ties, such as publications, project a better properties of two compounds known as than expected net contribution to ACS DuP 630 and DuP 983. These com reserves. However, the society must take pounds inhibit an enzyme that forms a $13.5 million charge in next year's (lZR)-hydroxyeicosatetrenoic acid ("12budget because of changed accounting R-HETE"). 12-K-HETE is a metabolic regulations on medical insurance for re product of fatty acids that seems to be found only in diseased, inflammed tis tired employees. Ernest Carpentersue. The Searle compound is in phase-II testing (thousands of symptomatic pa tients) for psoriasis in the U.S. and ul From Washington, D.C cerative colitis in Japan. Though the drug is orally effective, only topical for mulations are now being tested—a cream in the U.S. and an enema in Ja pan. The Du Pont Merck compound is Compounds that may offer new hope still undergoing testing on animals, for sufferers from inflammatory diseas and will start clinical testing in 1993. es are being developed at two pharma As Djuric explains, inflammation is ceutical companies. exacerbated by secretion of LTB4 from The new drugs are now undergoing irritated white blood cells called neu testing for psoriasis and ulcerative coli trophils. LTB4 summons other neutro tis. But they attack fundamental pro phils to the site and stimulates the neu cesses of inflammatory disease, and so trophils to release proteolytic enzymes. may also be effective against rheuma SC-41930 binds to receptors on neutro toid arthritis. Research on the com phil surfaces, and prevents them from pounds was described last week by chemists from the two companies at a symposium held by the Division of Medicinal Chemistry at the American Chemical Society national meeting. At an Applied Superconductivity Con Stevan W. Djuric of G. D. Searle & ference in Chicago last week, Dti Pont Co., Skokie, 111., presented data on a scientists reported preparing high-quali compound still known only as SC- ty thin films of thallium-containing su 41930. The compound blocks receptors perconductors in a single deposition of an inflammatory mediating agent step, eliminating the usual second step called leukotriene B4 (LTB4). Djuric de of furnace annealing to bring out the scribed it as the first orally effective material's superconducting properties. agent that has this effect. This is the first time any thallium su R. R. Harris of Du Pont Merck Phar perconductor has been prepared by such maceutical Co., Wilmington, sketched an in-situ process, says Alan Lauder, Du Pont's business program manager for superconductivity. Du Pont says the new capability Imerging drugs target basic promises to improve the fabrication of lisease processes multilayer superconducting films with smoother surfaces and more sophisticat ed functions. This, in turn, could lead to improved components for microwave and electronic devices, including the higher speed computers of the future. Thallium-containing superconductors have sparked great interest, in part be cause bulk samples can operate at tem peratures as high as about 127 Κ—the current record for the superconducting transition temperature (Tc). Such rela tively high temperatures would provide a greater margin of safety (in case of coolant loss) for devices cooled with liq DuP-983 uid nitrogen, which boils at 77 K. How ever, thin films of these thallium-con
New drugs may fight inflammatory diseases
releasing LTB4. Thus, the inflammatory cascade is stopped at the start. Harris notes that production of 12-RHETE in diseased tissue is based on a cytochrome P450 system. Because the most familiar P450 system is that in yeast, Du Pont Merck researchers made great progress in finding inhibitors of 12-RHETE synthesis by studying varying structures of known antifungal drugs. They decided to focus on two agents with similar structures, DuP 630 and DuP 983. All three compounds are chiral, capa ble of existing as two optical isomers. Reflecting the fluid regulatory climate surrounding the effectiveness of specific enantiomers of chiral drugs, Searle is de veloping its compound as a racemate, whereas Du Pont Merck is bringing along its two compounds as single enantiomers. Djuric says the two enantiomers of SC41930 are equal in effect. But Searle has a second-generation LTB4 inhibitor much farther back in its pipeline that it will d e velop as an enantiomer. Stephen Stinson
Thallium superconductor films prepared in situ taining materials have been inherently difficult to produce because of the high volatility of thallium. To avoid this problem, the research ers—Dean W. Face and Joseph P. Nestlerode of Du Ponfs Experimental Sta tion near Wilmington, Del.—grew the superconducting thallium-barium-calci um-copper oxide film at relatively low temperatures of 500 to 600 °C "That's a tremendous improvement—a major ad vance," comments physicist Allen M. Hermann of the University of Colorado, whose group reported the first thallium superconductor in 1988. At the conven tional temperatures used to process su perconducting films (up to 890 °C), the thallium would have evaporated. Lowering the processing temperature, Hermann explains, makes it easier to fabricate device structures consisting of layers of different materials, such as su perconductors and insulators. "High processing temperatures are evil because they degrade the interfaces between su perconductors and other materials," he tells C&EN. Ideally, scientists would like to do this processing at room tempera ture, he adds, but 500 °C is quite reason able. "It allows a lot of flexibility." The process involves simultaneous sputtering of barium, calcium, copper, AUGUST 31,1992 C&EN 11
NEWS OF THE
WEEK
