MEETING BRIEFS FROM PACIFICHEM '89
New process makes oolvohenvlene sulfide Vanadyl bis(acetonylacetonate) catalyzes oxidative polymerization of diphenyl disulfide to polyphenylene sulfide at 25 °C and 1 atm, accorclng to research assistant Kimihisa Yamamoto of Waseda University, Tokyo. Trifluoromethanesulfonic acid and trifluoroacetic anhydride are needed for acidification, and the reaction consumes atmospheric oxygen. The process is lower in cost than the current reaction of p-dichlorobenzene with sodium sulfide, he says, and offers possibilities of such substituted polymers as the 2-methyl and 2,6-dimethyl resins. Working with research assistant Mitsutosh» Jikei and polymer chemistry professors Hiroyuki Nishide and Eishun Tsuchida, Yamamoto achieved yields of 5000 % based on vanadium. Hypertension compound synthesized A natural substance that is possibly partly responsible for high blood pressure in humans has been synthesized at Peptide Institute of the Protein Research Foundation, Osaka, according to institute director Tetsuo Shiba. This accomplishment may pin down the structure of the substance and open routes to analogs for study. Called digoxinlike immunoreactive substance (DLIS-2), the compound was isolated by others from blood of patients with essential hypertension and its structure partly determined by mass spectrometry. Working with researcher Kaoru Inami, Shiba made a lysophosphatidyteerine containing all cis-5,8,11,14-nonadecatetraenoic acid, whose activity closely resembles that of DLIS-2. LysophosphatkJic acids are 3-glycerophosphoric acids esterified with fatty acids at C-1. Simple method lengthens carbohydrate chains A simple, high-yield technique to convert an aldose to the next higher ketose was sketched by chemical engineering professor Toshihiko Matsumoto of Tokyo Institute of Polytechnics, Kanagawa, Japan. In work with graduate student Tatsuya Enomoto and chemical engineering professor Toshikazu Kurosaki, for example, Matsumoto converted D-arabinose to the diethytthioketal, acetylated this, and freed tetraacetylarabinose with aqueous cadmium carbonate/ mercuric chloride. Reaction of this aldehyde with formaldehyde, catalyzed by 3-ethylbenzothiazolium bromide and triethylamine, gave 3,4,5,6-tetraacetyl-D-fructose, which was hydrolyzed to D-fructose in 88% yield with barium hydroxide solution. The yield of L-fructose from L-arabinose was 78% and of D-sorbose from D-xylose 100%. But the severity of the deacetylation step limited the yield of opsicose from D-ribose to only 34%. Ethanol regenerates NADPH in yeast reductions A way to avoid foul odors and messy frothing of carbon dioxide from u$e of sugars in yeast-mediated reductions of ketones has been devised by chemistry professor Tadashi Kometani of Toyama National College of Technology, Japan. Sugar metabolism regenerates the reduced cofactor 36
January 8, 1990 CAEN
nicotinamide adenine dinucleotide phosphate (NADPH) needed to reduce the ketone. Working with chemistry professor Eitaro Kitatsuji of Toyama and food science professor Ryuichi Matsuno of Kyoto University, Kometani ran reductions in 200 mM aqueous ethanol, whose oxidation in an air atmosphere regenerated NADPH. U.S. workers have previously used oxidation of ethanol by alcohol dehydrogenase and aldehyde dehydrogenase to regenerate NADPH in syntheses with pure, immobilized enzymes. For example, reduction of ethyl acetoacetate at Toyama gave (SH+)-ethyl 3-hydroxybutanoate in 67 % yield and 95 % enantiomeric excess. Modified virus confers immunity in chickens A modified avian leukosis virus (ALV) has been used to create transgenic chickens that are resistant to infection with ALV, according to Lyman Crittenden, a researcher with the USDA's Regional Poultry Research Laboratory, East Lansing, Mich. Crittenden and USDA coworker Donald Salter created a strain of ALV that delivers part of the viral genome to chicken cells without inducing disease. Newly laid eggs are injected with the modified virus, which apparently delivers viral DNA to the chicken embryo DNA. Chicken cells with viral DNA integrated into their DNA produce viral proteins that coat the cells and protect them from penetration by the virus. The offspring of such chickens should inherit the trait, Crittenden says. "Studies in cell culture suggest that this approach can be extended to other retroviruses and to herpes viruses in several species of animals," he notes. Cockroaches identified by gas chromatography There are 45 identified species of the Blatella cockroach, notes David A. Carlson, a research chemist at USDA's laboratory in Gainesville, Fla. They include B. germanica, the well-known household pest, and B. asahinai, an Okinawan native that has recently invaded southwest Florida. In devising pest control strategies, it is important to know which species one is dealing with. Unfortunately, they all look alike to the uninitiated, and even expert taxonomists have difficulty telling them apart. Now, Carlson says, gas chromatography has come to the rescue. GC analyses of the cockroaches' articular hydrocarbons show the composition patterns to be species-specific in both sexes of adults and nymphs, providing positive identification. Dried museum specimens work, and fresh cockroaches give equally good results. Bacteria degrade cellulose, fix nitrogen A large number of newly discovered bacteria are unique in that they can degrade cellulose in plant materials while at the same time fixing nitrogen from the air, according to J. Michael Gould, a biochemist at USDA's Northern Regional Research Center, Peoria, III. With their ability to fix nitrogen (thereby producing ammonia), the bacteria have the potential to "increase the protein content of normally deficient crop by-products such as wheat and rice straw," Gould says,
MEETING BREFS FROM PACIFICHEM '89
making such material more useful as animal feeds. Gould and USDA coworker Lee B. Dexter isolated the bacteria from 17 different sources, ranging from Illinois acorns to Texas ants to Wisconsin bog soil. Of the 194 organisms discovered to date, 30 appear to be new strains or species of the genus Bacillus, while the others fit into no existing classification, Gould says. They apparently have been overlooked in the past because they can both fix nitrogen and degrade cellulose, and most assays look for organisms that can do one or the other.
