Molecules

70 KiB

Open AccessArticle

Ultrasound Assisted Synthesis of 5,9-Dimethylpentadecane and 5,9-Dimethylhexadecane – the Sex Pheromones of Leucoptera coffeella

by Nhuan Ngoc Doan, Thach Ngoc Le, Hao Cong Nguyen, Poul Erik Hansen and Fritz Duus

Molecules 2007, 12(8), 2080-2088; https://doi.org/10.3390/12082080 - 28 Aug 2007

Cited by 12 | Viewed by 13298

Abstract

Racemic 5,9-dimethylpentadecane and 5,9-dimethylhexadecane, the major and minor constituents, respectively, of the sex pheromone of Leucoptera coffeella, have been synthesized from citronellol in 56-58% overall yield through six steps. Ultrasound irradiation efficiently supported tosylation of alcohols (two steps) as well as the [...] Read more.

Racemic 5,9-dimethylpentadecane and 5,9-dimethylhexadecane, the major and minor constituents, respectively, of the sex pheromone of Leucoptera coffeella, have been synthesized from citronellol in 56-58% overall yield through six steps. Ultrasound irradiation efficiently supported tosylation of alcohols (two steps) as well as the subsequent cross coupling reactions with the pertinent Grignard reagents (also two steps). Full article

► Show Figures

Scheme 1

135 KiB

Open AccessArticle

Microwave Assisted Condensation Reactions of 2-Aryl Hydrazonopropanals with Nucleophilic Reagents and Dimethyl Acetylenedicarboxylate

by Khadijah M. Al-Zaydi and Rita M. Borik

Molecules 2007, 12(8), 2061-2079; https://doi.org/10.3390/12082061 - 24 Aug 2007

Cited by 32 | Viewed by 13456

Abstract

The reaction of methyl ketones 1a-g with dimethylformamide dimethylacetal (DMFDMA) afforded the enaminones 2a-g, which were coupled with diazotized aromatic amines 3a,b to give the corresponding aryl hydrazones 6a-h. Condensation of compounds 6a-h with some aromatic heterocyclic amines afforded iminoarylhydrazones 9a-m. Enaminoazo compounds [...] Read more.

The reaction of methyl ketones 1a-g with dimethylformamide dimethylacetal (DMFDMA) afforded the enaminones 2a-g, which were coupled with diazotized aromatic amines 3a,b to give the corresponding aryl hydrazones 6a-h. Condensation of compounds 6a-h with some aromatic heterocyclic amines afforded iminoarylhydrazones 9a-m. Enaminoazo compounds 12a,b could be obtained from condensation of 6c with secondary amines. The reaction of 6e,h with benzotriazolylacetone yielded 14a,b. Also, the reaction of 6a,b,d-f,h with glycine and hippuric acid in acetic anhydride afforded pyridazinone derivatives 17a-f. Synthesis of pyridazine carboxylic acid derivatives 22a,b from the reaction of 6b,e with dimethyl acetylenedicarboxylate (DMAD) in the presence of triphenylphosphine at room temperature is also reported. Most of these reactions were conducted under irradiation in a microwave oven in the absence of solvent in an attempt to improve the product yields and to reduce the reaction times. Full article

► Show Figures

Figure 1

256 KiB

Open AccessArticle

Antibacterial Effect of Five Zingiberaceae Essential Oils

by Krittika Norajit, Natta Laohakunjit and Orapin Kerdchoechuen

Molecules 2007, 12(8), 2047-2060; https://doi.org/10.3390/12082047 - 23 Aug 2007

Cited by 83 | Viewed by 17857 | Retraction

Abstract

Essential oil obtained by hydrodistillation and two different solvent extractions (petroleum ether and ethanol) from five Zingiberaceae species: ginger (Zingiber officinale Roscoe.), galanga (Alpinia galanga Sw.), turmeric (Curcuma longa L.), kaempferia (Boesenbergia pandurata Holtt.) and bastard cardamom (Amomum [...] Read more.

Essential oil obtained by hydrodistillation and two different solvent extractions (petroleum ether and ethanol) from five Zingiberaceae species: ginger (Zingiber officinale Roscoe.), galanga (Alpinia galanga Sw.), turmeric (Curcuma longa L.), kaempferia (Boesenbergia pandurata Holtt.) and bastard cardamom (Amomum xanthioides Wall.) was characterized. Volatile components of all extracts were analyzed by gas chromatographymass spectrometry (GC-MS). The major components of ginger, turmeric, galangal, bastard cardamom and kaempferia were zingiberene, turmerone, methyl chavicol, and γ-terpinene, respectively. Their antibacterial effects towards Escherichia coli, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes were tested by a disc diffusion assay. Essential oil of kaempferia and bastard cardamom obtained by hydrodistillation extraction could inhibit growth of all tested bacteria. Essential oil of ginger extracted by hydrodistillation had the highest efficiency against three positive strains of bacteria (S. aureus, B. cereus and L. monocytogenes), with a minimum concentration to inhibit B. cereus and L. monocytogenes of 6.25 mg/mL. Full article

► Show Figures

Figure 1

142 KiB

Open AccessArticle

Two Novel Lanostane Triterpenoids from Ganoderma Sinense

by Yin Qiao, Xian-min Zhang and Ming-hua Qiu

Molecules 2007, 12(8), 2038-2046; https://doi.org/10.3390/12082038 - 23 Aug 2007

Cited by 31 | Viewed by 11032

Abstract

Two novel lanostane-type triterpenes, Ganolactone B and Ganoderiol A triacetate, were isolated from the fruiting bodies of G. sinense, together with six known compounds. The structures of the two new triterpenes were determined as 3β,7β- dihydroxy-11,15-dioxo-lanosta-8-en-24→20 lactone (1) [...] Read more.

