bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antiarrhythmic Drugs
Authors: von Philipsborn Gerda , Oberdorf Anton , Binnig Fritz , Franke Albrecht 
Published: April 2004

AbstractThe article contains sections titled:1.Antiarrhythmic Drugs1.1.Physiology1.2.Disorders of Cardiac Rhythm (Arrhythmias)1.3.Cardiac Action Potentials1.4.General Aspects of Pharmacology1.5.General Aspects of Chemistry2.Individual Antiarrhythmic Drugs  2.1.Class I Drugs: Sodium Channel Blockers2.1.1.Class I a Drugs2.1.2.Class I b Drugs2.1.3.Class I c Drugs2.2.Class II Drugs: β‐Receptor Blocking Agents2.3.Class III Drugs: Agents Increasing the Action Potential Duration2.4.Class IV Drugs: Calcium Channel Blockers2.5.New Antiarrhythmic Drugs
Leather Imitates
Authors: Zürbig Claus , Kruse Hans‐Hinrich 
Published: April 2004

Abstract

The article contains sections titled:

1.

Definition and History

2.

Properties

3.

Raw Materials

3.1.

Carrier Materials

3.2.

Coating Materials

3.3.

Lacquers for Finishing

4.

Production

4.1.

Layer Composition

4.2.

Coating

4.2.1.

Coating Devices

4.2.2.

Coating Processes

4.2.3.

Finishing

5.

Quality Specifications and Analysis

6.

Economic Aspects and Uses
Magnesium Alloys
Authors: Aune Terje Kr. , Gjestland Haavard , Haagensen Johanna Øster , Kittilsen Bjørn , Skar Jan Ivar , Westengen Håkon 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Commercial Alloys, Product Forms, and Uses3.Metallurgy of Magnesium Alloys3.1.Magnesium ‐ Aluminum Alloys3.2.Grain‐Refined Magnesium ‐ Zirconium Alloys3.3.New Developments4.Production Methods for Magnesium Alloys5.Manufacture of Articles from Magnesium Alloys5.1.Shaping5.2.Joining5.3.Finishing6.Corrosion and Corrosion Control6.1.Effect of Composition and Structure6.2.Effect of the Environment6.3.Galvanic Corrosion7.Environmental Aspects8.Economic Aspects
Maleic and Fumaric Acids
Authors: Lohbeck Kurt , Haferkorn Herbert , Fuhrmann Werner , Fedtke Norbert 
Published: April 2004

AbstractThe article contains sections titled:1.Maleic Acid2.Maleic Anhydride (MA)2.1.Properties2.2.Production2.2.1.Oxidation of Benzene2.2.2.Dehydration of Aqueous Maleic Acid Solutions2.2.3.Oxidation of C4Hydrocarbons2.2.4.Purification2.2.5.Byproducts, Construction Materials, Effluent, and Discharge Air2.3.Quality, Storage, and Transportation2.4.Uses3.Citraconic and Mesaconic Acids4.Fumaric Acid5.Toxicology
Biocides
Authors: Payne Ken R. , Hill Edward 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Chemical Biocides2.1.Phenolics2.2.Chlorine and Chlorine‐Releasing Compounds2.3.Iodine and Iodophores2.4.Quaternary Ammonium Compounds2.5.Biguanides2.6.Peroxygens2.7.Alcohols2.8.Aldehydes2.9.Hydroxybenzoate Esters2.10.Heavy Metals3.Application of Biocides3.1.Factors Affecting Biocide Selection3.2.Challenge Testing3.3.Spoilage3.4.Monitoring3.5.Predetermined and Automatic Biocide Additions
Nitrates and Nitrites
Authors: Laue Wolfgang , Thiemann Michael , Scheibler Erich , Wiegand Karl Wilhelm 
Published: April 2004

