene (5.4%). Anticholinesterase and anti-inflammatory activity were also evaluated using the Ellman method and lipoxygenase (LOX) enzyme, respectively, in which the essential oil revealed weak inhibitory activity against the acetylcholinesterase (AChE) (I%: 30.2%) and butyrylcholinesterase (BChE) (I%: 32.5%), while moderate inhibitory activity was reported in the LOX (I%: 70.2%). The approach adopted in this study and results are reported for the first time which could be useful for the characterization, pharmaceutical and therapeutic applications of the essential oil from Dipterocarpus genus.

Abstract

To achieve efficient utilization of compression wood (CW), a deeper insight into the molecular interactions is necessary. In particular, the role of lignin in the wood needs to be better understood, especially concerning how lignin contributes to its mechanical properties. For this reason, the properties of CW and normal wood (NW) from Chinese fir (Cunninghamia lanceolata) have been studied on a molecular scale by means of polarized Fourier transform infrared (FTIR) spectroscopy, under both static and dynamic loading conditions. Under static tensile loading, only molecular deformations of cellulose were observed in both CW and NW. No participation of lignin could be detected. In relation to the macroscopic strain, the molecular deformation of the cellulose C-O-C bond was greater in NW than in CW as a reflection of the higher microfibril angle and the lower load taken up by CW. Under dynamic deformation, a larger contribution of the lignin to stress transfer was detected in CW; the molecular deformation of the lignin being highly related to the amplitude of the applied stress. Correlation analysis indicated that there was a direct coupling between lignin and cellulose in CW, but there was no evidence of such a direct coupling in NW.