Two novel lanostane-type triterpenes, Ganolactone B and Ganoderiol A triacetate, were isolated from the fruiting bodies of G. sinense, together with six known compounds. The structures of the two new triterpenes were determined as 3β,7β- dihydroxy-11,15-dioxo-lanosta-8-en-24→20 lactone (1) and 3β,24,26-triacetoxy-5α-lanosta-7,9(11)-dien-25-ol (2), respectively, by chemical and spectroscopic means. Full article

► Show Figures

Figure 1

145 KiB

Open AccessArticle

New Polyhydroxylated Furostanol Saponins with Inhibitory Action against NO Production from Tupistra chinensis Rhizomes

by Lan-Lan Xu, Kun Zou, Jun-Zhi Wang, Jun Wu, Yuan Zhou, Fei-Jun Dan and Jing Yang

Molecules 2007, 12(8), 2029-2037; https://doi.org/10.3390/12082029 - 23 Aug 2007

Cited by 26 | Viewed by 10558

Abstract

Two furostanol saponins were obtained from the rhizomes of Tupistra chinensis Bak. Their structures were determined as 5β-furost-δ²⁵⁽²⁷⁾-en-1β,2β,3β,4β,5β,7α,22ξ,26- octaol-6-one-26-O-β-D-glucopyranoside (1) and 5β-furost-δ²⁵⁽²⁷⁾-en-1β,2β,3β,4β,5β,6β, 7α,22ξ,26-nonaol-26-O-β-D-glucopyranoside (2), on the basis of chemical and spectroscopic evidence. Both compounds displayed marked inhibitory action against [...] Read more.

Two furostanol saponins were obtained from the rhizomes of Tupistra chinensis Bak. Their structures were determined as 5β-furost-δ²⁵⁽²⁷⁾-en-1β,2β,3β,4β,5β,7α,22ξ,26- octaol-6-one-26-O-β-D-glucopyranoside (1) and 5β-furost-δ²⁵⁽²⁷⁾-en-1β,2β,3β,4β,5β,6β, 7α,22ξ,26-nonaol-26-O-β-D-glucopyranoside (2), on the basis of chemical and spectroscopic evidence. Both compounds displayed marked inhibitory action against NO production in rat abdomen macrophages induced by lipopolysaccharide (LPS) at 40 μg/mL. Full article

► Show Figures

Figure 1

86 KiB

Open AccessArticle

An Improved Synthesis of 4-Chlorocoumarin-3-sulfonyl Chloride and Its Reactions with Different Bidentate Nucleophiles to Give Pyrido[1',2':2,3]- and Thiazino[3',2':2,3]-1,2,4-Thiadiazino[6,5-c]Benzopyran-6-one 7,7-Dioxides

by Ahmed Jashari, Evamarie Hey-Hawkins, Bozhana Mikhova, Gerald Draeger and Emil Popovski

Molecules 2007, 12(8), 2017-2028; https://doi.org/10.3390/12082017 - 22 Aug 2007

Cited by 12 | Viewed by 10935

Abstract

An improved synthetic method affording 4-chlorocoumarin-3-sulfonyl chloride (4) in very good yield (ca. 85 %) is reported. This compound was reacted with various bidentate nucleophiles such as 2-aminopyridines and 2-aminothiazoles in order to obtain substituted pyrido- and thiazino-1,2,4-thiadiazino-benzopyranone dioxides (potential anticancer and anti-HIV [...] Read more.

An improved synthetic method affording 4-chlorocoumarin-3-sulfonyl chloride (4) in very good yield (ca. 85 %) is reported. This compound was reacted with various bidentate nucleophiles such as 2-aminopyridines and 2-aminothiazoles in order to obtain substituted pyrido- and thiazino-1,2,4-thiadiazino-benzopyranone dioxides (potential anticancer and anti-HIV agents). These reactions occurred rapidly at room temperature giving yellowish precipitates, which are insoluble in common organic solvents, making the purification process challenging. Further investigation has shown that these fused heterocycles are not stable and decompose with opening of the 1,2,4-thiadiazine ring. Full article

► Show Figures

Figure 1

104 KiB

Open AccessArticle

Synthesis of Novel Derivatives of 4-Amino-3-(2-Furyl)-5-Mercapto-1,2,4-Triazole as Potential HIV-1 NNRTIs

by Jingde Wu, Xinyong Liu, Xianchao Cheng, Yuan Cao, Defeng Wang, Zhong Li, Wenfang Xu, Christophe Pannecouque, Myriam Witvrouw and Erik De Clercq

Molecules 2007, 12(8), 2003-2016; https://doi.org/10.3390/12082003 - 22 Aug 2007

Cited by 45 | Viewed by 10941

Abstract

A series of 5-alkylthio (2a-d), 4-arylideneamino (3a-d) and 4-arylideneamino- 5-alkylthio derivatives (4a-f) of 4-amino-3-(2-furyl)-5-mercapto-1,2,4-triazole (1) were synthesized by alkylation of the parent compound with alkyl halides and condensation with aldehydes, respectively. Sulfanyl dimers 5a-d and 4-iminomethyl dimer 6 were correspondingly prepared by reaction [...] Read more.

