Microwave-assisted and scandium triflate catalyzed synthesis of tetrahydrobenzo[<Emphasis Type="Italic">a</Emphasis>]xanthen-11-ones

Abstract  

Synthesis of 12-aryl-8,9,10,12-tetrahydro-benzo[a]xanthen-11-ones was achieved by one-pot condensation of β-naphthol, substituted benzaldehydes, and 1,3-dicarbonyl compounds catalyzed by Sc(OTf)₃ under microwave irradiation in excellent isolated yields. The catalyst was recycled up to four cycles with no appreciable loss in catalytic activity. The compounds were evaluated for Src kinase activity and anticancer activity.     

Reversed-phase high performance liquid chromatographic method for the determination of lansoprazole, omeprazole and pantoprazole sodium sesquihydrate in presence of their Acid-induced degradation products

A simple sensitive, selective and accurate reversed-phase high performance liquid chromatographic method was developed and validated for the quantitative determination of lansoprazole, omeprazole and pantoprazole sodium sesquishydrate in the presence of their acid-induced degradation products. The three compounds were monitored at 280 nm using Nova-Pak C(18) column and a mobile phase consisting of 0.05 M potassium dihydrogen phosphate : methanol : acetonitrile (5 : 3 : 2 v/v/v). Linearity ranges were 2-20 mug ml(-1), 2-36 mug ml(-1) and 0.5-20 mug ml(-1) for lansoprazole, omeprazole and pantoprazole, respectively. The corresponding recoveries were 100.61+/-0.84%, 100.50+/-0.80% and 99.78+/-0.88%. The minimum detection limits were 0.55, 0.54 and 0.03 mug ml(-1) for lansoprazole, omeprazole and pantoprazole, respectively. The method could be successfully applied to the determination of pure, laboratory prepared mixtures and pharmaceutical dosage forms. The results obtained were compared with the reported methods for lansoprazole and pantoprazole or the official U.S.P method for omeprazole.     

Chrysosporazines Revisited: Regioisomeric Phenylpropanoid Piperazine P-Glycoprotein Inhibitors from Australian Marine Fish-Derived Fungi

A library of fungi previously recovered from the gastrointestinal tract (GIT) of several fresh, commercially sourced Australian mullet fish was re-profiled for production of a rare class of phenylpropanoid piperazine alkaloids (chrysosporazines) using an integrated platform of; (i) miniaturized 24-well plate cultivation profiling (MATRIX), (ii) UPLC-DAD and UPLC-QTOF-MS/MS (GNPS) chemical profiling, and; (iii) precursor directed biosynthesis to manipulate in situ biosynthetic performance and outputs; to detect two new fungal producers of chrysosporazines. Chemical analysis of an optimized PDA solid phase cultivation of Aspergillus sp. CMB-F661 yielded the new regioisomeric chrysosporazine T (1) and U (2), while precursor directed cultivation amplified production and yielded the very minor new natural products azachrysosporazine T1 (3) and U1 (4), and the new unnatural analogues neochrysosporazine R (5) and S (6). Likewise, chemical analysis of an optimized M1 solid phase cultivation of Spiromastix sp. CMB-F455 lead to the GNPS detection of multiple chrysosporazines and brasiliamides, and the isolation and structure elucidation of chrysosporazine D (7) and brasiliamide A (8). Access to new chrysosporazine regioisomers facilitated structure activity relationship investigations to better define the chrysosporazine P-glycoprotein (P-gp) inhibitory pharmacophore, which is exceptionally potent at reversing doxorubrin resistance in P-gp over expressing colon carcinoma cells (SW600 Ad300).     

First Evidence of Anti-Steatotic Action of Macrotympanain A1, an Amphibian Skin Peptide from Odorrana macrotympana

Many different amphibian skin peptides have been characterized and proven to exert various biological actions, such as wound-healing, immunomodulatory, anti-oxidant, anti-inflammatory and anti-diabetic effects. In this work, the possible anti-steatotic effect of macrotympanain A1 (MA1) (FLPGLECVW), a skin peptide isolated from the Chinese odorous frog Odorrana macrotympana, was investigated. We used a well-established in vitro model of hepatic steatosis, consisting of lipid-loaded rat hepatoma FaO cells. In this model, a 24 h treatment with 10 µg/mL MA1 exerted a significant anti-steatotic action, being able to reduce intracellular triglyceride content. Accordingly, the number and diameter of cytosolic lipid droplets (LDs) were reduced by peptide treatment. The expression of key genes of hepatic lipid metabolism, such as PPARs and PLINs, was measured by real-time qPCR. MA1 counteracted the fatty acid-induced upregulation of PPARγ expression and increased PLIN3 expression, suggesting a role in promoting lipophagy. The present data demonstrate for the first time a direct anti-steatotic effect of a peptide from amphibian skin secretion and pave the way to further studies on the use of amphibian peptides for beneficial actions against metabolic diseases.     

Impacts of external electric fields on the permeation of glycerol and water molecules through aquaglyceroporin-7: molecular dynamics simulation approach

The European Physical Journal E - The current research numerically investigates the Marangoni convection in a cylindrical annulus filled with hybrid nanofluid saturated porous media. The interior...     

On the average degree of some irreducible characters of a finite group

Let G be a finite group and N be a non-trivial normal subgroup of G, such that the average degree of irreducible characters in $\mathrm{Irr}(G|N)$ is less than or equal to 16/5. Then, we prove that N is solvable. Also, we prove the solvability of G, by assuming that the average degree of irreducible characters in $\mathrm{Irr}(G|N)$ is strictly less than 16/5. We show that the bounds are sharp.