bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening Analyses of Pinosylvin Stilbenes, Resin Acids and Lignans in Norwegian Conifers
Authors: Hovelstad Hanne , Leirset Ingebjorg , Oyaas Karin , Fiksdahl Anne
Published: October 2008

The content and distribution of stilbenes and resin acids in Scots pine (Pinus sylvestris) and spruce (Picea abies), sampled in central Norway, have been examined. The contents of pinosylvin stilbenes in pine heartwood/living knots were 0.2-2/2-8 % (w/w). No stilbenes could be detected in spruce (Picea abies). The resin acid contents of pine sapwood/heartwood and knots were 1-4 and 5-10 % (w/w), respectively. Minor amounts of resin acids (< 0.2/< 0.04 %w/w) were identified in spruce wood/knots. The lignan content in knots of Norwegian spruce was 6.5 % (w/w). Diastereomerically pure hydroxymatairesinol (HMR, 84 % of total lignans) was readily isolated from this source since only minor quantities (2.6 % of total lignans) of the allo-HMR diastereomer was detected. Insignificant amounts of lignans were present in the sapwood. Lignans could not be detected in the sapwood or knots of Norwegian sallow (Salix caprea), birch (Betula pendula) or juniper (Juniperus communis).
Polymer – Supported Cobalt (II) Catalysts for the Oxidation of Alkenes
Authors: Błaż Edyta , Pielichowski Jan
Published: October 2008

Polymer-supported heterogeneous catalysts in a form of complexes of 8-hydroxy- quinoline with cobalt acetate were synthesized. Conjugated polymers – polyaniline (PANI), poly-o-toluidine (POT), poly-o-anisidine (POA) – were used as supports. Oxidation reactions of aliphatic and aromatic hydrocarbons were carried out in the presence of molecular oxygen at atmospheric pressure and epoxides or ketones were obtained as the main products with high selectivity.
Synthetic Studies on Erythromycin Derivatives: Reactivity of the C12-21 Alkene
Authors: Chen Wei-Min
Published: October 2008

The reactivity of the C12-21 alkene of some erythromycin A derivatives was studied. This double bond was easily oxidized to the corresponding epoxide with excellent stereoselectivity. A single crystal X-ray structure showed that the epoxide moiety was on the same side as the acetonide. When an erythromycin derivative containing a C12-21 alkene was treated with diazomethane a [3+2] cycloaddition affording a pyrazoline occurred. In the case of 6-O-allylated erythromycin derivatives the C12-21 alkene was selectively epoxidized in the presence of the 6-O-allyl moiety. These results show that the C12-21 alkene is an active reaction site, which can be used for useful further modification of erythromycin derivatives.
Synthesis and Antimicrobial Activity of Some Derivatives on the Basis (7-hydroxy-2-oxo-2H-chromen-4-yl)-acetic Acid Hydrazide
Authors: Cacic Milan , Trkovnik Mladen , Cacic Frane , Has-Schon Elizabeth
Published: October 2008

(7-Hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid hydrazide (2) was prepared from (7-hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid ethyl ester (1) and 100% hydrazine hydrate. Compound 2, is the key intermediate for the synthesis of several series of new compounds such as Schiff’s bases 3a-l, formic acid N'-[2-(7-hydroxy-2-oxo-2H- chromen-4-yl)acetyl] hydrazide (4), acetic acid N'-[2-(7-hydroxy-2-oxo-2H-chromen-4- yl)-acetyl] hydrazide (5), (7-hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid N'-[2-(4- hydroxy-2-oxo-2H-chromen-3-yl)-2-oxoethyl] hydrazide (6), 4-phenyl-1-(7-hydroxy-2- oxo-2H-chromen- 4-acetyl) thiosemicarbazide (7), ethyl 3-{2-[2-(7-hydroxy-2-oxo-2H- chromen-4-yl)-acetyl]hydrazono}butanoate (8), (7-hydroxy-2-oxo-2H-chromen-4-yl)- acetic acid N'-[(4-trifluoromethylphenylimino)methyl] hydrazide (9) and (7-hydroxy-2- oxo-2H-chromen-4-yl)acetic acid N'-[(2,3,4-trifluorophenylimino)-methyl] hydrazide (10). Cyclo- condensation of compound 2 with pentane-2,4-dione gave 4-[2-(3,5- dimethyl-1H-pyrazol-1-yl)-2-oxoethyl]-7-hydroxy-2H-chromen-2-one (11), while with carbon disulfide it afforded 7-hydroxy-4-[(5-mercapto-1,3,4-oxadiazol-2-yl)methyl]-2H- chromen-2-one (12) and with potassium isothiocyanate it gave 7-hydroxy-4-[(5- mercapto-4H-1,2,4-triazol-3-yl)methyl]-2H-chromen-2-one (14). Compound 7 was cyclized to afford 2-(7-hydroxy-2-oxo-2H-chromen-4-yl)-N ́-(4-oxo-2-phenylimino- thiazolidin-3-yl) acetamide (15).
A Simple Synthetic Route to Methyl 3-Fluoropyridine-4-carboxylate by Nucleophilic Aromatic Substitution
Authors: Tjosaas Freddy , Fiksdahl Anne
Published: October 2008

The nitro group of methyl 3-nitropyridine-4-carboxylate (1) has successfully been replaced by fluoride anion via nucleophilic aromatic substitution to give the 3-fluoro- pyridine-4-carboxylate 2.
Synthesis and Antidepressant Evaluation of Three para-Benzoquinone Mono-oximes and Their Oxy Derivatives
Authors: De Sousa Damião Pergentino , Schefer Renata Rabelo , Brocksom Ursula , Brocksom Timothy John
Published: October 2008

A series of three para-benzoquinone mono-oximes and four oxy-derivatives were prepared and tested for their antidepressant properties. The (4E) oxime of 2-isopropyl-5- methyl-para-benzoquinone (4) and the corresponding 2-diethylamino-ethyl derivative (10) present antidepressant activities and were slightly more potent than the reference standard.
Dechlorophyllation by Electrocoagulation
Authors: Jumpatong Kanlaya , Phutdhawong Weerachai , Buddhasukh Duang
Published: October 2008

Electrocoagulation was used for dechlorophyllation of alcoholic extracts from five plants. The results showed that for every plant extract studied, electrocoagulation was more efficient than the classical solvent extraction method in removing plant pigments, while not affecting the important secondary metabolites in those extracts.
Synthesis and Structural Characterization of the Sodium Salt of a New Sulfonate-containing Water Soluble N-Donor Ligand⎯ Self-assembly in the Solid State by π−π Stacking Interactions
Authors: Zhang Yonglian , Liang Hong-Chang
Published: October 2008