A series of 5-alkylthio (2a-d), 4-arylideneamino (3a-d) and 4-arylideneamino- 5-alkylthio derivatives (4a-f) of 4-amino-3-(2-furyl)-5-mercapto-1,2,4-triazole (1) were synthesized by alkylation of the parent compound with alkyl halides and condensation with aldehydes, respectively. Sulfanyl dimers 5a-d and 4-iminomethyl dimer 6 were correspondingly prepared by reaction with alkane dibromides and 1,4-diformylbenzene. Mannich base 7 was also synthesized by aminomethylation of the 3-sulfanyltriazole 1 at the N1 position. The newly designed and synthesized substituted s-triazole derivatives were assayed for anti-HIV-1 activity by examination of their inhibition of HIV-1-induced cytopathogenicity in MT-4 cells and by determination of their inhibitory effect on HIV-1 reverse transcriptase. Compound 4e was found to be the most active inhibitor against HIV- 1 replication in cell culture (EC₅₀ = 12 μM) and against HIV-1 reverse transcriptase (IC₅₀ = 43.5 μM), which provided a good lead for further optimization. Full article

► Show Figures

Figure 1

20 KiB

Open AccessEditorial

Full Open Access Publishing Policy Imposed in 2007: Molecules Publishes Many More Papers This Year – More than 2000 Pages Published up to Issue 8

by Shu-Kun Lin

Molecules 2007, 12(8), 2001-2002; https://doi.org/10.3390/12082001 - 22 Aug 2007

Cited by 5 | Viewed by 5265

Abstract

We are proud to be publishing page 2000 of the current volume of Molecules, in this issue 8 (August 2007), while last year we published only 1014 pages during the whole year.[...] Full article

1189 KiB

Open AccessReview

Supramolecular Chirality in Crystalline Assemblies of Bile Acids and Their Derivatives; Three-Axial, Tilt, Helical, and Bundle Chirality

by Mikiji Miyata, Norimitsu Tohnai and Ichiro Hisaki

Molecules 2007, 12(8), 1973-2000; https://doi.org/10.3390/12081973 - 22 Aug 2007

Cited by 47 | Viewed by 13506

Abstract

Steroidal bile acids and their derivatives exhibit characteristic inclusion behaviors in the crystalline state. Their crystals present varied assemblies due to asymmetric molecular structures, which relate to supramolecular properties through cooperative weak interactions. An overview indicates that the steroidal assemblies lie in an [...] Read more.

Steroidal bile acids and their derivatives exhibit characteristic inclusion behaviors in the crystalline state. Their crystals present varied assemblies due to asymmetric molecular structures, which relate to supramolecular properties through cooperative weak interactions. An overview indicates that the steroidal assemblies lie in an intermediate position among various molecules and have hierarchical structures such as primary, secondary, tertiary, and host-guest assemblies like proteins. Such an interpretation brought about the idea that the assemblies with dimensionality present supramolecular chirality such as three-axial, tilt, helical, bundle, and complementary chirality. This concept of the supramolecular chirality enables us to understand formation of chiral crystals starting from the molecular chirality of the steroidal molecules. Full article

(This article belongs to the Special Issue Bile Acids)

► Show Figures

Figure 1

64 KiB

Open AccessCommunication

Targeted Synthesis of 1-(4-Hydroxyiminomethylpyridinium)-3-pyridiniumpropane Dibromide – A New Nerve Agent Reactivator

by Kamil Kuca, Kamil Musilek, Martin Paar, Daniel Jun, Petr Stodulka, Martina Hrabinova and Jan Marek

Molecules 2007, 12(8), 1964-1972; https://doi.org/10.3390/12081964 - 20 Aug 2007

Cited by 17 | Viewed by 9593

Abstract

Preparation of 1-(4-hydroxy-iminomethylpyridinium)-3-pyridiniumpropane dibromide is described. This compound represents a new acetylcholinesterase (AChE) reactivator, which has no substituents on the second pyridinium ring as found in other commonly used AChE reactivators. The reactivation ability of this reactivator was tested on tabun- and cyclosarin-inhibited [...] Read more.

Preparation of 1-(4-hydroxy-iminomethylpyridinium)-3-pyridiniumpropane dibromide is described. This compound represents a new acetylcholinesterase (AChE) reactivator, which has no substituents on the second pyridinium ring as found in other commonly used AChE reactivators. The reactivation ability of this reactivator was tested on tabun- and cyclosarin-inhibited AChE. According to the results obtained, the new compound (without substitution and with decreased molecule size) showed increased reactivation potency in case of cyclosarin inhibited AChE. A potent oxime for treatment of tabun and cyclosarin-caused intoxications was thus obtained via slight modification of the reactivator structure (compared to trimedoxime and K027). Full article

► Show Figures

Figure 1

116 KiB

Open AccessArticle

Antioxidant Capacity and In Vitro Prevention of Dental Plaque Formation by Extracts and Condensed Tannins of Paullinia cupana

by Elza Yamaguti-Sasaki, Lia Akina Ito, Vanessa Cristina Dias Canteli, Tânia Mara Antonelli Ushirobira, Tânia Ueda-Nakamura, Benedito Prado Dias Filho, Celso Vataru Nakamura and João Carlos Palazzo de Mello

Molecules 2007, 12(8), 1950-1963; https://doi.org/10.3390/12081950 - 20 Aug 2007

Cited by 78 | Viewed by 18523

Abstract

Chemical evaluation of the semi-purified fraction from the seeds of guaraná, Paullinia cupana H.B.K. var. sorbilis (Mart.) Ducke, yielded the following compounds: caffeine, catechin, epicatechin, ent-epicatechin, and procyanidins B₁, B₂, B₃, B₄, A₂, [...] Read more.

