Monoterpenoids from the Fruit of Gardenia jasminoides

Eight new monoterpenoids, jasminoside J ( 1 ), jasminoside K ( 2 ), 6′‐O‐trans‐sinapoyljasminoside B ( 3 ), 6′‐O‐trans‐sinapoyljasminoside L ( 4 ), jasminosides M–P ( 5 – 8 ), together with three known analogues, jasminoside C ( 9 ), jasminol E ( 10 ), and sacranoside B ( 11 ), were isolated from the fruit of Gardenia jasminoides Ellis (Rubiaceae). Their structures were elucidated by spectral and chemical methods.     

Four New Terpenoids from Xylaria sp. 101

One new diterpenoid, xylarenolide ( 1 ), and three new sesquiterpenoids, xylaranol A ( 2 ), xylaranol B ( 3 ), and xylaranic acid ( 4 ), were obtained from the fungal strain Xylaria sp. 101, which was isolated from the fruiting body of Xylaria sp. collected in Gaoligong Mountain, Yunnan Province. Their structures were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, and by HR‐Q‐TOF mass spectrometry. Their antimicrobial activities were evaluated.     

Phytoquinoids and Secoprezizaane‐Type Sesquiterpenes from Illicium arborescens

A phytochemical investigation of the MeOH extract of Illicium arborescens yielded the two new phytoquinoid epimers, 2,3‐didehydro‐5‐O‐methyl‐11‐epiillifunone E ( 1 ) and 2,3‐didehydro‐5‐O‐methylillifunone E ( 2 ), as well as five new sesquiterpene lactones (8,9‐secoprezizaane‐type sesquiterpenes). Two of them, i.e., 3 and 4 , were minwanensin‐type sesquiterpenes, the other two, i.e., 5 and 6 , had the anisatin‐type (or floridanolide type) skeleton, and the fifth, i.e., 7 , was a dunnianin‐type sesquiterpene. Their structures were established by analyses of 1D‐ and 2D‐NMR, HR‐MS, and chemical evidence. The in vitro cytotoxic activity of compounds 1 – 7 was tested against four human tumor cell lines, including HeLa (cervical epitheloid), WiDr (colon), Daoy (medulloblastoma), and Hep2 (liver carcinoma) human‐tumor cells.     

Dispersive liquid-liquid microextraction based on the solidification of floating organic droplet for the determination of polychlorinated biphenyls in aqueous samples

In the proposed method, an extraction solvent with a lower toxicity and density than the solvents typically used in dispersive liquid-liquid microextraction was used to extract seven polychlorinated biphenyls (PCBs) from aqueous samples. Due to the density and melting point of the extraction solvent, the extract which forms a layer on top of aqueous sample can be collected by solidifying it at low temperatures, which form a layer on top of the aqueous sample. Furthermore, the solidified phase can be easily removed from the aqueous phase. Based on preliminary studies, 1-undecanol was selected as the extraction solvent, and a series of parameters that affect the extraction efficiency were systematically investigated. Under the optimized conditions, enrichment factors for PCBs ranged between 494 and 606. Based on a signal-to-noise ratio of 3, the limit of detection for the method ranged between 3.3 and 5.4 ng L⁻¹. Good linearity, reproducibility and recovery were also obtained.     

Isopiestic Determination of Water Activity on the System LiNO<Subscript>3</Subscript>+KNO<Subscript>3</Subscript>+H<Subscript>2</Subscript>O at 273.1 and 298.1 K

Water activities in the ternary LiNO₃+KNO₃+H₂O system and its sub-binary systems have been measured by the isopiestic method at 273.1 and 298.1 K. The measured results were treated by a Pitzer-Simonson-Clegg thermodynamic model, from which the predicted solubility isotherms were compared with the experimental results. Based on this comparison, the reliability of the measured results was discussed. The measured results help in predicting the phase diagram of the ternary system, as well as other multi-component systems based on the ternary system.     

Bi3In4S10 and Bi14.7In11.3S38: Two new bismuth sulfides with interesting Bi-Bi bonding

Two new ternary bismuth chalcogenides, Bi₃In₄S₁₀ and Bi_14.7In_11.3S₃₈, were synthesized from the reactions of binary sulfides via a two-step flux technique. Single-crystal X-ray diffraction analyses indicate that Bi₃In₄S₁₀ crystallizes in the non-centrosymmetric space group Pm and Bi_14.7In_11.3S₃₈ crystallizes in the centrosymmetric space group P2₁/m. Both compounds adopt three-dimensional frameworks. A distinct structural feature in the two structures is the presence of chains of Bi atoms with alternating short Bi-Bi bonds of around 3.1 Å and longer distances of around 4.6 Å. The optical band gaps of 1.42(2) eV for Bi₃In₄S₁₀ and 1.45(2) eV for Bi_14.7In_11.3S₃₈ were deduced from the diffuse reflectance spectra.     