The synthesis, spectroscopic characterization, and X-ray crystal structure ofthe sodium salt of a new sulfonated water-soluble ligand, sodium 2-(2-pyridin-2-yl-ethylamino)-benzenesulfonate (L) are described. Compound L crystallizes in thecentrosymmetric space group Pbcn, orthorhombic, a=31.930(13) å, b=7.153(3) å,c=14.193(6) å, α=90.00, β=90.00, γ=90.00, V=3220(2) å3, Z=9. π−π stacking contactsinvolving interactions between the π-donor benzene and the π-acceptor pyridine systemsreinforce and direct the self-assembly of the structural motifs in the solid state.
Synthesis and Molecular Structure of 6-Amino-3-benzylmercapto-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one
Authors: Hwang Long-Chih , Tu Chun-Hsie , Wang Jung-Hui , Lee Gene-Hsiang
Published: October 2008

The title compound 6-amino-3-benzylmercapto-1,2,4-triazolo[3,4-f][1,2,4]-triazin-8(7H)-one (4), molecular formula C11H10N6OS, was obtained by the reaction of3-amino-2-benzyl-6-hydrazino-1,2,4-triazin-5(2H)-one (3) with carbon disulfide in awater/pyridine mixture. Compound 4 can also be synthesized by reacting6-amino-3(2H)mercapto-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one (7) with benzylbromide in methanolic ammonia water. The compound crystallizes in the monoclinicspace group P21/c with a = 7.2926(15), b = 14.456(2), c = 11.436(2) å, β = 105.30(2)°, V= 1162.9(4) å3 and Z = 4, resulting in a density Dcalc of 1.567 g/cm3. Molecules of 4 arelinked by extensive intermolecular N-H···N and N-H···O hydrogen bonding [graph set R22 (9)]. The structure is further stabilized by π-π stacking interactions. 2
Synthesis of New Chiral Amines with a Cyclic 1,2-Diacetal Skeleton Derived from (2R, 3R)-(+)-Tartaric Acid
Authors: Barros M. Teresa , Phillips Ana Maria Faísca
Published: October 2008

The syntheses of new chiral cyclic 1,2-diacetals from (2R, 3R)-( )-tartaric acidare described. C2-symmetrical diamines were prepared via direct amidation of the tartrate orfrom the corresponding bismesylate via reaction with sodium azide. For C1-symmetricalcompounds, the Appel reaction was used to form the key intermediate, amonochlorocarbinol, from the diol. Some of the new chiral compounds, produced in good tohigh yields, may be potentially useful as asymmetric organocatalysts or as nitrogen andsulfur chelating ligands for asymmetric metal catalyzed reactions. Thus, a bis-N-methyl-methanamine derivative, used in substoichiometric amounts, was found to catalyze theenantioselective addition of cyclohexanone to (E)-β-nitrostyrene with highdiastereoselectivity (syn / anti = 92:8), albeit giving moderate optical purity (syn: 30 %).
L-Proline Catalyzed Michael Additions of Thiophenols to α,β-Unsaturated Compounds, Particularly α-Enones, in the Ionic Liquid [bmim]PF6
Authors: Kotrusz Peter , Toma Stefan
Published: October 2008

L-Proline catalyzed additions of 13 different thiols to 11 different α-enoneMichael acceptors in [bmim] PF6 are reported. Reasonable to high yields of the reactionproducts were isolated in most cases.
Synthesis and Spectroscopic Studies of New Schiff Bases
Authors: Siddiqui Hamid Latif , Iqbal Amjid , Ahmad Saeed , Weaver W.
Published: October 2008

Five novel Schiff bases have been prepared from o-formylphenoxyacetic acidand a series of aminothiazoles to form a number of potentially biologically activecompounds. The structures of these Schiff bases have been characterized using IR and 1H-and 13C-NMR spectroscopy.
2,6-Dichloro-9-thiabicyclo[3.3.1]nonane: Multigram Display of Azide and Cyanide Components on a Versatile Scaffold
Authors: Díaz David Díaz , Converso Antonella , Sharpless K. Barry , Finn M. G.
Published: October 2008

2,6-Dichloro-9-thiabicyclo[3.3.1]nonane, easily available by an improved condensation of sulfur dichloride, sulfuryl chloride, and 1,5-cyclooctadiene, is a well- behaved scaffold for the nucleophilic substitution of azides and cyanides via neighboring- group participation by the sulfur atom. The products are isolated in high yields with purity >95% by simple extraction and washing protocols.
A Java Chemical Structure Editor Supporting the Modular Chemical Descriptor Language (MCDL)
Authors: Trepalin Sergei V. , Yarkov Alexander V. , Pletnev Igor V. , Gakh Andrei A.
Published: October 2008

A compact Modular Chemical Descriptor Language (MCDL) chemical structure editor (Java applet) is described. The small size (approximately 200 KB) of the applet allows its use to display and edit chemical structures in various Internet applications. The editor supports the MCDL format, in which structures are presented in compact canonical form and is capable of restoring bond orders as well as of managing atom and bond drawing overlap. A small database of cage and large cyclic fragment is used for optimal representation of difficult-to-draw molecules. The improved algorithm of the structure diagram generation can be used for other chemical notations that lack atomic coordinates (SMILES, InChI).
Substituted Pyrazinecarboxamides: Synthesis and Biological Evaluation
Authors: Dolezal Martin , Palek Lukas , Vinsova Jarmila , Buchta Vladimir , Jampilek Josef , Kralova Katarina
Published: October 2008

Condensation of the corresponding chlorides of some substituted pyrazine-2-carboxylic acids (pyrazine-2-carboxylic acid, 6-chloropyrazine-2-carboxylic acid, 5-tert-butylpyrazine-2-carboxylic acid or 5-tert-butyl-6-chloropyrazine-2-carboxylic acid) withvarious ring-substituted aminothiazoles or anilines yielded a series of amides. Thesyntheses, analytical and spectroscopic data of thirty newly prepared compounds arepresented. Structure-activity relationships between the chemical structures and the anti-mycobacterial, antifungal and photosynthesis-inhibiting activity of the evaluatedcompounds are discussed. 3,5-Bromo-4-hydroxyphenyl derivatives of substitutedpyrazinecarboxylic acid, 16-18, have shown the highest activity against Mycobacteriumtuberculosis H37Rv (54-72% inhibition). The highest antifungal effect againstTrichophyton mentagrophytes, the most susceptible fungal strain tested, was found for5-tert-butyl-6-chloro-N-(4-methyl-1,3-thiazol-2-yl)pyrazine-2-carboxamide (8, MIC =31.25 μmol·mL-1). The most active inhibitors of oxygen evolution rate in spinachMolecules 2006, 11 243 chloroplasts were the compounds 5-tert-butyl-6-chloro-N-(5-bromo-2-hydroxyphenyl)- pyrazine-2-carboxamide (27, IC50 = 41.9 μmol·L-1) and 5-tert-butyl-6-chloro-N-(1,3- thiazol-2-yl)-pyrazine-2-carboxamide (4, IC50 = 49.5 μmol·L-1).
Isolation and Biological Activity of New and Known Diterpenoids From Sideritis stricta Boiss. & Heldr.
Authors: Kilic Turgut
Published: October 2008

