Molecules

160 KiB

Open AccessArticle

Synthesis and Biological Activity of Some New Pyrazoline and Pyrrolo[3,4-c]pyrazole-4,6-dione Derivatives: Reaction of Nitrilimines with Some Dipolarophiles

by Nada M. Abunada, Hamdi M. Hassaneen, Nadia G. Kandile and Omar A. Miqdad

Molecules 2008, 13(4), 1011-1024; https://doi.org/10.3390/molecules13041011 - 29 Apr 2008

Cited by 49 | Viewed by 10371

Abstract

Several 1,3-diaryl-5-(cyano-, aminocarbonyl- and ethoxycarbonyl-)-2-pyrazoline, pyrrolo[3,4-c]pyrazole-4,6-dione and 1,3,4,5-tetraaryl-2-pyrazoline derivativeswere prepared by the reaction of nitrilimine with different dipolarophilic reagents. The newcompounds were characterized using IR, ¹H-NMR, ¹³C-NMR and mass spectra. Biologicalscreening of some compounds is reported. Full article

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104 KiB

Open AccessArticle

Spectral Data of Two New Asymmetric Sesquiterpene Alcohols: (14R)-β-Oplopenol and (14S)-β-Oplopenol

by Julien Paolini, Jean-Marie Desjobert, Alain Muselli and Jean Costa

Molecules 2008, 13(4), 1004-1010; https://doi.org/10.3390/molecules13041004 - 29 Apr 2008

Cited by 2 | Viewed by 6864

Abstract

The epimeric sesquiterpene alcohols (14R)-β-oplopenol and (14S)-β-oplopenolwere obtained by LiAlH₄ reduction of β-oplopenone. The complete ¹H- and ¹³C-NMRassignments of these two new sesquiterpene alcohols have been made using 1D and 2DNMR techniques, including COSY, NOESY, HSQC, HMBC experiments. Full article

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59 KiB

Open AccessArticle

Novel Spiroannulated 3-Benzofuranones. Synthesis and Inhibition of the Human Peptidyl Prolyl cis/trans Isomerase Pin1

by Manfred Braun, Anahita Hessamian-Alinejad, Boris Féaux De Lacroix, Birte Hernandez Alvarez and Gunter Fischer

Molecules 2008, 13(4), 995-1003; https://doi.org/10.3390/molecules13040995 - 29 Apr 2008

Cited by 27 | Viewed by 11306

Abstract

The novel 3H-spiro[1-benzofuran-2-cyclopentan]-3-one skeleton has been madeaccessible by different routes. One- and two-step protocols lead to tricyclic and tetracyclicbenzofuranones 2 and 3, respectively. A four-step synthesis to spirocompound 4 isdescribed. The novel spirocyclic benzofuranones display modest to no inhibition of thehuman peptidyl prolyl [...] Read more.

The novel 3H-spiro[1-benzofuran-2-cyclopentan]-3-one skeleton has been madeaccessible by different routes. One- and two-step protocols lead to tricyclic and tetracyclicbenzofuranones 2 and 3, respectively. A four-step synthesis to spirocompound 4 isdescribed. The novel spirocyclic benzofuranones display modest to no inhibition of thehuman peptidyl prolyl cis/trans isomerase Pin1. Full article

(This article belongs to the Special Issue Spiro Compounds)

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285 KiB

Open AccessArticle

Fluorinated Analogs of Malachite Green: Synthesis and Toxicity

by George A. Kraus, Insik Jeon, Marit Nilsen-Hamilton, Ahmed M. Awad, Jayeeta Banerjee and Bahram Parvin

Molecules 2008, 13(4), 986-994; https://doi.org/10.3390/molecules13040986 - 27 Apr 2008

Cited by 28 | Viewed by 15295

Abstract

A series of fluorinated analogs of malachite green (MG) have been synthesizedand their toxicity to Saccharomyces cerevisiae and a human ovarian epithelial cell lineexamined. The toxicity profiles were found to be different for these two species. Twoanalogs, one with 2,4-difluoro substitution and the [...] Read more.

A series of fluorinated analogs of malachite green (MG) have been synthesizedand their toxicity to Saccharomyces cerevisiae and a human ovarian epithelial cell lineexamined. The toxicity profiles were found to be different for these two species. Twoanalogs, one with 2,4-difluoro substitution and the other with 2-fluoro substitution seem tobe the most promising analogs because they showed the lowest toxicity to the human cells. Full article

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284 KiB

Open AccessArticle

Microwave-Enhanced Sulphated Zirconia and SZ/MCM-41 Catalyzed Regioselective Synthesis of β-Amino Alcohols Under Solvent-Free Conditions

by Guillermo Negrón-Silva, C. Xochitl Hernández-Reyes, Deyanira Angeles-Beltrán, Leticia Lomas-Romero and Eduardo González-Zamora

Molecules 2008, 13(4), 977-985; https://doi.org/10.3390/molecules13040977 - 26 Apr 2008

Cited by 15 | Viewed by 10006

Abstract

A solvent-free approach for the regioselective synthesis of β-amino alcohols inshorter reaction times and higher yields, compared to conventional heating is described. Itinvolves microwave (MW) exposure of undiluted reactants in the presence of sulphatedzirconia (SZ) or sulphated zirconia over MCM-41 (SZM) as catalyst. [...] Read more.