Chemical evaluation of the semi-purified fraction from the seeds of guaraná, Paullinia cupana H.B.K. var. sorbilis (Mart.) Ducke, yielded the following compounds: caffeine, catechin, epicatechin, ent-epicatechin, and procyanidins B₁, B₂, B₃, B₄, A₂, and C₁. Measurement of the antioxidant activity by reduction of the DPPH radical confirmed the anti-radical properties of the aqueous (AqE) and crude (EBPC) extracts and semi-purified (EPA and EPB) fractions. The EPA fraction showed radical-scavenging activity (RSA) and protected DPPH from discoloration at 5.23±0.08 (RSD%=1.49) μg/mL, and for the phosphomolybdenum complex showed a higher Relative Antioxidant Capacity (RAC) at 0.75±0.01 (1.75). The EPA fraction had a total polyphenolics content of 65.80%±0.62 (RSD%=0.93). The plant drug showed 5.47% ± 0.19 (RSD%=3.51) and 6.19% ± 0.08 (RSD%=1.29) for total polyphenolics and methylxanthines, respectively. In vitro assessment of the antibacterial potential of the Paullinia cupana extracts against Streptococcus mutans showed that these could be used in the prevention of bacterial dental plaque. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

► Show Figures

Figure 1

154 KiB

Open AccessArticle

Palladate Salts from Chiral Pyridinium Ionic Liquids: Synthesis and Crystal Structures

by Emmanuel Tourneux, Heinz Gornitzka, Jean-Daniel Marty and Nancy Lauth-de Viguerie

Molecules 2007, 12(8), 1940-1949; https://doi.org/10.3390/12081940 - 20 Aug 2007

Cited by 10 | Viewed by 11180

Abstract

This paper reports the preparation, characterization and the crystal X-ray structures of metal-containing ionic liquid complexes based on chiral pyridinium cations and tetrachloropalladate (II) [PdCl₄]^2-. Full article

(This article belongs to the Special Issue Heterocycles)

► Show Figures

Figure 1

194 KiB

Open AccessReview

Biological Activities of Hydrazone Derivatives

by Sevim Rollas and S. Güniz Küçükgüzel

Molecules 2007, 12(8), 1910-1939; https://doi.org/10.3390/12081910 - 17 Aug 2007

Cited by 1108 | Viewed by 37804

Abstract

There has been considerable interest in the development of novel compounds with anticonvulsant, antidepressant, analgesic, antiinflammatory, antiplatelet, antimalarial, antimicrobial, antimycobacterial, antitumoral, vasodilator, antiviral and antischistosomiasis activities. Hydrazones possessing an azometine -NHN=CH- proton constitute an important class of compounds for new drug development. Therefore, [...] Read more.

There has been considerable interest in the development of novel compounds with anticonvulsant, antidepressant, analgesic, antiinflammatory, antiplatelet, antimalarial, antimicrobial, antimycobacterial, antitumoral, vasodilator, antiviral and antischistosomiasis activities. Hydrazones possessing an azometine -NHN=CH- proton constitute an important class of compounds for new drug development. Therefore, many researchers have synthesized these compounds as target structures and evaluated their biological activities. These observations have been guiding for the development of new hydrazones that possess varied biological activities. Full article

► Show Figures

Figure 1

85 KiB

Open AccessArticle

Synthesis and In-vitro Antitumor Activity of 1-[3-(Indol-1-yl)prop-1-yn-1-yl]phthalazines and Related Compounds

by Norbert Haider, Tamara Kabicher, Johann Käferböck and Angelika Plenk

Molecules 2007, 12(8), 1900-1909; https://doi.org/10.3390/12081900 - 17 Aug 2007

Cited by 33 | Viewed by 7654

Abstract

A series of novel 3-(indol-1-yl)prop-1-yn-1-yl-substituted phthalazines and related azines was prepared via a concise pathway by palladium-catalyzed cross-coupling of appropriate halo-azines and N-propargylindoles. Some of the compounds exhibited significant antitumor activity in an in-vitro assay. Full article

► Show Figures

Figure 1

127 KiB

Open AccessArticle

Synthesis of Novel Steroid-Peptoid Hybrid Macrocycles by Multiple Multicomponent Macrocyclizations Including Bifunctional Building Blocks (MiBs)

by Daniel G. Rivera and Ludger A. Wessjohann

Molecules 2007, 12(8), 1890-1899; https://doi.org/10.3390/12081890 - 17 Aug 2007

Cited by 35 | Viewed by 12658

Abstract

Two new groups of cholane-peptoid hybrid macrocycles were produced by implementing novel combinations of the MiB methodology. Steroid-based hybrid macrolactams including heterocycle and aryl moieties were obtained by utilizing cholanic dicarboxylic acids and diamines in a bidirectional double Ugi-Four-Component (Ugi-4CR) based macrocyclization protocol. [...] Read more.

Two new groups of cholane-peptoid hybrid macrocycles were produced by implementing novel combinations of the MiB methodology. Steroid-based hybrid macrolactams including heterocycle and aryl moieties were obtained by utilizing cholanic dicarboxylic acids and diamines in a bidirectional double Ugi-Four-Component (Ugi-4CR) based macrocyclization protocol. Alternatively, N-substituted cyclocholamides were produced from a cholanic pseudo-amino acid by an Ugi-4CR-based cyclooligomerization approach. Both types of macrocycles are steroid-peptoid hybrid macrocycles containing exocyclic peptidic chains. These novel frameworks are a result of the use of bile acids bifunctionalized with carboxylic and amino functionalities as bifunctional building blocks of the Ugi-MiB approach. Full article

(This article belongs to the Special Issue Bile Acids)

► Show Figures

Figure 1

168 KiB

Open AccessReview

Exploitation of Bile Acid Transport Systems in Prodrug Design

by Elina Sievänen

Molecules 2007, 12(8), 1859-1889; https://doi.org/10.3390/12081859 - 16 Aug 2007

Cited by 113 | Viewed by 18941

Abstract

The enterohepatic circulation of bile acids is one of the most efficient recycling routes in the human body. It is a complex process involving numerous transport proteins, which serve to transport bile acids from the small intestine into portal circulation, from the portal [...] Read more.

