bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the Antimicrobial and Antioxidant Activities of Origanum dictamnus Extracts before and after Encapsulation in Liposomes
Authors: Gortzi Olga , Lala Stavros , Chinou Ioanna , Tsaknis John
Published: October 2008

The antioxidant and antimicrobial activity of methanol or dichloromethane extracts of O. dictamnus, produced from wild and organic cultivated specimens, were determined. The Rancimat and malondialdehyde (MDA) by HPLC methods were used to measure the antioxidant action, in comparison with that of the common commercial antioxidants butylated hydroxytoluene (BHT) and α-tocopherol. The extracts that presented high antioxidant activity were encapsulated in liposomes and their antioxidant action was again estimated using differential scanning calorimetry (DSC). Thermaloxidative decomposition of the samples (pure liposomes and encapsulated extracts) and the modification of the main transition temperature for the lipid mixture and the splitting of the calorimetric peak in the presence of the antioxidants were also studied by the DSC method. All extracts showed antioxidant and antimicrobial activities. Their action proved superior to α-tocopherol. The methanol extract of organic cultivated O. dictamnus (240 ppm) showed higher activity than butylated hydroxytoluene. After encapsulation in liposomes the antioxidant as well as antimicrobial activities proved to be higher than those of the same extracts in pure form.
Cancer Preventive Mechanismsof the Green Tea Polyphenol (-)-Epigallocatechin-3-gallate
Authors: Chen Lei , Zhang Hong-Yu
Published: October 2008

Accumulating evidence indicates that consumption of tea, especially green tea, is good for preventing cancer. To elucidate the cancer preventive mechanisms of green tea, much effort has been devoted to investigating the anticancer effects of (-)-epigallocatechin-3-gallate (EGCG), the major component of green tea. It has been revealed that EGCG restrained carcinogenesis in a variety of tissues through inhibition of mitogen-activated protein kinases (MAPK), growth factor-related cell signaling, activation of activator protein 1 (AP-1) and nuclear factor-B (NF-κB), topoisomerase I, matrix metalloproteinases and other potential targets. Therefore, EGCG is a multipotent anticancer agent, which not only provides solid evidence to support the anticancer potential of green tea, but also offers new clues for discovering multiple-targeted anticancer drugs.
Bis(trimethylsilyl)chromate Catalyzed Oxidations of Alcohols to Aldehydes and Ketones with Periodic Acid
Authors: Asadolah Karim , Heravi Majid M , Hekmatshoar Rahim , Majedi Soma
Published: October 2008

A facile, selective and high yielding bis(trimethylsilyl) chromate (BTSC) catalyzed selective oxidation of alcohols to aldehydes and ketones with periodic acid is reported.
Synthesis, Antiviral and Antifungal Bioactivity of 2-Cyano-acrylate Derivatives Containing Phosphonyl Moieties
Authors: Lv Yin-Pu , Wang Xian-You , Song Bao-An , Yang Song , Yan Kai , Xu Guang-Fang , Bhadury Pinaki S , Liu Fang , Jin Lin-Hong , Hu De-Yu
Published: October 2008

Alkyl 2-cyano-3-methylthio-3-phosphonylacrylates were synthesized by the reaction of alkyl 2-cyano-3,3-dimethylthioacrylates with dialkyl phosphites. The structures of the new compounds were characterized by elemental analyses, IR, 1H-, 13C- and 31P-NMR spectral data. These compounds were tested in vitro against pathogenic fungi, namely, Fusarium graminearum, Cytospora mandshurica and Fusarium oxysporum. Amongst all compounds, 2d and 2t were found to be effective against the tested fungi at 50μg/mL. A half-leaf method was used to determine the in vivo protective, inactivation and curative efficacies of the title products against tobacco mosaic virus (TMV). Title compounds 2a and 2b were found to possess good in vivo curative, protection and inactivation effects against TMV with inhibitory rates at 500 mg/L of 60.0, 89.4 and 56.5 and 64.2, 84.2 and 61.2 %, respectively. To the best of our knowledge, this is the first report on the antiviral and antifungal activity of alkyl 2-cyano-3-methylthio-3-phosphonylacrylates.
A New Type of NADH Model Compound: Synthesis and Enantioselective Reduction of Benzoylformates to the Corresponding Mandelates
Authors: Zhao Jia , Wang Nai-Xing , Wang Wu-Wei , Liu Yan-Hong , Li Li , Wang Gui-Xia , Yu Jin-Lan , Tang Xin-Liang
Published: October 2008

A new type of NADH model compound with good reactivity and enantioselectivity has been synthesized in good yields by an efficient and convenient synthetic method. The structures of these model compounds were confirmed by 1H and 13C-NMR and MS.
Synthesis and Fluorescence Properties of 5,7-Diphenylquinoline and 2,5,7-Triphenylquinoline Derived from m-Terphenylamine
Authors: Qi Shujian , Shi Kehui , Gao Hongyin , Liu Qiancai , Wang Hong
Published: October 2008

Synthesis of 5,7-phenylquinoline from the Skraup reaction of m-terphenyl-amine and glycerol in the presence of acid is reported. Further reaction of 5,7-diphenyl-quinoline with phenyl lithium prepared in situ led to the formation of 2,5,7-triphenyl-quinoline. All of the products and their intermediates were characterized and the UV-Vis and photo-luminescence (PL) spectra of m-terphenylamine, 5,7-diphenylquinoline and 2,5,7-triphenylquinoline are also reported.
β-Orcinol Metabolites from the Lichen Hypotrachyna revoluta
Authors: Papadopoulou Panagiota , Tzakou Olga , Vagias Constantinos , Kefalas Panagiotis , Roussis Vassilios
Published: October 2008

Four new β-orcinol metabolites, hypotrachynic acid (1), deoxystictic acid (2), cryptostictinolide (3) and 8 ́-methylconstictic acid (4) along with the metabolites 8 ́-methylstictic acid (5), 8 ́-methylmenegazziaic acid (6), stictic acid (7), 8 ́-ethylstictic acid (8) and atranorin (9), that have been previously described, were isolated for the first time from the tissue extracts of the lichen Hypotrachyna revoluta (Flörke) Hale. The structures of the new metabolites were elucidated on the basis of extensive spectroscopic analyses. Radical scavenging activity (RSA) of the metabolites isolated in adequate amounts, was evaluated using luminol chemiluminescence and comparison with Trolox®.
Evaluation of Antioxidative Activity of Croatian Propolis Samples Using DPPH· and ABTS·+ Stable Free Radical Assays
Authors: Jasprica Ivona , Bojic Mirza , Mornar Ana , Besic Erim , Bucan Kajo , Medic-Saric Marica
Published: October 2008

