Molecules

171 KiB

Open AccessArticle

Highly Volatile Constituents of Vetiveria zizanioides Roots Grown under Different Cultivation Conditions

by Patcharee Pripdeevech, Sugunya Wongpornchai and Ampan Promsiri

Molecules 2006, 11(10), 817-826; https://doi.org/10.3390/11100817 - 25 Oct 2006

Cited by 35 | Viewed by 11405

Roots of Vetiveria zizanioides Nash (Mae Hae; Thai ecotype) planted in three different cultivation systems (normal soil, normal soil with added microbes and semi- hydroponically) were extracted using a simultaneous steam distillation and solvent extraction (SDE) apparatus. Yields of the essential oils obtained [...] Read more.

Roots of Vetiveria zizanioides Nash (Mae Hae; Thai ecotype) planted in three different cultivation systems (normal soil, normal soil with added microbes and semi- hydroponically) were extracted using a simultaneous steam distillation and solvent extraction (SDE) apparatus. Yields of the essential oils obtained were 0.27, 0.18 and 0.06%, respectively. The separation profiles obtained by comprehensive two-dimensional gas chromatography (GC×GC) and solid phase microextraction (SPME)-GC×GC analyses of the crude essential oils showed a total of 156 and 48 well-resolved components, respectively. The highly volatile fractions isolated from the three essential oils by SPME were subjected to analysis by GC-MS and 42 compounds were identified in total. Volatile component profiles of the oils obtained by normal soil and semi-hydroponic cultivation were similar, whereas a quantitative difference was noted in some major volatiles when the cultivation system containing microbes was utilized. Full article

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56 KiB

Open AccessArticle

New Caulerpenyne-derived Metabolites of an Elysia Sacoglossan from the South Indian Coast

by M. Letizia Ciavatta, M. Pilar Lopez Gresa, Margherita Gavagnin, Emiliano Manzo, Ernesto Mollo, Lisette D’Souza and Guido Cimino

Molecules 2006, 11(10), 808-816; https://doi.org/10.3390/11100808 - 25 Oct 2006

Cited by 13 | Viewed by 10705

Abstract

Chemical analysis of the secondary metabolite pattern of the sacoglossan mollusc Elysia cf. expansa, collected along South Indian coasts, showed the presence of the typical Caulerpa-derived sesquiterpene caulerpenyne (1) and two new minor co- occurring metabolites, the compounds dihydrocaulerpenyne (4) and expansinol (5). [...] Read more.

Chemical analysis of the secondary metabolite pattern of the sacoglossan mollusc Elysia cf. expansa, collected along South Indian coasts, showed the presence of the typical Caulerpa-derived sesquiterpene caulerpenyne (1) and two new minor co- occurring metabolites, the compounds dihydrocaulerpenyne (4) and expansinol (5). The chemical characterization of these molecules, structurally related to 1, is reported Full article

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160 KiB

Open AccessArticle

Synthetic Studies Towards the ent-Labdane Diterpenoids: Rearrangement of ent-Halimanes

by Isidro S. Marcos, María J. Sexmero, Felix A. Hernández, Marta Corrales, Pilar Basabe, David Díez and Julio G. Urones

Molecules 2006, 11(10), 792-807; https://doi.org/10.3390/11100792 - 24 Oct 2006

Cited by 6 | Viewed by 9950

Abstract

For the first time ent-labdanes have been synthetised starting from ent-halimic acid, following a route that is the reverse of the biosynthetic one leading to the former compounds. Full article

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88 KiB

Open AccessArticle

Synthesis and Properties of Novel Unsymmetrical Donor Molecules Containing p-Acetoxy- or p-Hydroxyphenyl Units

by Lakhemici Kaboub, Slimane Fradj and Abdelkrim Gouasmia

Molecules 2006, 11(10), 776-785; https://doi.org/10.3390/11100776 - 21 Oct 2006

Cited by 4 | Viewed by 6956

Abstract

We report the synthesis and properties of eight new tetrathiafulvalene (TTF) derivatives containing two different functionalities, prepared with the aim of obtaining stable organic materials. The four acetoxyphenyl- and four hydroxyphenyl TTFs were synthesized via Wittig-type condensations. The electrochemical properties of these redox-active [...] Read more.