The enterohepatic circulation of bile acids is one of the most efficient recycling routes in the human body. It is a complex process involving numerous transport proteins, which serve to transport bile acids from the small intestine into portal circulation, from the portal circulation into the hepatocyte, from the hepatocyte into the bile, and from the gall bladder to the small intestine. The tremendous transport capacity and organ specificity of enterohepatic circulation combined with versatile derivatization possibilities, rigid steroidal backbone, enantiomeric purity, availability, and low cost have made bile acids attractive tools in designing pharmacological hybrid molecules and prodrugs with the view of improving intestinal absorption, increasing the metabolic stability of pharmaceuticals, specifically targeting drugs to organs involved in enterohepatic circulation, as well as sustaining therapeutically reasonable systemic concentrations of active agents. This article briefly describes bile acid transport proteins involved in enterohepatic circulation, summarizes the key factors affecting on the transport by these proteins, and reviews the use of bile acids and their derivatives in designing prodrugs capable of exploiting the bile acid transport system. Full article

(This article belongs to the Special Issue Bile Acids)

► Show Figures

Figure 1

386 KiB

Open AccessArticle

(-)-Epicatechin-3-gallate, a Green Tea Polyphenol Is a Potent Agent Against UVB-induced Damage in HaCaT Keratinocytes

by Chieh-Chen Huang, Wen-Bin Wu, Jia-You Fang, Han-Sun Chiang, Shao-Kuan Chen, Bing-Huei Chen, Ying-Ting Chen and Chi-Feng Hung

Molecules 2007, 12(8), 1845-1858; https://doi.org/10.3390/12081845 - 14 Aug 2007

Cited by 60 | Viewed by 17324

Abstract

(-)-Epicatechin-3-gallate (ECG) is a polyphenolic compound similar to (-)-epigallocatechin-3-gallate (EGCG) which is abundant in green tea. Numerous workers have proposed that EGCG protects epidermal cells against UVB-induced damage. However, little has been known about whether ECG protects keratinocytes against UVB-induced damage. We decided [...] Read more.

(-)-Epicatechin-3-gallate (ECG) is a polyphenolic compound similar to (-)-epigallocatechin-3-gallate (EGCG) which is abundant in green tea. Numerous workers have proposed that EGCG protects epidermal cells against UVB-induced damage. However, little has been known about whether ECG protects keratinocytes against UVB-induced damage. We decided to investigate the protective effects and underlying mechanisms of ECG on UVB-induced damage. Cell viability was determined by the MTT assay. Activation of ERK1/2, p38 and JNK was analyzed by Western blotting. Intracellular H₂O₂ production and DNA content was analyzed by flow cytometry. Lipid peroxidation was assayed by colorimetry. In our study, we found that ECG dose-dependently attenuated UVB-induced keratinocyte death. Moreover, ECG markedly inhibited UVB-induced cell membrane lipid peroxidation and H₂O₂ generation in keratinocytes, suggesting that ECG can act as a free radical scavenger when keratinocytes were photodamaged. In parallel, H₂O₂-induced the activation of ERK1/2, p38 and JNK in keratinocytes could be inhibited by ECG. UVB-induced pre-G1 arrest leading to apoptotic changes of keratinocytes were blocked by ECG. Taken together, we provide here evidence that ECG protects keratinocytes from UVB-induced photodamage and H₂O₂-induced oxidative stress, possibly through inhibition of the activation of ERK1/2, p38 and JNK and/or scavenging of free radicals. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

► Show Figures

Figure 1

92 KiB

Open AccessArticle

Radical-scavenging Activity of the Reaction Products of Isoeugenol with Thiol, Thiophenol, Mercaptothiazoline or Mercaptomethylimidazole Using the Induction Period Method

by Yoshinori Kadoma, Wakako Kumada, Yuhta Asai, Yoshiaki Sugita, Ichiro Yokoe and Seiichiro Fujisawa

Molecules 2007, 12(8), 1836-1844; https://doi.org/10.3390/12081836 - 13 Aug 2007

Cited by 6 | Viewed by 8329

Abstract

The reaction products in the presence of Lewis acid of isoeugenol (1) with ethanethiol, thiophenol, 2-mercaptothiazoline or 2-mercapto-1-methylimidazole (ISO-S1 – ISO-S-4) were obtained. The radical-scavenging activity of these compounds was investigated using the induction period method for polymerization of methyl methacrylate (MMA) initiated [...] Read more.

The reaction products in the presence of Lewis acid of isoeugenol (1) with ethanethiol, thiophenol, 2-mercaptothiazoline or 2-mercapto-1-methylimidazole (ISO-S1 – ISO-S-4) were obtained. The radical-scavenging activity of these compounds was investigated using the induction period method for polymerization of methyl methacrylate (MMA) initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN) and benzoyl peroxide (BPO) and monitored by differential scanning calorimetry (DSC). For BPO, the stoichiometric factor (number of free radicals trapped by one mole of antioxidant moiety, n) declined in the order isoeugenol (1.8) > ISO-S-1 (1.6) > ISO-S-2 (1.2 ) > ISOS- 3 (0.9) > ISO-S-4 (0.3), whereas for AIBN, their n values were about 1, except for ISOS- 3 (0.6). The ratio of the rate constant of inhibition to that of propagation (k_inh/k_p) for BPO declined in the order ISO-S-4 (56) > ISO-S-3 (15) > ISO-S-2 (11) >ISO-S-1 (9) > isoeugenol (8). Similarly, for AIBN the k_inh/k_p of the reaction products (33-57) was greater than that of isoeugenol (31). The reaction products of isoeugenol with a SH group showed greater inhibition rate constants (kinh) than the parent compound isoeugenol. Full article

► Show Figures

Figure 1

74 KiB

Open AccessCommunication

Effect of Cooking Processes on the Contents of Two Bioactive Carotenoids in Solanum lycopersicum Tomatoes and Physalis ixocarpa and Physalis philadelphica Tomatillos

by María P. Elizalde-González and Socorro G. Hernández-Ogarcía

Molecules 2007, 12(8), 1829-1835; https://doi.org/10.3390/12081829 - 13 Aug 2007

Cited by 17 | Viewed by 10630

Abstract

Calculation of the HPLC chromatographic retention times of different carotenoids supported our improved chromatographic separation of β-carotene and lutein in four tomatoes and two tomatillo varieties in fresh form and after three different cooking procedures: pot boiling, cooking in a pressure cooker and [...] Read more.

