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The biosynthetic pathways of phytosterols and steroidal saponins are located in two adjacent branches which share cycloartenol as substrate. The rate-limiting enzyme S-adenosyl-L-methionine-sterol-C24-methyltransferase 1 (SMT1) facilitates the metabolic flux toward phytosterols. It catalyzes the methylation of the cycloartenol in the side chain of the C24-alkyl group, to generate 24(28)-methylene cycloartenol. In this study, we obtained two full-length sequences of SMT1 genes from Pari polyphylla, designated PpSMT1-1 and PpSMT1-2. The full-length cDNA of PpSMT1-1 was 1369 bp long with an open reading frame (ORF) of 1038 bp, while the PpSMT1-2 had a length of 1222 bp, with a 1005 bp ORF. Bioinformatics analysis confirmed that the two cloned SMTs belong to the SMT1 family. The predicted function was further validated by performing in vitro enzymatic reactions, and the results showed that PpSMT1-1 encodes a cycloartenol-C24-methyltransferase, which catalyzes the conversion of cycloartenol to 24-methylene cycloartenol, whereas PpSMT1-2 lacked this catalytic activity. The tissue expression patterns of the two SMTs revealed differential expression in different organs of Paris polyphylla plants of different developmental stage and age. These results lay the foundation for detailed genetic studies of the biosynthetic pathways of steroid compounds, which constitute the main class of active substances found in P. polyphylla. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) represent a promising alternative to lithium-ion batteries, owing to the much higher abundance and lower cost of sodium resources in comparison with lithium. However, the electrode materials of SIBs usually suffer from more severe issues, such as low specific capacity and poor cyclability, owing to the much larger Na+ diameter and drastic volumetric variations during sodiation/desodiation. Hence, it is still a huge challenge to develop superior electrode materials for reversible Na storage. In comparison with the crystalline materials conventionally used in batteries, amorphous ones may offer a more stable framework for the uptake of Na. To address these issues, a porous composite composed of amorphous Co2P and N,B-co-doped carbon (A-Co2P/C xN yB z-650) is prepared by controlling the annealing temperature at 650 °C after freeze-drying the precursors. As-prepared A-Co2P/C xN yB z-650 exhibits much better Na-storage properties in terms of higher Na-storage capacity, longer cycling stability, and excellent rate performance compared with the crystalline counterparts. These may benefit from the fact that the amorphous framework can provide easier Na+ accessibility and better strain accommodation, originating from volumetric variations during sodiation/desodiation. More importantly, the electrolyte for all of the electrochemical tests are NaPF6 based, which is more accessible for practical applications because of its higher safety compared with the commonly used NaClO4-based electrolyte. [ABSTRACT FROM AUTHOR]

The authors designed two flexible ligand molecules, namely, (N1,N1,N3,N3-tetrakis(4-methylbenzyl)propane-1,3-diamine) (L1) and (N1,N1,N3,N3-tetrabenzylpropane-1,3-diamine) (L2), with (CH2)3alkyl chains attached to the two N atoms. The ligands are double protonated and can react with tetrachloride metal dianion [XCl4]2–(X = Zn, Hg) in the presence of methanol solvent, leading to a series of new inclusion complexes, (CH3OH)2⊂ [L1]2H+· [ZnCl4]2–(crystal1), (CH3OH)0.5⊂ [L2]2H+·[HgCl4]2(crystal2), and CH3OH ⊂ {[L2]2H+}0.5· {[ZnCl4]2–}0.5(crystal3). The molar ratios of methanol and ligand are 2:1, 1:2, and 2:1 in the three crystals, respectively. The structures were characterized by NMR and single-crystal X-ray diffractions. The effect of guest methanol molecules on the formation of supramolecular assemblies was discussed. The ligand can adopt different molecular arrangements as so to suit for the demands of same guest species. From the structural view point, we showed the relationship between the diversity of inclusion hosts and conformational flexibility of ligand. [ABSTRACT FROM AUTHOR]

In this work, we have utilized the second-sphere coordination approach toward the construction of supramolecular inclusion solids Cl · 2H2O ⊂ [H2L1]0.5 · [CuCl4]0.5 (Crystal 1) and Cl ⊂ [H2L1] · [TeCl6]0.5 (Crystal 2). The chloride anions can be encapsulated inside the host assemblies formed by the diamine molecule (4,6-dimethyl-1,3-phenylene)bis(N,N-dibenzylmethane) (L1) and the metal complexes ([CuCl4]2- and [TeCl6]2-) via second-sphere coordination. The complexes have been structurally characterized by X-ray crystallography, indicating that weak C-H ··· Cl hydrogen-bonding synthons play a significant role in the construction of second-sphere coordination complexes. 2-D networks are formed in both complexes by the interconnection of 1-D networks through multiple C-H ··· Cl hydrogen-bonding interactions with [CuCl4]2- and [TeCl6]2-. The guest chlorides are encapsulated inside the host cages through N-H ··· Cl hydrogen bonds. [ABSTRACT FROM AUTHOR]

Layered P2-type Na 0.53 MnO 2 nanorods is prepared by a simple solution reaction. When used as cathode material for sodium ion batteries, the P2-Na 0.53 MnO 2 delivers a high reversible capacity up to 135.7 mA h g −1 (theoretical capacity is 140 mA h g −1 ) at 0.1 C in the voltage range of 2–4.3 V vs. Na + /Na, corresponding to 0.51 mol of Na insertion/extraction. It presents good cycling performance and high rate capabilities. After 50 cycles, the capacity is just fading about 6.8% at the rate of 2 C. The significant behaviour of fast charging makes it be very attractive for practical application. The electrochemical impedance spectroscopy and galvanostatic intermittent titration technique are employed to investigate its sodium diffusion kinetics. The ex-situ X-ray diffraction technology is also used to study the intercalation/de-intercalation of sodium ions and the phase transition in the charging/discharging processes. [ABSTRACT FROM AUTHOR]