Scholars@Duke
Barbara R. Shaw

Barbara R. Shaw

William T. Miller Distinguished Professor Emeritus of Chemistry
Chemistry
barbara.r.shaw@duke.edu
Box 90346, Durham, NC 27708-0346
1105 French Family Science Ctr, Box 90346, Chemistry Department, Durham, NC 27708-0346

Selected Publications

Synthesis, Hydrolysis, and Protonation-Promoted Intramolecular Reductive Breakdown of Potential NRTIs: Stavudine α-P-Borano-γ-P-N-l-tryptophanyltriphosphates.

Journal Article Molecules (Basel, Switzerland) · January 2015 Phosphorus-modified prodrugs of dideoxynucleoside triphosphates (ddNTPs) have shown promise as pronucleotide strategies for improving antiviral activity compared to their parent dideoxynucleosides. Borane modified NTPs offer a promising choice as nucleosid ... Full text Cite

Versatility of borane nucleic acids mimics for coding, decoding and modulating genetic information.

Journal Article Nucleic acids symposium series (2004) · January 2007 This presentation will focus on the targeted regulation of gene expression, effective siRNA silencing with boranophosphates, and suppression of drugresistant reverse transcriptase by boranophosphate nucleotide analogues. ... Full text Cite

Synthesis of nucleoside boranophosphoramidate prodrugs conjugated with amino acids.

Journal Article The Journal of organic chemistry · March 2005 [structure: see text] Nucleoside boranophosphates and nucleoside amino acid phosphoramidates have been shown to be potent antiviral and anticancer agents with the potential to act as nucleoside prodrugs. A combination of these two types of compounds result ... Full text Cite

Model synthesis of nucleoside boranophosphoramidate with amino acid for prodrug purpose.

Journal Article Nucleosides, nucleotides & nucleic acids · January 2005 A model synthesis of a nucleoside boranophosphoramidate prodrug with (L)-tryptophan methyl ester was accomplished in a one-pot reaction via an H-phosphonate approach. This new type of compound is expected to possess the potent antiviral and anticancer adva ... Full text Cite

Incorporation of ribonucleoside 5'-(alpha-P-borano)triphosphates into a 20-mer RNA by T7 RNA polymerase.

Journal Article Nucleosides, nucleotides & nucleic acids · January 2005 The enzymatic synthesis of short boranophosphate RNA was studied by comparing the yield and pattern of abortive products of in vitro transcription at steady-state conditions with that of normal RNA. Boranophosphate short RNA can be readily synthesized by T ... Full text Cite

Synthesis of 5-(1-propynyl)-2'-deoxyuridine 5'-(alpha-P-borano)triphosphate and kinetic characterization as a substrate for mmlv reverse transcriptase.

Journal Article Nucleosides, nucleotides & nucleic acids · January 2005 In order to introduce pyrimidine C5-propynyl modification into boranophosphate oligodeoxyribonucleotides (BP- ODNs), 5-(1-propynyl)-2'-deoxyuridine 5'-(alpha-P-borano) triphosphate (d5PUTPalphaB) was synthesized. The two diastereomers were separated by rev ... Full text Cite

The effect of a single boranophosphate substitution with defined configuration on the thermal stability and conformation of a DNA duplex.

Journal Article Nucleosides, nucleotides & nucleic acids · January 2005 Substitution of one non-bridging oxygen in a natural phosphodiester internucleotide linkage with a borano (-BH3) group results in a chiral phosphorus center in boranophosphate. UV thermal melting profiles were recorded for DNA duplexes formed between a DNA ... Full text Cite

Affinity of (alpha-P-borano)-NTP analogs to rabbit muscle pyruvate kinase.

Journal Article Nucleosides, nucleotides & nucleic acids · January 2005 The binding affinity of (alpha-P-borano) and other NTP analogs to rabbit muscle pyruvate kinase (PK) was investigated using a fluorescence quenching approach to obtain structure-activity relationships for substrate specificity of nucleotide analogs. ... Full text Cite

RNA interference using boranophosphate siRNAs: structure-activity relationships.

Journal Article Nucleic Acids Res · 2004 In RNA interference (RNAi), short double-stranded RNA (known as siRNA) inhibits expression from homologous genes. Clinical or pre-clinical use of siRNAs is likely to require stabilizing modifications because of the prevalence of intracellular and extracell ... Full text Link to item Cite

Reading, writing, and modulating genetic information with boranophosphate mimics of nucleotides, DNA, and RNA.