Calculation of the HPLC chromatographic retention times of different carotenoids supported our improved chromatographic separation of β-carotene and lutein in four tomatoes and two tomatillo varieties in fresh form and after three different cooking procedures: pot boiling, cooking in a pressure cooker and microwaving. A good separation was achieved experimentally using an Ultrasphere ODS column and gradient elution with an acetonitrile-tetrahydrofuran-water mobile phase. It was shown that diverse tomato species contained different amounts of β-carotene (6-400 μg/100 mg) and lutein (2-30 μg/100 mg). The concentration in fresh samples was higher than in cooked tomatoes. The β–carotene content in fresh tomatillo varied between 2 and 20 μg/100 mg. Microwaving caused partial destruction of the β-carotene and lutein in tomatillos. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

► Show Figures

Figure 1

105 KiB

Open AccessArticle

Synthesis of Novel Benzimidazolyl-substituted Acrylonitriles and Amidino-substituted Benzimidazo[1,2-a]Quinolines

by Marijana Hranjec and Grace Karminski-Zamola

Molecules 2007, 12(8), 1817-1828; https://doi.org/10.3390/12081817 - 13 Aug 2007

Cited by 30 | Viewed by 8698

Abstract

A series of novel benzimidazole derivatives 3-10 were synthesized. Benzimidazolyl-substituted acrylonitriles 3 and 4 underwent a photochemical dehydrocyclization reaction to give the corresponding mono- and dicyano-substituted benzimidazo[1,2-a] quinolines 5 and 6. Pinner reaction of these compounds did not give the expected [...] Read more.

A series of novel benzimidazole derivatives 3-10 were synthesized. Benzimidazolyl-substituted acrylonitriles 3 and 4 underwent a photochemical dehydrocyclization reaction to give the corresponding mono- and dicyano-substituted benzimidazo[1,2-a] quinolines 5 and 6. Pinner reaction of these compounds did not give the expected mono- and diamidines, but rather only compounds 7-10, with amido groups at 6-position were isolated. A mechanism for the reaction is proposed. Acyclic compounds 3 and 4, as well as cyclic benzimidazo[1,2-a]quinolines 5-8, exhibit interesting spectroscopic properties and are potential biologically active compounds. Full article

► Show Figures

Figure 1

149 KiB

Open AccessArticle

A Study on 4-Acylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones

by Muzaffer Alkan, Haydar Yüksek, Fatih İslamoğlu, Sule Bahçeci, Mustafa Calapoğlu, Mahfuz Elmastaş, Hüseyin Akşit and Mustafa Özdemir

Molecules 2007, 12(8), 1805-1816; https://doi.org/10.3390/12081805 - 13 Aug 2007

Cited by 26 | Viewed by 9385

Abstract

Five novel 3-alkyl-4-phenylacetylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) were synthesized by the reactions of 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with phenylacetyl chloride and characterized by elemental analyses and IR, ¹HNMR, ¹³C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with [...] Read more.

Five novel 3-alkyl-4-phenylacetylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) were synthesized by the reactions of 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with phenylacetyl chloride and characterized by elemental analyses and IR, ¹HNMR, ¹³C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. In addition, these new compounds and five recently reported 3-alkyl-4-(pmethoxybenzoylamino)- 4,5-dihydro-1H-1,2,4-triazol-5-ones (3) were screened for their antioxidant activities. Full article

► Show Figures

Figure 1

75 KiB

Open AccessArticle

Synthesis of Some New Anils: Part 1. Reaction of 2-Hydroxy-benzaldehyde and 2-Hydroxynaphthaldehyde with 2-Aminopyridene and 2-Aminopyrazine

by Abdullah M. Asiri and Khadija O. Badahdah

Molecules 2007, 12(8), 1796-1804; https://doi.org/10.3390/12081796 - 13 Aug 2007

Cited by 42 | Viewed by 14610

Abstract

New Schiff bases derived from 2-aminopyridene and 2-aminopyrazine have been synthesized. The UV-Visible spectra of the compounds have been investigated in acetonitrile and toluene. The compounds were in tautomeric equilibrium (enol-imine O– H···N, keto-amine O···H–N forms) in polar and nonpolar solvents. For some [...] Read more.

New Schiff bases derived from 2-aminopyridene and 2-aminopyrazine have been synthesized. The UV-Visible spectra of the compounds have been investigated in acetonitrile and toluene. The compounds were in tautomeric equilibrium (enol-imine O– H···N, keto-amine O···H–N forms) in polar and nonpolar solvents. For some derivatives the keto-amine form was observed in both toluene and acetonitrile. ¹H-NMR and IR results showed that all Schiff bases studied favor the enol-imine form over the keto form in a weakly polar solvent such as deuterochloroform. Full article

► Show Figures

Figure 1

184 KiB

Open AccessReview

Synthetic Approaches to Heterocyclic Ligands for Gd-Based MRI Contrast Agents

by Elena Pérez-Mayoral, Jordi Soler-Padrós, Viviana Negri, Sebastián Cerdán and Paloma Ballesteros

Molecules 2007, 12(8), 1771-1795; https://doi.org/10.3390/12081771 - 9 Aug 2007

Cited by 7 | Viewed by 12961

Abstract

Magnetic Resonance Imaging (MRI) methods are currently used in the clinic for the non invasive detection and characterization of a wide variety of pathologies. Increases in the diagnostic efficiency of MRI have been helped by both the design of dedicated MR sequences revealing [...] Read more.