A solvent-free approach for the regioselective synthesis of β-amino alcohols inshorter reaction times and higher yields, compared to conventional heating is described. Itinvolves microwave (MW) exposure of undiluted reactants in the presence of sulphatedzirconia (SZ) or sulphated zirconia over MCM-41 (SZM) as catalyst. Both acid materialscan be easily recovered and reused. Full article

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268 KiB

Open AccessArticle

Synthesis and Biological Activity of Peptide Derivatives of Iodoquinazolinones/Nitroimidazoles

by Rajiv Dahiya, Anil Kumar and Rakesh Yadav

Molecules 2008, 13(4), 958-976; https://doi.org/10.3390/molecules13040958 - 24 Apr 2008

Cited by 47 | Viewed by 12307

Abstract

Two substituted quinazolinyl/imidazolyl-salicylic acids 5, 6 were synthesized bythe reaction of 6-iodo-2-methylbenzoxazin-4-one/5-nitroimidazole with 5-aminosalicylicacid (5-ASA). Coupling of compounds 5 and 6 with different amino acid esterhydrochlorides, dipeptide and tripeptide methyl esters yielded novelquinazolino/imidazolopeptide derivatives 5a-f and 6a-g. The chemical structures of allnewly synthesized [...] Read more.

Two substituted quinazolinyl/imidazolyl-salicylic acids 5, 6 were synthesized bythe reaction of 6-iodo-2-methylbenzoxazin-4-one/5-nitroimidazole with 5-aminosalicylicacid (5-ASA). Coupling of compounds 5 and 6 with different amino acid esterhydrochlorides, dipeptide and tripeptide methyl esters yielded novelquinazolino/imidazolopeptide derivatives 5a-f and 6a-g. The chemical structures of allnewly synthesized compounds were confirmed by means of FT-IR, ¹H- and ¹³C-NMR, MSand elemental analysis. Selected peptide ester derivatives were further hydrolyzed by usinglithium hydroxide (LiOH) to afford the corresponding acid derivatives 5ba-da and 6e_a-g_a.All peptide derivatives were assayed for antimicrobial and anthelmintic activities againsteight pathogenic microbes and three earthworm species. Among the tested compounds, 5e,5d, 6e and their hydrolyzed analogs 5d_a and 6e_a exhibited higher antimicrobial activityagainst Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans, and 5_a,6g and 6g_a displayed better antifungal activity against the dermatophytes Trichophytonmentagrophytes and Microsporum audouinii. Moreover, 6f and its hydrolyzed derivative6f_a showed good anthelmintic activity against Megascoplex konkanensis, Pontoscotexcorethruses and Eudrilus eugeniea at dose of 2 mg mL^–1. Full article

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686 KiB

Open AccessArticle

CuO and Ag₂O/CuO Catalyzed Oxidation of Aldehydes to the Corresponding Carboxylic Acids by Molecular Oxygen

by Qingyong Tian, Daxin Shi and Yaowu Sha

Molecules 2008, 13(4), 948-957; https://doi.org/10.3390/molecules13040948 - 21 Apr 2008

Cited by 84 | Viewed by 12772

Abstract

Furfural was oxidized to furoic acid by molecular oxygen under catalysis by 150nm-sized Ag₂O/CuO (92%) or simply CuO (86.6%). When 30 nm-size catalyst was used,the main product was a furfural Diels-Alder adduct. Detailed reaction conditions andregeneration of catalysts were investigated. Under [...] Read more.

Furfural was oxidized to furoic acid by molecular oxygen under catalysis by 150nm-sized Ag₂O/CuO (92%) or simply CuO (86.6%). When 30 nm-size catalyst was used,the main product was a furfural Diels-Alder adduct. Detailed reaction conditions andregeneration of catalysts were investigated. Under optimal conditions, a series of aromaticand aliphatic aldehydes were oxidized to the corresponding acids in good yields. Full article

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123 KiB

Open AccessCommunication

Efficient and Eco-Friendly Preparation of 4-Methyl-5-formyl-thiazole

by Nan Bai, Yaowu Sha and Ge Meng

Molecules 2008, 13(4), 943-947; https://doi.org/10.3390/molecules13040943 - 21 Apr 2008

Cited by 11 | Viewed by 8164

Abstract

4-Methyl-5-formylthiazole, an intermediate for synthesizing cefditoren pivoxil,was prepared in good yield by Pd/BaSO₄ catalyzed hydrogenation of 4-methylthiazole-5-carboxylic acid chloride. Detailed reaction conditions have been studied. Full article

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177 KiB

Open AccessCommunication

Acid-catalyzed Epimerization of Kobophenol A to Carasinol B

by Kejun Cheng, Gaolin Liang and Changqi Hu

Molecules 2008, 13(4), 938-942; https://doi.org/10.3390/molecules13040938 - 19 Apr 2008

Cited by 5 | Viewed by 10591

Abstract

The conversion from kobophenol A into carasinol B, two main chemicalconstituents of Caragana sinica, was confirmed by in vitro acid-catalyzed epimerization.The result provides important information about the biotransformation of kobophenol A inplants and its metabolism in rats. Full article

(This article belongs to the Special Issue Heterocycles)

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100 KiB

Open AccessArticle

New Monoterpenoid Coumarins from Clausena anisum-olens

by Yun-Song Wang, Hong-Pin He, Jing-Hua Yang, Ying-Tong Di and Xiao-Jiang Hao

Molecules 2008, 13(4), 931-937; https://doi.org/10.3390/molecules13040931 - 19 Apr 2008

