Co-Dissolved Isostructural Polyoxovanadates to Construct Single-Atom-Site Catalysts for Efficient CO2 Photoreduction.

We explored a co-dissolved strategy to embed mono-dispersed Pt center into V2 O5 support via dissolving [PtV9 O28 ]7- into [V10 O28 ]6- aqueous solution. The uniform dispersion of [PtV9 O28 ]7- in [V10 O28 ]6- solution allows [PtV9 O28 ]7- to be surrounded by [V10 O28 ]6- clusters via a freeze-drying process. The V centers in both [PtV9 O28 ]7- and [V10 O28 ]6- were converted into V2 O5 via a calcination process to stabilize Pt center. These double separations can effectively prevent the Pt center agglomeration during the high-temperature conversion process, and achieve 100 % utilization of Pt in [PtV9 O28 ]7- . The resulting Pt-V2 O5 single-atom-site catalysts exhibit a CH4 yield of 247.6 µmol g-1 h-1 , 25 times higher than that of Pt nanoparticle on the V2 O5 support, which was accompanied by the lactic acid photooxidation to form pyruvic acid. Systematical investigations on this unambiguous structure demonstrate an important role of Pt-O atomic pair synergy for highly efficient CO2 photoreduction.

Oxidation of N-Alkyl(iso)quinolinium Salts Over TEMPO@Metal-Organic Framework Heterogeneous Photocatalyst†.

Quinolones and isoquinolones are of particular importance to pharmaceutical industry due to their diverse biological activities. However, their synthetic protocols were limited by high toxicity, high energy consumption, poor functional group tolerance and noble metal catalyst. This study concerns the development of a series of TEMPO@PCN-222 (TEMPO: 2,2,6,6-tetramethylpiperidinyl-1-oxy; PCN: porous coordination network) composite photocatalysts by coordinating different amount of 4-carboxy-TEMPO with the secondary building units of PCN-222. Upon visible-light irradiation, photogenerated holes in the highest occupied molecular orbital of PCN-222 can smoothly transfer to TEMPO, which can significantly boost the photosynthesis of bioactive (iso)quinolones from readily available N-alkyl(iso)quinolinium salts. TEMPO@PCN-222 exhibits an outstanding catalytic stability and substrate tolerance with a 1-methyl-2-quinolinone yield of 86.7 %, over four times that with PCN-222 (21.4 %). This work provides a new route to construct composite photocatalysts from abundant starting materials for efficient photosynthesis of high value-added chemicals.

Synergistic Effect over Sub-nm Pt Nanocluster@MOFs Significantly Boosts Photo-oxidation of N-alkyl(iso)quinolinium Salts.

Quinolones and isoquinolones are of interest to pharmaceutical industry owing to their potent biological activities. Herein, we first encapsulated sub-nm Pt nanoclusters into Zr-porphyrin frameworks to afford an efficient photocatalyst Pt0.9@PCN-221. This catalyst can dramatically promote electron-hole separation and 1O2 generation to achieve synergistic effect first in the metal-organic framework (MOF) system, leading to the highest activity in photosynthesis of (iso)quinolones in >90.0% yields without any electronic sacrificial agents. Impressively, Pt0.9@PCN-221 was reused 10 times without loss of activity and can catalyze gram-scale synthesis of 1-methyl-5-nitroisoquinolinone at an activity of 175.8 g·gcat-1, 22 times higher than that of PCN-221. Systematic investigations reveal the contribution of synergistic effect of photogenerated electron, photogenerated hole, and 1O2 generation for efficient photo-oxidation, thus highlighting a new strategy to integrate multiple functional components into MOFs to synergistically catalyze complex photoreactions for exploring biologically active heterocyclic molecules.

Development and in vivo/in vitro evaluation of novel herpetrione nanosuspension.