Nine known and one new ent-kaurene diterpenoid were isolated from the acetone extract of Sideritis stricta Boiss & Heldr. The new compound, identified as ent-1β-hydroxy-7α-acetyl-15β,16β-epoxykaurane (1) by IR, 1D and 2D NMR techniques and mass spectra, was isolated along with sideroxol (2), 7-acetyl sideroxol (3), 7-epicandicandiol (4), linearol (5), ent-7α,15β,18-trihydroxy-kaur-16-ene (6), ent-7α-acetyl,15,18-dihydroxy-kaur-16-ene (7), foliol (8), sideridiol (9) and siderol (10). The antibacterial and antifungal activities of these compounds and the whole crude acetone extract were evaluated against E. coli, S. aureus, K. pneumeonia and C. albicans.
ZrOCl2·8H2O: An Efficient, Cheap and Reusable Catalyst for the Esterification of Acrylic Acid and Other Carboxylic Acids with Equimolar Amounts of Alcohols
Authors: Sun Hong-Bin , Hua Ruimao , Yin Yingwu
Published: October 2008

Esterifications of carboxylic acids with equimolar amount of alcohols could beefficiently catalyzed by ZrOCl2·8H2O. Acrylate esters were obtained in good yields undersolvent-free conditions at ambient temperature. The esterification of other carboxylicacids with alcohols also proceeded at ambient temperature or at 50 oC to afford esters inhigh yields. If the esterification was performed in toluene under azeotropic refluxconditions to remove water, both the catalytic activity of ZrOCl2·8H2O and the rate ofesterification could be increased greatly. Furthermore, in the present catalytic system, theesters could be easily separated from the reaction mixtures and the catalyst could beeasily recovered and reused.
Microwave Assisted Synthesis of N-Arylheterocyclic Substituted-4-aminoquinazoline Derivatives
Authors: Liu Gang , Yang Song , Song Baoan , Xue Wei , Hu Deyu , Jin Linhong , Lu Ping
Published: October 2008

A simple, efficient, and general method has been developed for the synthesis of various N-aryl heterocylic substituted-4-aminoquinazoline compounds from 4-chloro- quinazoline and aryl heterocyclic amines under microwave irradiation using 2-propanol as solvent. The advantages of the use of microwave irradiation in relation to the classical method were demonstrated.
Reactions of (Benzamidomethyl)triethylammonium Chloride with Some Inorganic Nucleophiles in Aqueous Media
Authors: Popovski Emil , Bogdanov Jane , Najdoski Metodija , Hey-Hawkins Evamarie
Published: October 2008

A variety of benzamidomethyl derivatives were prepared in water under alkaline conditions (pH>9) via reaction of (benzamidomethyl)triethylammonium chloride (1) with different inorganic nucleophiles. Reaction of 1 with hydroxylamine did not give the expected mono(benzamidomethyl)-hydroxylamine (3) but rather gave N,N- di(benzamidomethyl)hydroxylamine (2). Reactions of 1 with sodium azide and potassium cyanide gave benzamidomethyl azide (4a) and benzamidomethyl cyanide (4b) respectively. Potassium thiocyanate and sodium iodide reacted with 1, and the anion- exchanged products (benzamidomethyl)triethylammonium isothiocyanate (5a) and (benzamidomethyl)triethylammonium iodide (5b) were thus obtained. Cyanamide and potassium cyanate reacted readily with 1 and both gave the same mixture of di(benzamidomethyl)amine (7) and tri(benzamidomethyl)amine (8). All the reactions occurred smoothly, under mild conditions, to give the products in moderate to high yields.
Improved Synthesis of Substituted 6,7-Dihydroxy-4-quinazolineamines: Tandutinib, Erlotinib and Gefitinib
Authors: Knesl Petr , Röseling Dirk , Jordis Ulrich
Published: October 2008

The synthesis of three substituted 6,7-dihydroxy-4-quinazolineamines: tandutinib (1), erlotinib (2) and gefitinib (3) in improved yields is reported. The intermediates were characterized by NMR and the purities determined by HPLC.
Catalytic Properties of the Dioxomolybdenum Siloxide MoO2(OSiPh3)2 and its 2,2'-Bipyridine Adduct MoO2(OSiPh3)2(bpy)
Authors: Bruno Sofia M. , Monteiro Bernardo , Balula Maria Salete , Lourenço Catarina , Valente Anabela A. , Pillinger Martyn , Ribeiro-Claro Paulo , Gonçalves Isabel S.
Published: October 2008

The tetrahedral triphenylsiloxy complex MoO2(OSiPh3)2 (1) and its Lewis baseadduct with 2,2'-bipyridine, MoO2(OSiPh3)2(bpy) (2), were prepared and characterised byIR/Raman spectroscopy, and thermogravimetric analysis. Both compounds catalyse theepoxidation of cis-cyclooctene at 55 oC using tert-butylhydroperoxide (t-BuOOH) isdecane as the oxidant, giving 1,2-epoxycyclooctane as the only product. The best resultswere obtained in the absence of a co-solvent (other than the decane) or in the presence of1,2-dichloroethane, while much lower activities were obtained when hexane oracetonitrile were added. With no co-solvent, catalyst 1 (initial activity 272 mol·molMo-1·h-1for a catalyst:substrate: oxidant molar ratio of 1:100:150) is much more active than 2(initial activity 12 mol·molMo–1·h–1). The initial reaction rates showed first orderdependence with respect to the initial concentration of olefin. With respect to the initialamount of oxidant, the rate order dependence for 1 (1.9) was higher than that for 2 (1.6).The dependence of the initial reaction rate on reaction temperature and initial amount ofcatalyst was also studied for both catalysts. The lower apparent activation energy of 1 (11kcal·mol–1) as compared with 2 (20 kcal·mol–1) is in accordance with the higher activity ofthe former.
Solvent Effects in Electrocoagulation of Selected Plant Pigments and Tannin
Authors: Chairungsi Neeranuch , Jumpatong Kanlaya , Phutdhawong Weerachai , Buddhasukh Duang
Published: October 2008

