A series of heteroleptic platinum(II) complexes of the general formula [PtX( i PrEug)(NHC)] (2-7) bearing the organometallic π/σ-chelator i PrEug (isopropyl eugenoxyacetate), with varying X (halido) and NHC (N-heterocyclic carbene) ligands derived from imidazole, benzimidazole, and triazole, were prepared and fully characterized by elemental analyses, ESI mass spectrometry, and IR and NMR spectroscopy. Complexes 3 and 5-7 were also characterized by single-crystal X-ray diffraction. These air-stable complexes are rare examples of platinum(II)
Two new, aramatosides A and B (1 and 2), together with seven known oleanane-type triterpene saponins (3-9) were isolated from the leaves of Aralia armata. Their structures were determined by combination of HR-ESI-MS, 1D and 2D NMR spectral data as well as comparison with the previous literature.Compounds 6-9 exhibited cytotoxic effects towards three human cancer cell lines (HT29, A2058, and A549) with IC 50 values ranging from 2.01 ± 0.17 to 18.8 ± 1.17 µM. Especially, compound 7 (narcissiflorin) showed significant cytotoxic activity against HT29 and A549 cell lines with IC 50 values of 2.02 ± 1.65 and 2.01 ± 0.17 µM, respectively, which are smaller than those of positive control irinotecan hydrochloride (IC 50 values of 10.3 ± 1.32 and 9.89 ± 0.19 µM).
Natural rubber processing wastewater contains high concentrations of organic compounds, nitrogen, and other contaminants. In this study, a treatment system composed of a baffled reactor (BR), an upflow anaerobic sludge blanket (UASB) reactor, and a downflow hanging sponge (DHS) reactor was used to treat natural rubber processing wastewater in Vietnam. The BR showed good total suspended solids removal of 47.6%, as well as acidification of wastewater. The UASB reactor achieved a high chemical oxygen demand (COD) removal efficiency of 92.7% ± 2.3% and energy recovery in the form of methane with an organic loading rate of 12.2 ± 6.6 kg-COD·m·day. The DHS reactor showed a high performance in residual organic matter removal from UASB effluent. In total, the system achieved high-level total COD removal of 98.6% ± 1.2% and total suspended solids removal of 98.0% ± 1.4%. Massive parallel 16S rRNA gene sequencing of the retained sludge in the UASB reactor showed the predominant microbial phyla to be Bacteroidetes, Firmicutes, Proteobacteria, WWE1, and Euryarchaeota. Uncultured bacteria belonging to the phylum Bacteroidetes and Phylum WWE1 were predominant in the UASB reactor. This microbial assemblage utilizes the organic compounds contained in natural rubber processing wastewater. In addition, the methane-producing archaea Methanosaeta sp. and Methanolinea sp. were detected.
The interaction between the dinuclear chelate ring complex [Pt(μ-Cl)( i PrEug)]2 (1) ( i PrEug: deprotonated isopropyl eugenoxyacetate) and 1,3-diisopropylbenzimidazolium bromide ( i Pr2-bimy·HBr) has been studied for the first time. The result shows that the chloride bridges in 1 are easily cleaved by the i Pr2-bimy in the present of base to form a mixture (Phh) of two complexes [PtBr( i PrEug)( i Pr2-bimy)] (2) and [PtCl( i PrEug)( i Pr2-bimy)] (3), and the molar ratio of 2:3 in Phh depends on the used base Ag2O or Na2CO3/NaOOCCH3/NaHCO3/NaOH. The reaction of Phh with NaBr afforded complex 2 with high yield. The structure of 2 was determined by weight method, ESI-MS, IR, 1 H NMR, 13 C NMR, HSQC spectroscopies and single-crystal X-ray diffraction. The NMR and XRD studies also reveal that the introdution of i Pr2bimy leads to a weakening of the Pt-(C9=C10) bond and strengthening of the Pt-C5 bond in 2.
Special pair chlorophylls arranged in a cofacial dimeric structure play an important role in the initial step of light induced electron transfer of photosynthetic reaction centers of bacteria and plants. For mimicking the natural photosynthetic reaction center we aimed on synthesis of an artificial special pair 13 constructed from two chlorin subunits 5a, b and a rigid biphenylene spacer moiety 11. Due to the reduced C2h symmetry of the chlorin units compared with so far used D4h porphyrins and due to the rigid spacer a cofacial dimer of defined symmetry and distance was obtained.
Heats of mixing at 25°C have been measured for the following 24 systems : Sn(ClzHz5)4 with five linear and three branched alkanes, dioctyl ether with the same alkanes (except C5), cis-dec-5-ene with trans-dec-5-ene, cis-and trans-decene with n-C12, n-C1 6, br-C6, br-C1 6. Orientational order in long chain non-alkane molecules was investigated. It was found to be present between the chains of Sn(C12H&. Compounds in which the C-C sequence of an alkane is interrupted by C-0-C (dioctyl ether) appear to retain part of the orientational order, but interruption by a double bond (dec-5-ene) destroys the order. The heat of mixing profile of a given compound with the linear alkane series and that of the branched alkane gives information on the orientational order of this compound in the pure liquid state. Correlation of the heats or of the calculated Xll parameter with the Bothorel J orientational order parameter is made.
Eight platinum(II) complexes of the formula [PtCl-(arylolefin)(NHC)] (2−9) with varying NHCs and arylolefin chelators have been prepared and analyzed by spectroscopic and spectrometric methods. The study reveals that the binding of the arylolefins is influenced by remote ring substituents and by the NHC spectator ligands. A more strongly donating NHC exhibits an increased trans influence and weakens the olefinic donor notably, which could lead to its premature dissociation. Cytotoxicity studies on four human cancer cell lines indicate that a stronger binding of the arylolefin is more beneficial. The highest cytotoxic effects (IC 50 = 0.18−0.70 μM) were observed for the complex [PtCl(Meug)(IMes)] (3), containing a more weakly donating NHC and the strongest arylolefin donor.
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