Cited by 37 | Viewed by 9783

Abstract

Two new monoterpenoid coumarins: anisucumarin A (1) and B (2), a pair ofepimers, were isolated from Clausena anisum-olens. Their structures were establishedbased on extensive spectroscopic analyses. Full article

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127 KiB

Open AccessArticle

Selective Dendritic Fluorescent Sensors for Zn(II)

by Feng Wang, Ruogu Peng and Yaowu Sha

Molecules 2008, 13(4), 922-930; https://doi.org/10.3390/molecules13040922 - 19 Apr 2008

Cited by 19 | Viewed by 9635

Abstract

A series of dendritic 8-hydroxyquinoline (8-HQ) and 5-dialkyl(aryl)aminomethyl-8-HQ derivatives were synthesized and their fluoroionophoric properties towardrepresentative alkali, alkaline earth, group IIIA and transition metal ions wereinvestigated. Among the selected ions, Zn(II) enhanced the fluorescence of N-di-(methoxycarbonylethyl)aminoethyl-3-[4-(8-hydroxyquinolin-5-ylmethyl)piperazin-1-yl]-propanoic amide] (7) by 31-fold, while Al(III) caused [...] Read more.

A series of dendritic 8-hydroxyquinoline (8-HQ) and 5-dialkyl(aryl)aminomethyl-8-HQ derivatives were synthesized and their fluoroionophoric properties towardrepresentative alkali, alkaline earth, group IIIA and transition metal ions wereinvestigated. Among the selected ions, Zn(II) enhanced the fluorescence of N-di-(methoxycarbonylethyl)aminoethyl-3-[4-(8-hydroxyquinolin-5-ylmethyl)piperazin-1-yl]-propanoic amide] (7) by 31-fold, while Al(III) caused enhancement to some extent. Theabsence of any significant fluorescence enhancement by the other ions examined renders 7a highly useful Zn(II)-selective fluorescent sensor. Full article

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201 KiB

Open AccessArticle

Antimicrobial and Antioxidative Activities of Bioactive Constituents from Hydnophytum formicarum Jack.

by Supaluk Prachayasittikul, Prasit Buraparuangsang, Apilak Worachartcheewan, Chartchalerm Isarankura-Na-Ayudhya, Somsak Ruchirawat and Virapong Prachayasittikul

Molecules 2008, 13(4), 904-921; https://doi.org/10.3390/molecules13040904 - 18 Apr 2008

Cited by 130 | Viewed by 15037

Abstract

Hydnophytum formicarum Jack. (Rubiaceae) is a medicinal plant whose tuberspossesses cardiovascular, anti-inflammatory and antiparasitic effects and have been usedfor the treatment of hepatitis, rheumatism and diarrhea. Herein we report the isolation of itsactive constituents and the testing of their antimicrobial activity against 27 [...] Read more.

Hydnophytum formicarum Jack. (Rubiaceae) is a medicinal plant whose tuberspossesses cardiovascular, anti-inflammatory and antiparasitic effects and have been usedfor the treatment of hepatitis, rheumatism and diarrhea. Herein we report the isolation of itsactive constituents and the testing of their antimicrobial activity against 27 strains ofmicroorganisms using an agar dilution method and of their antioxidative activity using theDPPH and SOD assays. The results show that the crude hexane, dichloromethane, ethylacetate and methanol extracts exert such activities. Particularly, the crude ethyl acetateextract exhibits antigrowth activity against many Gram-positive and Gram-negativebacteria with MIC 256 μg/mL. Shewanella putrefaciens ATCC 8671 is completelyinhibited at a lower MIC (128 μg/mL). Interestingly, Corynebacterium diphtheriae NCTC10356 is inhibited by all the tested extracts. Significantly, the ethyl acetate extract is alsothe most potent antioxidant, showing 83.31% radical scavenging activity with IC50 8.40μg/mL in the DPPH assay. The other extracts display weak to moderate antioxidativeMolecules 2008, 13905activities, ranging from 28.60-56.80% radical scavenging. The SOD assay shows thatmethanol extract exhibits the highest activity (74.19% inhibition of superoxide radical).The dichloromethane and ethyl acetate extracts display comparable SOD activity. Thepromising bioactivities of the crude ethyl acetate extract guided the first isolation ofbioactive flavonoid and phenolic compounds: isoliquiritigenin (2), protocatechualdehyde(3), butin (4) and butein (5) from this species. Their structures have been fully establishedby 1D and 2D NMR. In addition, stigmasterol was isolated from the crude hexane anddichloromethane extracts. The antimicrobial and cytotoxic activities of compounds 3-5were evaluated. The tested compounds were inactive against HuCCA-1 and KB cell lines,showing ED50> 10 μg/mL. Protocatechualdehyde (3) completely inhibits the growth ofPlesiomonas shigelloides with MIC ≤60 μg/mL. As a result, we propose that Hydnophytumformicarum Jack. can serve as a new source enriched with potent antioxidative andantimicrobial agents. Full article

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103 KiB

Open AccessArticle

Cytoprotective Efficacy of Amifostine Against Radiation- Induced Rectal Toxicity: Objective and Subjective Grading Scales for Radiomucositis

by Vassilis E. Kouloulias and John R. Kouvaris

Molecules 2008, 13(4), 892-903; https://doi.org/10.3390/molecules13040892 - 18 Apr 2008

Cited by 9 | Viewed by 10506

Abstract

Curative radiation therapy of pelvic malignancies, frequently results in doselimitingtoxicities such as serous, mucoid, or more rarely, bloody diarrhea. Several studieshave evaluated the cytoprotective effects of amifostine in preventing rectal mucositisassociated with radiation treatment. We searched Medline for published comparativestudies that evaluated the [...] Read more.