AbstractThe article contains sections titled:1.Sodium Nitrate1.1.Properties1.2.Occurrence1.3.Production1.3.1.Chile Saltpeter1.3.2.Synthetic Sodium Nitrate1.4.Product Forms, Storage, and Transportation1.5.Uses1.6.Economic Aspects2.Potassium Nitrate2.1.Properties2.2.Occurrence2.3.Production2.3.1.Bacterial Production of Saltpeter2.3.2.Converted Saltpeter2.3.3.Potassium Nitrate from Calcium Nitrate2.3.4.Potassium Nitrate from Ammonium Nitrate2.3.5.Potassium Nitrate from Potassium Chloride and Nitric Acid2.4.Product Forms, Storage, and Transportation2.5.Uses2.6.Economic Aspects3.Calcium Nitrate3.1.Properties3.2.Occurrence3.3.Production3.3.1.Calcium Nitrate from Limestoneand Nitric Acid3.3.2.Calcium Nitrate as a Byproduct of the Odda Process3.4.Product Forms, Storage, and Transportation3.5.Uses3.6.Economic Aspects4.Sodium Nitrite4.1.Properties4.2.Production4.3.Product Forms, Storage, and Transportation4.4.Uses4.5.Economic Aspects5.Potassium Nitrite5.1.Properties5.2.Production5.3.Uses6.Ammonium Nitrite6.1.Properties6.2.Production6.3.Uses7.Calcium Nitrite7.1.Properties7.2.Production7.3.Uses8.Analysis of Nitrates and Nitrites9.Environmental Aspects10.Toxicology and Occupational Health
Oxidation
Authors: Franz Gerhard , Sheldon Roger A. 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Thermodynamics; Stability of Hydrocarbons3.Reaction Types4.Homolytic Oxidation4.1.Historical Development; Reaction Mechanism; Radical Reactivity4.2.Kinetics of Autoxidation4.3.Differences between Liquid‐ and Gas‐Phase Autoxidations4.4.Homolytic Oxidation in the Liquid Phase4.4.1.Secondary Reactions of Radicals, Peroxides, and other Intermediates4.4.2.Metal Catalysis in Homolytic Liquid‐Phase Oxidation4.4.3.Inhibitors of Homolytic Liquid‐Phase Oxidation4.4.4.Special Cases of Homolytic Oxidation4.4.5.Process Technology of Homolytic Liquid‐Phase Oxidation4.5.Homolytic Gas‐Phase Oxidation4.6.Gas Explosions and Safety Data5.Heterolytic Oxidation5.1.Heterolytic Oxidation in the Liquid Phase5.2.Heterogeneously Catalyzed Gas‐Phase Oxidation5.2.1.Oxidation Catalysts5.2.2.Process Technology of Heterogeneously Catalyzed Oxidations
Phosgene
Authors: Schneider Wolfgang , Diller Werner 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Properties2.1.Physical Properties2.2.Chemical Properties2.2.1.Reactions with Organic Compounds2.2.2.Reactions with Inorganic Compounds3.Production4.Storage and Transportation5.Quality and Analysis6.Waste‐Gas Treatment and Monitoring7.Safety Precautions8.Uses9.Economic Aspects10.Toxicology and Occupational Health
Plasticizers
Authors: Cadogan David F. , Howick Christopher J. 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction1.1.Definition1.2.Types of Plasticization1.3.Types of Plasticizer2.Plasticizers in Common Use2.1.Market Overview2.2.Phthalate Esters2.3.Adipate Esters2.4.Trimellitate Esters2.5.Phosphate Esters2.6.Sebacate and Azelate Esters2.7.Polyester Plasticizers2.8.Sulfonate Esters2.9.Specialty Phthalate Esters2.10.Secondary Plasticizers3.Mechanism of Plasticizer Action3.1.The Lubricity Theory3.2.The Gel Theory3.3.The Free‐Volume Theory3.4.Solvation–Desolvation