Analysis of whole samples can lead to errors if a biological material that contains several subunits with different element levels is altered by physiological or pathological factors so that the relative subunit proportions change. In addition, element distribution data can provide valuable information on element metabolism, sites of action, and biological function. Speciation is also important, they say, because biological effects depend on the chemical form in which an element is present in a tissue. ci*\\if\rΙ\χΐ\ΠΓΜΠΡΟ
Surfactants used to detect water pollutants Chemistry professor lasiah M. Warner and coworker Lisa Blyshak at Emory University, Atlanta, are synthesizing surfactants incorporating photochemical constituents that can interact with pollutants in water. According to Warner, the concept may lead to a new, inexpensive method for detecting such pollutants. The surfactant molecules interact with selected organic pollutants dissolved in an organic solvent. The photochemical interaction between the pollutant and the surfactant is measured with a fluorescence detector. The procedure is expected to be particularly useful for detecting such environmentally important compounds as polyaromatic molecules with polar substituents. Warner says that the test, when developed, could provide such selective tests at less than $20 per analysis. New Medfly lure lasts longer Mediterranean fruit flies may someday be fought chemically by daubing telephone poles with a gel containing malathion and Ceralure, a powerful new chemical attractant, according to entomologist Roy T. Cunningham of USDA's Agricultural Research Service. Current practice is to spray infested areas by helicopter with a mixture of malathion and bait. Trimedlure, the lure now used in traps to detect Medfly infestations, doesn't last long enough to use the telephone approach. However, Ceralure, developed by Cunningham and ARS chemist Terrence P. McGovern, remains effective two to four times longer than Trimedlure. If Ceralure in gel can attract flies for at least two weeks, Cunningham says, it may turn out to be a practical, economical option for control. Ceralure's chemical name is ethyl-4(and 5)-iodo-trans-2methylcyclohexanecarboxylate. Elemental analysis of biological subunits Trace element analysis of biological materials should be done not only on whole samples but also in biological subunits such as certain types of cells and subcellular components, according to Dietrich Behne of Hahn-MeitnerInstrtut, West Berlin, and G. Venkatesh Iyengar of the National Institute of Standards & Technology. The researchers explain that trace element concentrations can vary considerably among different types of cells and subcellular units, and elements also can be present in several binding forms.
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A new technique for systematizing odor description terms could lead to a more objective understanding of the odor qualities of chemical compounds, according to Hidetsugu Abe and coworkers at Toyohashi University of Technology, Japan. Abe explains that although visual, tactile, and auditory stimuli can be measured objectively by physical methods, the olfactory and gustatory senses are much more qualitative. In an effort to place odor description on a more quantitative basis, the researchers identified 126 odor terms used to describe 1710 different compounds in a reference work on perfume and flavor chemicals and subjected the terms to cluster analysis. The resulting map of overlap relations among odor descriptors has 19 obvious clusters of odor terms, four of which—defined by the terms fruity, floral, herbaceous, and green—are large sets that subsume most other terms. The group hopes that this line of study eventually will lead to an objective method for discriminating among organic compound odors based on multiple semiconductor gas sensors and pattern recognition analysis. New drinking-water additive standards readied On April 7, a public-private partnership program that sets new standards for drinking-water products will replace the drinking-water additives program currently administered by EPA. Although states are responsible for keeping drinking water safe, most have relied on EPA's list of approved additives. The new standards, explains Michael B. Cook, director of the EPA Office of Drinking Water, were developed in a partnership among EPA, states, water utilities, private testing organizations, and the industries affected. The new standards—known as National Sanitation Foundation (NSF) Standards 60 and 61—cover all types of additive products: direct additives such as disinfectants as well as indirect additives such as substances that would leach or migrate from pipes. NSF, a not-for-profit corporation based in Ann Arbor, Mich., that tests and certifies the safety of products coming into contact with food and drinking water, was the lead group in the consortium. Other members are the Association of State Drinking Water Administrators, the American Water Works Association, and the American Water Works Association Research Foundation. NSF's certification authority is not exclusive, according to Cook, and EPA is willing to work with other potential certifiers, he says. January 8, 1990 C&EN 37