Journal Article Annals of the New York Academy of Sciences · December 2003 The P-boranophosphates are efficient and near perfect mimics of natural nucleic acids in permitting reading and writing of genetic information with high yield and accuracy. Substitution of a borane (-BH3) group for oxygen in the phosphate ester bond create ... Full text Cite

Synthesis of acyclothymidine triphosphate and alpha-P-boranotriphosphate and their substrate properties with retroviral reverse transcriptase.

Journal Article Organic letters · July 2003 [reaction: see text] The first example of an acyclonucleoside alpha-P-boranotriphosphate has been synthesized via a phosphoramidite approach in a one-pot reaction with good yield. The presence of the alpha-P-BH(3) in 5b results in a 9-fold increase in effi ... Full text Cite

One-pot synthesis of an AZT boranophosphate conjugated with tyrosine: a potential prodrug candidate.

Journal Article Nucleosides, nucleotides & nucleic acids · May 2003 A one-pot synthesis of P-tyrosinyl(P-O)-5'-P-AZT boranophosphate 7 via a phosphoramidite method is described. The P-boranophosphate diastereomers were separated by RP-HPLC, and their structures were confirmed by NMR and MS. ... Full text Cite

RNase H activation by stereoregular boranophosphate oligonucleotide.

Journal Article Nucleosides, nucleotides & nucleic acids · May 2003 A stereoregular all-(Sp)-boranophosphate oligodeoxyribonucleotide (BH3(-)-ODN) 15-mer was synthesized using an enzymatic approach. The BH3(-)-ODN formed a hybrid with the complementary RNA 15-mer and induced RNase H hydrolysis of the RNA strand at ODN conc ... Full text Cite

Incorporation of (alpha-P-borano)-2',3'-dideoxycytidine 5'-triphosphate into DNA by drug-resistant MMLV reverse transcriptase and Taq DNA polymerase.

Journal Article Nucleosides, nucleotides & nucleic acids · May 2003 The Rp-stereoisomer of 5'-(alpha-P-borano)triphosphates of 2'-deoxycytidine (Rp-dCTPalphaB) and 2',3'-dideoxycytidine (Rp-ddCTPalphaB) were synthesized. Their steady-state kinetics of incorporation by ddNTP-resistant enzymes, e.g., MMLV reverse transcripta ... Full text Cite

Introduction of the alpha-P-borano-group into deoxynucleoside triphosphates increases their selectivity to HIV-1 reverse transcriptase relative to DNA polymerases.

Journal Article Nucleosides, nucleotides & nucleic acids · March 2003 A series of 2'-deoxynucleoside 5'-triphosphates (dNTPs) and their alpha-P-thio or alpha-P-borano analogues, i.e., (Sp-dNTPalphaS), (Rp-dNTPalphaB) and (Sp-dNTPalphaB) were studied as substrates for DNA dependent DNA polymerases and HIV-1 reverse transcript ... Full text Cite

Synthesis of nucleoside 3',5'-cyclic boranophosphorothioate, a new type of cyclic nucleotide.

Journal Article Chemical communications (Cambridge, England) · December 2002 The first examples of a borane-containing doubly P-modified chiral cyclic nucleoside monophosphate (cNMP), e.g., thymidine and 5-fluoro-2'-deoxyuridine 3',5'-cyclic boranophosphorothioates, have been synthesized; these cNMP analogues with increased lipophi ... Full text Cite

Evaluating the specificity of antisense oligonucleotide conjugates. A DNA array analysis.

Journal Article The Journal of biological chemistry · June 2002 Antisense oligonucleotides are potentially powerful tools for selective control of cellular and viral gene expression. Crucial to successful application of this approach is the specificity of the oligonucleotide for the chosen RNA target. Here we apply DNA ... Full text Cite

Conjugates of antisense oligonucleotides with the Tat and antennapedia cell-penetrating peptides: effects on cellular uptake, binding to target sequences, and biologic actions.