Magnetic Resonance Imaging (MRI) methods are currently used in the clinic for the non invasive detection and characterization of a wide variety of pathologies. Increases in the diagnostic efficiency of MRI have been helped by both the design of dedicated MR sequences revealing specific aspects of the pathology and by the development of more sensitive and selective Contrast Agents (CAs), capable of more precisely delineating the borderline regions. In the present review we focus on the synthetic strategies used to obtain MRI CAs containing heterocyclic rings. Full article

► Show Figures

Figure 1

96 KiB

Open AccessArticle

High-Yielding Synthesis of Methyl Orthoformate-Protected Hydroxytyrosol and Its Use in Preparation of Hydroxytyrosyl Acetate

by Augusto Gambacorta, Daniela Tofani and Antonella Migliorini

Molecules 2007, 12(8), 1762-1770; https://doi.org/10.3390/12081762 - 8 Aug 2007

Cited by 10 | Viewed by 12526

Abstract

The new methyl orthoformate of the powerful antioxidant hydroxytyrosol (or 2- (3,4-dihydroxyphenyl)ethanol) has been synthesized by a two-step high yielding procedure. The protection stabilizes hydroxytyrosol against fast oxidation and allows both easy chromatographic purification and long term storage. The protective group is hydrolyzed [...] Read more.

The new methyl orthoformate of the powerful antioxidant hydroxytyrosol (or 2- (3,4-dihydroxyphenyl)ethanol) has been synthesized by a two-step high yielding procedure. The protection stabilizes hydroxytyrosol against fast oxidation and allows both easy chromatographic purification and long term storage. The protective group is hydrolyzed over pH = 10 and below pH = 5, thus allowing the release of the active principle under physiological conditions. The use of the methyl orthoformate-protected hydroxytyrosol allows the preparation of protected hydroxytyrosyl esters, like the acetate herein reported, by selective esterification of the alcoholic function. The subsequent quantitative deprotection under non-aqueous and mild conditions affords the hydroxytyrosyl acetate in high yields. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

► Show Figures

Figure 1

58 KiB

Open AccessCommunication

Two Step Synthesis of a Non-symmetric Acetylcholinesterase Reactivator

by Kamil Musilek, Kamil Kuca, Vlastimil Dohnal, Daniel Jun, Jan Marek and Vit Koleckar

Molecules 2007, 12(8), 1755-1761; https://doi.org/10.3390/12081755 - 7 Aug 2007

Cited by 10 | Viewed by 8663

Abstract

The newly developed and very promising acetylcholinesterase reactivator (E)-1- (2-hydroxyiminomethylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide was prepared using two different pathways via a two-step synthesis involving the appropriate (E)-1-(4-bromobut-2-enyl)-2- or 4-hydroxyiminomethyl-pyridinium bromides. Afterwards, purities and yields of the desired product prepared by both [...] Read more.

The newly developed and very promising acetylcholinesterase reactivator (E)-1- (2-hydroxyiminomethylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide was prepared using two different pathways via a two-step synthesis involving the appropriate (E)-1-(4-bromobut-2-enyl)-2- or 4-hydroxyiminomethyl-pyridinium bromides. Afterwards, purities and yields of the desired product prepared by both routes were compared. Finally, its potency to reactivate several nerve agent-inhibited acetylcholinesterases was tested. Full article

► Show Figures

Figure 1

467 KiB

Open AccessReview

Supra-molecular Association and Polymorphic Behaviour In Systems Containing Bile Acid Salts

by Marco Calabresi, Patrizia Andreozzi and Camillo La Mesa

Molecules 2007, 12(8), 1731-1754; https://doi.org/10.3390/12081731 - 7 Aug 2007

Cited by 73 | Viewed by 17097

Abstract

A wide number of supra-molecular association modes are observed in mixtures containing water and bile salts, BS, (with, eventually, other components). Molecular or micellar solutions transform into hydrated solids, fibres, lyotropic liquid crystals and/or gels by raising the concentration, the temperature, adding electrolytes, [...] Read more.

A wide number of supra-molecular association modes are observed in mixtures containing water and bile salts, BS, (with, eventually, other components). Molecular or micellar solutions transform into hydrated solids, fibres, lyotropic liquid crystals and/or gels by raising the concentration, the temperature, adding electrolytes, surfactants, lipids and proteins. Amorphous or ordered phases may be formed accordingly. The forces responsible for this very rich polymorphism presumably arise from the unusual combination of electrostatic, hydrophobic and hydrogen-bond contributions to the system stability, with subsequent control of the supra-molecular organisation modes. The stabilising effect due to hydrogen bonds does not occur in almost all surfactants or lipids and is peculiar to bile acids and salts. Some supra-molecular organisation modes, supposed to be related to malfunctions and dis-metabolic diseases in vivo, are briefly reported and discussed. Full article

(This article belongs to the Special Issue Bile Acids)

► Show Figures

Figure 1

84 KiB

Open AccessArticle

Synthesis, Antibacterial, Antifungal and Antiviral Activity Evaluation of Some New bis-Schiff Bases of Isatin and Their Derivatives

by Aliasghar Jarrahpour, Dariush Khalili, Erik De Clercq, Chanaz Salmi and Jean Michel Brunel

Molecules 2007, 12(8), 1720-1730; https://doi.org/10.3390/12081720 - 7 Aug 2007

Cited by 313 | Viewed by 20459

Abstract

Twelve new bis-Schiff bases of isatin, benzylisatin and 5-fluoroisatin 3a-3l were prepared by condensation of isatin, benzylisatin and 5-fluoroisatin with primary aromatic amines. The chemical structures of the products were confirmed by ¹H- and ¹³CNMR, IR and mass spectral data. The [...] Read more.

