Aerobic oxidative desulfurization via magnetic mesoporous silica-supported tungsten oxide catalysts

It is usually difficult to remove dibenzothiophenes from diesel fuels by oxidation with molecular oxygen as an oxidant.In the study,tungsten oxide was supported on magnetic mesoporous silica by calcination to form a magnetically separable catalyst for oxidative desulfurization of diesel fuel.By tuning different calcining temperatures,the catalyst calcined at 500℃showed a high catalytic activity with molecular oxygen as the oxidant.Under optimal reaction conditions,the sulfur removal of DBT reached 99.9%at 120℃after 8 h.Furthermore,the removals of 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene could also get up to 98.2%and 92.3%under the same conditions.The reaction mechanism was explored by selective quenching experiments and FT-IR spectra.

Chemical Constituents from Barks of Lannea coromandelica

Objective To study the chemical constituents from the barks of Lannea coromande/ica. Methods The chemical constituents were isolated and purified by column chromatography on silica gel column. NMR spectra were used for structural identification. Results Thirteen compounds were isolated and identified as quercetin （1）, （2S,3S,4R, lOLg-2-[（2＂R）-2＇-hydroxytetracosanoyl amino]-10-octadecene-l,3,4- triol （2）, aralia cerebroside （3）, 5,5＇-dibuthoxy-2,2＇-bifuran （4）, ^-sitosteryl- 3^-glucopyranoside-6＇-O-palmitate （5）, B-sitosterol palmitate （6）, myricadiol （7）, protocatechuic acid （8）, p-hydroxybenzoic acidethyl ester （9）, isovanillin （10）, trans- cinnamicacid （I 1）, palmiticacid （12）, and stearicacid （13）. Conclusion Compounds 2-13 are isolated from this plant for the first time.

Meroterpenoids Possessing Diverse Rearranged Skeletons with Anti-inflammatory Activity from the Mangrove-Derived Fungus Penicillium sp. HLLG-122

Fifteen new meroterpenoids, littoreanoids A—O (1—15), including three rearranged skeleton meroterpenoids (1—3), were isolated from the mangrove-derived fungus Penicillium sp. HLLG-122. Compound 1 was a novel berkeleyacetal-derived meroterpenoid featuring an unusual spirocyclic 2-oxaspiro[5.5]undeca-4,7-dien-3-one moiety. Compound 2 possessed an unusual 6/6/6/6/6 pentacyclic system with a novel 1-hydroxy-7,7-dimethyl-2-oxabicyclo[2.2.2]octan-5-yl acetate moiety. Compound 3 was an unusual 6/7/6/5/6/5/4 polycyclic systems containing a β-lactone ring. The structures and absolute configurations of new compounds were elucidated by HRESIMS, NMR spectroscopy, single crystal X-ray diffraction analysis, and electronic circular dichroism calculations. The plausible biosynthetic pathways of 1—3 were also proposed. Compounds 6 and 11 exhibited anti-inflammatory effects with IC_(50) values of 30.41 and 19.02 μmol/L, respectively. The bioactive compound 11 was selected for the investigation of preliminary mechanism using molecular docking and Western blotting experiments. Compound 11 could suppress the levels of TNF-α and IL-6, and down-regulate the protein expression of iNOS and COX-2 in RAW 264.7 cells.

Sesquiterpenoids from Curcuma wenyujin dreg and their biological activities

Four new sesquiterpenoids, 4,8-dioxo-6βhydroxyl-7β,l 1-epoxycarabrane （1）, 4,8-dioxo-6βhydroxyl- 7β,11-epoxycarabrane （2）, wenyujinins Q and R （3-4）, and nine known sesquiterpenoids （5-13） were isolated from the Curcuma wenyujin （C wenyujin） dreg. Their structures and relative configurations wereelucidated using 1D, 2D NMR, and HR-ESI-MS data. All the compounds were isolated for the first time from the C wenyujin dreg and evaluated for their antibacterial and antifungal activities. Compounds 3, 5- 8 exhibited strong broad-spectrum antifungal activities against tested nine pathogenic fungi.

New luminescent cyclometalated iridium(Ⅲ) complexes containing fluorinated phenylisoquinoline-based ligands: Synthesis, structures,photophysical properties and DFT calculations

Two new fluorinated phenylisoquinoline-based iridium（Ⅲ） complexes,[Ir（f2piq）2（bipy）][PF6]（3a） and[Ir（fmpiq）2（bipy）][PF6]（3b）（f2piq = l-（2,4-difluorophenyl）isoquinoline,fmpiq = 1-（4-fluoro-2-methylphenyl）isoquinoline,bipy = 2,2＇-bipyridine）,have been synthesized and fully characterized.Single crystal X-ray diffraction study has been undertaken on complexes 3a and 3b,which show that each adopts the distorted octahedral coordination geometry with the cis-C,C＇ and trans-N,N＇ configuration.The photoluminescence spectra of 3a and 3b exhibit yellow and orange emission maxima at 584 and 600 nm,respectively.The frontier molecular orbital diagrams and the lowest-energy electronic transitions of 3a-3b have been calculated with density functional theory（DFT） and time-dependent DFT（TD-DFT）.The absorption and emission spectra of complex 3b is red-shifted relative to those of complex 3a,as a consequence of the nature of the methyl group.