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(Br−)CH3-Pyridinium-MOF-1 integrated reactive Lewis acid sites and Br− nucleophilic anions and exhibited efficient catalytic activity for the cycloaddition of CO2 to epoxides.

Building metal-organic frameworks (MOFs) covalently modified by onium halides is a promising approach to develop efficient MOF-based heterogeneous catalysts for the cycloaddition of CO

A MOF with strong deep blue light emission and high quantum efficiency has high selectivity and sensitivity for detecting 2,6-dichloro-4-nitroaniline.

Litsea cubeba is an evergreen tree from the Lauraceae family, with the common name of mountain pepper in Taiwan. The extracts from different parts such as the bark, leaf, root and fruit have various medicinal properties and have been extensively used in traditional Chinese medicine. SnO2 nanoparticles (NPs) were synthesized using an extract of Litsea cubeba fruit based on response surface methodology (RSM). The phytochemicals present in the extract of Litsea cubeba fruit played a crucial role in the NP formation, which could be confirmed by Fourier-Transform Infrared Spectrometer (FTIR). Analysis of variance (ANOVA) was used to evaluate the validation of the RSM models and indicated that the quadratic model was highly significant and suitable to represent the response of the NP formation yield. The optimum parameters were determined using the Design Expert Program and were as follows: extract volume ratio 30.0%, pH 6.3 and reaction temperature 44.4 °C. Using the optimal reaction conditions from the central composite design (CCD) of RSM, the SnO2 NPs were prepared and characterized by field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The FE-SEM results showed that the SnO2 NPs were spherical, and XRD results showed that the NPs had a tetragonal crystal structure. Furthermore, the photodegradation kinetics of malachite green by the SnO2 NPs was represented well with a pseudo first-order model.

A biological synthesis of SnO 2 nanoparticles (NPs) was carried out using the extract from Litsea cubeba fruit with extraction parameters optimized for yield enhancement. The SnO 2 nanoparticles were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), Fourier transform infrared analysis (FTIR) and UV–Visible spectroscopy. The synthesized SnO 2 nanoparticles have an irregular morphology and are approximately 30 nm in size. The results show that the extract of Litsea cubeba fruits was a reducing agent. In addition, SnO 2 NPs not only have good photocatalytic activity for Congo red dye degradation but also have high antioxidant capacity against DPPH free radicals.

Arctigenin is the main active ingredient of Fructus Arctii for the treatment of type 2 diabetes. In this study, the pharmacokinetics of arctigenin in normal and type 2 diabetic rats following oral and intravenous administration was investigated. As compared to normal rats, Cmax and AUC(0-10h) values of oral arctigenin in diabetic rats increased by 356.8% and 223.4%, respectively. In contrast, after intravenous injection, the Cmax and AUC(0-10h) values of arctigenin showed no significant difference between diabetic and normal rats. In order to explore how the bioavailability of oral arctigenin increased under diabetic condition, the absorption behavior of arctigenin was evaluated by in situ single-pass intestinal perfusion (SPIP). The results indicated that arctigenin was a substrate of P-glycoprotein (P-gp). The absorption difference of arctigenin in the normal and diabetic rats could be eliminated by the pretreatment of classic P-gp inhibitor verapamil, suggesting that P-gp might be the key factor causing the absorption enhancement of arctigenin in diabetic rats. Further studies revealed that the uptake of rhodamine 123 (Rho123) in diabetic rats was significantly higher, indicating that diabetes mellitus might impair P-gp function. Consistently, a lower mRNA level of P-gp in the intestine of diabetic rats was found. In conclusion, the absorption of arctigenin after oral administration was promoted in diabetic rats, which might be partially attribute to the decreased expression and impaired function of P-gp in intestines.

To develop a simple and highly sensitive high performance liquid chromatography with electrospray ionization mass spectrometric (LC-ESI-MS) method for the simultaneous determination of madecassoside and its major metabolite madecassic acid in rat plasma, and compare the pharmacokinetics of the two compounds in normal and collagen-induced arthritis (CIA) rats. Glycyrrhetinic acid was used as the internal standard (IS). Chromatographic separation was accomplished on an Inertsil ODS-3 column, using a gradient elution with the mobile phase composed of acetonitrile and water acidified with 0.1% (V/V) formic acid. Detection was achieved by ESI-MS under the negative selected ion monitoring (SIM) mode. In normal and CIA rats, madecassoside (30 mg·kg(-1)) was orally administered for 21 consecutive days from the day of arthritis onset. For madecassoside, the linear range was 10-1 000 ng·mL(-1) with the square regression coefficient (r) of 0.998 9, while for madecassic acid, the linear range was 10-500 ng·mL(-1) with the square regression coefficient (r) of 0.996 1. The lower limit of quantification was 10 ng·mL(-1) for both analytes. The intra- and inter-day precision ranged from 1.78% to 13.42% for madecassoside and 2.30% to 14.90% for madecassic acid, and the accuracy was between -0.95% and 6.30% for madecassoside and between -1.48% and 5.34% for madecassic acid. The average recoveries of madecassoside, madecassic acid and IS from spiked plasma samples were > 81%. The developed method was successfully applied to the pharmacokinetic study of madecassoside and madecassic acid in rats after an oral administration of madecassoside. During initial 7 days of dosing, the cmax and AUC of madecassoside were greatly decreased and Vd/F was markedly increased in CIA rats, and no significant difference was observed on the first day of dosing. In contrast, the T1/2, cmax and AUC of madecassic acid were significantly increased, and Ke of madecassic acid was greatly decreased in CIA rats compared with normal rats. Along with repeated administration of madecassoside, the differences of pharmacokinetic parameters of both madecassoside and madecassic acid between CIA and normal rats gradually subsided. The pharmacokinetic characteristics of both madecassoside and madecassic acid in rats were significantly altered by arthritis status, and the differences of pharmacokinetic parameters between arthritis and normal rats coincide with the severity of arthritis.