Propolis is one of the richest sources of plant phenolics (flavonoids and phenolic acids), which are widely recognized as rather strong antioxidants. The aim of our work was to use colored stable free radical (DPPH· and ABTS·+) spectrophotometric and thin-layer chromatographic (TLC) assays to study the antioxidative behavior of the phenolics (caffeic acid, galangin and pinocembrin) most commonly present in Croatian propolis samples obtained from different Croatian regions. We propose a mathematical model providing a more sophisticated interpretation of the obtained results and a new parameter named antioxidative efficiency (AOE) is introduced. The kinetic behaviour of chosen standards determined by spectrophotometric assays follows the exponential decrease of the absorption curve. Explained numerically, AOE represents the absolute value of the first derivative of an absorbance curve in the point A0/e (where A0 is the absorbance measured at t = 0 and e is the natural logarithm base). The advantage of this newly introduced parameter is that it provides an easy and accurate mutual comparison between the rates of antioxidative efficiency of different propolis samples. A TLC assay was only applicable in the case of the DPPH· radical. Dose-response curves were described using a linear function with AOE expressed as a coefficient of the slope. The chromatographic method was shown to be very rapid, reliable and easy-to-perform.
Evaluation of the Activity of the Sponge Metabolites Avarol and Avarone and their Synthetic Derivatives Against Fouling Micro- and Macroorganisms
Authors: Tsoukatou Maria , Maréchal Jean Philippe , Hellio Claire , Novaković Irena , Tufegdzic Srdan , Sladić Dusan , Gašić Miroslav J , Clare Anthony S , Vagias Constantinos , Roussis Vassilios
Published: October 2008

The sesquiterpene hydroquinone avarol (1) was isolated from the marine sponge Dysidea avara, whereas the corresponding quinone, avarone (2), was obtained by oxidation of avarol, and the significantly more lipophilic compounds [3’-(p-chloro-phenyl)avarone (3), 3’,4’-ethylenedithioavarone (4), 4’-isopropylthioavarone (5), 4’-tert-butylthioavarone (6), 4’-propylthioavarone (7), 4’-octylthioavarone (8)] were obtained by nucleophilic addition of thiols or p-chloroaniline to avarone. All these compounds were tested, at concentrations ranging from 0.5 to 50 μg/mL, for their effect on the settlement of the cyprid stage of Balanus amphitrite, for toxicity to both nauplii and cyprids and for their growth inhibitory activity on marine bacteria (Cobetia marina, Marinobacterium stanieri, Vibrio fischeri and Pseudoalteromonas haloplanktis) and marine fungi (Halosphaeriopsis mediosetigera, Asteromyces cruciatus, Lulworthia uniseptata and Monodictys pelagica).
Lupane Triterpenoids from Acacia mellifera with Cytotoxic Activity
Authors: Mutai Charles , Abatis Dennis , Vagias Constantinos , Moreau Dimitri , Roussakis Christos , Roussis Vassilios
Published: October 2008

Three new pentacyclic triterpenoids: (20R)-3-oxolupan-30-al (1), (20S)-3-oxolupan-30-al (2) and (20R)-28-hydroxylupen-30-al-3-one (3), along with (20S)-3β-hydroxylupan-30-al (4), the latter previously described as a constituent of an epimeric mixture, were isolated from Acacia mellifera. In addition, the known metabolites 30-hydroxylup-20-(29)-en-3-one (5), 30-hydroxylup-20-(29)-en-3β-ol (6), atranorin, methyl 2,4-dihydroxy-3,6 dimethyl benzoate, sitosterol-3β-O-glucoside and linoleic acid were found in the analyzed plant species for the first time. The structures of the new metabolites were elucidated by extensive spectroscopic analyses and their relative stereochemistry was determined by NOESY experiments. The new metabolite 3 exhibited significant cytotoxic activity against the NSCLC-N6 cell line, derived from a human non-small-cell bronchopulmonary carcinoma.
Effects of Quercetin on Mushroom Tyrosinase and B16-F10 Melanoma Cells
Authors: Kubo Isao , Nitoda Teruhiko , Nihei Ken-ichi
Published: October 2008

In searching for tyrosinase inhibitors from plants using L-3,4-dihydroxyphenylalanine (L-DOPA) as a substrate, quercetin was found to be partially oxidized to the corresponding o-quinone under catalysis by mushroom tyrosinase (EC 1.14.18.1). Simultaneously, L-DOPA was also oxidized to dopaquinone and both o-quinones were further oxidized, respectively. The remaining quercetin partially formed adducts with dopaquinone through a Michael type addition. In general, flavonols form adducts with dopaquinone as long as their 3-hydroxyl group is free. Quercetin enhanced melanin production per cell in cultured murine B16-F10 melanoma cells, but this effect may be due in part to melanocytotoxicity. The concentration leading to 50% viable cells lost was established as 20 μM and almost complete lethality was observed at 80 μM.
Antioxidant Activity of a New Aromatic Geranyl Derivative of the Resinous Exudates from Heliotropium glutinosum Phil.
Authors: Modak Brenda , Rojas Macarena , Torres René , Rodilla Jesús , Luebert Federico
Published: October 2008

Heliotropium glutinosum Phil. (Heliotropiceae) is a resinous bush that grows at a height of 2000 m in Chañaral, Chile. From the resinous exudates of Heliotropium glutinosum Phil. a new aromatic geranyl derivative: 4-methoxy-3-[(2)-7’-methyl-3’-hydroxymethyl-2’,6’-octadienyl] phenol (1) and three flavonoids: 5,3'-dihydroxy-7,4'-dimethoxyflavanone (2), 5,4'-dihydroxy-7-methoxyflavanone (3) and 4'-acetyl-5-hydroxy-7-methoxyflavanone (4) were isolated and their structures were determined. Their antioxidant activity were evaluated using the bleaching of ABTS and DPPH derived cation radical methods and expressed in terms of FRE (fast reacting equivalents) and TRE (total reacting equivalents), where FRE is a good measure of the quick protection of a given compound against oxidants and TRE measures the degree of long-term protection of the antioxidant, or how effective it is against a strong oxidative stress.
Coordination Compounds Based on 1,2,3,4-Tetrahydro-isoquinoline-3-carboxylic Acid
Authors: Jansa Petr , Macháček Vladimír , Nachtigall Petr , Wsól Vladimír , Svobodová Markéta
Published: October 2008