Electrocoagulation of a plant extract and certain substances representative of selected classes of plant pigments, viz. chlorophyll, a carotenoid, a phenolic substance and a tannin, was performed in ethanol containing varying amounts of water (15-75%). The results showed that the extent and efficiency of coagulation of these substances tends to vary in a manner directly related to the water content of the solvent, although the tannin and the phenolic substance were less sensitive to the solvent composition and are equally well coagulated in all solvent systems studied. The findings can be applied to the removal of these substances from aqueous alcoholic plant extracts using the electrocoagulation technique.
A Handy and Solventless Direct Route to Primary 3-[3-Aryl)-1,2,4-oxadiazol-5-yl]propionamides Using Microwave Irradiation
Authors: Neves Ricardo A.W. , Srivastava Rajendra M.
Published: October 2008

A one-step, simple and straightforward synthesis of the title amides from the corresponding carboxylic acids, urea and imidazole under microwave irradiation is described.
Synthesis and Antitumor Evaluation of Novel Derivatives of 6-Amino-2-phenylbenzothiazoles
Authors: Racane Livio , Stojkovic Ranko , Tralic-Kulenovic Vesna , Karminski-Zamola Grace
Published: October 2008

Novel derivatives of 6-amino-2-phenylbenzothiazole bearing differentsubstituents (amino, dimethylamino or fluoro) on the phenyl ring were prepared as thecorresponding hydrochloride salts. 6-Nitro-2-(substituted-phenyl)benzothiazoles (1-6) weresynthesized by condensation reactions of substituted benzaldehydes with 2-amino-5-nitrothiophenol. Nitro derivatives were reduced to the amino derivatives with SnCl2/HCl.Water soluble hydrochloride salts of 6-amino-2-(substituted-phenyl)benzothiazole (13-19)were prepared using concentrated or gaseous HCl. Compounds 13-19 were found to exertcytostatic activities against malignant human cell lines: cervical (HeLa), breast (MCF-7),colon (CaCo-2), laryngeal carcinoma (Hep-2), and normal human fibroblast cell lines (WI-38).
An Improved NMR Study of Liposomes Using 1-Palmitoyl-2-oleoyl-sn-glycero-3-phospatidylcholine as Model
Authors: Cruciani Oscar , Mannina Luisa , Sobolev Anatoli P. , Cametti Cesare , Segre AnnaLaura
Published: October 2008

In this paper we report a comparative characterization of Small UnilamellarVesicles (SUVs), Large Unilamellar Vesicles (LUVs) and Multilamellar Vesicles (MLVs)prepared from 1-palmitoyl-2-oleoyl-sn-glycero-3-phospatidylcholine (POPC), carried outusing two NMR techniques, namely High Resolution NMR in solution and HighResolution–Magic Angle Spinning (HR-MAS). The size and size distributions of thesevesicles were investigated using the dynamic light scattering technique. An improvedassignment of the 1H-NMR spectrum of MLVs is also reported.
Experimental and Theoretical Study of Lanthanide Complexes Based on Linear and Macrocyclic Polyaminopolycarboxylic Acids Containing Pyrazolylethyl Arms
Authors: Pérez-Mayoral Elena , Soriano Elena , Cerdán Sebastián , Ballesteros Paloma
Published: October 2008

We report the synthesis of two novel Gd(III)-complexes derived from linear and macrocyclic polyaminopolycarboxylic acids 1 and 2, which contain a 3,5- dimethylpyrazolyl-ethyl arm, and a study of their relaxivity properties. The relationships between the experimental and theoretical results have provided interesting information about the kinetic and thermodynamic stability of these complexes.
Synthesis of Novel Sterically Demanding Carbo- and Heterocyclic β-Ketoesters
Authors: Mihovilovic Marko D. , Fischer Thomas C. M. , Stanetty Peter
Published: October 2008

We present an easy method for the synthesis of β-ketoesters starting from variouscarbocyclic and heterocyclic carboxylic acids and esters. The β-ketoester side-chain wasintroduced by a sequence involving α-deprotonation and quenching with CO2, conversion tothe corresponding acid chloride and subsequent chain elongation using deprotonated ethylacetate.
Selective Enzymatic Reduction of Aldehydes
Authors: Sello Guido , Orsini Fulvia , Bernasconi Silvana , Di Gennaro Patrizia
Published: October 2008

Highly selective enzymatic reductions of aldehydes to the corresponding alcohols was performed using an E. coli JM109 whole cell biocatalyst. A selective enzymatic method for the reduction of aldehydes could provide an eco-compatible alternative to chemical methods. The simplicity, fairly wide scope and the very high observed chemoselectivity of this approach are its most unique features.
Molecules 2002, 7, 885-895
Authors: McPhee Derek
Published: October 2008

n/a
First Synthesis of 3-Acetyl-2-aminothiophenes Using the Gewald Reaction
Authors: Eller Gernot A. , Holzer Wolfgang
Published: October 2008

Novel 3-acetyl-2-aminothiophenes were prepared from cyanoacetone and1,4-dithianyl-2,5-diols using a modified Gewald reaction. The syntheses of thecorresponding acetamides, as well as that of 3-acetyl-2-amino-5-nitrothiophene – aninteresting building-block for thiophene azo dyes – are reported. Detailed spectroscopicinvestigations (1H-NMR, 13C-NMR, MS, IR) of the obtained compounds are presented.
Synthesis of New 4(3H)-Quinazolinone Derivatives Using 5(4H)-Oxazolones
Authors: Hamidian Hooshang , Tikdari Ahmad Momeni , Khabazzadeh Hojatollah
Published: October 2008

New derivatives of 5(4H)-quinazolinone containing 2-imidazolin-5-one rings have been prepared from 5(4H)-oxazolone derivatives.
Theoretical Studies on the Tautomerism of 1,5,6,7-Tetrahydro-4H-indazol-4-ones
Authors: Medina Carlos Pérez , López Concepción , Claramunt Rosa M.
Published: October 2008

Computational studies on three tautomeric forms of four 1,5,6,7-tetrahydro- 4H-indazol-4-one derivatives: 1,5,6,7-tetrahydro-4H-indazol-4-one (1), 6,6-dimethyl- 1,5,6,7-tetrahydro-4H-indazol-4-one (2), 3-methyl-1,5,6,7-tetrahydro-4H-indazol-4-one (3) and 3,6,6-trimethyl-1,5,6,7-tetrahydro-4H-indazol-4-one (4), have been performed at different levels, ranging from semiempirical AM1, ab initio Hartree-Fock HF/6-31G* and HF/6-31G** to B3LYP/6-31G** density functional calculations. These calculations have been used to establish the most stable tautomer, which in all cases was in agreement with the experimental data.
Synthesis and Antifungal Bioactivities of 3-Alkylquinazolin- 4-one Derivatives
Authors: Ouyang Guiping , Zhang Peiquan , Xu Gangfang , Song Baoan , Yang Song , Jin Linhong , Xue Wei , Hu Deyu , Lu Ping , Chen Zhuo
Published: October 2008