Equilibrium3.5.Generalized Structure Theories3.6.Specific Interactions and Interaction Parameters4.Plasticized PVC4.1.Applications Technology4.1.1.Suspension PVC4.1.2.Emulsion PVC4.2.Effect of Plasticizer Choice on the Properties of Flexible PVC4.2.1.Plasticizer Efficiency4.2.2.High‐Temperature Performance4.2.3.Low‐Temperature Performance4.2.4.Gelation Properties4.2.5.Migration and Extraction4.2.6.Plastisol Viscosity and Viscosity Ageing4.2.7.Windscreen Fogging4.2.8.Summmary5.Plasticization of Polymers Other Than PVC5.1.Requirements for Plasticization5.2.Plasticization of Other Polymers6.Toxicology and Environmental Aspects6.1.Toxicity Studies on Plasticizer Esters6.2.Plasticizers in the Environment6.3.Storage and Handling
Plastics, Additives
Authors: Wolf Rainer , Kaul Bansi Lal 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Antioxidants2.1.Purpose and Requirements2.2.Chemical Classes2.3.Mechanism of Action2.4.Test Methods2.5.Uses2.6.Legal Aspects2.7.Economic Aspects3.Light Stabilizers3.1.Purpose and Requirements3.2.Chemical Classes3.3.Mechanism of Action3.4.Test Methods3.5.Uses3.6.Economic Aspects4.Heat Stabilizers for Poly(Vinyl Chloride)4.1.Purpose and Requirements4.2.Chemical Classes4.2.1.Metal‐Containing Stabilizers4.2.2.Metal‐Free Stabilizers4.3.Mechanism of Action4.4.Test Methods4.5.Uses4.6.Economic Aspects5.Lubricants, Slip, Antiblocking, and Mold‐Release Agents5.1.Purpose and Requirements5.2.Chemical Classes5.3.Mechanism of Action5.4.Test Methods5.5.Uses5.6.Economic Aspects6.Flame Retardants6.1.Purpose and Requirements6.2.Chemical Classes6.3.Mechanism of Action6.4.Test Methods and Standards6.5.Uses6.6.Toxicology6.7.Economic Aspects7.Fillers and Coupling Agents7.1.Purpose and Requirements7.2.Forms and Chemical Structures7.3.Mechanism of Action7.4.Test Methods7.5.Uses7.6.Economic Aspects8.Dyes and Pigments8.1.Requirements8.2.Pigments8.2.1.Inorganic Pigments8.2.2.Organic Pigments8.2.3.Dyes9.Miscellaneous Additives9.1.Nucleating Agents9.2.Antistatic Agents9.3.Impact Modifiers9.4.Chemical Blowing Agents9.5.Optical Brighteners
Plastics, Analysis
Authors: Elgert Karl‐Friedrich 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Polymer Isolation3.Preliminary Tests for Polymer Identification4.Chemical Analysis4.1.Heteroelements and Functional Groups4.2.Separation and Identification Schemes4.3.Spectroscopic Methods5.Molecular Mass Determination5.1.Absolute Methods5.1.1.Membrane Osmometry5.1.2.Lowering of Vapor Pressure5.1.3.Ultracentrifugation5.1.4.Light Scattering5.2.Relative Methods5.3.Determination of Molecular Mass Distribution6.Determination of Sequential Structure6.1.NMR Spectroscopy6.2.Pyrolysis Gas Chromatography7.Determination of Chemical Heterogeneity
Polycarbonates
Authors: Serini Volker 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Properties2.1.Bisphenol A Polycarbonate2.2.Modified Bisphenol A Polycarbonate2.3.Bisphenol A Polycarbonate with Additives3.Production3.1.Interfacial Polycondensation3.2.Melt Transesterification4.Processing5.Uses6.Economic Aspects7.Recycling8.Toxicology and Environmental Aspects
Polymer Blends
