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Summary Background: Derivatives of D-glucosamine and D-galactosamine represent an important family of the cell surface glycan components and their fluorinated analogs found use as metabolic inhibitors of complex glycan biosynthesis, or as probes for the study of protein–carbohydrate interactions. This work is focused on the synthesis of acetylated 3-deoxy-3-fluoro, 4-deoxy-4-fluoro and 3,4-dideoxy-3,4-difluoro analogs of D-glucosamine and D-galactosamine via 1,6-anhydrohexopyranose chemistry. Moreover, the cytotoxicity of the target compounds towards selected cancer cells is determined. Results: Introduction of fluorine at C-3 was achieved by the reaction of 1,6-anhydro-2-azido-2-deoxy-4-O-benzyl-β-D-glucopyranose or its 4-fluoro analog with DAST. The retention of configuration in this reaction is discussed. Fluorine at C-4 was installed by the reaction of 1,6:2,3-dianhydro-β-D-talopyranose with DAST, or by fluoridolysis of 1,6:3,4-dianhydro-2-azido-β-D-galactopyranose with KHF2. The amino group was introduced and masked as an azide in the synthesis. The 1-O-deacetylated 3-fluoro and 4-fluoro analogs of acetylated D-galactosamine inhibited proliferation of the human prostate cancer cell line PC-3 more than cisplatin and 5-fluorouracil (IC50 28 ± 3 μM and 54 ± 5 μM, respectively). Conclusion: A complete series of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine is now accessible by 1,6-anhydrohexopyranose chemistry. Intermediate fluorinated 1,6-anhydro-2-azido-hexopyranoses have potential as synthons in oligosaccharide assembly.

The synthesis of 2-bromo[6]helicene was revised and improved up to 51% yield. Its reactivity was thoroughly investigated, and a library of 17 different carbon, boron, nitrogen, phosphorus, oxygen and sulfur substituted derivatives was prepared. The racemization barrier for 2-bromo[6]helicene was determined, and the usage of enantiomers in the synthesis of optically pure helicenes was rationalized. The three most energy-demanding reactions using enantiomerically pure 2-bromo[6]helicene were tested in order to confirm the predicted enantiomeric excess.

Photosynthetic cyanobacteria, heterotrophic bacteria, free-living amoebae, and ciliated protozoa may support growth of Legionella pneumophila. Studies were done with two tap water cultures (WS1 and WS2) containing L. pneumophila and associated microbiota to characterize growth-supporting activity and assess the relative importance of the microbiota in supporting multiplication of L. pneumophila. The water cultures were incubated in the dark at 35°C. The growth-supporting factor(s) was separated from each culture by filtration through 1-jim-pore-size membrane filters. The retentate was then suspended in sterile tap water. Multiplication of L. pneumophila occurred when both the retentate suspension and the filtrate from either culture were inoculated into sterile tap water. L. pneumophila did not multiply in tap water inoculated with only the filtrate, even though filtration did not reduce the concentration of L. pneumophila or heterotrophic bacteria in either culture. Growth-supporting activity of the retentate suspension from WS1 was inactivated at 60°C but unaffected at 0, 25, and 45°C after 30-min incubations. Filtration experiments indicated that the growthsupporting factor(s) in WS1 was 2 to 5 jum in diameter. Ciliated protozoa were not detected in either culture. Hartmannellid amoebae were conclusively demonstrated in WS2 but not in WS1. L. pneumophila multiplied in tap water inoculated with the amoebae (103/ml) and the 1-jim filtrate of WS2. No multiplication occurred in tap water inoculated with the filtrate only. Growth-supporting activity for L. pneumophila may be present in plumbing systems; hartmannellid amoebae appear to be important determinants of multiplication of L. pneumophila in some tap water cultures.

Electrophilic aromatic substitution in the calix[n]arene series is a well-established procedure leading exclusively to para-substituted derivatives. An unprecedented regioselectivity of the mercuration reaction leading to the meta-substituted calix[4]arenes is described. These compounds represent a new type of substitution pattern in classical calixarene chemistry and open the door for the straightforward synthesis of inherently chiral receptors based on calixarenes.

Grape cane, leaves and grape marc are waste products from viticulture, which can be used to obtain secondary stilbene derivatives with high antioxidant value. The presented work compares several extraction methods: maceration at laboratory temperature, extraction at elevated temperature, fluidized-bed extraction, Soxhlet extraction, microwave-assisted extraction, and accelerated solvent extraction. To obtain trans-resveratrol, trans-ε-viniferin and r2-viniferin from grape cane of the V. vinifera variety Cabernet Moravia, various conditions were studied: different solvents, using powdered versus cut cane material, different extraction times, and one-step or multiple extractions. The largest concentrations found were 6030 ± 680 µg/g dry weight (d.w.) for trans-resveratrol, 2260 ± 90 µg/g d.w. for trans-ε-viniferin, and 510 ± 40 µg/g d.w. for r2-viniferin. The highest amounts of stilbenes (8500 ± 1100 µg/g d.w.) were obtained using accelerated solvent extraction in methanol.

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A dairy farm, sewage plant, and backwash water were among sources of protozoa in the raw water treated by the Pittsburgh, Pa., water utility. Giardia and Cryptosporidium were monitored monthly for two years to determine their occurrence in the Allegheny and Youghiogheny rivers, their source, and the efficiency of their removal by the Pittsburgh Drinking Water Treatment Plant. Sources investigated included a dairy farm stream, treated effluent from a sewage plant, and several samples from combined sewer overflows, all of which regularly contribute parasites to rivers. Raw, settled, filtered, and filter backwash waters were also sampled. Clarification and filtration generally control passage of protozoa into the drinking water, but small numbers of Cryptosporidium occasionally pass through even in the absence of treatment difficulties. Cysts and oocysts are also reintroduced into the drinking water plant via recycling of backwash water.