Here, we report two novel POM-based MOFs: a nano-caged hybrid compound [Ni2(BIMB)2(MoVI4MoV2O19)] (1), whose cages are based on [Mo6O19]4− units and a [Mo6O19]2−-templated framework [Zn4(BIMB)4(PO4)2(Mo6O19)]·2H2O (2) (BIMB = 1,4-bis(1-imidazolyl)benzene). According to topological analysis, the first is a 3D (4,6)-connected self-penetrating framework with polycatenanes motif. In contrast, the second metal–organic framework has no interpenetration for the templated [Mo6O19]2− occupying the cavity. The UV-vis absorption spectrum of 1 was investigated to prove the existence of MoV atoms and the typical peak at 577 nm can be attributed to MoV → MoVI charge transfer. Furthermore, the diffuse reflectivity spectrum shows that its band gap can be assessed as 3.06 eV, which can be regarded as a wide gap semiconductor. Additionally, cyclic voltammogram of compound 1 shows two redox peaks in the range of 0–800 mV in H2SO4 aqueous solution.

Two novel nanoporous metal–organic frameworks (MOFs) based on the same binuclear nickel secondary building units, {[Ni2(H2O)(BDC)2(BIMB)2]·6DMF}n (1) and {[Ni2(H2O)(BDC)2(BIMB)2]·5DMAc}n (2) (H2BDC = terephthalic acid, BIMB = 1,4-bis(1-imidazolyl)benzene and DMF = N,N′-dimethylformamide, DMAc = N,N′-dimethylacetamide) have been synthesized by self-assembly of Ni(NO3)2·6H2O, BIMB and H2BDC in different solvents (DMF and DMAc), respectively. Different linking modes between terephthalate and binuclear nickel building units in 1 and 2 lead to an interesting phenomenon that their host frameworks are isomeric to each other and have the same three periodic eight-connected self-penetrating nets with novel 420.68 topology. Powder X-ray diffraction (PXRD) results indicate that 1 and 2 both have reversible framework transformations in an acetone/guest solvent molecule system.

Background & Objective: Nasopharyngeal carcinoma (NPC) is an epithelial neoplasm with high occurrence rates in southern China. The disease often metastasizes to regional lymphnodes at a very early stage. Local recurrences and metastasis occur frequently in patients with NPC and are a leading cause of death, despite improvements on treatment modalities. The molecular mechanism underlying the metastasis of nasopharyngeal carcinoma remains poorly understood, however, and requires additional elucidation. The aim of this study was to explore possible NPC gene candidates that may play key roles in NPC metastasis. Methods: Subtractive suppression hybridization (SSH) was performed to isolate differentially expressed clones between the metastatic 5-8F and non-metastatic 6-10B nasopharyngeal carcinoma cell lines. Differentially expressed clones were screened and confirmed by reverse Northern blotting. The sequences of cDNA fragments were subsequently analyzed and compared to known sequences in Genbank. Results & Discussion: The SSH library contained thousands of positive clones. Random analysis of 300 clones by PCR demonstrated that 269 clones contained inserted fragments. Reverse Northern blot confirmed that 20 out of 192 clones examined were significantly up-regulated in the 5-8F cell line. Among these 20 clones, 16 were previously identified genes (flotilin-2, ezrin, pim-3, fli-1, mel, neugrin, znf216, ASB1, raly, UBE2A, keratin6A, TMED7, EIF3S9, FTL, two ribosomal proteins RPL21 and RPL16), two were predicted genes (c9orf74 and MDS006), and two sequences shared no homology with known genes listed in GenBank and may represent novel genes. The proposed functions of the genes identified in this study include cell signal transduction, cell survival, transcription regulation, cell mobility, protein synthesis, and DNA damage repair. Flotillin-2, fli-1, pim-3 and ezrin have previously been reported to be associated with tumor metastasis and progression. The remaining up-regulated genes identified in this study have not been reported to be markers of metastasis and may represent new candidates of NPC metastasis-related genes. The Results of this study may provide novel points of therapeutic intervention for NPC.

By modulating the synthetic strategy based on changing substituents on the ligand and solvent used in the synthesis, a series of metal organic frameworks (MOFs) of two chiral binaphthol-like ligands of 4-(1H-imidaozol-1-yl)benzoic acid (HIBA) and 4-(1H-2-methylimidazol-1-yl)benzoic acid (HMIBA) with various interpenetrating topologies have been synthesized under solvothermal conditions: Zn(IBA)2 (1), Co(IBA)2 (2), Cd(IBA)2·H2O·1.7DMF (3), Cd(MIBA)2·H2O·1.3DMF (4), Co(MIBA)2·H2O·1.3DMF (5) and Cd(MIBA)2·0.5H2O·1.2DMA (6) (DMF = N,N-dimethylformamide and DMA = N,N′-dimethylacetamide). X-ray diffraction study reveals that compounds 1 and 2 crystallize in tetragonal crystal system with chiral space groupsP4122 and P4322, respectively, indicating that they are a pair of structural enantiomers, having a twofold interpenetrating (4,4)-net. Compound 3 crystallizes in orthorhombic crystal system and non-centrosymmetric space group Pca21, which can be defined as an abnormal fourfold [2 + 2] interpenetrating diamond net. The isostructural compounds 4 and 5 crystallize in tetragonal crystal system and space group P4212, representing a chiral structure and a normal mode of fourfold interpenetrating diamondoid net. Compound 6 crystallizes in non-centrosymmetric space group Aba2 and exhibits a normal mode of fourfold diamondoid interpenetrating net.