Journal Article Pharmaceutical research · June 2002 PurposeThe attainment of effective intracellular delivery remains an important issue for pharmacologic applications of antisense oligonucleotides. Here, we describe the synthesis, binding properties, and biologic properties of peptide-oligonucleot ... Full text Cite

Synthesis of prodrug candidates: conjugates of amino acid with nucleoside boranophosphate.

Journal Article Organic letters · June 2002 [structure: see text] Preparation of antiviral and anticancer prodrug candidates, P-tyrosinyl(P-O)-5'-P-nucleosidyl boranophosphates, is described. One-pot synthesis via a phosphoramidite method resulted in the title compounds with good yields. The P-boran ... Full text Cite

Boron-containing aptamers to ATP.

Journal Article Nucleic acids research · March 2002 Boron neutron capture therapy (BNCT), an experimental treatment for certain cancers, destroys only cells near the boron; however, there is a need to develop highly specific delivery agents. As nucleic acid aptamers recognize specific molecular targets, we ... Full text Cite

Boranophosphates as mimics of natural phosphodiesters in DNA.

Journal Article Current medicinal chemistry · August 2001 In boranophosphate-oligodeoxynucleosides (BH(3)(-)-ODN) a borane group replaces one of the two non-bridging oxygen atoms in the phosphodiester backbone of the naturally occurring congener. The chemical and biophysical properties of BH(3)(-) ODN are reviewe ... Full text Cite

Synthesis of new classes of boron-containing nucleotides.

Journal Article Nucleosides, nucleotides & nucleic acids · April 2001 Four different types of boron-modified nucleotides are reported: P-boranophosphorothioates, P-cyanoboranophosphates, P-boranomethylphosphonates, and P3'-N5'-boranophosphoramidates. Synthesis of dinucleoside borano-phosphorothioates and nucleoside P-borano- ... Full text Cite

Synthesis of oligonucleoside boranophosphates via an H-phosphonate method without nucleobase protection.

Journal Article Nucleosides, nucleotides & nucleic acids · April 2001 Short oligonucleoside boranophosphates containing all four nucleosides were synthesized on solid support using base-unprotected nucleoside H-phosphonate monomers. This strategy avoided irreversible base modifications during the boronation procedure. Struct ... Full text Cite

Borane-amine complexes--versatile reagents in the chemistry of nucleic acids and their analogs.

Journal Article Nucleosides, nucleotides & nucleic acids · April 2001 A new method for synthesis of N-alkylated nucleosides was developed. Exceptionally mild and selective conversion of N-acyl to the corresponding N-alkyl nucleosides was achieved by reduction with borane-amine complexes. The borane-amine complexes were also ... Full text Cite

Synthesis of a novel nucleic acid mimic: P-boranomethylphosphonate.

Journal Article Nucleosides, nucleotides & nucleic acids · April 2001 A new type of non-ionic nucleotide analogue with a doubly modified internucleotide linkage, P-boranomethylphosphonate, has been successfully synthesized and characterized. Dithymidine boranomethylphosphonate 5 is the first example of a P-boranomethylphosph ... Full text Cite

Novel 3',5'-cyclic nucleotide analogue: adenosine 3',5'-cyclic boranomonophosphate.

Journal Article Organic letters · March 2001 A general procedure for the first synthesis of a 3',5'-cyclic boranomonophosphate was established. Specifically, adenosine 3',5'-cyclic boranomonophosphosphate (cyclic AMPB, 4c), a P-borane (BH(3)) analogue of adenosine 3',5'-cyclic monophosphate (cAMP), w ... Full text Cite

Synthesis and separation of diastereomers of uridine 2',3'-cyclic boranophosphate.

Journal Article Bioorganic & medicinal chemistry letters · March 2001 The first boron-containing 2',3'-cyclic phosphate-modified analogue, uridine 2',3'-cyclic boranophosphate (2',3'-cyclic-UMPB), was synthesized. 5'-O-Protected uridine was cyclophosphorylated by diphenyl H-phosphonate to yield uridine 2',3'-cyclic H-phospho ... Full text Cite

Synthesis of a novel triphosphate analogue: Nucleoside α-P-borano, α-P-thiotriphosphate

Journal Article Chemical Communications · November 7, 2000 The first boranothiotriphosphate compound, thymidine 5'-[α-P-borano, α-P-thio]triphosphate, in which borane and sulfur replace the two non-bridging oxygens of the α-phosphate in natural nucleoside triphosphates (NTPs), has been synthesized; some chemical p ... Full text Cite

