Imprinted [G-3]8-T(3,5-OHPh)P (6)To a solution of 102 mg (9.88mmol) of 5 dissolved in 15 ml of THF, was added 10 ml of2.5 M aqueous KOH. The reaction mixture was stirred vigorously at reflux until thereaction was complete by TLC. The reaction was stopped by removing the THF underreduced pressure. The resulting aqueous layer was extracted with CHCl3(3 £ 25 ml). Thecombined organic layers were washed with 1 M aqueous HCl and water, and concentratedunder reduced pressure. The product was dried under vacuum to afford 41.5 mg (43%) of6 as a beige powder:1H NMRd7.23 (bs, 16H), 6.51 (bs, 152H), 5.86 (bs, ,4H), 5.60 (bs,,60H), 5.12 (bs, ,8H), 4.86 (bs, 96H), 3.92 (bs, 128H), 2.45 (bs, 128H); MS (MALDI–TOF) m/z 9,710.8 ðM þNaþ2 31C2H42 C44H14N4Þ; 9,756.0 ðM þKþ2 30C2H42C44H14N4Þ; 9,779.8 ðM þKþ2 29C2H42 C44H14N4Þ; 9,810.7 ðM þKþ2 28C2H42C44H14N4Þ: Analysis: calculated for C588H600O128: C, 72.70; H, 6.22; N, 0.00; Ru, 0.00.Found: C, 70.83; H, 6.19; N, 0.00; Ru, 0.00.Received 28 February; accepted 28 May 2002; doi:10.1038/nature00877.1. Wulff, G. & Sarhan, A. The use of polymers with enzyme-analogous structures for the resolution ofracemates. Angew. Chem. Int. Edn Engl. 11, 341–343 (1972).2. Shea, K. J. Molecular imprinting of synthetic network polymers: the de novo synthesis ofmacromolecular binding and catalytic sites. Trends Polym. Sci. 2, 166–173 (1994).3. Andersson, L., Sellergren, B. & Mosbach, K. 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This work wasfunded by the NIH and the US Army Research Office. I.Z. thanks the Arnold and MabelBeckman Foundation for a Beckman fellowship.Competing interests statementThe authors declare that they have no competing financial interests.Correspondence and requests for materials should be addressed to S.C.Z.(e-mail: [email protected])...............................................................Tungsten isotope evidence from,3.8-Gyr metamorphosed sedimentsfor early meteorite bombardmentof the EarthRonny Schoenberg*, Balz S. Kamber*, Kenneth D. Collerson*& Stephen Moorbath†* Advanced Centre for Queensland University Research Excellence (ACQUIRE),The University of Queensland, St Lucia, Queensland 4072, Australia† Department of Earth Sciences, University of Oxford, Parks Road,Oxford OX1 3PR, UK.............................................................................................................................................................................The ‘Late Heavy Bombardment’ was a phase in the impact historyof the Moon that occurred 3.8–4.0 Gyr ago, when the
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