Curative radiation therapy of pelvic malignancies, frequently results in doselimitingtoxicities such as serous, mucoid, or more rarely, bloody diarrhea. Several studieshave evaluated the cytoprotective effects of amifostine in preventing rectal mucositisassociated with radiation treatment. We searched Medline for published comparativestudies that evaluated the use of amifostine to reduce radiation-induced toxicity associatedwith pelvic irradiation. In ten studies there was an evidence-based cytoprotection (P less than 0.05)by amifostine. Although results are variable, current evidence suggests that amifostine mayhave a radioprotective effect in the rectal mucosa, particularly when administeredintrarectally. Significant improvements were seen in both symptomatic and objective(rectosigmoidoscopy) end points. There is a need to conduct well-designed clinical trialswith sufficient numbers of participants to confirm these findings together with a costbenefitstudy. Objective measurements using rectosigmoidoscopy are superior tosubjective measures such as WHO or RTOG/EORTC toxicity grading scales. Full article

(This article belongs to the Special Issue Prodrugs)

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573 KiB

Open AccessArticle

A Structure-Activity Study of Antibacterial Diterpenoids

by Alejandro Urzúa, Marcos C. Rezende, Carolina Mascayano and Loretta Vásquez

Molecules 2008, 13(4), 882-891; https://doi.org/10.3390/molecules13040822 - 17 Apr 2008

Cited by 114 | Viewed by 12248

Abstract

An analysis of the antibacterial activities of 15 terpenoids, eleven of which werepreviously described by us and four were extracted from the literature, suggested twostructural requirements for activity of these and related compounds: a hydrophobic moiety,consisting of a substituted decalin skeleton, and a [...] Read more.

An analysis of the antibacterial activities of 15 terpenoids, eleven of which werepreviously described by us and four were extracted from the literature, suggested twostructural requirements for activity of these and related compounds: a hydrophobic moiety,consisting of a substituted decalin skeleton, and a hydrophilic region possessing onehydrogen-bond-donor group. These structural requirements are responsible for an optimalinsertion of these and related compounds into cell membranes, as suggested by the resultsof docking some of these compounds into a model phospholipid bilayer. Full article

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141 KiB

Open AccessArticle

Development of an Enzyme-linked Immuno-Sorbent Assay (ELISA) Method for Carbofuran Residues

by Jinyi Yang, Hong Wang, Yueming Jiang, Yuanming Sun, Ke Pan, Hongtao Lei, Qing Wu, Yudong Shen, Zhili Xiao and Zhenlin Xu

Molecules 2008, 13(4), 871-881; https://doi.org/10.3390/molecules13040871 - 17 Apr 2008

Cited by 31 | Viewed by 11813

Abstract

The haptens 4-[[(2,3-dihydro-2,2-dimethyl-7-benzofuranyloxy)carbonyl]-amino]butanoic acid (BFNB) and 6-[((2,3-dihydro-2,2-dimethyl-7-benzofuranyloxy)-carbonylamino]hexanoic acid (BFNH) were synthesized and then used to develop a rapid,specific and sensitive ELISA method to determine residues of the pesticide carbofuran in avariety of matrices. A hybridoma cell line (5D3) producing anti-carbofuran monoclonalantibodies (MAbs) was [...] Read more.

The haptens 4-[[(2,3-dihydro-2,2-dimethyl-7-benzofuranyloxy)carbonyl]-amino]butanoic acid (BFNB) and 6-[((2,3-dihydro-2,2-dimethyl-7-benzofuranyloxy)-carbonylamino]hexanoic acid (BFNH) were synthesized and then used to develop a rapid,specific and sensitive ELISA method to determine residues of the pesticide carbofuran in avariety of matrices. A hybridoma cell line (5D3) producing anti-carbofuran monoclonalantibodies (MAbs) was also established. Based on the MAbs in combination with theheterologous hapten BFNH coupled to either horseradish peroxidase (HRP) or ovalbumin(OVA), four ELISAs (formats I-IV) for the quantification of carbofuran were developedand compared. Among them, the optimized format II (the conjugate-coated directcompetitive ELISA) showed the best characteristics, with an IC50 value of 18.49 ng/mL, alimit of detection of 0.11 ng/mL and the shortest assay time (1 h). This ELISA method wasthen applied to the determinations of carbofuran in environmental water, soil and foodsamples. The relative standard deviations (R.S.D.s) ranged from 1.8% to 21.3% and themean recoveries were 104.6%, 108.3%, 106.3% and 100.1% for water, soil, lettuce andcabbage, respectively. Thus, the ELISA method of format II exhibited the potential todevelop commercial ELISA kits for a rapid detection of carbofuran for human health andenvironmental safety. Full article

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169 KiB

Open AccessArticle

Effects of Leucine-enkephalin on Catalase Activity and Hydrogen Peroxide Levels in the Haemolymph of the Pacific Oyster (Crassostrea gigas)

by Dong-wu Liu, Zhi-wei Chen and Hong-zhi Xu

Molecules 2008, 13(4), 864-870; https://doi.org/10.3390/molecules13040864 - 15 Apr 2008

Cited by 8 | Viewed by 10977

Abstract

The nervous and immune systems of invertebrates can exchange informationthrough neuropeptides. Furthermore, some opioid peptides can function as endogenousimmune system messengers and participate in the regulation of the immune responses. Thepresent study was designed to investigate the effects of leucine-enkephalin (L-ENK) on theactivity [...] Read more.

