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
