NEWS
Golay Award Nominations Sought
Prehistoric Gene
Nominations are being sought from the chromatographic community for the 1991 M.J.E. Golay Award. The award, consisting of a medal, a scroll, and an endowment, is presented annually to a scientist or scientists who made significant contributions to the evolution of capillary chromatography. The 1991 award, sponsored by Perkin-Elmer, will be presented at next year's International Symposium on Capillary Chromatography to be held May 13-16 in Riva del Garda, Italy. Five copies of the nominating documents discussing specific achievements should be sent to C. A. Cramers, Eindhoven University of Technology, Laboratory Instrumental Analysis, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; (31) 40-479-111 or fax: (31) 40-442-576. Deadline is October 1.
A team of scientists led by botantist Michael Clegg, University of California at Riverside, has succeeded in making copies of and sequencing a plant gene from a DNA segment determined to be at least 17 million years old. The DNA was taken from a preserved magnolia leaf found in clay sediments that once were the bed of an ancient lake. A comparison with modern magnolia tree genes indicates that this gene averages one mutation every 1 million years. The leaf sample was found in what is called the Miocene Clarkia deposit, located in the St. Maries River Valley of northern Idaho. Radioisotope dating has determined that the age of the deposit is between 17 million and 20 million years. Embedded in the sediment are the remains of plants, insects, and fish—all preserved under cold, anaerobic conditions. The scientists managed to collect and amplify, via the polymerase chain reaction, a 4.2-kb double-stranded DNA fragment containing the chloroplast plant gene rfecL. This gene encodes the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase. Because rbcL· is not found in fungi or bacteria, the gene is not a contamination product. A comparison with sequences of the same chloroplast gene from contemporary species of magnolia trees yielded the average mutation rate. "The next major question," says Clegg, "is how often can we find materials in such a good state of preservation? If we can find it, this research could open a whole new field of molecular paleontology."
Sunny Developments Two recent announcements have advanced research aimed at exploiting sunlight for energy. Researchers with Kopin Corporation in Taunton, MA, have fabricated a thin-film GaAs solar cell submodule for converting sunlight to electricity. The cell operates at a confirmed record efficiency of 21%. Meanwhile, chemists at Arizona State University have announced the synthesis of a photosynthesis-mimicking molecular assembly with a quantum yield of 0.83. The solar cell, funded through the Solar Energy Research Institute, consists of a 5-Mm-thick crystalline GaAs layer bonded to a cover glass. A thin-film cell offers the advantage of low material consumption while retaining the efficiency of crystalline semiconductors. Kopin has produced experimental submodules of the cell measuring 16 cm 2 , which at this high efficiency generate 0.32 kW of electrical power delivered at 3.4 V. Arizona State's photosynthetic molecule was created by a team of chemists led by Devens Gust, Thomas Moore, and Ana Moore. They refer to their product as a pentad molecule, indicating the five "pieces" of the chain. As shown in the figure below, from left to right, the molecule strings together a carotenoid polyene, a Zn porphyrin, a free-base porphyrin, and a two-quinone molecule. Excitation of the molecule in chloroform at 650 nm triggers a series of events that send an electron to the end quinone and the positive charge to the carotenoid. When the charges are physically separated, the excited molecule has a lifetime of 55 ms. A similar separating of charges occurs in photosynthetic chloroplasts. Adds Thomas Moore, "[These molecules] may be better suited for driving cbemical reactions than for producing electricity."
For Your Information Iota Sigma Pi, the national honor society for women chemists, has chosen electrochemist Janet Osteryoung of the State University of New York at Buffalo to receive this year's National Honorary Membership. She will receive the award June 16 at the sorority's national convention in Chicago.
ANALYTICAL CHEMISTRY, VOL. 62, NO. 11, JUNE 1, 1990 · 627 A