Synthesis of a boron analogue of glucose-conjugated nucleoside diphosphate: Nucleoside α-P-boranodiphosphoglucose

Journal Article Tetrahedron Letters · August 26, 2000 Analogues of nucleoside diphosphohexoses are useful for investigating the role of nucleotidyl sugars in oligosaccharide metabolism. Here, adenosine α-P-boranodiphosphoglucose 4, a boron analogue of ADP-glucose in which borane (BH3) replaces the non-bridgin ... Full text Cite

Antisense inhibition of P-glycoprotein expression using peptide-oligonucleotide conjugates.

Journal Article Biochemical pharmacology · July 2000 Antisense oligonucleotides are potentially a powerful tool for the therapeutic manipulation of genes associated with cancer. However, pharmacological applications of oligonucleotides have been hindered by the inability to effectively deliver these compound ... Full text Cite

Boronated Nucleic Acid Mimics: Antisense and DNA Chip Applications

Journal Article Antisense and Nucleic Acid Drug Development · 2000 Cite

Individual isomers of dinucleoside boranophosphates as synthons for incorporation into oligonucleotides: Synthesis and configurational assignment

Journal Article Helvetica Chimica Acta · January 1, 2000 Individual isomers of the protected boranophosphates 5a and 5b, i.e., the N6-benzyl-2'-deoxy-5'-O-(4,4'dimethoxytrityl)adenosin-3'-yl 2'-deoxy-4- O-(4-nitrophenyl)uridin-5'-yl boranophosphates, were synthesized via stereospecific silylation and boronation ... Full text Cite

Synthesis of boron-containing ADP and GDP analogues: Nucleoside 5'-(Pα- boranodiphosphates)

Journal Article Helvetica Chimica Acta · January 1, 2000 New 5'-(Pα-boronated) analogues of the naturally occurring nucleoside diphosphates ADP and GDP were synthesized in good yields, i.e., adenosine 5'- (Pα-boranodiphosphate) (ADPαB; 5a) and guanosine 5'-(Pα-boranodiphosphate) (GDPαB; 5b). Their diastereoisome ... Full text Cite

Synthesis and properties of a novel phosphodiester analogue, nucleoside boranophosphorothioate

Journal Article Chemical Communications · August 21, 1999 The first boranophosphorothioate [(RO)2P(S)(BH3)-] mimic of a phosphodiester compound, dithymidine boranophosphorothioate, has been synthesized; while it is water soluble, this new analogue is more lipophilic and nuclease resistant than natural nucleoside ... Full text Cite

Synthesis of diuridine 3',5'-boranophosphate: H-phosphonate approach

Journal Article Tetrahedron Letters · June 18, 1999 Diuridine 3',5'-boranophosphate, the RNA analogue of boranophosphate nucleic acids, was synthesized by a new approach via the H-phosphonate. Two diastereomers of diuridine 3',5'-boranophosphate were separated by reverse phase HPLC. ... Full text Cite

Boranophosphate nucleic acids--a versatile DNA backbone.

Journal Article Nucleosides & nucleotides · June 1999 Important chemical and biochemical properties of boranophosphate DNA and RNA oligonucleotides are reviewed. Stereoregular boranophosphate oligomers can be synthesized enzymatically and form stable duplexes with DNA. Fully boronated, non-stereoregular oligo ... Full text Cite

Synthesis of 5-substituted 2'-deoxycytidine 5'-(alpha-P-borano)triphosphates, their incorporationinto DNA and effects on exonuclease.

Journal Article Nucleic acids research · April 1999 Direct PCR sequencing with boronated nucleotides provides an alternative to current PCR sequencing methods. The positions of boranophosphate-modified nucleotides incorporated randomly into DNA during PCR can be revealed directly by exonuclease digestion to ... Full text Cite

Synthesis of dithymidine boranophosphates via stereospecific boronation of H-phosphonate diesters and assignment of their configuration

Journal Article Tetrahedron Letters · March 12, 1999 The absolute configurations of the two dithymidine boranophosphate isomers were established by chemical correlation with the H-phosphonate isomers. All chemical transformations leading from H-phosphonate diesters to boranophosphate diesters were found to b ... Full text Cite

Boranophosphates support the RNase H cleavage of polyribonucleotides.

