rescent signalfromglucosamine but avoids any signals from glucose or ammonium centers in amino acids or simple amines that might be present in a biosystem." British chemists have developed a selecSelwayan Saini, lecturer in physical tive sensor for D-glucosamine, an amino chemistry and sensors at Cranfield Universugar that stimulates collagen and carti- sity, England, comments that the work is lage production in the body and im- particularly significant because two chemproves joint function. ically different sites are required to enhance "Glucosamine has attracted a lot of at- the fluorescent signal. "This moleculartention as a therapeutic aid for arthritis," based recognition approach can be likened says codeveloper Tony D. James, Royal So- to a chemical-based logic gate where two ciety Research Fellow at the University of different chemical inputs are required to Birmingham, England. "As far as I am elicit a sensor response," he says. aware, this is thefirstglucosamine sensor. Cooper and James suggest that their The system works in an aqueous system at fluorescent photoinduced electron-transneutral pH, which is important if the sen- fer system can be used with other bindsor is to be used to detect glucosamine ing sites to design new and selective molevels in blood or tissue samples." lecular receptors for important biological James and graduate student Christo- molecules. pher R. Cooper synthesized a sensor mol"I cannot see, in principle, why the ecule based onfluorescentphotoinduced approach should not be applied further electron transfer. An anthracene unit acts afield," says Saini. "More elaborate strucas thefluorophoreand an azacrown ether tures should be constructible and, with unit and a boronic acid unit as the recep- better understanding of the underlying tor (Chem. Commun., 1997,1419). chemistry, should result in a gradual evoWhen light is shone on the sensor lution in this new approach." molecule, lone-pair electrons on both niMichael Freemantle trogen atoms transfer to the anthracene unit, reducing thefluorescenceintensity. In the presence of D-glucosamine hydrochloride, however, the azacrown ether and boronic acid bind the ammonium terminal and diol parts of the amino sugar, respectively. The dual binding suppresses photoinduced electron transfer and enhances fluorescence. There was something for both sides when The sensor "gives a very high level of the U.K. High Court handed down its offiselectivity over other species present," cial decision last week on Union Carbide's says A. Prasanna de Silva, chemistry profes- charge that BP Chemicals had infringed its sor at the Queen's University of Belfast, Unipol polyethylene process patent. Northern Ireland. "It picks out the fluoTwo major points were decided by the High Court. First, that Union Carbide's patent covering condensation-mode technology for producing polyethylene is valSensor has azacrown id. And second, that BP Chemicals' highether and boronic acid productivity Innovene polyethylene proreceptor units cess does not infringe Carbide's patent. The ruling allows the two technologies to compete on their merits for the lucrative polyethylene licensing business. At stake for both Carbide and BP Chemicals is a licensing business that is big and growing. BP Chemicals, for example, has licensees with a combined manufacturing capacity of slightly more than 7.7 billion lb per year of polyethylene. By one estimate, Caifoide—through its Univation Technologies licensing joint venture with Exxon—and BP Chemicals have about one-third of the licensing market each. Other international competitors, including Borealis, DSM, Montell, Nova, Lyon-
Fluorescent sensor detects glucosamine
Carbide versus BP: U.K. court settles patent battle
dell, and Targor (a joint venture of BASF and Hoechst), share the remaining third. The court decision—the first actual court test of its 1985 Unipol process patent for polyethylene and polypropylene—means that "Carbide's patent position in condensing mode has been established beyond question," says Roger Staub, chairman of Univation. With its patent judged valid, Carbide will be able to claim damages against BP Chemicals. The British company, which argued that the patent was not valid because of the strength of the prior art, never contested the assertion that it had infringed the patent in the process it used at its plant at Grangemouth, Scotland, from 1990 to 1995. However, BP Chemicals retrofitted the Grangemouth plant in 1995 as a showcase for its new Innovene high-productivity process. Since then, the company has put all its marketing muscle into efforts to license that technology. So for BP Chemicals, the ruling dispels a cloud that had hung over its high-productivity process, which received a U.S. patent in July 1996. Dow Chemical—BP Chemicals' licensing partner—"was very happy to hear this outcome," says Martin Howard, BP Chemicals' head of licensing. Patricia Layman
Tax relief, balanced budget deal done There was jubilation and much self-congratulation in Washington, D.C., last week, as the Administration and Congress after months of negotiations finally reached agreement on a package of budget savings and corporate and individual tax relief designed to lead to a balanced federal budget by 2002. For the U.S. chemical industry, what isn't in the package may be almost as important as what is. President Bill Clinton said he was "particularly pleased that the first balanced budget in a generation is also the best education budget in a generation and the best for future generations." He pointed out that the budget includes $35 billion in tax relief to help families pay for college. The agreement extends for 12 months to June 30,1998, the tax credit companies can take, under certain circumstances, for increasing their R&D expenditures. Extended as well is an alternative method for calculating the credit, which the Chemical Manufacturers Association (CMA) was inAUGUST 4, 1997 C&EN 11