Syntheses of 2,6-bis[((3S)-3-(methoxycarbonyl)-1,2,3,4-tetrahydroisoquinolin-2-yl)carbonyl]pyridine and its coordination compounds with Cu2+, Co2+, Co3+, or Fe3+ are described. By means of 1H- and 13C-NMR spectra it was proved that 2,6-bis[((3S)-3-(methoxycarbonyl)-1,2,3,4-tetrahydroisoquinolin-2-yl)carbonyl]pyridine as well as its coordination compound with Co3+ exist in the form of a mixture of three conformers, differing in the conformations at the two amide groups present. The prepared coordination compounds were tested in the enantioselective catalysis of the nitroaldol addition of nitromethane with 2-nitrobenzaldehyde or 4-nitrobenzaldehyde, and in the Michael addition of ethyl 2-oxocyclohexanecarboxylate to but-3-en-2-one.
Antimicrobial Activity and Spectral, Magnetic and Thermal Studies of Some Transition Metal Complexes of a Schiff Base Hydrazone Containing a Quinoline Moiety
Authors: Al-Sha’alan Nora H
Published: October 2008

A series of new copper(II), cobalt(II), nickel(II), manganese(II), iron(III), and uranyl(VI) complexes of the Schiff base hydrazone 7-chloro-4-(benzylidene-hydrazo)quinoline (HL) were prepared and characterized. The Schiff base behaves as a monobasic bidentate ligand. Mononuclear complexes with the general composition [ML2(Cl)m(H2O)2(OEt)n]·xEtOH (M = Cu(II), Co(II), Ni(II), Mn(II), Fe(III) or UO2(VI); m and n = 0-1; x = 1-3) were obtained in the presence of Li(OH) as a deprotonating agent. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, infrared, electronic spectra, magnetic susceptibility and conductivity measurements. An octahedral geometry was suggested for all the complexes except the Cu(II) and UO2(VI) ones. The Cu(II) complex has a square-planar geometry distorted towards tetrahedral, while the UO2(VI) complex displays its favored heptacoordination. The Schiff base ligand, HL, and its complexes were tested against one strain Gram +ve bacteria (Staphylococcus aureus), Gram -ve bacteria (Escherichia coli), and Fungi (Candida albicans). The prepared metal complexes exhibited higher antibacterial activities than the parent ligand and their biopotency is discussed.
Biotransformations of Imbricatolic Acid by Aspergillus niger and Rhizopus nigricans Cultures
Authors: Schmeda-Hirschmann Guillermo , Aranda Carlos , Kurina Marcela , Rodríguez Jaime A , Theoduloz Cristina
Published: October 2008

Microbial transformation of imbricatolic acid (1) by Aspergillus niger afforded 1α-hydroxyimbricatolic acid (2), while transformation with Rhizopus nigricans yielded 15-hydroxy-8,17-epoxylabdan-19-oic acid (3). When the diterpene 1 was added to a Cunninghamella echinulata culture, the main products were the microbial metabolites mycophenolic acid (4) and its 3-hydroxy derivative 5. All the structures were elucidated by spectroscopic methods. The cytotoxicity of these compounds towards human lung fibroblasts and AGS cells was assessed. While 4 and 5 showed low cytotoxicity, with IC50 values > 1000 μM against AGS cells and fibroblasts, 1α-hydroxyimbricatolic acid (2) presented moderate toxicity towards these targets, with IC50 values of 307 and 631 μM, respectively. The structure of 2 is presented for the first time.
Synthesis and Cytotoxic Activity of Some 3-Benzyl-5-Arylidenefuran-2(5H)-ones
Authors: Teixeira Róbson Ricardo , Barbosa Luiz Cláudio , Maltha Célia Regina Alvares , Rocha Marcelo Eça , Bezerra Daniel Pereira , Costa-Lotuf Letícia Veras , Pessoa Cláudia , Moraes Manoel Odorico
Published: October 2008

3-Benzyl-furan-2(5H)-one (2a) and 3-(4-bromobenzyl)-furan-2(5H)-one (2b) were treated with TBDMSOTf and converted into the corresponding tert-butyldimethyl-silylfuran ethers. These furans were further condensed with several aromatic aldehydes affording compounds 5-14 with general 3-benzyl-5-arylidene-furan-2(5H)-one structures in 31% to 98% yields. Such compounds are analogues of the naturally occurring nostoclide lactones, reported to present moderate cytotoxic activity. Compounds 5-14 were submitted to an in vitro bioassay against the HL-60, HCT-8, SF295 and MDA-MB-435 cancer cell lines using the MTT cytotoxicity assay.
Structure Elucidation of a Pyrazolo[3,4]pyran Derivative by NMR Spectroscopy
Authors: Liu Xuehui , Cui Yuxin
Published: October 2008

The structure of a representative pyrazolo[3,4]pyran derivative was determined by 1D and 2D NMR techniques. Complete 1H and 13C chemical shifts for this compound are reported. Careful analysis of the HMBC (Heteronuclear Multi-Bond Correlation) spectrum helped to elucidate the configuration of the derivative around C7 and C8. The results showed that the characteristic double-strong and double-weak cross peak pattern in the HMBC spectrum for C7 and C8 might be useful for establishing the structures of other pyrazolo[3,4]pyran derivatives.
Synthesis of Sulfonamides and Evaluation of Their Histone Deacetylase (HDAC) Activity
Authors: Oh Seikwan , Moon Hyung–In , Son Il–Hong , Jung Jae–Chul
Published: October 2008