Journal Article Antisense & nucleic acid drug development · February 1999 Modification of the phosphodiester linkages in DNA by replacing one of the nonbridging oxygens with borane, BH3, produces an isoelectronic mimic of DNA called boranophosphates. Nonstereoregular oligodeoxyribonucleoside all-boranophosphates are shown here f ... Full text Cite

Synthesis and Separation of Diastereomers of Ribonucleoside 5'-(alpha-P-Borano)triphosphates.

Journal Article The Journal of organic chemistry · August 1998 Nucleoside boranophosphates, in which one of the phosphate oxygens is replaced by a borane group, are isoionic and isoelectronic analogues of naturally occurring nucleotides. Boranophosphates also are biochemically important congeners of phosphorothioates ... Full text Cite

A convenient synthesis of 2'-deoxyribonucleoside 5'-(α-P- borano)triphosphates

Journal Article Tetrahedron · May 14, 1998 A new class of nucleotides, with one of the two non-bridging oxygens at α-phosphorus replaced by a borane (BH3) group, has shown potential applications in DNA sequencing. We have developed a convenient method for the synthesis of the 2'-deoxy-5'-(α-P-boran ... Full text Cite

Studies on base-boronated oligonucleotides. 2 (1). Incompatibility of DMT and cyanoborane groups during oligonucleotide synthesis.

Journal Article Bioconjugate chemistry · November 1997 The cyanoborane (-BH2CN) nucleosides and nucleotides are a new class of compounds that mimic natural and synthetic congeners in many ways and exhibit interesting biochemical and biophysical properties. The B-N bond is isoelectronic with the C-N+ bond of N7 ... Full text Cite

Conformational studies of dithymidine boranomonophosphate diastereoisomers.

Journal Article Bioorganic & medicinal chemistry · May 1997 The boranophosphate ester nucleotides are a new class of nucleic acid analogues that are isoelectronic and isostructural to normal phosphodiester nucleic acids and that maintain the anionic charge of the nucleic acid backbone. The two P-diastereoisomers of ... Full text Cite

Direct PCR sequencing with boronated nucleotides.

Journal Article Nucleic acids research · April 1997 A method is described to simultaneously amplify and sequence DNA using a new class of nucleotides containing boron. During the polymerase chain reaction, boron-modified nucleotides, i.e. 2'-deoxynucleoside 5'-alpha-[P-borano]-triphosphates, are incorporate ... Full text Cite

One-Step PCR Sequencing with Boronated Nucleotides

Journal Article Nucleic Acids Research · 1997 Cite

Boranophosphate oligonucleotides: New synthetic approaches

Journal Article Nucleosides and Nucleotides · January 1, 1997 Recently our laboratory reported a new backbone-modified class of oligonucleotides, with a borane (BH3-) group replacing one of the non- bridging oxygen atoms. Here we present two new approaches to synthesize the boranophosphate oligonucleotides. All-stere ... Full text Cite

Accelerated deamination of cytosine residues in UV-induced cyclobutane pyrimidine dimers leads to CC-->TT transitions.

Journal Article Biochemistry · August 1996 The rate of UV-induced deamination of cytosine to uracil at a specific site in double-stranded (ds) DNA was monitored using a genetic reversion assay. M13mp2C141 ds DNA was exposed to 160 J/m2 UV (254 nm), incubated at 37 degrees C, pH 7.4, for various tim ... Full text Cite

Hydrolysis of thymidine boranomonophosphate and stepwise deuterium substitution of the borane hydrogens. 31P and 11B NMR studies

Journal Article Journal of the American Chemical Society · July 17, 1996 The α-P-boranophosphate nucleosides comprise a new class of modified nucleotides that may find use as therapeutic and DNA diagnostic agents. Hydrolysis of thymidine 5'-boranomonophosphate, d(p(B)T), has been studied in H2O and D2O using 1H, 31P, and 11B NM ... Full text Cite

2′-Deoxycytidine-N3-cyanoborane

Journal Article Acta Crystallographica Section C: Crystal Structure Communications · July 15, 1996 The structure of the P212121 form of 2′-deoxycytidine-N3-cyanoborane, C10H15BN4O4, has been determined. The sugar is in the 2E puckering mode and the C5′-O5′ bond has a tg conformation while the relative orientation of the sugar and the base remains anti. ... Full text Cite

Base-boronated dinucleotides: synthesis and effect of N7-cyanoborane substitution on the base protons.