The nervous and immune systems of invertebrates can exchange informationthrough neuropeptides. Furthermore, some opioid peptides can function as endogenousimmune system messengers and participate in the regulation of the immune responses. Thepresent study was designed to investigate the effects of leucine-enkephalin (L-ENK) on theactivity of catalase (CAT) and hydrogen peroxide (H₂O₂) content in the haemolymph ofthe Pacific Oyster (Crassostrea gigas). The CAT activity and H₂O₂ content wereinvestigated after the haemolymph of the species was exposed to 1, 5, and 50 μg/mL of LENK.The results indicate that the intracellular and extracellular CAT activity wasincreased with increasing concentration of L-ENK, while the intracellular and extracellularH₂O₂ content was decreased with increasing concentration of L-ENK. L-ENK mayregulate the intracellular and extracellular CAT activity and H2O2 content via binding withopioid neuropeptide receptors on immunocytes of the oysters. The data strongly suggestsan involvement of opioid peptides in the regulation of the antioxidant defence systems ofCrassostrea gigas. Full article

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210 KiB

Open AccessArticle

Blue Organic Light-emitting Supramolecular Microfibers: The Self-assembly of a 1,2,4-Triazolo[1,5-a]pyrimidine Derivative

by Zu-Ming Liu, Hong-Bo Wang, Xiao-Lei Zhu, Hai-Yang Tu and Guang-Fu Yang

Molecules 2008, 13(4), 855-863; https://doi.org/10.3390/molecules13040855 - 12 Apr 2008

Cited by 2 | Viewed by 8168

Abstract

The design and synthesis of 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-2-thioaceto-(2-fluorobenzyl) hydrazone (TPTH), which self-assembled into supramolecularmicrofibers with blue organic light-emitting properties, is reported. This is the firstoccurrence of the molecular self-assembly of 1,2,4-triazolo[1,5-a]pyrimidine derivatives. Full article

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130 KiB

Open AccessArticle

Synthesis and Total ¹H- and ¹³C-NMR Assignment of Cephem Derivatives for Use in ADEPT Approaches

by Lorena Blau, Renato Farina Menegon, Elizabeth Igne Ferreira, Antonio Gilberto Ferreira, Elisangela Fabiana Boffo, Leila Aley Tavares, Vladimir Constantino Gomes Heleno and Man-Chin Chung

Molecules 2008, 13(4), 841-854; https://doi.org/10.3390/molecules13040841 - 10 Apr 2008

Cited by 6 | Viewed by 10566

Abstract

We report the synthesis and total NMR characterization of 5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylic acid-3-[[[(4’’-nitrophenoxy)carbonyl]oxy]-methyl]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide (5), a new cephalosporinderivative. This compound can be used as the carrier of a wide range of drugs containingan amino group. The preparation of the intermediate product, 5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid-3-[methyl 4-(6-methoxyquinolin-8-ylamino)pentylcarbamate]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide [...] Read more.

We report the synthesis and total NMR characterization of 5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylic acid-3-[[[(4’’-nitrophenoxy)carbonyl]oxy]-methyl]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide (5), a new cephalosporinderivative. This compound can be used as the carrier of a wide range of drugs containingan amino group. The preparation of the intermediate product, 5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid-3-[methyl 4-(6-methoxyquinolin-8-ylamino)pentylcarbamate]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide (6), as well as the synthesis of the antimalarial primaquine prodrug 5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid-3-[methyl 4-(6-methoxyquinolin-8-ylamino)pentylcarbamate]-8-oxo-7-[(2-thienyloxoacetyl)amino]- 5-dioxide (7) are alsodescribed, together with their total ¹H- and ¹³C-NMR assignments. Full article

(This article belongs to the Special Issue Prodrugs)

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Open AccessArticle

Simple and Efficient Microwave Assisted N-Alkylation of Isatin

by María Sol Shmidt, Ana María Reverdito, Lautaro Kremenchuzky, Isabel Amalia Perillo and María Mercedes Blanco

Molecules 2008, 13(4), 831-840; https://doi.org/10.3390/molecules13040831 - 10 Apr 2008

Cited by 80 | Viewed by 14946

Abstract

We present herein the results of microwave promoted N-alkylations of isatin (1)with different alkyl, benzyl and functionalized alkyl halides. Reactions were carried outunder different conditions, always employing methodologies compatible with MW assistedchemistry. Generation of isatin anion employing diverse bases and solvents or using [...] Read more.