A simple synthesis of sulfonamides 4–22 as novel histone deacetylase (HDAC) inhibitors is described. The key synthetic strategies involve N–sulfonylation of L–proline benzyl ester hydrochloride (2) and coupling reaction of N–sulfonyl chloride 3 with amines in high yields. It was found that several compounds showed good cellular potency with the most potent compound 20 exhibiting an IC50 = 2.8 μM in vitro.
Synthesis and Anti-tumor Activities of Novel [1,2,4]triazolo[1,5-a]pyrimidines
Authors: Zhao Xiang-Lin , Zhao Yan-Fang , Guo Shu-Chun , Song Hai-Sheng , Wang Ding , Gong Ping
Published: October 2008

A series of novel [1,2,4]triazolo[1,5-a]pyrimidine derivatives has been designed and synthesized in order to find novel anti-tumor compounds. The structures of all the compounds were confirmed by IR, 1H-NMR, MS and elemental analysis. Their anti-tumor activities against cancer cell lines (HT-1080 and Bel-7402) were tested by the MTT method in vitro. Among them, compound 19 displayed the best anti-tumor activity with IC50 values of 12.3 μM and 6.1 μM against Bel-7402 and HT-1080 cell lines respectively.
Neuroprotective Activity of Triterpenoid Saponins from Platycodi radix Against Glutamate-induced Toxicity in Primary Cultured Rat Cortical Cells
Authors: Son Il Hong , Park Yong Hoon , Lee Sung Ik , Yang Hyun Duk , Moon Hyung-In
Published: October 2008

During our investigation of the neuroprotective activity of Platycodi radix we found that an aqueous extract of this folk medicine exhibited significant protection against glutamate-induced toxicity in primary cultured rat cortical cells. In order to clarify the neuroprotective mechanism(s) of this observed effect, activity-guided isolation was performed to seek and identify active fractions and components. By such fractionation, four known triterpene saponin compounds - platycodins A, C and D and deapioplatycodin D - were isolated from the n-butanol fraction. Among these four compounds, platycodin A exhibited significant neuroprotective activities against glutamate-induced toxicity, exhibiting cell viability of about 50 %, at concentrations ranging from 0.1 μM to 10 μM. Therefore, the neuroprotective effect of Platycodi radix might be due to the inhibition of glutamate-induced toxicity by the saponin compounds it contains.
Phenolic Compounds and Antimicrobial Activity of Olive (Olea europaea L. Cv. Cobrançosa) Leaves
Authors: Pereira Ana Paula , Ferreira Isabel CFR , Marcelino Filipa , Valentão Patricia , Andrade Paula B , Seabra Rosa , Estevinho Leticia , Bento Albino , Pereira José Alberto
Published: October 2008

We report the determination of phenolic compounds in olive leaves by reversed-phase HPLC/DAD, and the evaluation of their in vitro activity against several microorganisms that may be causal agents of human intestinal and respiratory tract infections, namely Gram positive (Bacillus cereus, B. subtilis and Staphylococcus aureus), Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae) and fungi (Candida albicans and Cryptococcus neoformans). Seven phenolic compounds were identified and quantified: caffeic acid, verbascoside, oleuropein, luteolin 7-O-glucoside, rutin, apigenin 7-O-glucoside and luteolin 4’-O-glucoside. At low concentrations olive leafs extracts showed an unusual combined antibacterial and antifungal action, which suggest their great potential as nutraceuticals, particulalry as a source of phenolic compounds.
Flavanol Derivatives from Rhizophora stylosa and Their DPPH Radical Scavenging Activity
Authors: Li Dong-Li , Li Xiao-Ming , Peng Ze-Yu , Wang Bin-Gui
Published: October 2008

A new acetylated flavanol, 3,7-O-diacetyl (–)-epicatechin (3), and seven known flavanol derivatives, (–)-epicatechin (1), 3-O-acetyl (–)-epicatechin (2), 3,3′,4′,5,7-O-pentaacetyl (–)-epicatechin (4), (+)-afzelechin (5), (+)-catechin (6), cinchonain Ib (7), and proanthocyanidin B2 (8), were isolated from the stems and twigs of the mangrove plant Rhizophora stylosa and identified. The crude extract, the different fractions and all of the purified compounds were evaluated for DPPH radical scavenging activity.
Stereoselective Syntheses of Fluorescent Non-Natural Aromatic Amino Acids Based on Asymmetric Michael Additions
Authors: Chen Heru , Zhong Xianbin , Wei Jin
Published: October 2008

Four fluorescent non-natural aromatic amino acids have been synthesized based on a key stereoselective Michael addition reaction. S-1-Phenylethylamine was employed as both the source of amine and the stereoselectivity controller. The overall yields were moderate (30-50%). Fluorescent properties of some of the fluorophores were also investigated. It was found that compounds with a dimethylamino group bonded to the aromatic ring display intramolecular charge transfer fluorescence.
Facile Synthesis of Optically Active Imidazole Derivatives
Authors: Marek Ales , Kulhanek Jiri , Ludwig Miroslav , Bures Filip
Published: October 2008

Five optically active imidazole derivatives have been synthesized via a facile 4-step reaction sequence starting from commercially available and inexpensive N-Cbz amino acids. While microwave assisted condensation was unsuccessful, the condensation of the corresponding α-bromoketones with formamidine acetate in liquid ammonia was revealed to be a useful method for the synthesis of such imidazole derivatives. The derivatives thus prepared are structurally-related to histamine.
Synthesis of 5-Dialkyl(aryl)aminomethyl-8-hydroxyquinoline Dansylates as Selective Fluorescent Sensors for Fe3+
Authors: Peng Ruogu , Wang Feng , Sha Yaowu
Published: October 2008

A series of 5-dialkyl(aryl)aminomethyl-8-hydroxyquinoline dansylates were synthesized and their fluoroionophoric properties toward representative alkali ions, alkaline earth ions and transition metal ions were investigated. Among the selected ions, Fe3+ caused considerable quenching of the fluorescence, while Cr3+ caused quenching to some extent. The absence of any significant fluorescence quenching effects of the other ions examined, especially Fe2+, renders these compounds highly useful Fe3+-selective fluorescent sensors.
Synthesis and Biological Evaluation of Some Novel Schiff’s Bases from 1,2,4-Triazole
Authors: Ye Xiao-Xia , Chen Zhen-Fei , Zhang An-Jiang , Zhang Li-Xue
Published: October 2008