Journal Article Nucleic acids research · June 1996 Boron-modified nucleic acids comprise a new set of DNA mimics that have potential biological and therapeutic applications. A series of nine dinucleotides containing N7-cyanoborane-2'-deoxyguanosine ((7b)dG) at the 3', 5' or both positions of the phosphodie ... Full text Cite

2′-Deoxycytidine-N(3)-cyanoborane monohydrate

Journal Article Acta Crystallographica Section C: Crystal Structure Communications · March 15, 1996 The structure of the title compound, [4-amino-1-(2-deoxy-β-D-ribofuranosyl)-2-oxo-1H-3-pyrimidinio]-(cyano) borate, C10H15BN4O4.H2O, features an interaction of 2.05 (4) Å between an H atom of the -BH2CN group and an H atom of the -NH2 group. The -C≡N group ... Full text Cite

Boron-containing oligodeoxyribonucleotide 14mer duplexes: enzymatic synthesis and melting studies.

Journal Article Nucleic acids research · November 1995 A set of three 14mer oligodeoxyribonucleotides of sequence d(5'-CTATGGCCTCAG*CT-3'/3'-GATACCGGAGTCGA-5') containing G* variants either as 2'-deoxyguanosine phosphate (unmodified), N7-cyanoborane 2'-deoxyguanosine phosphate (base-modified) or 2'-deoxyguanos ... Full text Cite

N7-cyanoborane-2'-deoxyguanosine 5'-triphosphate is a good substrate for DNA polymerase.

Journal Article Biochemistry · September 1995 The 5'-triphosphate of the boronated nucleoside analog N7-cyanoborane-2'-deoxyguanosine (7bdGTP) was synthesized, and a series of experiments was initiated to assess the potential of the compound to serve as a substrate for DNA polymerases. We show here th ... Full text Cite

Anti-inflammatory and anti-osteoporotic activities of base-boronated nucleosides and phosphate-boronated nucleotides in rodents.

Journal Article Journal of pharmaceutical sciences · October 1994 The 2'-deoxyribonucleoside cyanoboranes were effective anti-inflammatory agents in rodents at 2-8 mg/kg; they blocked induced edema, septic shock, and pleurisy. Overall compounds 3',5'-O-(bis- (triisopropylsilyl)-2'-deoxyinosine (1), 3',5'-O-bis(triisoprop ... Full text Cite

Bisulfite induces tandem double CC-->TT mutations in double-stranded DNA. 2. Kinetics of cytosine deamination.

Journal Article Biochemistry · April 1994 Deamination of cytosine to uracil in double-stranded DNA (ds DNA) by sodium bisulfite has been monitored with a sensitive genetic assay. In this system, reversion of a mutant in the lacZ alpha gene coding sequence of bacteriophage M13mp2 C141 was detected ... Full text Cite

Echinomycin, a bis-intercalating agent, induces C-->T mutations via cytosine deamination.

Journal Article Mutation research · August 1993 Echinomycin, a bis-intercalating, antitumor drug, has been studied for its ability to induce the deamination of cytosine to uracil (C-->U) in double-stranded DNA. We have employed a sensitive lacZ alpha-complementation reversion assay to detect G.C-->A.T m ... Full text Cite

Cytosine deamination in mismatched base pairs.

Journal Article Biochemistry · July 1993 The rate of deamination of cytosine in mismatched base pairs has been determined. Incubation of M13mp2 nicked heteroduplex DNA molecules containing T.C or C.C mispairs in the lacZ alpha-complementation gene results in deamination of cytosine to uracil, pro ... Full text Cite

Kinetics of bisulfite-induced cytosine deamination in single-stranded DNA.

Journal Article Biochemistry · April 1993 The rate of bisulfite-induced deamination of cytosine to uracil in single-stranded (ss) DNA at physiological temperature and pH was monitored by a sensitive genetic assay. The assay is based on reversion of a mutation in the lacZ alpha gene of bacteriophag ... Full text Cite

Hypolipidemic activity of boronated nucleosides and nucleotides in rodents.