A simple, efficient, and general method has been developed for the synthesis ofvarious 3-alkylquinazolin-4-one derivatives from quinazolin-4-one treated with alkylbromides under phase transfer catalysis condition. The structures of the compounds werecharacterized by elemental analysis, IR, 1H-NMR and 13C-NMR spectra. Title compound6-bromo-3-propylquinazolin-4-one (3h) was found to possess good antifungal activity.
Synthesis and Analgesic Activity Evaluation of Some Agmatine Derivatives
Authors: He Hongxia , Liu Mengjia , Zheng Zhibing , Liu Ying , Xiao Junhai , Su Ruibin , Hu Chun , Li Jin , Li Song
Published: October 2008

A series of N,N’-disubstituted-2-nitroethene-1,1-diamine and N,N’-disubstituted- N’’-cyanoguanidine derivatives were prepared and evaluated for in vivo analgesic activity. The blood brain barrier (BBB) VolSurf model was used to predict the BBB permeation profiles of our synthesized compounds. Some compounds show both remarkable analgesic activity and good BBB permeation profiles, and these compounds might be developed for treatment of opioid tolerance and dependence.
Synthesis of New trans-2-Benzyl-3-(furan-2-yl)-4-substituted-1,2,3,4-tetrahydroisoquinolinones
Authors: Kandinska Meglena I. , Kozekov Ivan D. , Palamareva Mariana D.
Published: October 2008

The reaction of homophthalic anhydride and N-(furan-2-yl-methylidene)- benzylamine in different solvents and varying temperatures was studied in detail. Mixtures of the expected trans- and cis-1,2,3,4-tetrahydroisoquinoline-4-carboxylic acids trans-5 and cis-5, alongwith by-products 6 and 7 were obtained in dichloroethane or benzene. In pyridine, used for the first time, the reaction became completely diastereoselective, giving only the trans isomer. The carboxylic acid group of trans-5 was transformed in four steps into cyclic aminomethyl groups which yielded various new tetrahydroisoquinolinones trans- 11a-g, incorporating both a known fragment of pharmacological interest and various pharmacophoric substituents.
Hypervalent Iodine–Mediated Ring Contraction Reactions
Authors: Silva Luiz F.
Published: October 2008

Hypervalent iodine reagents constitute a powerful tool in modern synthetic organic chemistry, promoting several important reactions. One such reaction is the ring contraction of cycloalkenes and cycloalkanones promoted by iodine(III) compounds, such as iodobenzene diacetate, iodosylbenzene, iodotoluene difluoride, and [hydroxy(tosyloxy)- iodo]benzene (Koser ́s reagent). This review covers all the literature related to the ring contraction of cyclic ketones and olefins promoted by iodine(III) species.
A Convenient Asymmetric Synthesis of a β-amino Ester with Additional Functionalization as a Precursor for Peptide Nucleic Acid (PNA) Monomers
Authors: Garrido Narciso M. , Díez David , Domínguez Sara H. , Sánchez M. Rosa , García Mercedes , Urones Julio G.
Published: October 2008

We report the asymmetric synthesis of di-3-pentyl (3S,αS,7E)-3-N-benzyl-N- α-methylbenzylamino-dec-7-enedioate (9), which contains the correct functionalization to produce δ-amino acid derivatives to be used as monomers for Peptide Nucleic Acid (PNA) formation With this aim, thymine-pentanoic acid 15 and some of its ester derivatives were obtained, their reactivity was studied and the noteworthy ethyl ester 12 was quantitatively produced by transesterification of methyl ester 11, thus paving the way for the synthesis of the thymine-containing amino ester IV, which has been designed as a building block for a Nucleic-Acid analog with a chiral, flexible peptide backbone
Synthesis, Molecular Structure and Characterization of Allylic Derivatives of 6-Amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]-triazin-8(7H)-one
Authors: Hwang Long-Chih , Jane Shin-Yi , Lai Hsing-Yi , Tu Chun-Hsien , Lee Gene-Hsiang
Published: October 2008

1-Allyl- (2) and 7-allyl-6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one (3) were obtained via the 18-crown-6-ether catalyzed room temperature reactionof 6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one (1) with potassiumcarbonate and allyl bromide in dry acetone. The structures of these two derivatives wereverified by 2D-NMR measurements, including gHSQC and gHMBC measurements. Theminor compound 2 may possess aromatic character. A single crystal X-ray diffractionexperiment indicated that the major compound 3 crystallizes from dimethyl sulfoxide in themonoclinic space group P21/n and its molecular structure includes an attached dimethylsulfoxide molecule, resulting in the molecular formula C10H16N6O2S. Molecular structuresof 3 are linked by extensive intermolecular N-H···N hydrogen bonding [graph set C 1 (7)]. 1Each molecule is attached to the dimethyl sulfoxide oxygen via N-H···O intermolecularhydrogen bonding. The structure is further stabilized by π-π stacking interactions.
Syntheses and Structural Studies of Schiff Bases Involving Hydrogen Bonds
Authors: Perona Almudena , Sanz Dionisia , Claramunt Rosa M. , Elguero José
Published: October 2008

New Schiff bases have been prepared by reacting 3-hydroxy-4-pyridine- carboxaldehyde with various amines. NMR spectroscopic methods provided clear evidence that the Schiff bases exist in the solid state and in solution as hydroxyimino tautomers with the E-configuration. A study of the stabilities of the tautomeric forms and the different conformers has been carried out using density functional calculations at the B3LYP/6-31G** level.
Ionic Liquid-promoted Ring-closure Reactions between 1,4-Dihydroxyanthraquinone and Diamines
Authors: Le Zhang-Gao , Xie Zong-Bo , Ying Min
Published: October 2008

The reaction of 1,4-Dihydroxyanthraquinone with diamines was carried out in thepresence of CuCl2, CuCl in the ionic liquid [Bmim]PF6, [Bmim]BF4 or [Bmim]Cl·CuCl.
Synthesis of New Bis-1,2,4-Triazole Derivatives
Authors: Bekircan Olcay , Bektas Hakan
Published: October 2008