Authors: Bussink Jan , van de Grampel Hendrik T. 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Market Requirements3.Blend Technologies3.1.Thermodynamics3.2.Compatibility3.3.Compounding3.4.Reactive Compounding3.5.Mechanical Properties3.6.Additives4.Property and Application Profiles of Selected Blends4.1.Polyolefins4.2.Poly(Vinyl Chloride)4.3.Styrene Polymers and Copolymers4.4.Polyamides4.5.Poly(2,6‐Dimethyl‐1,4‐phenylene Ether)4.6.Polycarbonates4.7.Polyesters4.8.Polyetherimides4.9.Polysulfones4.10.Polyoxymethylenes4.11.Polyarylates and Copolyarylate ‐ Carbonate Blends4.12.Poly(Phenylene Sulfide)5.General Application Technology5.1.Processing of Blends5.2.Design Technology6.Future Developments6.1.Recycling6.2.New Developments6.3.Outlook7.Acknowledgement
Polymers, Electrically Conducting
Authors: Naarmann Herbert 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Synthetic Routes3.Principles of Electrical Conduction4.Orientation Processes5.Types of Electrically Conducting Organic Materials5.1.Polyacetylene5.2.Polydiacetylenes5.3.Polypyrrole5.4.Polythiophene5.5.Polyphenylene5.6.Poly(Phenylene Sulfide)5.7.Poly(Phenylene Vinylene)5.8.Polyaniline5.9.Miscellaneous Polymers6.Uses
Poly(Vinyl Ethers)
Authors: Schröder Gerd 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Production3.Industrial Processes3.1.Batch Bulk Polymerization of Vinyl Methyl Ether3.2.Continuous Bulk Polymerization of Vinyl Ethyl Ether3.3.Continuous Solution Polymerization of Vinyl Isobutyl Ether3.4.Environmental Protection4.Properties and Uses5.Copolymers6.Toxicology
Powder Metallurgy and Sintered Materials
Authors: Kaysser Wolfgang A. , Weise Wolfgang 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction1.1.Production Routes1.2.Product Groups1.3.History and Developments1.4.Economic Aspects2.Powder Production2.1.Mechanical Methods2.1.1.Mechanical Disintegration of Melts2.1.2.Mechanical Disintegration of Solids2.2.Physicochemical Methods2.3.Chemical Methods3.Powder Properties and Characterization4.Powder Conditioning5.Pressing and Forming at Ambient Temperatures5.1.Uniaxial Pressing5.2.Isostatic Pressing, Cold Rolling, and Extrusion5.3.Pouring, Preforming, and Injection Molding6.Sintering6.1.The Sintering Process6.1.1.Solid‐State Sintering6.1.2.Liquid‐Phase Sintering6.2.Sintering Furnaces and Atmospheres7.Pressing and Shaping at Elevated Temperature7.1.Hot Pressing and Hot Isostatic Pressing7.2.Sinter Forging and other Methods8.Structural Parts8.1.Structural Ferrous Parts8.1.1.Low‐Alloyed Steels8.1.2.High‐Alloyed Steels8.1.3.Secondary Operations8.2.Copper and Copper Alloys8.3.Aluminum and Aluminum Alloys9.High‐Performance Materials9.1.High‐Melting Metals and Alloys9.2.Light Alloys9.2.1.High‐Performance Aluminum Alloys9.2.2.Titanium and Titanium Alloys9.2.3.Magnesium and Beryllium9.3.High‐Temperature Nickel and Cobalt Superalloys9.4.Magnetic Materials9.5.Hardmetals and Cermets9.6.Metal ‐ Ceramic Composites9.7.Electric Contact Materials9.7.1.Contact Materials for Low‐Voltage Switchgear9.7.2.Contact Materials for High‐Voltage Switchgear10.Parts with Inherent, Functional Porosity
Pyrotechnics
Authors: Krone Uwe , Lancaster Ronald 
Published: April 2004