We present herein the results of microwave promoted N-alkylations of isatin (1)with different alkyl, benzyl and functionalized alkyl halides. Reactions were carried outunder different conditions, always employing methodologies compatible with MW assistedchemistry. Generation of isatin anion employing diverse bases and solvents or using thepreformed isatin sodium salt was tested. The best results were achieved using K₂CO₃ orCs₂CO₃ and a few drops of N,N-dimethylformamide or N-methyl-2-pyrrolidinone. Thesereactions present noteworthy advantages over those carried out employing conventionalheating. Full article

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128 KiB

Open AccessArticle

Synthesis of New N-Arylpyrimidin-2-amine Derivatives Using a Palladium Catalyst

by Ibrahim Mustafa El-Deeb, Jae Chun Ryu and So Ha Lee

Molecules 2008, 13(4), 818-830; https://doi.org/10.3390/molecules13040818 - 9 Apr 2008

Cited by 13 | Viewed by 11482

Abstract

New N-aryl-4-(pyridin-3-yl)pyrimidin-2-amine derivatives were synthesizedfrom the corresponding amines, applying optimized Buchwald-Hartwig aminationconditions using dichlorobis(triphenylphosphine)Pd(II), xantphos and sodium tertbutoxidein refluxing toluene under a nitrogen atmosphere. The target N-aryl derivativeswere obtained in moderate to good yields ranging from 27% to 82%. The proceduredescribed could be [...] Read more.

New N-aryl-4-(pyridin-3-yl)pyrimidin-2-amine derivatives were synthesizedfrom the corresponding amines, applying optimized Buchwald-Hartwig aminationconditions using dichlorobis(triphenylphosphine)Pd(II), xantphos and sodium tertbutoxidein refluxing toluene under a nitrogen atmosphere. The target N-aryl derivativeswere obtained in moderate to good yields ranging from 27% to 82%. The proceduredescribed could be widely employed for the preparation of new heterocyclic compounds.The structures of the new compounds were confirmed by FT-NMR, FT-IR and elementalanalysis. Full article

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45 KiB

Open AccessArticle

Variability of Two Essential Oils of Kundmannia sicula (L.) DC., A Traditional Algerian Medicinal Plant

by Lakhdar Djarri, Kamel Medjroubi, Salah Akkal, Abdelhakim Elomri, Elisabeth Seguin, Marie-Laure Groult and Philippe Vérité

Molecules 2008, 13(4), 812-817; https://doi.org/10.3390/molecules13040812 - 8 Apr 2008

Cited by 15 | Viewed by 8857

Abstract

The essential oils of the aerial parts of Kundmannia sicula (L.) DC collectedfrom two Algerian localities, El Kala (near the coast) and Béjaia (from a meadow about 10km from the coast), were analysed by GC and GC-MS. Although both samples showedsimilar overall chemical [...] Read more.

The essential oils of the aerial parts of Kundmannia sicula (L.) DC collectedfrom two Algerian localities, El Kala (near the coast) and Béjaia (from a meadow about 10km from the coast), were analysed by GC and GC-MS. Although both samples showedsimilar overall chemical compositions, the major components of the Béjaia sample wereidentified as being spathulenol (14.8%), caryophyllene oxide (12.2%), salvial-4(14)en-1-one (10.1%), 1,5-epoxysalvial-4(14)ene (5.2%) and germacrene D (3.2%), while in the ElKala sample the main compounds were found to be salvial-4(14)en-1-one (16.4%), 1,5-epoxysalvial-4(14)ene (6.5%), chrysanthenyl acetate (5.2%) and α-amorphene (2.9%). Full article

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Open AccessArticle

Preparation of Zinc (II) and Cadmium (II) Complexes of the Tetradentate Schiff Base Ligand 2-((E)-(2-(2-(pyridine-2-yl)- ethylthio)ethylimino)methyl)-4-bromophenol (PytBrsalH)

by Lotf A. Saghatforoush, Ali Aminkhani, Sohrab Ershad, Ghasem Karimnezhad, Shahriar Ghammamy and Roya Kabiri

Molecules 2008, 13(4), 804-811; https://doi.org/10.3390/molecules13040804 - 8 Apr 2008

Cited by 66 | Viewed by 12428

Abstract

We describe the synthesis and characterization of two new zinc (II) andcadmium (II) complexes of the tetradentate dissymmetric Schiff base ligand 2-((E)-(2-(2-(pyridine-2-yl)ethylthio)ethylimino)methyl)-4-bromophenol (PytBrsalH), prepared from 1-(2-pyridyl)-3-thia-5-aminopentane (pyta) and 5-bromosalicylaldehyde. The complexeswere synthesized by treating an ethanolic solution of the ligand with equimolar amounts [...] Read more.

We describe the synthesis and characterization of two new zinc (II) andcadmium (II) complexes of the tetradentate dissymmetric Schiff base ligand 2-((E)-(2-(2-(pyridine-2-yl)ethylthio)ethylimino)methyl)-4-bromophenol (PytBrsalH), prepared from 1-(2-pyridyl)-3-thia-5-aminopentane (pyta) and 5-bromosalicylaldehyde. The complexeswere synthesized by treating an ethanolic solution of the ligand with equimolar amounts ofappropriate metal salts in 1 M methanolic solution of NaOH or alternatively, by a moredirect route in which the two reactants are added to a solution of the ligand immediatelyafter formation of the latter and prior to any isolation. The complexes were characterizedby elemental analysis, FTIR, ¹H-NMR, electronic spectra and molar conductivity.According to obtained data, the probable coordination geometries of zinc and cadmium inthese complexes with mixed N, S and O donor atoms are tetrahedral- and octahedral-like,respectively. Both complexes were found to be 1:1 electrolyte systems in acetonitrile. Full article

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172 KiB

Open AccessArticle

Contribution to the Analysis of the Essential Oil of Helichrysum italicum (Roth) G. Don. – Determination of Ester Bonded Acids and Phenols

by Josip Mastelić, Olivera Politeo and Igor Jerković

Molecules 2008, 13(4), 795-803; https://doi.org/10.3390/molecules13040795 - 7 Apr 2008

Cited by 48 | Viewed by 14569

Abstract

The essential oil of Helichrysum italicum (Roth) G. Don (everlasting orImmortelle essential oil) was isolated by hydrodistillation and analysed by GC and GCMS.Forty four compounds were identified. The main components were α-pinene(12.8%), 2-methyl-cyclohexyl pentanoate (11.1 %), neryl acetate (10.4%), 1,7-di-epi-α-cedrene (6.8%) and other [...] Read more.