A series of new 1,2/1,3-bis[o-(N-methylidenamino-3-aryl-5-phenyl-4H-1,2,4-triazole-4-yl)phenoxy]ethane/propane derivatives 4 were prepared in good yields bytreatment of 4-amino-3-aryl-5-phenyl-4H-1,2,4-triazoles 2 with certain bis-aldehydes 1.Compounds 4 were reduced with NaBH4 to afford the corresponding 1,2/1,3-bis[o-(N-methylamino-3-aryl-5-phenyl-4H-1,2,4-triazole-4-yl)phenoxy]ethane/propane derivatives5. All new compounds were characterized by IR, 1H-NMR, 13C-NMR and mass spectraldata.
Host-Guest Chemistry of Tolbutamide
Authors: Herranz Fernando , Santa María Mª Dolores , Claramunt Rosa M.
Published: October 2008

The molecular recognition features of tolbutamide with four synthetic hosts have been studied by means of NMR titrations, NOESY experiments and Monte Carlo (MC) conformational search. The interaction strength and the most probable structure reveal new insights on the recognition phenomena of this urea derivative in comparison with close related compounds.
Solid Phase Synthesis of a Metronidazole Oligonucleotide Conjugate
Authors: Walsh Andrew J. , Davis Michael L. , Fraser William
Published: October 2008

Direct, solid phase synthesis of an oligonucleotide conjugate of the antibioticdrug metronidazole was accomplished by the phosphoramidite method. Removal ofprotecting groups and cleavage from the controlled pore glass (CPG) solid support wassuccessful using mild conditions (20% Et3N in pyridine, then conc. NH3 (aq) at rt for 30min) whereas standard conditions (conc. NH3 (aq) at 55 °C for 16 h) cleaved the drug.
Delayed Open Access or Permanent Non-Open Access
Authors: Lin Shu-Kun
Published: October 2008

Since last year, we have resumed use of a two tier publication system, whereby we have continued to offer full Open Access publication to those authors willing to contribute financially to support this option, while providing authors with the alternative choice of free publication without Open Access for those who prefer not to pay [1].[...]
Synthesis of Some Thienopyrimidine Derivatives
Authors: El-Baih Fatma E. M. , Al-Blowy Hanan A. S. , Al-Hazimi Hassan M.
Published: October 2008

Thioxothienopyrimidinones, alkylthio- and arylalkylthiothienopyrimidinones, thienopyrimidinones, thienopyrimidines a thienopyrimidinedione and a thienotriazolo- pyrimidinone were prepared from 2-amino-3-carboethoxy-4,5-disubstituted thiophenes and 2-amino-3-cyano-4,5-disubstituted thiophenes via reactions with different reagents.
Electrocoagulation of Quinone Pigments
Authors: Chairungsi Neeranuch , Jumpatong Kanlaya , Suebsakwong Patiwat , Sengpracha Waya , Phutdhawong Weerachai , Buddhasukh Duang
Published: October 2008

Some representative quinones, viz. one naphthoquinone (plumbagin) and five anthraquinones (alizarin, purpurin, chrysazin, emodin, and anthrarufin), were subjected to electrocoagulation. It was found that the rate and extent of coagulation of these compounds appears to correlate with the number and relative position of their phenolic substituent groups, and that all of the coagulated quinones could be recovered. Attempts were then made to electrochemically isolate three quinones, namely plumbagin, morindone and erythrolaccin, from natural sources.
[Hydroxy(tosyloxy)iodo]benzene Mediated α-Azidation of Ketones
Authors: Prakash Om , Pannu Kamaljeet , Prakash Richa , Batra Anita
Published: October 2008

Reaction of various ketones with [hydroxy(tosyloxy)iodo]benzene (HTIB) followed by treatment of the α-tosyloxy ketones thus generated in situ with NaN3 offers a one-pot procedure for the synthesis of α-azido ketones. The HTIB used in this conversion may also be generated in situ by using iodosobenzene in combination with p-toluene- sulphonic acid.
A Novel Biosurfactant, 2-Acyloxyethylphosphonate, Isolated from Waterblooms of Aphanizomenon flos-aquae
Authors: Kaya Kunimitsu , Morrison Louise F. , Codd Geoffrey A. , Metcalf James S. , Sano Tomoharu , Takagi Hiroo , Kubo Takuya
Published: October 2008

A novel biosurfactant, 2-acyloxyethylphosphonate, was isolated from waterblooms of Aphanizomenon flos-aquae. Its structure was elucidated by chemical degradation and HRFABMS, GC/EI-MS and 1D- and 2D-NMR spectral analyses. The surfactant contained one mole of 2-hydroxyethylphosphonate and one mole of fatty acid, with hexadecanoic acid accounting for 84.1% of the total fatty acid content. The structure was confirmed by synthesis of 2-oleoyloxyethylphosphonate from ethylene oxide, phosphorus acid and oleic acid chloride. Considering the isolated surfactant molecule as hexadecanoyloxyethylphosphonic acid (mw. 364), the critical micelle concentration (CMC) was about 22 mM.
Chemical Composition and Antimicrobial Activity of the Essential Oil from Ambrosia trifida L.
Authors: Wang Peng , Kong Chui Hua , Zhang Chao Xian
Published: October 2008

The essential oil obtained by steam distillation of dried aerial parts of Ambrosia trifida L. from Northeast China was analyzed by GC and GC–MS. The essential oil yield based on dried plant material was 0.12% and thirty-five compounds (corresponding to 86.7% of the total weight) were identified. The main components were: bornyl acetate (15.5%), borneol (8.5%), caryophyllene oxide (8.3%), α-pinene (8.0%), germacrene D (6.3%), β-caryophyllene (4.6%), trans-carveol (2.9%), β-myrcene (2.6%), camphor (2.4%) and limonene (3.2%). A. trifida essential oil demonstrated bactericidal and fungicidal activity against six bacterial strains and two fungal strains, using the agar diffusion method.
Novel Reaction of N,N'-Bisarylmethanediamines with Formaldehyde. Synthesis of Some New 1,3,5-Triaryl-1,3,5-hexahydrotriazines
Authors: Ghandi Mehdi , Salimi Farshid , Olyaei Abolfazl
Published: October 2008

The acid-catalyzed cyclocondensation of N,N'-bisaryl (aryl = 2-pyrimidinyl, 2- pyrazinyl and 4-nitrophenyl) methanediamines 5a-c with aqueous formaldehyde in refluxing acetonitrile leads to the formation of the corresponding 1,3,5-triaryl-1,3,5-hexa- hydrotriazines 6a-c. The stoichiometric reactions of 2-aminopyrimidine and 2-amino- pyrazine with aqueous formaldehyde in acetonitrile under reflux conditions also afforded 6a and 6b, respectively. Treatment of 2-aminopyrimidine with aqueous formaldehyde in a 3:2 ratio yielded N,N',N"-tris(2-pyrimidinyl)dimethylenetriamine (7a) as a sole product, which upon subsequent reaction with formaldehyde also afforded 6a. The reaction of N,N'-biphenylmethanediamine with formaldehyde was also investigated.
Novel Furanoid α-Substitued α-Amino Acid as a Potent Turn Mimic in Peptide Synthesis
Authors: Martinková Miroslava , Gonda Jozef , Raschmanová Jana
Published: October 2008