Abstract
The article contains sections titled:

1.

Introduction

2.

Pyrotechnic Compositions

3.

Pyrotechnic Effects

4.

Fireworks

4.1.

Shop Fireworks

4.1.1.

Toy Fireworks

4.1.2.

Garden Fireworks

4.2.

Display Fireworks

5.

Pyrotechnics for Industrial and Military Use

6.

Production

7.

Legal Aspects; Storage and Transportation
Reinforced Plastics
Authors: Ehrenstein Gottfried W. , Kabelka Josef 
Published: April 2004

Abstract
The article contains sections titled:

1.

Introduction, Classification

1.1.

Fiber‐Reinforced Polymers

1.2.

Particulate Polymer Composites

1.3.

Laminar Polymer Composites

2.

Reinforced Plastic Components

2.1.

Reinforcing Fibers

2.1.1.

Glass Fibers

2.1.2.

Graphite (Carbon) Fibers

2.1.3.

Aramid Fibers

2.1.4.

Other Continuous Fibers

2.1.5.

Other Discontinuous Fibers

2.2.

Fillers

2.3.

Polymeric Matrices

3.

Fabrication of Polymer Composites

3.1.

Hand Lay‐up Technique

3.2.

Spray‐up

3.3.

Filament Winding

3.4.

Pultrusion

3.5.

Bag Molding

3.6.

Sheet Molding Compounds (SMC)

3.7.

Thick Molding Compounds (TMC)

3.8.

Bulk (or Dough) Molding Compounds (BMC, DMC)

3.9.

Prepregs

3.10.

Reinforced Reaction Injection Molding (RRIM)

3.11.

Resin Transfer Molding (RTM)

4.

Physical and Chemical Properties

5.

Quality Specifications

6.

Economic Aspects
Release Agents
Authors: Lammerting Helmut 
Published: April 2004

Abstract

The article contains sections titled:

1.

Introduction

2.

Physical and Chemical Background

3.

Raw Materials

3.1.

Waxes

3.2.

Metallic Soaps

3.3.

Oils and Fats

3.4.

Silicones

3.5.

Polyoxyalkylenes

3.6.

Fluorocarbons

4.

Methods of Application

5.

Uses

5.1.

Processing Polyurethane Foam

5.2.

Processing Glass Fiber Reinforced Plastics

5.3.

Processing Thermoplastics

5.4.

Processing Rubber

5.5.

Metal Industry

5.6.

Glass Industry

5.7.

Woodworking

5.8.

Food Industry
Sintered Steel and Iron
Authors: Cohrt Henri , Enders Martin 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Iron and Steel Powders2.1.Powder Production2.1.1.Reduced Metal Powders2.1.2.Atomized Powders2.1.3.Electrolytic Iron Powders2.1.4.Carbonyl Iron Powders2.2.Powder Properties3.Forming and Sintering3.1.Forming3.1.1.Gravity Sintering3.1.2.Uniaxial Pressing3.1.3.Cold Isostatic Pressing3.1.4.Metal Injection Molding3.1.5.Powder Rolling3.1.6.Slip Casting3.2.Sintering3.3.Consolidation Processes Involving Simultaneous Application of Pressure and Heat3.3.1.Powder Forging3.3.2.Hot Isostatic Pressing3.3.3.Extrusion3.3.4.Spray Compacting3.3.5.High‐Velocity Compacting4.Secondary Operations5.Strength Properties
Strontium and Strontium Compounds
Authors: MacMillan J. Paul , Park Jai Won , Gerstenberg Rolf , Wagner Heinz , Köhler Karl , Wallbrecht Peter 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Properties3.Occurrence4.Mining and Processing5.Chemical Digestion of Ores6.Strontium Compounds6.1.Strontium Carbonate6.2.Strontium Nitrate6.3.Strontium Chloride6.4.Strontium Chromate7.Strontium Metal8.Toxicology
Sulfur Dioxide
Authors: Müller Hermann 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Properties3.Raw Materials for Sulfur Dioxide Production4.Production from Elemental Sulfur4.1.Sulfur Burning Processes4.2.Heat Recovery4.3.Impurities and their Removal4.4.Two‐Stage Sulfur Combustion5.Production by Pyrite Roasting5.1.Importance of Impurities5.2.Thermodynamics and Kinetics5.3.Roasting Processes5.4.Roasting of Arsenical Pyrite5.5.Production in Nonferrous Metal Sulfide Ore Processing5.5.1.Copper Smelting5.5.2.Nickel Smelting5.5.3.Zinc Blende Roasting5.5.4.Lead Smelting5.6.Production by Decomposition of Sulfuric Acid and Sulfates5.6.1.Waste Sulfuric Acid Processing5.6.2.Sulfate Decomposition5.7.Production from Waste Gases5.7.1.Combustion of Hydrogen Sulfide5.7.2.Recovery from Flue Gases6.Cleaning of Crude Sulfur Dioxide Gas Streams6.1.Constituents of Roaster and Metallurgical Gases6.2.Cleaning Systems7.Production of Pure Sulfur Dioxide7.1.Chemical Production from Sulfur Trioxide7.2.Separation from Sulfur Dioxide‐Containing Gases8.Construction Materials9.Industrial Output and Uses10.Analysis11.Environmental Aspects and Toxicology12.Acknowledgement
Sulfuric Acid and Sulfur Trioxide
Authors: Müller Hermann 
Published: April 2004