We have synthesized a number of novel Schiff’s bases from 4-amino-3-(D-glucoheptonic-hexitol-1-yl)-1H-1,2,4-triazole-5-thione. By attaching D-glucoheptonic-hexitol-1-yl residues to 1,2,4-triazole at the 3-position, the solubility of the title compounds has been improved greatly. All the products have been characterized by elemental analysis, IR, 1H-NMR, 13C-NMR and MS. The plant-growth regulating effects of the title compounds were examined. From the biological activity results, we found that most compounds showed weak to moderate activities.
Antiradical Activity of Paulownia tomentosa (Scrophulariaceae) Extracts
Authors: Smejkal Karel , Holubova Pavla , Zima Ales , Muselik Jan , Dvorska Margita
Published: October 2008

Paulownia tomentosa is a large indecidous tree planted mostly for its fast growing wood and decoratative purposes. The tree is also used in traditional Chinese medicine. As a part of our study of natural polyphenols, the fruits of Paulownia tomentosa were extracted by EtOH and than subjected to liquid/liquid extraction. Fractions were analysed by TLC and HPLC to determine presence of phenolic substantaces. We identified and quantified acteoside (1) and isoacteoside (2) in the EtOAc and n-BuOH extracts; mimulone (3) and diplacone (4) in the MeOH extract. To determine the antiradical activity of extracts we used the anti DPPH and peroxynitrite assays. The activity was expressed as Trolox C equivalents, IC50 for DPPH scavenging and a time dependency course was established. The polyphenols content was determined; results were expressed as gallic acid equivalents. Using these methods we found the fractions of the n-BuOH, EtOAc and MeOH extracts that display antiradical activity, which could be exploited as potential pharmaceuticals.
Solar Ultraviolet-B Radiation Increases Phenolic Content and Ferric Reducing Antioxidant Power in Avena sativa
Authors: Ruhland Christopher T. , Fogal Mitchell J. , Buyarski Christopher R. , Krna Matthew A.
Published: October 2008

We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm) on the maximum photochemical efficiency of photosystem II (Fv/Fm), bulk-soluble phenolic concentrations, ferric-reducing antioxidant power (FRAP) and growth of Avena sativa. Treatments involved placing filters on frames over potted plants that reduced levels of biologically effective UV-B by either 71% (reduced UV-B) or by 19% (near-ambient UV-B) over the 52 day experiment (04 July - 25 August 2002). Plants growing under near-ambient UV-B had 38% less total biomass than those under reduced UV-B. The reduction in biomass was mainly the result of a 24% lower leaf elongation rate, resulting in shorter leaves and less total leaf area than plants under reduced UV-B. In addition, plants growing under near-ambient UV-B had up to 17% lower Fv/Fm values early in the experiment, and this effect declined with plant age. Concentrations of bulk-soluble phenolics and FRAP values were 17 and 24% higher under near-ambient UV-B than under reduced UV-B, respectively. There was a positive relationship between bulk-soluble phenolic concentrations and FRAP values. There were no UV-B effects on concentrations of carotenoids (carotenes + xanthophylls).
Composition and Enantiomeric Analysis of the Essential Oil of the Fruits and the Leaves of Pistacia vera from Greece
Authors: Tsokou Anastasia , Georgopoulou Katerina , Melliou Eleni , Magiatis Prokopios , Tsitsa Eugenia
Published: October 2008

The essential oils of the fruits and the leaves of pistachio (Pistacia vera L.) were analyzed by GC and GC/MS. Fresh unripe pistachio fruits were richer in essential oil (0.5 %, w/w) than the leaves (0.1 %, w/w). Twenty one compounds were identified in the essential oil of the fruits and the major components were (+)-α-pinene (54.6 %) and terpinolene (31.2 %). The enantiomeric ratio of the major constituents of the essential oil of the fruits was determined using chiral GC/MS and it was found that the (+)/(-)-α-pinene ratio was 99.5:0.5, (+)/(-)-limonene 80:20, (+)/(-)-β-pinene 96:4, and (+)/(-)-α-terpineol 0:100. Thirty three compounds were identified in the essential oil of the leaves and the major components were found to be α-pinene (30.0 %), terpinolene (17.6 %) and bornyl acetate (11.3 %).
Synthesis and Antibacterial Properties of New 8-Nitrofluoroquinolone Derivatives
Authors: Al-Hiari Yusuf M. , Al-Mazari Inas Saleh , Shakya Ashok K. , Darwish Rula M. , Abu-Dahab Rana
Published: October 2008

The objective of this research was the preparation of new 8-nitrofluoroquinolone models and investigation of their antibacterial properties. The work initially involved large scale preparation of the synthon 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (3), followed by introduction of substituted primary amine appendages at the C-7 position to give derivatives 9a-g, in which the amino group is appended to substituted benzenes or aromatic heterocycles, is part of a primary α-amino acid or just a simple primary aliphatic amine. This nucleophilic aromatic substitution step was a very simple procedure since the 8-nitro group of the above synthon facilitated the addition of weak nucleophiles at C-7. All compounds prepared were fully identified and characterized using NMR, IR, EA and MS, and were consistent with expected structures. The prepared targets and the intermediates have shown interesting antibacterial activity against gram positive and/or gram negative strains. In particular, the p-toluidine, p-chloroaniline and aniline derivatives showed good activity against S. aureus with MIC range ≈ 2-5 μg/mL. In conclusion, more lipophilic groups seem to enhance activity against gram positive strains.
Synthesis of Novel Nitro-substituted Triaryl Pyrazole Derivatives as Potential Estrogen Receptor Ligands
Authors: Naoum Fotini , Kasiotis Konstantinos M , Magiatis Prokopios , Haroutounian Serkos A
Published: October 2008

Novel tetrasubstituted pyrazole derivatives bearing a nitro substituent on their A-phenol ring were synthesized and their binding affinity towards the estrogen receptor (ER) subtypes ERα and ERβ was determined. Among compounds tested, the 2-nitrophenol derivative 5c was found to bind satisfactorily to both estrogen receptor subtypes (RBAα=5.17 and RBAβ=3.27). In general, the introduction of a nitro group into the A ring of these compounds was found to benefit their ERβ binding abilities.
(-)-Catechin in Cocoa and Chocolate: Occurence and Analysis of an Atypical Flavan-3-ol Enantiomer
Authors: Kofink Michael , Papagiannopoulos Menelaos , Galensa Rudolf
Published: October 2008