and oxygen atoms onto a substrate in the presence of thallium oxide (T120) vapor. The resulting film of TH3a2CaCu207 begins losing resistance to current—a hallmark of superconductivity—at temperatures as high as about 80 K. The r e searchers find that substituting yttrium atoms for some of the calciums during sputtering can raise the Tc to 97 K. This is exciting, they say, because this Tc is among the highest ever reported for films of any composition grown in such a one step process. A further step of "soaking" the films in an oxygen atmosphere at 700 °C is required to obtain the best superconducting properties, they note. The films have other highly desirable properties, such as being extremely smooth and aligned with the crystal structure of the underlying substrate. "In-situ processing gives you smoother films than any high-temperature postanneal process," Lauder points out. Thin films of other thallium superconductors, such as the composition ^Ba 2 Ca 2 Cu 3 O 10 , with a Tc of 125 K, still must be made via the older two-step process, Lauder adds. But "we are in the process of applying the in-situ process to other [superconducting compositions]." Ron Dagani
Dollar plunge may lift U.S. chemical exports The U.S. chemical industry seems to be reacting calmly, even happily, so far to the dollar's plunge to record lows against the German mark. Over the past year, the dollar has fallen from a value of 1.75 deutsche marks to last Thursday's level of 1.40. Europe an financial markets are described as "roiled," and industry in the U.K.— especially chemicals and autos—is suffering a drop in exports owing to the English pound's ties to the mark. Europe's governments, in fact, are trying to ward off panic in their stock and financial markets. And German industry, at odds with its central bank, is bewailing its sharp drops in exports. But most U.S. chemical firms contacted by C&EN last week anticipate sharp increases in exports to Europe this year, especially if the dollar's weakness persists for more than another six months. They already are benefiting financially by debt refinancing, sale of dollars for marks by European affili12
AUGUST 31,1992 C&EN
ates, and other asset maneuverings—a process known as hedging. 'Translation gains of this sort will be the biggest gains," comments chemical analyst Jeffrey R. Spetalnick of securities firm Oppenheimer & Co. 'In trade," he adds, "high-value-added products will have the most advantage; commodities not so much, because they are based more on supply and demand." But the lower price of feedstocks, priced in dollars, will help commodity makers, he concedes. A financial source at Air Products & Chemicals says U.S. chemicals and the U.S. economy as a whole cannot help but benefit from an extended dollar decline. The impact on the U.S. economy would amount to a slight increase in inflation, higher interest rates, and increased competitiveness of U.S. products. The negative side would be psychological and political, reflecting the U.S.'s inability to manage its economy. And Wall Street would react negatively to a continued dollar decline if investors pull out of stocks denominated in weak dollars. The dollar's plunge is mainly due to actions by Germany's central bank, the Bundesbank, which is trying to stem inflation and cool Germany's economy by imposing high interest rates. High costs of restoration of the former East Germany have heightened pressure on the money supply, and the bank doesn't want such inflationary pressures to get out of hand. Because of high German interest rates—around 10%—dollars are flowing into Germany, thereby losing value and making European exports to the U.S. more expensive. Politics are a factor, too. The goal of economic unification has stabilized major European currencies against the mark, so a rise in the mark also means a rise in the English pound, French franc, and Italian lira, with a resulting negative impact on European industry. "Every country's in a different boat," says Geoffrey Merszei, treasurer for Dow Chemical-Europe. "It's not just the [mark] carrying all the other currencies, but also contradictory national monetary policies. I'm surprised that it had taken this long for the dollar to have declined." Merszei says Dow, by hedging, is benefiting from the situation like every other U.S. company. Companies contacted—Dow, Eastman, Pfizer, Monsanto, Air Products, and Hoechst-Celanese—all concur that the dollar drop is or can be a good thing
for their operations. Bruce Pickover, vice president of chemical industry consultants Chem Systems, says the weak dollar will improve earnings for major petrochemical exporters such as Dow and Du Pont. A Pfizer spokesman agrees that earnings for pharmaceuticals can benefit if the weak dollar continues through the end of the year. Others are a bit more cautious. Eastman Chemical's chief economist, Fred L. Conrad, says the dollar drop will have "negligible impact on earnings because companies generally have contracts running for at least six montlis." Spot sales, though, will benefit, he adds. A Hoechst-Celanese spokesman says the weak dollar will have little impact on earnings. Only about 6% of the company's $6.8 billion in sales worldwide went to Europe. Hoechst-Celanese's imports from its German parent also will have little effect on the company's earnings, although Hoechst-Celanese may pay a little more for those imports as a result of higher costs of raw materials. However, those imports are an even lower percentage of sales than exports. But Eastman's Conrad doesn't think Germany will be able to sustain its high interest levels, because German industry already is being hurt. For example, Bayer last week reported second-quarter earnings down 12% to $662 million. Despite all the turmoil surrounding the weak dollar, it has remained stable against the Canadian dollar. Canada is the U.S.'s biggest chemical trade partner, accounting for 15% of all U.S. chemical exports. Germany accounted for only 4%, and the European Community takes a whopping 26%. The lower dollar, however, isn't expected to nudge the U.S.'s overall chemical trade surplus above last year's figure of $18.8 billion. Allan Lenz, chief economist for the Chemical Manufacturers Association, says first-half 1992 figures project to a $17.7 billion surplus. Last year's figure was ballooned by the Persian Gulf War, which for several months gave U.S. companies a big trade advantage. Lenz says any industrial impact of currency fluctuations is hard to gauge. A lower dollar could spur movement of foreign manufacturing to the U.S., but the U.S. economy overall could be hurt, to the detriment of chemical makers. "We're doing no formal study of this," he says. "There's no model to separate out these various effects." Wil Lepkowski, Marc Reisch