AbstractThe article contains sections titled:1.Introduction2.Properties2.1.Physical Properties2.2.Chemical Properties3.Development of the Sulfuric Acid Industry3.1.Early Development3.2.Further Development of the Nitrogen Oxide Process3.3.Ascendency of the Contact Process3.4.Raw Materials Usage4.Production4.1.Production by Contact Processes4.1.1.Reaction Kinetics and Thermodynamics4.1.2.Catalysts4.1.3.Process Summary4.1.3.1.Gas Drying4.1.3.2.Catalytic Oxidation of Sulfur Dioxide4.1.3.3.Absorption of Sulfur Trioxide4.1.3.4.Acid Cooling4.1.4.Practical Versions of the Contact Process4.1.4.1.Double‐Absorption Process Based on Sulfur Combustion4.1.4.2.Double‐Absorption Processes Based on Metallurgical Gases4.1.4.3.Ordinary Single‐Absorption Processes4.1.4.4.Wet‐Catalysis Processes4.1.5.Tail‐Gas Treatment4.1.6.Economic Factors4.2.Production by Nitrogen Oxide Processes4.3.Regeneration of Spent Sulfuric Acid4.3.1.Introduction4.3.2.Reconcentration to 70 ‐ 75 % H2SO44.3.3.Concentration to 93 ‐ 98 % H2SO44.4.Production of Oleum5.Construction Materials5.1.Metallic Materials5.2.Nonmetallic Materials6.Uses of Sulfuric Acid and Economic Aspects6.1.Indirect Uses6.2.Direct Uses6.3.Economic Aspects7.Analytical Techniques7.1.Concentration Measurement7.2.Measurement of Impurities7.3.Analysis of Acid‐Plant Gas Streams8.Sulfur Trioxide8.1.Properties8.2.Manufacture8.3.Handling and Uses9.Toxicology9.1.Sulfuric Acid9.2.Sulfur Trioxide10.Acknowledgement
Talc
Authors: Tufar Werner 
Published: April 2004

Abstract

The article contains sections titled:

1.

Talc

1.1.

History

1.2.

Structure and Mineralogy

1.3.

Properties

1.4.

Occurrence and Origin

1.5.

Deposits

1.6.

Processing and Quality Specifications

1.7.

Uses

1.8.

Economic Aspects

1.9.

Toxicology

2.

Pyrophyllite

2.1.

Introduction

2.2.

Structure and Mineralogy

2.3.

Properties

2.4.

Formation

2.5.

Deposits

2.6.

Processing, Quality Requirements, and Uses

3.