Cocoa contains high levels of different flavonoids. In the present study, the enantioseparation of catechin and epicatechin in cocoa and cocoa products by chiral capillary electrophoresis (CCE) was performed. A baseline separation of the catechin and epicatechin enantiomers was achieved by using 0.1 mol·L−1 borate buffer (pH 8.5) with 12 mmol·L-1 (2-hydroxypropyl)-γ-cyclodextrin as chiral selector, a fused-silica capillary with 50 cm effective length (75 μm I.D.), +18 kV applied voltage, a temperature of 20°C and direct UV detection at 280 nm. To avoid comigration or coelution of other similar substances, the flavan-3-ols were isolated and purified using polyamide-solid-phase-extraction and LC-MS analysis. As expected, we found (-)-epicatechin and (+)-catechin inunfermented, dried, unroasted cocoa beans. In contrast, roasted cocoa beans and cocoa products additionally contained the atypical flavan-3-ol (-)-catechin. This is generally formed during the manufacturing process by an epimerization which converts (-)-epicatechin to its epimer (-)-catechin. High temperatures during the cocoa bean roasting process and particularly the alkalization of the cocoa powder are the main factors inducing the epimerization reaction. In addition to the analysis of cocoa and cocoa products, peak ratios were calculated for a better differentiation of the cocoa products.
Withdrawn Paper: Molecules 2005, 10, 1126-1134
Authors: McPhee Derek
Published: October 2008

n/a
Flavonoids and Strigolactones in Root Exudates as Signals in Symbiotic and Pathogenic Plant-Fungus Interactions
Authors: Steinkellner Siegrid , Lendzemo Venasius , Langer Ingrid , Schweiger Peter , Khaosaad Thanasan , Toussaint Jean-Patrick , Vierheilig Horst
Published: October 2008

Secondary plant compounds are important signals in several symbiotic and pathogenic plant-microbe interactions. The present review is limited to two groups of secondary plant compounds, flavonoids and strigolactones, which have been reported in root exudates. Data on flavonoids as signaling compounds are available from several symbiotic and pathogenic plant-microbe interactions, whereas only recently initial data on the role of strigolactones as plant signals in the arbuscular mycorrhizal symbiosis have been reported. Data from other plant-microbe interactions and strigolactones are not available yet. In the present article we are focusing on flavonoids in plant-fungalinteractions such as the arbuscular mycorrhizal (AM) association and the signaling between different Fusarium species and plants. Moreover the role of strigolactones in the AM association is discussed and new data on the effect of strigolactones on fungi, apart from arbuscular mycorrhizal fungi (AMF), are provided.
A Simplified Procedure for Indole Alkaloid Extraction from Catharanthus roseus Combined with a Semi-synthetic Production Process for Vinblastine
Authors: Verma Arvind , Laakso Into , Seppänen-Laakso Tuulikki , Huhtikangas Aarre , Riekkola Marja-Liisa
Published: October 2008

Dried leaves of Catharanthus roseus were extracted with aqueous acidic 0.1 M solution of HCl. Alkaloid-embonate complexes were obtained as precipitates by treating the extract with an alkaline (NaOH) solution of embonic acid (4,4-methylene-bis-3-hydroxynaphtalenecarboxylic acid). The precipitate mainly consisted of catharanthine and vindoline embonates and it was directly used as the starting material for a semi-synthesis of the anti-cancer bisindole alkaloid vinblastine. The coupling reaction involved oxidation of catharanthine in aqueous acidic medium by singlet oxygen (1O2), continuously produced in situ by the reaction between H2O2 with NaClO. An excess of NaBH4 was used for the reduction step. Analysis of the reaction mixture indicated a maximum yield of 20% for vinblastine at pH 8.3, based on the initial amount of catharanthine concentration. Direct-injection electrospray ionization mass spectrometry in positive ion mode was used for the identification of vinblastine. The mass spectra of vinblastine were dominated by the corresponding protonated molecular ion [M+H]+ at m/z 811 and the characteristic fragment ions matched with those of the standard compound.
Design and Synthesis of a Coumarin-based Acidichromic Colorant
Authors: Lin Shih-Lun , Kuo Pei-Yu , Yang Ding-Yah
Published: October 2008

This paper describes the fine-tuning of the acidichromic properties of a coumarin-containing colorant 1 by incorporation of electron-donating and electron-withdrawing substituents on the coumarin moiety. Colorant 1 can undergo two distinct and reversible color changes under both strongly acidic and basic conditions, but not in the presence of gaseous ammonia. The results indicated that the bromo-substituted compound 5b changes from red to yellow when exposed to gaseous ammonia, both in solution and on polycarbonate film, suggesting that an electron-withdrawing group at the 7-position of the coumarin moiety made the enolic hydrogen on 5b more susceptible to deprotonation by a base than in the unsubstituted compound 1.
Chlorine Anion Encapsulation by Molecular Capsules Based on Cucurbit[5]uril and Decamethylcucurbit[5]uril
Authors: Zhang Yun-Qian , Zhu Qian-Jiang , Xue Sai-Feng , Tao Zhu
Published: October 2008

Three barrel-shaped artificial molecular capsules 1-3, based on normal cucurbit[5]uril (Q[5]) and decamethylcucurbit[5]uril (Me10Q[5]), were synthesized and structurally characterized by single-crystal X-ray diffraction. Encapsulation of a chlorine anion in the cavity of a Q[5] or Me10Q[5] to form closed a molecular capsule with the coordinated metal ions or coordinated metal ions and water molecules in the crystal structures of these compounds is common. The three complexes [Pr2(C30H30N20O10)Cl3(H2O)13]3+3Cl-·5H2O (1), [Sr2(C40H50N20O10)(H2O)4Cl]3+3Cl-·2(HCl) 19H2O (2) and [K(C40H50N20O10)(H2O)Cl]·[Zn(H2O)2Cl2]·[ZnCl4]2-·2(H3O)+·8H2O (3) all crystallize as isolated molecular capsules.
A Novel and Efficient Synthesis of N,N-Dialkylaminoisopropyl- and O-alkylisopropyl-2-(1-alkyl-2-oxopropylidene)phosphonohydrazido Oximes - Potential Marine Fish Toxin Analogues. Part 1
Authors: Kumar Rajesh , Gupta Arvind K , Kaushik Mahabir P
Published: October 2008

