Onion waste is a renewable raw material, rich in different molecular species of the antioxidant quercetin. To utilize this resource, an environmentally sustainable procedure has been developed, using pressurized hot water to extract the quercetin species, followed by biocatalytic conversion of the quercetin glycosides to quercetin and carbohydrates. Two different recombinantly expressed thermostable b-glucosidases, Thermotoga neapolitana b-glucosidase A and B, were utilized as catalysts. These enzymes maintain activity at temperatures around 90 uC, and are therefore ideal to use in combination with hot water extraction. Our results, based on experimental design, showed that they converted quercetin glycosides to active quercetin in less than 10 min reaction time in water at 90 uC, pH 5.0. Experimental design showed that the optimal extraction conditions included three 5 min extraction cycles with water at 120 uC and 50 bars, giving a total extraction time of 15 min. Several different types of quercetin and isorhamnetin glycosides as well as kaempferol were detected in onion waste using LC-MS/MS analysis. After converting the different glycosidic compounds to their respective aglycones, the quercetin content was 10 to 50 mg g 21 dry weight of onion waste (RSD 8%). In summary, our research demonstrates that subcritical water extraction followed by b-glucosidase-catalyzed hydrolysis is a rapid method to determine the content of quercetin and isorhamnetin in onion samples, and is environmentally sustainable as it only uses water as solvent and enzymes as catalysts.

In a population-based case-control study carried out in Sweden in 1982-1984, the authors examined the association of pancreatic cancer with several dietary factors, coffee, alcohol, and tobacco. Analyses were based on 99 cases, 138 population controls, and 163 hospital controls. The cases were persons aged 40-79 years diagnosed with cancer of the exocrine pancreas at three surgical departments in Stockholm and Uppsala. The risk increased with higher consumption frequency of fried and grilled meat in the comparison with each series of controls (e.g., relative risk (RR) = 1.7 (90% confidence interval (CI) = 1.1-2.7) for weekly intake and RR = 13.4 (90% CI = 2.4-74.7) for almost daily intake, in the comparison with population controls). Furthermore, associations were found with other fried or grilled foods, but not with meat other than fried or grilled. The risk also increased with the intake of margarine (e.g., RR = 9.7 (90% CI = 3.1-30.2) for 15+ g of margarine on a slice of bread, in the comparison with population controls). In contrast, no excess risk was associated with high intake of butter. A low risk was associated with frequent consumption of fruits and vegetables, particularly carrots (RR = 0.3 (90% CI = 0.2-0.7)) and citrus fruits (RR = 0.5 (90% CI = 0.3-0.9)) for almost daily intake. No consistent associations were found with coffee, artificial sweeteners or alcohol consumption, but a threefold increase in risk was associated with smoking at least one pack of cigarettes per day.

Small interfering RNA (siRNA) is a highly potent drug in gene-based therapy with a challenge of being delivered in a sustained manner. Nanoparticle drug delivery systems allow for incorporating and controlled release of therapeutic payloads. We demonstrate that solid lipid nanoparticles can incorporate and provide sustained release of siRNA. Tristearin solid lipid nanoparticles, made by nanoprecipitation, were loaded with siRNA (4.4–5.5 weight percent loading ratio) using a hydrophobic ion pairing approach that employs the cationic lipid DOTAP. Intradermal injection of these nanocarriers in mouse footpads resulted in prolonged siRNA release over a period of 10–13 days. In vitro cell studies showed that the released siRNA retained its activity. Nanoparticles developed in this study offer an alternative approach to polymeric nanoparticles for encapsulation and sustained delivery of siRNA with the advantage of being prepared from physiologically well-tolerated materials.

Nucleophilic substitution reactions were performed in H2O/CO2 (w/c) microemulsions formed with an anionic perfluoropolyether ammonium carboxylate (PFPE COO-NH4 +) surfactant. These reactions between hydrophilic nucleophiles and hydrophobic substrates were accomplished in an environmentally benign microemulsion without requiring toxic organic solvents or phase transfer catalysts. For the synthesis of benzyl bromide from benzyl chloride and KBr, the yield was an order of magnitude higher in w/c microemulsions versus conventional water-in-oil (w/o) microemulsions. Benzoyl chloride and p-nitrophenyl chloroformate were hydrolyzed in w/c microemulsions with rate constants an order of magnitude faster than those in w/o microemulsions.

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The synthetic reaction between a hydrophobe, benzyl chloride, and a hydrophilic nucleophile, KBr, is reported in water-in-carbon dioxide (w/c) and carbon dioxide-in-water (c/w) emulsions. Emulsions containing equal amounts of water and CO2 were formed with both anionic perfluoropolyether ammonium carboxylate (PFPE COO-NH4 +) and nonionic poly(dimethylsiloxane)-g-poly(ethylene oxide) and poly(butylene oxide)-b-poly(ethylene oxide) surfactants, without the need for any added cosolvent. Higher yields of benzyl bromide were obtained in w/c and c/w emulsions (41−47%) as compared to water-in-octane emulsions (33%). Yields were much higher than in a previous study of the same reaction in a w/c microemulsion (Jacobson et al. J. Org. Chem., following paper in this issue), since the much larger amount of water in the emulsion allowed for a greater excess of KBr.

Please release me: Supercritical carbon dioxide was used as an antisolvent for the formation of nanoparticles that contain luciferin, a bioactive therapeutic, dispersed in poly(lactic acid) (PLA), a biodegradable polymer. These nanoparticles undergo slow and sustained drug release, which can be monitored by bioluminescence both in vitro and in vivo (see picture; ATP=adenosine triphosphate; ADP=adenosine diphosphate; Pi=inorganic phosphate).

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