The essential oil of Helichrysum italicum (Roth) G. Don (everlasting orImmortelle essential oil) was isolated by hydrodistillation and analysed by GC and GCMS.Forty four compounds were identified. The main components were α-pinene(12.8%), 2-methyl-cyclohexyl pentanoate (11.1 %), neryl acetate (10.4%), 1,7-di-epi-α-cedrene (6.8%) and other compounds. The oil was fractionated and ester-containingfraction was hydrolysed with KOH/H₂SO₄. The liberated volatiles were analysed by GCand GC-MS: three phenols and twenty seven volatile carboxylic acids were identified[70% low fatty acids (C₂-C₅), 15% C₁₀-C₁₂ acids and 15% other acids]. The main acidswere acetic acid (24.3%) propanoic acid (17.2%), 2-methylpropanoic acid (11.4%),dodecanoic acid (8.7%), 2-methylbutanoic acid (8.3%), (Z)-2-methylbutenoic acid(5.1%) and decanoic acid (4.6%). With respect to the identified bonded carboxylic acids,the minimal number of esters in the oil was twenty seven, but their overall quantity wasprobably larger due to different possible combinations of alcohols with acids to formesters. On the other hand, only six main esters were identified in the oil beforefractionation and hydrolysis. Full article

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Open AccessCommunication

Antimicrobial Activity of Three Baccharis Species Used in the Traditional Medicine of Northern Chile

by Glauco Morales, Adrián Paredes, Patricia Sierra and Luis A. Loyola

Molecules 2008, 13(4), 790-794; https://doi.org/10.3390/molecules13040790 - 6 Apr 2008

Cited by 73 | Viewed by 8180

Abstract

The antimicrobial activities of aqueous ethanol and chloroform extracts of threeBaccharis species currently used in Northern Chile folk medicine for the treatment ofseveral infectious and inflammatory disorders were tested against Gram-positive andnegative bacteria and fungal spp. using the agar-disc diffusion assay. The results [...] Read more.

The antimicrobial activities of aqueous ethanol and chloroform extracts of threeBaccharis species currently used in Northern Chile folk medicine for the treatment ofseveral infectious and inflammatory disorders were tested against Gram-positive andnegative bacteria and fungal spp. using the agar-disc diffusion assay. The results indicatedthat the activity was more pronounced against Gram-positive than against Gram-negativebacteria and yeast. No significant differences on the antibacterial activity were observed inthe aqueous ethanol versus chloroform extracts. None of the plant extracts evaluatedexhibited any activity against ten fungi tested. Full article

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Open AccessArticle

A Microwave-Assisted and Heteropolyacids-Catalysed Cyclocondensation Reaction for the Synthesis of 4(3H)-Quinazolinones

by Karima Ighilahriz, Baya Boutemeur, Fariza Chami, Cherifa Rabia, Maâmar Hamdi and Safouane M. Hamdi

Molecules 2008, 13(4), 779-789; https://doi.org/10.3390/molecules13040779 - 3 Apr 2008

Cited by 55 | Viewed by 11639

Abstract

We have investigated a microwave–assisted synthesis of 4(3H)–quinazolinonesby condensation of anthranilic acid, orthoesters (or formic acid) and substituted anilines,using Keggin-type heteropolyacids (H₃PW₁₂O₄₀·13H₂O, H₄SiW₁₂O₄₀·13H₂O,H₄SiMo₁₂O [...] Read more.

We have investigated a microwave–assisted synthesis of 4(3H)–quinazolinonesby condensation of anthranilic acid, orthoesters (or formic acid) and substituted anilines,using Keggin-type heteropolyacids (H₃PW₁₂O₄₀·13H₂O, H₄SiW₁₂O₄₀·13H₂O,H₄SiMo₁₂O₄₀·13H₂O or H₃PMo₁₂O₄₀·13H₂O) as catalysts. We found that the the use of H₃PW₁₂O₄₀·13H₂O acid coupled to microwave irradiation allows a solvent-free, rapid (~ 13min) and high-yielding reaction. Full article

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160 KiB

Open AccessArticle

Marine Bifunctional Sphingolipids from the Sponge Oceanapia ramsayi

by Julia Bensemhoun, Isabelle Bombarda, Maurice Aknin, Robert Faure, Jean Vacelet and Emile M. Gaydou

Molecules 2008, 13(4), 772-778; https://doi.org/10.3390/molecules13040772 - 1 Apr 2008

Cited by 6 | Viewed by 9517

Abstract

During the course of our continuing studies on marine natural lipid products,two known sphingolipids have been isolated for the first time from a specimen of themarine sponge Oceanapia ramsayi collected at Itampolo on the west coast of Madagascarin the Indian Ocean. The structures [...] Read more.