A novel and efficient method for the synthesis of N,N-dialkylaminoisopropyl- and O-alkylisopropyl-2-(1-alkyl-2-oxopropylidene)phosphonohydrazido oximes (4) using activated silica as dehydrating agent has been developed. The reaction involves the condensation of substituted diacetyl monoxime and N,N-dialkylaminoisopropyl-phosphono hydrazide or O-alkylisopropylphosphono hydrazides and gave the corresponding analogues of a naturally occurring fish toxin in excellent yields under mild conditions.
Synthesis of 4-Aryl Substituted 3,4-Dihydropyrimidinones Using Silica-chloride Under Solvent Free Conditions
Authors: Karade Hitendra N , Sathe Manisha , Kaushik M P
Published: October 2008

This paper describes an improved procedure for the efficient and facile synthesis of 4-aryl substituted 3, 4-dihydropyrimidinones under mild reaction conditions with excellent yields using inexpensive silica chloride under solvent free conditions.
Synthesis and Characterization of a Metal Complex Containing Naringin and Cu, and its Antioxidant, Antimicrobial, Antiinflammatory and Tumor Cell Cytotoxicity
Authors: Pereira Regina MS , Andrades Norma ED , Paulino Niraldo , Sawaya Alexandra CHF , Eberlin Marcos N , Marcucci Maria C , Favero Giovani Marino , Novak Estela Maria , Bydlowski Sérgio Paulo
Published: October 2008

The antioxidant activity of flavonoids is believed to increase when they are coordinated with transition metal ions. However, the literature on this subject is contradictory and the outcome seems to largely depend on the experimental conditions. In order to understand the contribution of the metal coordination and the type of interaction between a flavonoid and the metal ion, in this study a new metal complex of Cu (II) with naringin was synthesized and characterized by FT-IR, UV-VIS, mass spectrometry (ESI-MS/MS), elemental analysis and 1H-NMR. The results of these analyses indicate that the complex has a Cu (II) ion coordinated via positions 4 and 5 of the flavonoid. The antioxidant, anti-inflammatory and antimicrobial activities of this complex were studied and compared with the activity of free naringin. The Naringin–Cu (II) complex 1 showed higher antioxidant, anti-inflammatory and tumor cell cytoxicity activities than free naringin without reducing cell viability.
Structural Characterisation by ESI-MS of Feruloylated Arabino-oligosaccharides Synthesised by Chemoenzymatic Esterification
Authors: Vafiadi Christina , Topakas Evangelos , Bakx Edwin J , Schols Henk A , Christakopoulos Paul
Published: October 2008

The chemoenzymatic synthesis of feruloylated arabino-oligosaccharides has been achieved, using a feruloyl esterase type C from Sporotrichum thermophile (StFaeC).The structure of the feruloylated products was confirmed by ESI-MSn.
Comparison of the Biological Properties of Several Marine Sponge-Derived Sesquiterpenoid Quinones
Authors: Motti Cherie A , Bourguet-Kondracki Marie-Lise , Longeon Arlette , Doyle Jason R , Llewellyn Lyndon E , Tapiolas Dianne M , Yin Ping
Published: October 2008

Eight naturally occurring marine-sponge derived sesquiterpenoid quinones wereevaluated as potential inhibitors of pyruvate phosphate dikinase (PPDK), a C4 plantregulatory enzyme. Of these, the hydroxyquinones ilimaquinone, ethylsmenoquinone andsmenoquinone inhibited PPDK activity with IC50’s (reported with 95% confidenceintervals) of 285.4 (256.4 – 317.7), 316.2 (279.2 – 358.1) and 556.0 (505.9 – 611.0) μM,respectively, as well as being phytotoxic to the C4 plant Digitaria ciliaris. The potentialanti-inflammatory activity of these compounds, using bee venom phospholipase A2(PLA2), was also evaluated. Ethylsmenoquinone, smenospongiarine, smenospongidine andilimaquinone inhibited PLA2 activity (% inhibition of 73.2 + 4.8 at 269 μM, 61.5 + 6.1 at242 μM, 41.0 + 0.6 at 224 μM and 36.4 + 8.2 at 279 μM, respectively). SAR analysesindicate that a hydroxyquinone functionality and a short, hydroxide/alkoxide side-chain atC-20 is preferred for inhibition of PPDK activity, and that a larger amine side-chain at C-20 is tolerated for PLA2 inhibitory activity.
Synthesis and Characterization of
5,10,15,20-Tetra[3-(3-trifluoromethyl)phenoxy] Porphyrin
Authors: Tidwell Cynthia P , Bharara Prakash , Rudeseal Gretchen , Rudeseal Tiffany , Rudeseal Frank H , Simmer Christine A , McMillan Dugald , Lanier Katherine , Fondren L Dalila , Folmar LaTasha L , Belmore Ken
Published: October 2008

The newly synthesized 5,10,15,20-tetra[3-(3-trifluoromethyl)phenoxy]porphyrin, TTFMPP, has been characterized using mass spectroscopy, 1H-, 13C- and 19F-NMR, MALDI-TOF mass spectrometry, UV-Vis and fluorescence spectrophotometry, andcyclic voltammetry. The NMR confirmed the structure of the compound and the massspectrum was in agreement with the proposed molecular formula. The UV-Vis absorptionspectrum of TTFMPP shows characteristic spectral patterns similar to those of tetraphenylporphryin, with a Soret band at 419 nm and four Q bands at 515, 550, 590, and 648 nm.Protonation of the porphyrin with TFA resulted in the expected red shift of the Soret band.Excitation at 419 nm gave an emission at 650 nm. The quantum yield of the porphyrin wasdetermined to be 0.08. Cyclic voltammetry was used to determine the oxidation andreduction potentials of the new porphyrin. Two quasi-reversible one-electron reductions at–1.00 and –1.32 V and a quasi-reversible oxidation at 1.20 V versus the silver/silverchloride reference electrode with tetrabutylammonium tetrafluoroborate as the supportingelectrolyte in methylene chloride were observed.
Atmospheric Pressure Microwave Assisted Heterogeneous Catalytic Reactions
Authors: Chemat-Djenni Zoubida , Hamada Boudjema , Chemat Farid
Published: October 2008