Synthesis and textural evolution of alumina particles with mesoporous structures

Alumina particles with mesostructures were synthesized through a chemical precipitation method by using different inorganic aluminum salts followed by a heterogeneous azeotropic distillation and calcination process. The obtained mesoporous γ-alumina particles were systematically characterized by the X-ray diffraction, transmission electron microscopy and nitrogen adsorption-desorption measurement. Effects of the aluminum salt counter anion, pH value and the azeotropic distillation process on the structural or textural evolution of alumina particles were investigated. It is found that Cl⁻ in the reaction solution can restrain the textural evolution of the resultant precipitates into two-dimensional crystallized pseudoboehmite lamellae during the heterogeneous azeotropic distillation, and then transformed into γ-Al₂O₃ particles with mesostructures after further calcination at 1173 K, whereas coexisting SO₄²⁻ can promote above morphology evolution and then transformed into γ-Al₂O₃ nanofibers after calcination at 1173 K. Moreover nearly all materials retain relatively high specific surface areas larger than 100 m² g⁻¹ even after calcinations at 1173 K.     

KBiMS4 (M=Si, Ge): Synthesis, structure, and electronic structure

Two new bismuth sulfides KBiSiS₄ and KBiGeS₄ have been synthesized by means of the reactive flux method. They adopt the RbBiSiS₄ structure type and crystallize in space group P2₁/c of the monoclinic system. The structure consists of (M=Si, Ge) layers separated by bicapped trigonal-prismatically coordinated K atoms. The M atom is tetrahedrally coordinated to four S atoms and the Bi atom is coordinated to a distorted monocapped trigonal prism of seven S atoms. The optical band gap of 2.25(2) eV for KBiSiS₄ was deduced from the diffuse reflectance spectrum. From a band structure calculation, the optical absorption for KBiSiS₄ originates from the layer. The Si 3p orbitals, Bi 6p orbitals, and S 3p orbitals are highly hybridized near the Fermi level. The orbitals of K have no contributions on both the upper of valence band and the bottom of conduction band.     

A new sample preparation method for determination of acidic drugs in sewage sludge applying microwave assisted solvent extraction followed by gas chromatography-mass spectrometry

This paper presents a new sample preparation procedure for determination of selected acidic pharmaceuticals (ibuprofen, naproxen, ketoprofen, and diclofenac) in sewage sludge using microwave assisted solvent extraction, dispersive matrix extraction (DME) followed by the conventionally applied solid phase extraction (SPE), derivatization, and gas chromatography-mass spectrometry. The recoveries calculated from analytical data of spiked sludge samples changed in the range of 80-105% ± 15% for the four pharmaceuticals in mixed and activated sludge depending on the efficiency of the clean-up procedure. The measured concentration values of ibuprofen and naproxen were identical in the mixed and the activated sludge samples. However, ketoprofen and diclofenac showed about twice as high concentration in activated sludge than in the mixed one independently of the applied extraction method. The typical concentration ranges of ibuprofen, naproxen, ketoprofen and diclofenac in sewage sludge were 10-30 ng/g, 30-50 ng/g, 50-130 ng/g, and 50-140 ng/g respectively.     

Application of DLLME Based on the Solidification of Floating Organic Droplets for the Determination of Dinitrobenzenes in Aqueous Samples

Dispersive liquid–liquid microextraction (DLLME) based on the solidification of floating organic droplets (DLLME-SFO) combined with gas chromatography-electron-capture detection (GC–ECD) has been developed for extraction and analysis of three dinitrobenzenes. The extraction conditions including extraction solvent, disperser solvent, extraction time, salt effect and temperature were investigated and optimized systematically. The limits of detection were 0.019 μg L^?1 for 1,4-dinitrobenzene, 0.079 μg L^?1 for 1,3-dinitrobenzene and 0.034 μg L^?1 for 1,2-dinitrobenzene. Moreover, it offered good repeatability and high recovery. This method was successfully applied to monitor DNBs in different water samples.