Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon (14C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable 14C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the 14C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2′-OHBDE68, 2′,6-diOH-BDE159, and a recently identified compound, 2′-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C12H22O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds.
Although salt formation is the most ubiquitous and effective method of increasing the solubility and dissolution rates of acidic and basic drugs, it consumes large quantities of organic solvents and is a batch process. Herein, we show that the dissolution rate of indomethacin (a poorly water-soluble drug) can be increased by using hot melt extrusion of a 1:1 (mol/mol) indomethacin:tromethamine mixture to form a highly crystalline salt, the physicochemical properties of which are investigated in detail. Specifically, pH-solubility studies demonstrated that this salt exhibited a maximal solubility of 19.34 mg/mL (>1000 times that of pure indomethacin) at pH 8.19. A solvent evaporation technique was also used for salt formation. Spectroscopic analyses (infrared, nuclear magnetic resonance) of both; demonstrated, in situ salt formation with proton transfer. Powder X-ray diffraction and differential scanning calorimetry confirmed the crystalline nature of salts formed by both methods. Even though a number of amorphous salts of acidic drugs have been reported, the formation of a crystalline salt of an acidic drug by hot melt extrusion is completely unprecedented, which makes this study an important benchmark for the pharmaceutical production industry.
Promising cytotoxic effects of several Gardenia species (Rubiaceae) have been established by many studies. The current study evaluated MTT-based cytotoxic activities of the crude extract from Gardenia thunbergia L. f. aerial parts and four fractions thereof, including nhexane, dichloromethane (DCM), ethyl acetate, and aqueous, against human leukemia (HL-60) and hepatoma (HepG2) cell lines, as well as the normal (WI38) cell line. Both non-polar fractions, n-hexane and dichloromethane, showed tumor-selective toxicities against both tested cancerous cell lines. These results sparked our interest in chemically characterising these bioactive fractions to reveal their cytotoxic components. The composition of n-hexane-soluble fraction was investigated via GC-MS analysis, while column chromatographic separation was used to isolate the components of DCM-soluble fraction. These isolated phytochemicals were identified via spectroscopic analyses. Besides, the chemotaxonomic value of the detected phytochemicals and their reported cytotoxic profiles were discussed.
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