A stereoselective approach has been developed to the new sugar amino acid and potential potent turn mimic 5-O-(tert-butyldimethylsilyl)-3-deoxy-1,2-O- isopropylidene-3-methoxycarbonylamino-α-D-xylofuranose 3-C-carboxylic acid (12), via the [3,3]-sigmatropic rearrangement of allylic thiocyanates (Z)-6 and (E)-7, prepared from D-xylose. The synthesis of a new dipeptide 13 is also described.
Synthesis and Anticancer Activities of Novel 1,4-Disubstituted Phthalazines
Authors: Li Juan , Zhao Yan-Fang , Yuan Xiao-Ye , Xu Jing-Xiong , Gong Ping
Published: October 2008

A series of novel 1-anilino-4-(arylsulfanylmethyl)phthalazines were designed and synthesized. The structures of all the compounds were confirmed by IR, 1H-NMR, elemental analysis and MS. The analogues 1-(3-chloro-4-fluoroanilino)-4-(3,4- difluorophenylthio-methyl)phthalazine (12) and 1-(4-fluoro-3-trifluoromethylanilino)-4- (3,4-difluorophenyl-thiomethyl)phthalazine (13) showed higher activity than a cisplatin control when tested in vitro against two different cancer cell lines using the microculture tetrazolium method (MTT) method.
1,4-Benzodiazepine N-Nitrosoamidines: Useful Intermediates in the Synthesis of Tricyclic Benzodiazepines
Authors: Fustero Santos , González Javier , Del Pozo Carlos
Published: October 2008

1,4-Benzodiazepine N-nitrosoamidines have been used as scaffolds for the preparation of different tricyclic derivatives. Replacement of the N-nitrosoamidine moiety through treatment with the nucleophiles acetylhydrazine, aminoacetaldehyde dimethylacetal and 1-amino-2-propanol, followed by an acid-catalyzed cyclization step, afforded triazolo and imidazobenzodiazepines 1, 6, and 7, respectively, in good yields. When acetylhydrazine is used as a nucleophile, the overall process provides an alternative route to alprazolam (1b) and triazolam (1c), respectively.
Synthesis and Molecular Structures of Two [1,4-bis(3-pyridyl)-2,3-diazo-1,3-butadiene]-dichloro-Zn(II) Coordination Polymers
Authors: Lee Gene-Hsiang , Wang Hsin-Ta
Published: October 2008

Two novel coordination polymers with 3D metal-organic frameworks (MOFs) have been synthesized by reacting 1,4-bis(3-pyridyl)-2,3-diazo-1,3-butadiene (L) with zinc dichloride. Both compounds have the same repeating unit consisting of a distorted tetrahedral Zn(II) center coordinated by two chlorides and two pyridyl nitrogen atoms of two bridging bismonodentate L ligands, however, different structural conformations have been found, one forming a helical chain and the other producing a square-wave chain. The intermolecular C−H···Cl hydrogen bonds in 1 and 2 play important roles in the formation of three-dimensional coordination polymers. Compound 1 crystallized in an orthorhombic space group Pna21 with a = 7.9652(3), b = 21.4716(7), c = 8.2491(3)Å, V = 1410.81(9) Å 3 and Z = 4. Compound 2 crystallized in a monoclinic space group P21/n with a = 9.1752(3), b = 14.5976(4), c = 10.3666(3) Å , β = 98.231(2)°, V = 1374.16(7) Å 3 and Z = 4.
One-Pot Synthesis of 5-Arylidene-2-Imino-4-Thiazolidinones under Microwave Irradiation
Authors: Kasmi-Mir Souad , Djafri Ayada , Paquin Ludovic , Hamelin Jack , Rahmouni Mustapha
Published: October 2008

A rapid and easy solvent free one-pot synthesis of 5-arylidene-2-imino-4- thiazolidinones by condensation of the thioureas with chloroacetic acid and an aldehyde under microwave-irradiation is described.
Epibatidine Alkaloid Chemistry: 5. Domino-Heck Reactions of Azabicyclic and Tricyclic Systems
Authors: Yolacan Çigdem , Bagdatli Emine , Öcal Nüket , Kaufmann Dieter E.
Published: October 2008

Palladium-catalyzed hydroarylations and additional domino reactions of aza- bicyclic and tricyclic norbornene derivatives were investigated and a series of new epibatidine analogues were synthesized.
Synthesis of Conformationally Constrained Aryl- or Heteroarylpiperazinyl Derivatives of Selected Imides as 5-HT1A Receptor Ligands
Authors: Kossakowski Jerzy , Krawiecka Mariola , Kuran Bożena
Published: October 2008

The preparation of a number of cyclic imide 5-HT1A receptor ligandderivatives has been described. Their structures were conformationally constrained byintroducing rigid linkers containing unsaturated bonds or aromatic benzene rings. Thesecompounds are expected to possess anxiolytic and antidepressant activity.
Development of Fluorous Lewis Acid-Catalyzed Reactions
Authors: Yoshida Akihiro , Hao Xiuhua , Yamazaki Osamu , Nishikido Joji
Published: October 2008

Organic synthetic methodology in the 21st century aims to conform to the principles of green sustainable chemistry (GSC) and we may expect that in the future, the realization of GSC will be an important objective for chemical industries. An important aim of synthetic organic chemistry is to implement waste-free and environmentally-benign industrial processes using Lewis acids as versatile as aluminum choride. A key technological objective of our work in this area has been to achieve a “catalyst recycling system that utilizes the high activity and structural features of fluorous Lewis acid catalysts”. Thus, we have developed a series of novel fluorous Lewis acid catalysts, namely the ytterbium(III), scandium(III), tin(IV) or hafnium(IV) bis(perfluoroalkanesulfonyl)amides or tris(perfluoro- alkanesulfonyl)methides. Our catalysts are recyclable and effective for acylations of alcohols and aromatics, Baeyer-Villiger reactions, direct esterifications and transesterifications in a fluorous biphasic system (FBS), in supercritical carbon dioxide and on fluorous silica gel supports.
Formal Synthesis of the ACE Inhibitor Benazepril·HCl via an Asymmetric Aza-Michael Reaction
Authors: Yu Luo-Ting , Huang Ji-Ling , Chang Ching-Yao , Yang Teng-Kuei
Published: October 2008

