[Study on patterns and characteristics of in vivo tissue distribution of anti-inflammatory extract of Tetrastigma hemsleyanum aerial part in healthy and inflammatory pathological model rats]

The concentrations of seven anti-inflammatory components in blood and tissues were determined by UPLC-MS/MS after oral administration of Tetrastigma hemsleyanum aerial part(THAA) in healthy and inflammatory pathological model rats. The determination was carried out by using positive and negative ion switching technique, and multiple reaction monitoring(MRM) mode. The tissue distributions of the seven components in different physiological states were compared, and the patterns and characteristics of the effective components of THAA were studied. The results revealed that the seven effective components have large drug-time-curve areas(AUC) in heart, brain, small intestine, and stomach in both normal rats and inflammatory pathological model rats. This suggests that the anti-inflammatory effective component groups in THAA extract can all penetrate the blood-brain barrier, and have a large distribution area in gastrointestinal tract. It is inferred that gastrointestinal reabsorption may be one of the causes of the bimodal distribution of the drug-time curve of the drug blood distribution graph. As compared to normal rats, the effective component groups in THAA extract have higher drug-time curve area(AUC) in heart, brain, small intestine, stomach, liver, spleen, lung, kidney, and muscle of inflammatory pathological model rats. Among them, the effective component groups have the largest distribution area in heart, brain, small intestine, and stomach. This suggests that the binding force of organ tissues and drugs in the body may change under pathological conditions. It is speculated that the heart, brain, small intestine, and stomach may be the target tissues of THAA to produce anti-inflammatory effect. The retention times of THAA effective component groups in various organ tissues of rats in different physiological states are all relatively short, and do not have much difference. This suggests that no effective component accumulates in body, and that the pathological state of inflammation does not affect the onset times of the effective component groups. This experiment elucidates the patterns and characteristics of the in vivo target-effecting tissue distribution of THAA anti-inflammatory extract, and provides an experimental basis for clinical treatment.

Preparation of Sulfamates and Sulfamides Using a Selective Sulfamoylation Agent

Sulfamates and sulfamides are prevalent in biological molecules, but their universal synthetic methods are limited. We herein report a sulfamoylation agent with high solubility and shelf stability. Various sulfamates and sulfamides can be synthesized directly from alcohols or amines by employing this agent with high selectivity and high yields. This protocol was also successfully used for late-stage sulfamoylation of pharmaceuticals containing a hydroxyl or amino group.

Non-transition Metal-Mediated Diverse Aryl-Heteroatom Bond Formation of Arylammonium Salts

Aryl–heteroatom (C–X) bonds ubiquitously exist in organic, medicinal, and material chemistry, but a universal method to construct diverse C–X bonds is lacking. Here we report our discovery of a convenient and efficient approach to construct various C–X bonds using arylammonium salts as the substrate via an S_NAr process. This strategy features mild reaction condition, no request of transition metal catalyst, and easy formation of various C–X bonds (C–S, C–Si, C–Sn, C–Ge, C–Se, C–N). The method was successfully applied to a late-stage functionalization of an existing antibiotic drug, to a Clickable reaction of NBD-based ammonium salt as turn-on fluorescent probe to recognize L-cysteine and homocysteine, and to the synthesis of a DNA encoded library (DEL) bearing different C–X bonds.

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An efficient approach to construct various C–heteroatom bonds

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Readily accessible ammonium salts as substrates

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No request of transition metal catalyst and broad functional group compatibility

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Great applicability in late-stage functionalization, fluorescent probe, and DEL

Design and Synthesis of Sulfonamide-1,2,3-Triazole Derivatives Bearing a Dithiocarbamate Moiety as Antiproliferative Agents

A series of nine novel 1-(4′-sulfamoylphenyl)-1,2,3-triazole derivatives bearing a 4-dithiocarbamylmethyl moiety were designed using the molecular hybridisation approach and synthesised by alkyne/azide click chemistry. Most of the synthesised compounds exhibited moderate to good antiproliferative activity against oesophagus, gastric and prostate cancer cell lines, but a compound containing a 4-( t-butoxycarbonyl)piperazinylthiocarbonyl moiety showed the highest activity. Against a prostate cancer cell line, it had an IC50 value of 2.4 μM, about 10-fold more active than 5-flurouracil. This work shows that novel sulfonamide-1,2,3-triazole derivatives bearing a dithiocarbamate moiety linked to a 4-substituted piperazine are promising lead compounds for the development of antitumour agents.

Synthesis of a novel PEG-block-poly(aspartic acid-stat-phenylalanine) copolymer shows potential for formation of a micellar drug carrier

A novel functionalised copolymer with three polymeric components, poly(ethylene glycol)-block-poly(aspartic acid-stat-phenylalanine), PEG-P(asp-phe), was synthesised and investigated for its potential to form micelles via ionic interactions with a model water-soluble drug, diminazene aceturate. Drug-free solutions of structurally related PEG-P(asp-phe) 5:6:4 and PEG-P(asp-phe) 5:4:6 copolymers indicated polymeric aggregation into micellar-type constructs. The size of PEG-P(asp-phe) 5:6:4 micelles was found to be pH and drug content-dependent. The drug-loaded systems existed as discreet units and were fairly uniform in size and shape. More drug could be included in the PEG-P(asp-phe) 5:6:4 micelles as compared to if only interaction with carboxyl groups from aspartic acid units was responsible for micelle formation, indicating the augmentative role of phenylalanine moieties in drug-incorporation. The slower in vitro drug release from PEG-P(asp-phe) 5:6:4 micelles as compared to PEG-Pasp (AB) micelles indicated the role of the phenylalanine moiety in controlling drug release. This study, therefore, confirmed the potential of a novel tri-component copolymer structure, PEG-P(asp-phe), for the formation of polyionic micelles for drug delivery.

Optimization of preparative conditions for poly-DL-lactide- polyethylene glycol microspheres with entrapped Vibrio cholera antigens

Poly-dl-lactide-polyethylene glycol (PELA) with different contents of polyethylene glycol(PEG) were synthesized and the PEG content was estimated according to the integral height of hydrogen shown in 1H-NMR. PELA microspheres containing V. cholera antigen, outer membrane protein (OMP) were prepared by a water-in-oil-in-water (W/O/W) based on solvent evaporation procedure. Antigen microspheres with smooth surface, suitable size for oral administration (0.5-5 microm), high loading efficiency (about 60%) and low level of residual solvent (lower than 20ppm) were obtained. Microspheres prepared from PELA with PEG content of about 10% achieved the highest loading efficiency among PELA copolymers and poly-dl-lactide (PLA) homopolymer, which suggested that microspheres size, morphology and the precipitation rate of polymer showed considerable relations with OMP loading efficiency. The regulation of the solvent components of the oil phase contributes to a stable emulsion W/O, and it is concluded that the stable emulsion W/O plays a significant role in improving the protein loading efficiency of obtained microspheres. The addition of stabilizer, such as gelatin and polyvinyl alcohol, into the internal water phase before emulsification produced no significant difference in OMP entrapment and microspheres size. A higher OMP loading efficiency was achieved by adding NaCl or adjusting the pH at the iso-electric point of OMP in the external water phase. It was indicated in vitro that PELA microspheres with smaller size showed larger extent of initial release and higher release rate, whereas microspheres with the diameter of 2.17 microm showed no apparent burst effect.