Chlorite
Detection of K‐ras exon 1 mutations by constant denaturant capillary electrophoresis
Authors: Zhao Chunxia , Xu Guowang , Shi Xianzhe , Ma Jianmei , Lu Shen , Yang Qing 
Published: April 2004

AbstractAmong various mutation detection methods, constant denaturant capillary electrophoresis (CDCE) is one of the most common techniques for rapid identiﬁcation of known or unknown mutations. In this report, a CDCE analysis method with homemade linear polyacrylamide (LPA) kit was developed on ABI 310 genetic analyzer, the effect and relationship of various denaturing factors in CDCE analysis were investigated and K‐ras gene mutations of 31 coloerctal cancer patients were detected. Results indicate that, with the increase of chemical danaturant concentration, the optimum temperature was lowered, and when the concentration of urea (formamide) was higher than 7 m (40%), the homoduplex and heteroduplex of mutant samples were separated with difﬁculty. Detection results of K‐ras gene in colorectal samples indicated that mutations were present in eight (26%) of 31 patients; most mutations were localized in codon 12, which is thought to be a critical step and plays an important role in human colorectal carcinogenesisas. Copyright © 2004 John Wiley & Sons, Ltd.
DPPH Radical Scavenging Activity of Ten Natural p‐Terphenyl Derivatives Obtained from Three Edible Mushrooms Indigenous to China
Authors: Liu Ji‐Kai , Hu Lin , Dong Ze‐Jun , Hu Qun 
Published: April 2004

AbstractThe antioxidant activities of ten natural p‐terphenyl derivatives, 1–10, obtained from the fruiting bodies of three edible mushrooms (Thelephora ganbajun, Thelephora aurantiotincta, Boletopsis grisea) indigenous to China were evaluated in comparison with BHA (‘butylated hydroxyanisole’=(1,1‐dimethylethyl)‐4‐methoxyphenol) and α‐tocopherol by the DPPH (‘1,1‐diphenyl‐2‐picrylhydrazyl’=2,2‐diphenyl‐1‐(2,4,6‐trinitrophenyl)hydrazyl) radical‐scavenging method. The compounds 1–3 showed significant antioxidant activity. The antioxidant activities of compounds 1–10 and reference compounds followed the order: 2>BHA>1>3>α‐tocopherol>10>9>6 >  5>8>7>4. The compound 2 exhibited the strongest radical‐scavenging activity with an EC50 value of 0.07 (EC50(BHA) 0.09; EC50(α‐tocopherol) 0.25).
Enantioselective Synthesis of (S)‐3‐Carboxy‐4‐((carboxy)difluoromethyl)phenylalanine in Protected Form and Its Incorporation into a PTP‐1B‐Directed Tripeptide
Authors: Kang Sang Uk , Gao Yang , Wu Li , Zhang Zhong‐Yin , Burke Terrence R. 
Published: April 2004

AbstractRecent findings have shown that, when expressed in the tripeptide platform, ‘Fmoc‐Glu‐Xxx‐Leu‐amide’, the phosphotyrosyl mimetic (pTyr), Xxx=(S)‐3‐carboxy‐4‐(carboxymethyl)‐Phe, provides higher PTP‐1B affinity than that obtained with Xxx=(S)‐difluorophosphonomethyl‐Phe (F2Pmp). This was of note, since difluorophosphonomethyl‐containing pTyr mimetics have typically exhibited higher PTP‐inhibitory potencies than carboxy‐based mimetics, indicating the potential value of 3‐carboxy‐4‐(carboxymethyl)‐Phe as a starting point for further analogue development. Therefore, relying on precedence that α‐fluorination often enhances PTP‐1B affinity, (S)‐3‐carboxy‐4‐((carboxy)difluoromethyl)‐Phe was designed as a PTP‐1B‐directed pTyr mimetic. Reported herein is the synthesis of this new amino acid analogue through application of commercially available Williams chiral auxiliary. The target was prepared in an orthogonally protected form suitable for peptide synthesis according to Fmoc chemistries and utilization for the synthesis of a PTP‐1B‐directed tripeptide bearing the sequence indicated above. Biological evaluation with in vitro PTP‐1B assays indicated nearly total loss of affinity for this peptide. Evidence is provided that the unexpected deleterious effect of fluorination is probably not related to pKa effects.