Photoexcitation of (diarylmethylene)amino benziodoxolones for alkylamination of styrene derivatives with carboxylic acids.

The alkylamination of alkenes using pristine carboxylic acids was achieved by the photoexcitation of (diarylmethylene)amino benziodoxolones (DABXs), which serve as both an oxidant and an aminating reagent (an iminyl radical precursor). The developed method is a simple photochemical reaction without the need for external photosensitizers and shows a broad substrate scope for aliphatic carboxylic acids leading to the formation of primary, secondary, and tertiary alkyl radicals, thus enabling the facile synthesis of various structurally complex amines. Mechanistic investigations including transient absorption spectroscopy measurements using a laser flash photolysis (LFP) method disclosed the unique photochemical reactivity of DABXs, which undergoes homolysis of their I-N bonds to give an iminyl radical and ortho-iodobenzoyloxy radical, the latter of which participates in the single-electron oxidation of carboxylates.

Self Nanoelmusifying Drug Delivery of Rosuvastatin: Bioavailability evaluation and in vitro - in vivo correlation.

BACKGROUND: Rosuvastatin, most commonly used in the form of calcium salt, belongs to the statin groups of synthetic antihyperlipidemic agents. Rosuvastatin possesses high permeability, however, its aqueous solubility is poor, causing a slow dissolution rate in water. Consequently, this dissolution rate has a decisive role in the release and absorption of rosuvastatin in the gastrointestinal tube. OBJECTIVE: The aims of this study were to evaluate the absorption of the drug from the self-nano emulsifying drug delivery system of rosuvastatin (Ros SNEDDS) compared to rosuvastatin substance and to develop a level-A in vitro-in vivo correlation (IVIVC) for Ros SNEDDS. METHOD: An in-house developed LC-MS/MS method was used to determine the concentrations of rosuvastatin in dog plasma. Six beagle dogs received an intravenous dose, Ros SNEDDS, rosuvastatin substance. In vitro dissolution of the Ros SNEDDS was carried out with different conditions. Correlation models were developed from the dissolution and absorption results of Ros SNEDDS. RESULTS: The results showed a 1.7-fold enhanced oral bioavailability and 2.1-time increase of rosuvastatin Cmax in Ros SNEDDS form, compared to the rosuvastatin substance. A 900 ml dissolution medium of pH of 6.6 has demonstrated its suitability, the in vitro dissolution model was studied and supported by the Weibull equation with a weighting factor of 1/y2 as it presented the lowest values of AIC. CONCLUSION: Ros SNEDDS demonstrated higher bioavailability of rosuvastatin in comparison to rosuvastatin substance and established a level A IVIVC used in future bioequivalence trials.

Tris(4'-Nitrobiphenyl)amine─An Octupolar Chromophore with High Two-Photon Absorption Cross-Section and Its Application for Uncaging of Calcium Ions in the Near-Infrared Region.

Compounds with high two-photon absorption (2PA) performance in the near-infrared region have attracted great attention because of their application in the material and biological science. In this study, we have developed a simple and novel octupolar chromophore, tris(4'-nitrobiphenyl)amine 1, with three nitro peripheral groups attached to a triphenylamine core via biphenyl linkers. A mono-branched analogue 2 has also been prepared to investigate the effects of octupolar and dipolar systems on photophysical and 2PA behaviors. Compound 1, despite having a much simpler structure than the previous three-branched scaffolds, exhibits comparable σ2 values, reaching 1330 GM at 730 nm and 900 GM at 820 nm in toluene. Combined with an outstanding σ2/MW ratio (2.2 GM g-1 mol) and a high fluorescence quantum yield (0.51), 1 displays potential as a promising two-photon (2P) probe for bioimaging. Subsequently, the ethylene glycol tetraacetic acid-substituted derivatives featuring octupolar (3 and 5) or dipolar (4 and 6) character have been synthesized and their one-photon (1P) and 2P photochemical reactions have been examined. Finally, 1P- and 2P-triggered uncaging of Ca2+ from these calcium chelators has been confirmed.

Berberine-loaded liposomes for oral delivery: Preparation, physicochemical characterization and in-vivo evaluation in an endogenous hyperlipidemic animal model.

Berberine (BBR) is a plant-origin quaternary isoquinoline alkaloid presenting exogenous cholesterol lowering and anti-hyperlipidemia therapeutic effects. The aim of this study was to design and generate BBR-loaded proliposomes (PLs) as solid templates for high-dose liposomes and consequently, to enhance the oral bioavailability and therapeutic effect of BBR. An air-suspension coating (layering) method was used for generating BBR-loaded PLs. The size, distribution size, morphology, and entrapment efficiency (EE) of the final reconstituted liposomes were assessed. The oral bioavailability and endogenous cholesterol lowering effects of BBR loaded in liposomes were investigated in rats and mice, respectively. The BBR-loaded PLs showed a smooth BBR-embedded film around micron-scale carrier particles (mannitol). The reconstituted BBR-loaded liposomes had a nano-scale average size (116.6 ± 5.8 nm), narrow size distribution (polydispersity index, PDI 0.269 ± 0.038), and high EE (87.8 ± 1.0%). The oral bioavailability of reconstituted BBR-loaded liposomes at a dose of 100 mg/kg in rats was increased even 628% compared to that obtained with pure BBR (according to 90% confidence interval). The BBR-loaded liposomes at the daily oral dose 100 mg/kg in P-407- reduced total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C) in hyperlipidemic mice by 15.8%, 38.2%, and 57.0%, respectively.