Herpetrione (HPE), is a new compound extracted from Herpetospermum caudigerum, which is proved to be a novel and potent antiviral agent. However, due to poor water solubility, oral bioavailability of the drug was relatively low. To improve the dissolution and absorption of the drug, formulation of HPE as nanosuspension has been performed in this study. HPE nanosuspension were produced by high pressure homogenization and transformed into dry powder by lyophilization. The nanosuspension was then investigated using photon correlation spectroscopy (PCS), zeta potential measurement, SEM and PXRD. To verify the theoretical hypothesis on the benefit of decreased particle size and increased surface area, in vitro dissolution characterization and in vivo pharmacokinetics were investigated. The inhibitory effect on HBsAg, HBeAg, and HBV-DNA of HPE nanosuspension in 2.2.15 cells was studied. Results showed that a narrow size distributed nanosuspension with a mean particle size of 286±1.3 nm, a polydispersity index of 0.18±0.06 and a zeta potential of -26.9±2.4 mV was obtained. The result of PXRD showed that HPE was amorphous state in both coarse powder and nanosuspension. In the in vitro dissolution test, HPE nanosuspension showed an increased dissolution velocity markedly. In the in vivo evaluation, compared to coarse HPE, nanosuspension exhibited significant increase in AUC(0-t), C(max) and decrease in T(max), MRT. The inhibitory effect of HBsAg, HBeAg, and HBV-DNA of 2.2.15 cells treated by HPE nanosuspension were stronger than those of the HPE. The in vitro activity experiments provided evidence for an enhanced efficacy of the HPE nanosuspension formulation compared to HPE coarse suspension. These results revealed that particle size reduction could enhance HPE dissolution rate and absorption in gastrointestinal tract, and nanosuspension might be a good choice for oral delivery of poor bioavailability drug like HPE.

Changes of pharmacokinetics of 6,7-dimethoxycoumarin in a rat model of alpha-naphthylisothiocyanate-induced experimental hepatic injury after Yinchenhao Decoction () treatment.

OBJECTIVE: To study the changes of pharmacokinetics of 6,7-dimethoxycoumarin in a rat model of alpha-naphthylisothiocyanate (ANIT)-induced experimental hepatic injury after oral administration of Yinchenhao Decoction (, YCHD) using an ultra pressure liquid chromatography (UPLC) method. METHODS: Rats were divided into a normal group and a model group, after modeled by 4% ANIT (75 mg/kg) for 48 h, they were orally administrated with YCHD extract at the dose of 0.324 g/kg, and then blood was collected from their orbital sinus after different intervals. Changes in liver function were monitored by the levels of liver enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST)] and bilirubins [total bilirubin (TBIL), direct bilirubin (DBIL)], the concentration of 6,7-dimethoxycoumarin in plasma were measured by UPLC, and the pharmaceutical parameters were calculated with DAS2.1.1 software. RESULTS: The concentration-time curve of both normal and modeled rats after oral administration of YCHD was obtained. Their time to maximum plasma concentration (t(max)) were both 0.25 h, the maximum concentration (C(max)) were 4.533 µg/mL and 6.885 µg/mL, and their area under concentration-time curve (AUC)(0→24h) were 16.272 and 32.981, respectively. There was a 51.88% and 100.46% increase in C(max) and AUC(0-t) (P<0.05), but there showed a 45.52% and 92.93% reduction in clearance of drug and volum of distribution (P<0.05), respectively. CONCLUSIONS: Hepatic injury could significantly influence the pharmacokinetics of 6,7-dimethoxycoumarin after oral administration of YCHD, the absorption and distribution process was accelerated in liver injured rats, but the metabolism and elimination process was slowed. And this may lead to a significant accumulation of 6,7-dimethoxycoumarin in the body.

Comparison of microcalorimetric fingerprint profiles of Lonicerae japonicae Flos and Lonicerae Flos.

To compare the microcalorimetric fingerprint profiles of Lonicerae japonicae Flos (Lj.F) and Lonicerae Flos (L.F), microcalormietry was applied to find the heat change regularity of Bacillus shigae (B. shigae) metabolism affected by Lj.F and L.F (we choose Lonicera macranthoides Hand.-Mazz in this paper) with different concentrations. The thermogenic curves and thermodynamics parameters were investigated as evaluation index, and then the date of experiment was studied by similarity analysis. All the results indicated that the Lj.F and Lonicera macranthoides Hand.-Mazz (L.m.H-M) significantly impacted the microbial growth and had good similarity in its inhibitory activities. The combination approach of chemical analysis with bioassay was developed and employed to ensure the safety and efficacy of Chinese herbal medicines.