During the course of our continuing studies on marine natural lipid products,two known sphingolipids have been isolated for the first time from a specimen of themarine sponge Oceanapia ramsayi collected at Itampolo on the west coast of Madagascarin the Indian Ocean. The structures were elucidated using NMR data and by comparisonwith literature data. The occurrence of these sphingolipids within other Oceanapia spp. isdiscussed. Full article

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Open AccessCorrection

Correction to Oz, H.S.; Ebersole, Jeffrey L. Application of Prodrugs to Inflammatory Diseases of the Gut. Molecules 2008, 13, 452-474

by Helieh S. Oz and Jeffrey L. Ebersole

Molecules 2008, 13(4), 771; https://doi.org/10.3390/molecules13040771 - 1 Apr 2008

Cited by 3 | Viewed by 6148

Abstract

n/a Full article

141 KiB

Open AccessCommunication

Novel Unsaturated Sucrose Ethers and Their Application as Monomers

by Carina C. Crucho, Krasimira T. Petrova, Rui C. Pinto and Maria T. Barros

Molecules 2008, 13(4), 762-770; https://doi.org/10.3390/molecules13040762 - 28 Mar 2008

Cited by 17 | Viewed by 10692

Abstract

Novel unsaturated ethers were synthesised in good yields starting from sucrose,using a two-step mild and efficient procedure based on the Gassman method, whichconsists in forming a vinyl group by the elimination of ethanol from mixed acetals withtrimethylsilyl trifluoromethanesulfonate in the presence of alkyl [...] Read more.

Novel unsaturated ethers were synthesised in good yields starting from sucrose,using a two-step mild and efficient procedure based on the Gassman method, whichconsists in forming a vinyl group by the elimination of ethanol from mixed acetals withtrimethylsilyl trifluoromethanesulfonate in the presence of alkyl amines. Mixed acetals arereadily obtained from the corresponding alcohols and ethyl vinyl ether, using an acidiccatalyst. Conventional etherification involving a primary halide was also examined. Themonomers thus obtained were successfully polymerised by a free radical mechanism,yielding unbranched linear and soluble polymers with pending sucrose moieties, and someof their physical properties were determined. Full article

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211 KiB

Open AccessArticle

Antioxidant Activity of Diphenylpropionamide Derivatives: Synthesis, Biological Evaluation and Computational Analysis

by Paolo Urbani, Anna Ramunno, Rosanna Filosa, Aldo Pinto, Ada Popolo, Erminia Bianchino, Stefano Piotto, Carmela Saturnino, Rocco De Prisco, Barbara Nicolaus and Giuseppina Tommonaro

Molecules 2008, 13(4), 749-761; https://doi.org/10.3390/molecules13040749 - 28 Mar 2008

Cited by 7 | Viewed by 8964

Abstract

We report the synthesis, antioxidant and antiproliferative activity and a QSARanalysis of synthetic diphenylpropionamide derivatives. Synthesis of these compounds wasachieved by direct condensation of 2,2- and 3,3-diphenylpropionic acid and appropriateamines using 1-propylphoshonic acid cyclic anhydride (PPAA) as catalyst. Compoundstructures were elucidated by NMR [...] Read more.

We report the synthesis, antioxidant and antiproliferative activity and a QSARanalysis of synthetic diphenylpropionamide derivatives. Synthesis of these compounds wasachieved by direct condensation of 2,2- and 3,3-diphenylpropionic acid and appropriateamines using 1-propylphoshonic acid cyclic anhydride (PPAA) as catalyst. Compoundstructures were elucidated by NMR analysis and their melting points were measured. Thein vitro antioxidant activity of these compounds was tested by evaluating the amount ofscavenged ABTS radical and estimating ROS and NO production in LPS stimulatedJ774.A1 macrophages. All compounds were tested for their effect on viability of cells andresults demonstrated that they are not toxic towards the cell lines used. The cytotoxicactivity of all compounds was evaluated by a Brine Shrimp Test. Full article

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Open AccessArticle

Comparative Studies on Conventional and Microwave Synthesis of Some Benzimidazole, Benzothiazole and Indole Derivatives and Testing on Inhibition of Hyaluronidase

by Oztekin Algul, Andre Kaessler, Yagmur Apcin, Akin Yilmaz and Joachim Jose

Molecules 2008, 13(4), 736-748; https://doi.org/10.3390/molecules13040736 - 27 Mar 2008

Cited by 74 | Viewed by 12852

Abstract

We have synthesized twelve 2-substituted benzimidazole, benzothiazole andindole derivatives using on both microwave irradiation and conventional heating methods.The microwave method was observed to be more beneficial as it provides an increase ofyield from 3% to 113% and a 95 to 98 % reduction [...] Read more.

We have synthesized twelve 2-substituted benzimidazole, benzothiazole andindole derivatives using on both microwave irradiation and conventional heating methods.The microwave method was observed to be more beneficial as it provides an increase ofyield from 3% to 113% and a 95 to 98 % reduction in time. All compounds were tested bya stains-all assay at pH 7 and by a Morgan-Elson assay at pH 3.5 for hyaluronidaseinhibitory activity at a concentration of 100 μM. The most potent compound was 2-(4-hydroxyphenyl)-3-phenylindole (12) with an IC₅₀ value of 107 μM at both pH 7 and 3.5. Full article

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Molecules, Volume 13, Issue 4 (April 2008) – 32 articles , Pages 716-1024

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