A formal enantioselective synthesis of benazepril·HCl (4), an anti- hypertensive drug, is reported. Our synthesis employed an asymmetric aza-Michael addition of L-homophenylalanine ethyl ester (LHPE, 1) to 4-(2-nitrophenyl)-4-oxo- but-2-enoic acid methyl ester (6) as the key step to prepare (2S,3’S)-2-(2-oxo-2,3,4,5- tetrahydro-1H-benzo[b]azepin-3-ylamino)-4-phenylbutyric acid ethyl ester (8), which is the key intermediate leading to benazepril·HCl (4).
Efficient Ce(NO3)3·6H2O-Catalyzed Solvent-Free Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones
Authors: Adib Mehdi , Ghanbary Khadijeh , Mostofi Manizheh , Ganjali Mohammad Reza
Published: October 2008

Cerium(III) nitrate hexahydrate efficiently catalyzes the three-component Biginelli reaction under solvent-free conditions of an aldehyde, a β-keto ester or β- diketone and urea or thiourea to afford the corresponding 3,4-dihydropyrimidin-2(1H)- ones or –thiones in excellent yields.
Application of the Solid-Phase Julia–Lythgoe Olefination in Vitamin D Side-Chain Construction
Authors: D'herde Jo N. , De Clercq Pierre J.
Published: October 2008

An example of the Julia–Lythgoe attachment of the vitamin D side chain to a solid-phase linked Inhoffen–Lythgoe diol derived CD-ring fragment is reported.
A Novel Triterpene from Centella asiatica
Authors: Yu Quan-Lin , Duan Hong-Quan , Takaishi Yoshihisa , Gao Wen-Yuan
Published: October 2008

A novel triterpene, 2α,3β,20,23-tetrahydroxyurs-28-oic acid (1), was isolated from the aerial part of Centella asiatica. Its structure was elucidated by spectroscopic methods, including 2D-NMR spectra. It displayed no activity against Hela and A549 cell lines at concentrations of 10 and 30 μg/mL, respectively.
Synthesis and Antiviral Bioactivities of α-Aminophosphonates Containing Alkoxyethyl Moieties
Authors: Xu Yingshu , Yan Kai , Song Baoan , Xu Gangfang , Yang Song , Xue Wei , Hu Deyu , Lu Ping , Ouyang Guiping , Jin Linhong , Chen Zhuo
Published: October 2008

A simple, efficient, and general method has been developed for the synthesis ofvarious α-aminophosphonate derivatives 4a-4l by treatment of substituted benzaldehydes andaniline with bis(2-methoxyethyl)- or bis(2-ethoxyethyl) phosphite under microwaveirradiation without solvents and catalysts. The products were characterized by elementalanalysis, IR, 1H-NMR, 13C- and 31P-NMR spectra. The X-ray crystallographic data of therepresentative compound 4l was determined. The new α-aminophosphonate derivatives werefound to possess moderate to good antiviral activity.
Cerebrosides from the Roots of Serratula chinensis
Authors: Ling Tiejun , Xia Tao , Wan Xiaochun , Li Daxiang , Wei Xiaoyi
Published: October 2008

A new cerebroside, 1-O-β-D-glucopyranosyl-(2S,3R,8E)-2-[(2’R)-2-hydroxy- palmitoylamino]-8-octadecene-1,3-diol, along with aralia cerebroside and 1-O-β-D- glucopyranosyl-(2S,3S,4R,8E)-2-[(2’R)-2-hydroxybehenoylamino]-8-octadecene-1,3,4-triol were isolated from the roots of Serratula chinensis S. Moore. The structure of the new cerebroside was established by spectroscopic and chemical means. Occurrence of cerebrosides in Serratula is reported here for the first time.
Synthesis and Characterisation of Eight Isomeric Bis(2-pyridyloxy)naphthalenes
Authors: O’Keefe Brendan J. , Steel Peter J.
Published: October 2008

Eight isomeric bis(2-pyridyloxy)naphthalenes have been prepared from reactions of 2-bromopyridine with the appropriate dihydroxynaphthalene and the products fully characterised by 1- and 2-D NMR spectroscopy.
Cytotoxicity of Two Triterpenoids from Nigella glandulifera
Authors: Tian Ze , Liu Yu-Ming , Chen Si-Bao , Yang Jun-Shan , Xiao Pei-Gen , Wang Liao , Wu Erxi
Published: October 2008

During an investigation of antitumor substances from Nigella glandulifera Freyn et Sint. (Ranunculaceae) the cytotoxicity of two oleanane triterpene saponins isolated from the seeds of this species, kalopanaxsaponins A and I, was evaluated against HepG2, drug resistant HepG2 (R-HepG2) (two hepatocyte cell lines) and primary cultured normal mouse hepatocytes. Evident cytotoxic activities were observed. Morphological observations and cell cycle analysis suggest that these compounds inhibit the proliferation of hepatoma by inducing apoptosis and consequently kalopanaxsaponins A and I may be potential therapeutic agents for the treatment of parental and drug resistant hepatoma.
An Efficient Synthesis of a Spirocyclic Oxindole Analogue
Authors: Teng Dawei , Zhang Hongxing , Mendonca A.
Published: October 2008

An efficient, scaleable synthesis approach towards the spirocyclic oxindole analogue 1’-(tert-butoxycarbonyl)-2-oxospiro[indoline-3,4’-piperidine]-5-carboxylic acid (1) is described. The key steps are dianion alkylation and cyclization of ethyl 2- oxindoline-5-carboxylate (4) and demethylation of the resulting spirocyclic oxindole ethyl 1’-methyl-2-oxospiro[indoline-3,4’-piperidine]-5-carboxylate (5). The target compound was obtained in an overall yield of 35 % over eight steps without resorting to chromatographic purification.
Asymmetric Synthesis of (7aS)-7a-Methyl-4,5,7,7a-tetrahydro-1H-indene-2,6-dione and Useful Derivatives Thereof
Authors: Demin Samuël , Van Haver Dirk , De Clercq Pierre J.
Published: October 2008

The enantioselective synthesis of the title compound, using Meyers' bicyclic lactam methodology, is described. This compound and a few of its derivatives are useful intermediates in natural product synthesis.
Glycerolipids from a Sarcotragus Species Sponge
Authors: Liu Yonghong , Jung Jee H. , Ji Hong , Zhang Si
Published: October 2008

One known and two new glycerolipids have been isolated from a Sarcotragus sp. marine sponge. The gross structures were established based on NMR and MS analysis.