Twelve new bis-Schiff bases of isatin, benzylisatin and 5-fluoroisatin 3a-3l were prepared by condensation of isatin, benzylisatin and 5-fluoroisatin with primary aromatic amines. The chemical structures of the products were confirmed by ¹H- and ¹³CNMR, IR and mass spectral data. The compounds were screened for antiviral activity against a panel of DNA and RNA viruses. Minimum cytotoxic and minimum virusinhibitory concentrations of these compounds were determined. Compounds 3c and 3i were the most cytotoxic in HEL cells. These newly synthesized bis-Schiff bases were also tested for their antibacterial and antifungal activities. They did not display activity against S. cerevisiae (ATCC 28383) or C. albicans (CIP 1180-79). Full article

► Show Figures

Figure 1

262 KiB

Open AccessReview

Phenolic Molecules in Virgin Olive Oils: a Survey of Their Sensory Properties, Health Effects, Antioxidant Activity and Analytical Methods. An Overview of the Last Decade Alessandra

by Alessandra Bendini, Lorenzo Cerretani, Alegria Carrasco-Pancorbo, Ana Maria Gómez-Caravaca, Antonio Segura-Carretero, Alberto Fernández-Gutiérrez and Giovanni Lercker

Molecules 2007, 12(8), 1679-1719; https://doi.org/10.3390/12081679 - 6 Aug 2007

Cited by 746 | Viewed by 43206

Abstract

Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to make it unique and a basic component of the Mediterranean diet. The importance of VOO is mainly attributed both to its high content of oleic acid a balanced contribution [...] Read more.

Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to make it unique and a basic component of the Mediterranean diet. The importance of VOO is mainly attributed both to its high content of oleic acid a balanced contribution quantity of polyunsaturated fatty acids and its richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of several human diseases. The polar phenolic compounds of VOO belong to different classes: phenolic acids, phenyl ethyl alcohols, hydroxy-isochromans, flavonoids, lignans and secoiridoids. This latter family of compounds is characteristic of Oleaceae plants and secoiridoids are the main compounds of the phenolic fraction. Many agronomical and technological factors can affect the presence of phenols in VOO. Its shelf life is higher than other vegetable oils, mainly due to the presence of phenolic molecules having a catechol group, such as hydroxytyrosol and its secoiridoid derivatives. Several assays have been used to establish the antioxidant activity of these isolated phenolic compounds. Typical sensory gustative properties of VOO, such as bitterness and pungency, have been attributed to secoiridoid molecules. Considering the importance of the phenolic fraction of VOO, high performance analytical methods have been developed to characterize its complex phenolic pattern. The aim of this review is to realize a survey on phenolic compounds of virgin olive oils bearing in mind their chemical-analytical, healthy and sensory aspects. In particular, starting from the basic studies, the results of researches developed in the last ten years will be focused. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

► Show Figures

Figure 1

35 KiB

Open AccessCommunication

Aqueous Ti(IV)-Catalyzed Diels-Alder Reaction

by Kyle E. Litz

Molecules 2007, 12(8), 1674-1678; https://doi.org/10.3390/12081674 - 4 Aug 2007

Cited by 8 | Viewed by 7718

Abstract

The aqueous Diels-Alder reaction of 1,3-cyclohexadiene with 1,4-benzoquinone was compared and contrasted to the same reaction catalyzed with Flextyl P™, a novel Ti(IV) performance catalyst. The catalyst improved conversion by 22% versus the uncatalyzed reaction and represents a rare example of a Ti(IV) [...] Read more.

The aqueous Diels-Alder reaction of 1,3-cyclohexadiene with 1,4-benzoquinone was compared and contrasted to the same reaction catalyzed with Flextyl P™, a novel Ti(IV) performance catalyst. The catalyst improved conversion by 22% versus the uncatalyzed reaction and represents a rare example of a Ti(IV) catalyzed Diels-Alder reaction in water. Full article

► Show Figures

Figure 1

369 KiB

Open AccessReview

Flavonoid Composition of Citrus Juices

by Giuseppe Gattuso, Davide Barreca, Claudia Gargiulli, Ugo Leuzzi and Corrado Caristi

Molecules 2007, 12(8), 1641-1673; https://doi.org/10.3390/12081641 - 3 Aug 2007

Cited by 599 | Viewed by 36800

Abstract

In the early nineties the presence of flavonoids in Citrus juices began to attract the attention of a number of researchers, as a result of their biological and physiological importance. This short review will explore two different aspects. The first part will focus [...] Read more.

In the early nineties the presence of flavonoids in Citrus juices began to attract the attention of a number of researchers, as a result of their biological and physiological importance. This short review will explore two different aspects. The first part will focus on analytical techniques for the characterization of juices from different Citrus fruits regarding their flavonoid content (even if present in only trace amounts), concentrating on the most widely used methods (LC-MS and LC-MS-MS). The second part analyzes data reported in the literature regarding the composition of Citrus juices. The main components that have been detected so far are flavanone-O-glycosides and flavone-O- or -C-glycosides. The presence of such derivatives in various hand-squeezed and industrial juices is discussed, with special emphasis on their correlation to different species. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Molecules, Volume 12, Issue 8 (August 2007) – 38 articles , Pages 1548-2088

Further Information

Guidelines

MDPI Initiatives

Follow MDPI