The purpose of the study was to investigate microwave selective heatingphenomena and their impact on heterogeneous chemical reactions. We also present a toolwhich will help microwave chemists to answer to such questions as “My reaction yields90% after 7 days at reflux; is it possible to obtain the same yield after a few minutes undermicrowaves?” and to have an approximation of their reactions when conducted undermicrowaves with different heterogeneous procedures. This model predicting reactionkinetics and yields under microwave heating is based on the Arrhenius equation, inagreement with experimental data and procedures.
Electrochemical Synthesis and Structural Characterization of a Novel Mixed-valence Copper (I)-copper (II) Complex: {[Bis(ethylenediamine) Copper (II)] Bis[diiodocuprate (I)]}
Authors: Fotouhi Lida , Dehghanpour Saeed , Heravi Majid M , Ardakani Mahboobeh Dashti
Published: October 2008

A novel, mixed-valent copper(I)-copper(II) complex, {[bis(ethylene-diamine)copper(II)] bis[diiodocuprate(I)]} (1), has been prepared by electrochemicaldissolution of a sacrificial copper anode in a solution of ethylenediamine (en), I2 andtetraethylammoniumperchlorate (TEAP) as supporting electrolyte in acetonitrile (AcN)and characterized by single-crystal X-ray structure determination. The crystal structure ofthe complex 1 shows that it consists of a CuI2 polymer formed from I- ligands bridgingCu(I) ions, with a nearly square planar geometry of bivalente Cu(II) atoms chelated by twoethylenediamine ligands. The results also show that direct electrosynthesis of the complexhad high current efficiency, purity and electrolysis yield.
An Efficient and Rapid Synthetic Route to Biologically Interesting Pyranochalcone Natural Products
Authors: Lee Yong Rok , Wang Xue , Xia Likai
Published: October 2008

An efficient and concise total synthesis of naturally occurring pyranochalcones was achieved from readily available 2,4-dihydroxyacetophenone and 2,4-dihydroxy-6- methoxyacetophenone. The key steps in the synthetic strategy were ethylenediamine diacetate-catalyzed benzopyran formation and aldol reactions.
Revised NMR data for Incartine: an Alkaloid from Galanthus elwesii
Authors: Berkov Strahil , Reyes-Chilpa Ricardo , Codina Carles , Viladomat Francesc , Bastida Jaume
Published: October 2008

Phytochemical studies on Galanthus elwesii resulted in the isolation of five alkaloids: incartine, hordenine, hippeastrine, 8-O-demethylhomolycorine and lycorine. The NMR data given previously for incartine were revised and completed by two-dimensional 1H-1H and 1H-13C chemical shift correlation experiments. In vitro studies on the bioactivity of incartine were carried out.
Non-Open Access and Its Adverse Impact on Molecules
Authors: Lin Shu-Kun
Published: October 2008

In 2005 and 2006 papers were published in MDPI journals in both non-Open Access (non-OA) and Open Access (OA) form [1,2].[...]
A Facile, Mild And Efficient One-Pot Synthesis of 2-Substituted Indole Derivatives Catalyzed By Pd(PPh3)2Cl2
Authors: Oskooie Hossien A. , Heravi Majid M. , Behbahani Farahnaz K.
Published: October 2008

2-Phenylindoles were prepared by heteroannulation of 2-haloaniline derivatives and phenylacetylene under mild conditions in a one-pot reaction catalyzed by Pd(PPh3)2Cl2.
Leufolins A and B, Potent Butyrylcholinesterase-inhibiting Flavonoid Glucosides from Leucas urticifolia
Authors: Noor Atia-tun , Fatima Itrat , Ahmad Ijaz , Malik Abdul , Afza Nighat , Iqbal Lubna , Latif Mehreen , Khan Sher    Bahadar
Published: October 2008

New flavonoidal glucosides leufolins A (1) and B (2), have been isolated from the ethyl acetate soluble fraction of the whole plants of Leucas urticifolia. Their structures were elucidated on the basis of extensive analysis of nuclear magnetic resonance (1D and 2D NMR) spectral data. Both of these compounds exhiited significant inhibitory potential against the enzyme butyrylcholinesterase.
The Anti-apoptosis Effects of Daidzein in the Brain of D-Galactose Treated Mice
Authors: Mao Zhen , Zheng Yuan-lin , Zhang Yan-qiu , Han Bao-ping , Zhu Xiao-wan , Chang Qing , Hu Xiang-bin
Published: October 2008

The purpose of this study was to explore the neuroprotective effects of daidzein on the apoptotic pathway in the hippocampus and cortex of D-galactose treated mice. For this purpose we have examined the expression of bcl-2 mRNA, bax mRNA and caspase-3 in the hippocampus and cortex of D-galactose-treated mice after fed with 10 or 5 mg/kg of daidzein. The results of in situ hybridization experiments indicate that daidzein could help increase the transcriptions of bcl-2 and decrease the transcriptions of bax in those brain regions of D-galactose-treated mice. Furthermore, immunohistochemical studies showed that daidzein could reduce the expression of caspase-3 in both brain regions. These results suggest that daidzein in soybean can inhibit the D-gal induced apoptosis via Bcl-2/Bax apoptotic pathway and be a potential medical candidate for neurodegeneration therapy.
Unusual Reactivity Patterns of 1,3,6,8-Tetraazatricyclo-[4.4.1.13,8]-dodecane (TATD) Towards Some Reducing Agents: Synthesis of TMEDA
Authors: Rivera Augusto , Rios-Motta Jaime
Published: October 2008

N,N,N ́,N ́-Tetramethylethylenediamine (TMEDA) can be synthesized by simple reduction of 1,3,6,8-tetraazatricyclo-[4.4.1.1.3,8]dodecane (TATD), an aminal cage type amine, with formic acid. The aminal can be converted to TMEDA in high yield very easily and in a very short time. We comment on the scope and limitations of the reduction of thisaminal and propose a possible reaction mechanism.