David Berkowitz

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Etoposide is one of the most successful chemotherapeutic agents used for the treatment of human cancers. The drug kills cells by inhibiting the ability of topoisomerase II to ligate nucleic acids that it cleaves during the double-stranded DNA passage reaction. Etoposide is composed of a polycyclic ring system (rings A-D), a glycosidic moiety at the C4(More)
Addresses the socialization process among marketing doctoral students. Four modes of doctoral student socialization are provided from depth interviews conducted with 28 purposively selected individuals. These four modes are based upon two characteristics: degree of program structure, or formal socialization; and degree of student-faculty interaction, or(More)
Described is an efficient heterologous expression system for Sulfolobus solfataricus ADH-10 (Alcohol Dehydrogenase isozyme 10) and its use in the dynamic reductive kinetic resolution (DYRKR) of 2-arylpropanal (Profen-type) substrates. Importantly, among the 12 aldehydes tested, a general preference for the (S)-antipode was observed, with high ee's for(More)
A set of bivalent mannose 6-phosphonate 'molecular rulers' has been synthesized to examine ligand binding to the M6P/IGF2R. The set is estimated to span a P-P distance range of 16-26A (MMFF energy minimization on the hydrated phosphonates). Key synthetic transformations include sugar triflate displacement for phosphonate installation and Grubbs I(More)
The use of NADH- and NADPH-dependent ketoreductases to access enantioenriched pharmaceutical building blocks is reported. Seven structurally diverse synthons are obtained, including those for atomoxetine (KRED 132), talampanel (RS1-ADH and CPADH), Dolastatin (KRED 132), and fluoxetine (KRED 108/132). Ethanol may be used as stoichiometric reductant,(More)
Uncontrolled pilot studies demonstrated promising results of endoscopic lung volume reduction using emphysematous lung sealant (ELS) in patients with advanced, upper lobe predominant emphysema. We aimed to evaluate the safety and efficacy of ELS in a randomised controlled setting.Patients were randomised to ELS plus medical treatment or medical treatment(More)
The glmS riboswitch is unique among gene-regulating riboswitches and catalytic RNAs. This is because its own metabolite, glucosamine-6-phosphate (GlcN6P), binds to the riboswitch and catalytically participates in the RNA self-cleavage reaction, thereby providing a novel negative feedback mechanism. Given that a number of pathogens harbor the glmS(More)
This study introduces new methods of screening for and tuning chiral space and in so doing identifies a promising set of chiral ligands for asymmetric synthesis. The carbafructopyranosyl-1,2-diamine(s) and salens constructed therefrom are particularly compelling. It is shown that by removing the native anomeric effect in this ligand family, one can tune(More)
Pyridoxal phosphate (PLP) dependent enzymes have the ability to manipulate amino acid substrates, serving variously as (i) racemases, transaminases, and beta-or gamma eliminases (all involving Cα-H bond cleavage); (ii) decarboxylases (Cα-CO2-bond cleavage), or (iii) retroaldolases (Cα-Cβ bond cleavage). Dunathan posited that stereoelectronics govern the key(More)