Journal Article Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · January 1993 Base-boronated nucleoside and phosphate-boronated nucleotides were potent hypolipidemic agents in rodents, lowering both serum cholesterol and triglyceride levels. Rat VLDL and LDL cholesterol levels were generally reduced and HDL cholesterol levels were s ... Full text Cite

The synthesis and anti-neoplastic activity of N2-isobutyryl-2'-deoxyguanosine-N7-cyanoborane derivatives.

Journal Article Die Pharmazie · November 1992 N2-Isobutyryl-2'-deoxyguanosine-N7-cyanoborane derivatives were observed to be potent antineoplastic agents and to be active against a number of human tissue culture tumor cells, e.g. Tmolt3 leukemia, HeLa-S3 uterine carcinoma. Selective agents were active ... Cite

Antineoplastic activity of boron-containing thymidine nucleosides in Tmolt3 leukemic cells.

Journal Article Anticancer research · July 1992 The sugar boronated thymidine nucleoside, 5' -0-[(triphenylphosphine-boryl) carbonyl]-3'-0-acetyl thymidine 1, and the boron-modified nucleoside phosphotriester, 5'-(diethylphosphite- cyanoborane)-3'-acetylthymidine 2, were successfully synthesized. Both c ... Cite

Variable temperature infrared spectroscopy of cytosine-guanine base pairs: tautomerism versus polarization.

Journal Article Journal of biomolecular structure & dynamics · April 1992 This report describes an infrared (IR) spectroscopic study of a model cytosine-guanine base pair. This base pair is part of a self-consistent experimental system based on lipophilic ribose derivatives of cytidine (C), guanosine (G) and O6-methylguanosine ( ... Full text Cite

The synthesis and antineoplastic activity of 2'-deoxy-nucleoside-cyanoboranes in murine and human culture cells.

Journal Article Anticancer research · March 1992 The guanine, inosine, adenine and cytidine deoxyriboside cyanoboranes proved to be cytotoxic and possess in vivo antineoplastic activity against murine and human single cells and cultured cells derived from solid tumor lines. The agents preferentially inhi ... Cite

From boron analogues of amino acids to boronated dna: Potential new pharmaceuticals and neutron capture agents

Journal Article Pure and Applied Chemistry · January 1, 1991 We have been extensively involved in the synthesis of isoelectronic and isostructural boron analogues of the a-amino acids. These have ranged from simple glycine analogues such as H3NBH2COOH and Me2NHBH2COOH to alanine analogues. A diverse variety of analo ... Full text Cite

A sensitive genetic assay for the detection of cytosine deamination: determination of rate constants and the activation energy.

Journal Article Biochemistry · March 1990 Previously it has not been possible to determine the rate of deamination of cytosine in DNA at 37 degrees C because this reaction occurs so slowly. We describe here a sensitive genetic assay to measure the rate of cytosine deamination in DNA at a single cy ... Full text Cite

In a Model C:G Base Pair, One Amino Group Rotates and the Other Does Not

Journal Article Journal of the American Chemical Society · January 1, 1990 Cytosine (C) and guanine (G) form Watson-Crick-type complexes in low-dielectric solvents. Dynamics of complexes between 3',5'-bis(triisopropylsilyl) derivatives of 2'-deoxynucleosides in deuteriochloroform were studied with 300-MHz 1H NMR. We have determin ... Full text Cite

Boron-Containing Nucleic Acids. 2.1 Synthesis of Oligodeoxynucleoside Boranophosphates

Journal Article Journal of the American Chemical Society · January 1, 1990 Full text Cite

Hydrolysis of N3-methyl-2'-deoxycytidine: model compound for reactivity of protonated cytosine residues in DNA.

Journal Article Mutation research · November 1989 Protonation of cytosine residues at physiological pH may occur in DNA as a consequence of both alkylation and aberrant base-pair formation. When cytosine derivatives are protonated, they undergo hydrolysis reactions at elevated rates and can either deamina ... Full text Cite

Boron-containing nucleic acids: Synthesis of cyanoborane adducts of 2'-deoxynucleosides

Journal Article Journal of the American Chemical Society · January 1, 1989 Full text Cite

Dimers, trimers, and tetramers of cytosine with guanine

Journal Article Journal of the American Chemical Society · January 1, 1989 Cytosine and guanine have been shown previously to form Watson-Crick type base pairs in nonaqueous solvents, suggesting that the monomers can be used to understand and possibly to predict structures of the polymeric nucleic acids. Yet, the poor solubility ... Full text Cite

Base stacking and molecular polarizability: effect of a methyl group in the 5-position of pyrimidines.

Journal Article Biochemical and biophysical research communications · October 1987 Substitution of a methyl group in the 5-position of pyrimidines increases melting temperatures and modifies biological properties of DNA. Increased DNA stability is often attributed to hydrophobic interactions between water and the methyl group. However, w ... Full text Cite

Protonated base pairs explain the ambiguous pairing properties of O6-methylguanine.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · April 1987 The base-pairing interactions of promutagenic O6-methylguanine (O6-MeGua) with cytosine and thymine in deuterated chloroform were investigated by 1H NMR spectroscopy. Nucleosides were derivatized at hydroxyl positions with triisopropylsilyl groups to obtai ... Full text Cite

DNA base modification: ionized base pairs and mutagenesis.

Journal Article Mutation research · April 1987 The nature of hydrogen bonding between normal and modified bases has been re-examined. It is proposed that hydrogen-bonding schemes may involve tautomeric, ionized or conformational forms (syn, anti and wobble). Several important cases are presented or rev ... Full text Cite

Diffusible factors are responsible for differences in nuclease sensitivity among chromatins originating from different cell types.

Journal Article Experimental cell research · September 1984 We have examined the kinetics of nuclease digestion of chromatin from committed and uncommitted cells in experiments where the nuclei are mixed and co-digested. Cultures of the sea urchin, Arbacia punctulata, were grown to the 16-cell stage in either [3H]t ... Full text Cite

Temporal Changes in Nucleosome Populations during Sea Urchin Early Development

Journal Article Biochemistry · January 1, 1984 The finding that the major H2A histone isolated in nucleosomes of a particular developmental stage corresponds to the major H2A subtype synthesized at and prior to that stage [Shaw, B. R., Cognetti, G., Sholes, W. M., & Richards, R. G. (1981) Biochemistry ... Full text Cite

IONIZED BASE-PAIRS - A PROBABLE CONSEQUENCE OF MUTAGENIC ALKYLATION OF DNA

Journal Article PROCEEDINGS OF THE AMERICAN ASSOCIATION FOR CANCER RESEARCH · January 1, 1984 Link to item Cite

Silver staining of histones in Triton-acid-urea gels.

Journal Article Analytical biochemistry · November 1983 A reliable method for silver staining histones in Triton-acid-urea gels was developed. Optimum staining is achieved by treating the gels either with amido black or a colorless, water-soluble analog of amido black, 2,7-naphthalenedisulfonic acid, prior to s ... Full text Cite

Structural differences in the chromatin from compartmentalized cells of the sea urchin embryo: differential nuclease accessibility of micromere chromatin.

Journal Article Nucleic acids research · November 1981 The chromatin structure of three cell types isolated from the 16-cell stage sea urchin embryo has been probed with micrococcal nuclease. In micromeres, the four small cells at the vegetal pole, the chromatin is found to be considerably more resistant to de ... Full text Cite

Hydrodynamic evidence in support of spacer regions in chromatin.

Journal Article Science (New York, N.Y.) · August 1977 Quasi-elastic light scattering and sedimentation velocity methods were used to study the hydrodynamic properties of purified dimer subunits obtained from partial digestion of chicken erythrocyte chromatin with staphylococcal nuclease. The experimental valu ... Full text Cite

Quasielastic light scattering by biopolymers. Conformation of chromatin multimers.

Journal Article Biochemical and biophysical research communications · November 1976 Full text Cite

Analysis of the Subunit Structure in Chicken Erythrocyte Chromatin

Journal Article Proc. Nat. Acad. Sci., USA · 1976 Cite

Chromatographic Separation of Chromatin Subunits

Journal Article Biochem. Biophys. Res. Commun. · 1974 Cite

A Model for Particulate Structure in Chromatin

Journal Article Nucleic Acids Res. · 1974 Cite

Electron Microscopy of Chromatin Subunit Particles

Journal Article Biochem. Biophys. Res. Commun. · 1974 Cite