We report the synthesis and properties of eight new tetrathiafulvalene (TTF) derivatives containing two different functionalities, prepared with the aim of obtaining stable organic materials. The four acetoxyphenyl- and four hydroxyphenyl TTFs were synthesized via Wittig-type condensations. The electrochemical properties of these redox-active molecules were studied by cyclic voltammetry. Charge transfer complexes with tetracyanoquinodimethane (TCNQ) were prepared by chemical redox reactions. The complexes have been proven to give conducting materials. The UV-VIS and IR spectra of the TCNQ salts were recorded and used to characterize and estimate the degree of charge transfer of these complexes. Full article

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74 KiB

Open AccessArticle

Pongaflavanol: a Prenylated Flavonoid from Pongamia pinnata with a Modified Ring A

by Hao Yin, Si Zhang, Jun Wu, Haihan Nan, Lijuan Long, Jin Yang and Qingxin Li

Molecules 2006, 11(10), 786-791; https://doi.org/10.3390/11100786 - 20 Oct 2006

Cited by 19 | Viewed by 9488

Abstract

A new prenylated flavon-4-ol with a modified ring A, which we have named pongaflavanol (1), was isolated from the stem bark of Pongamia pinnata along with the known compound tunicatachalcone (2). The structure of compound 1 was elucidated on the basis of spectroscopic [...] Read more.

A new prenylated flavon-4-ol with a modified ring A, which we have named pongaflavanol (1), was isolated from the stem bark of Pongamia pinnata along with the known compound tunicatachalcone (2). The structure of compound 1 was elucidated on the basis of spectroscopic data. Full article

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120 KiB

Open AccessArticle

Synthesis of New Unsymmetrical 4,5-Dihydroxy-2-imidazolidinones. Dynamic NMR Spectroscopic Study of the Prototropic Tautomerism in 1-(2-Benzimidazolyl)-3-phenyl-4,5-dihydroxy-2-imidazolidinone

by Mehdi Ghandi, Abolfazl Olyaei and Farshid Salimi

Molecules 2006, 11(10), 768-775; https://doi.org/10.3390/11100768 - 19 Oct 2006

Cited by 5 | Viewed by 10157

Abstract

The acid-catalyzed cyclocondensation in refluxing acetonitrile of aqueousglyoxal with N-heteroaryl-N'-phenylureas 4a-f (heteroaryl = 2-thiazolyl, 2-pyrimidinyl,2-pyrazinyl, 2-pyridinyl, 3-pyridinyl and 2-benzimidazolyl) led to the formation of thecorresponding 1-heteroaryl-3-phenyl-4,5-dihydroxy-2-imidazolidinones 5a-f. All theproducts were characterized by elemental and spectroscopic analyses. The free-energybarrier (∆GP≠ for prototropic tautomerism in [...] Read more.

The acid-catalyzed cyclocondensation in refluxing acetonitrile of aqueousglyoxal with N-heteroaryl-N'-phenylureas 4a-f (heteroaryl = 2-thiazolyl, 2-pyrimidinyl,2-pyrazinyl, 2-pyridinyl, 3-pyridinyl and 2-benzimidazolyl) led to the formation of thecorresponding 1-heteroaryl-3-phenyl-4,5-dihydroxy-2-imidazolidinones 5a-f. All theproducts were characterized by elemental and spectroscopic analyses. The free-energybarrier (∆GP≠ for prototropic tautomerism in 1-(2-benzimidazolyl)-3-phenyl-4,5-dihydroxy-2-imidazolidinone (5f) was determined by dynamic NMR studies to be 81 ± 2KJ molP^-1 Full article

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200 KiB

Open AccessArticle

Synthesis and Natural Distribution of Anti-inflammatory Alkamides from Echinacea

by George A. Kraus, Jaehoon Bae, Lankun Wu and Eve Wurtele

Molecules 2006, 11(10), 758-767; https://doi.org/10.3390/11100758 - 18 Oct 2006

Cited by 15 | Viewed by 7836

Abstract

The synthesis of the alkamides 2Z,4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (1) and 2Z,4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (5) was accomplished by organometallic coupling followed by introduction of the doubly unsaturated amide moiety. The distribution of these two amides in accessions of the nine species of [...] Read more.

The synthesis of the alkamides 2Z,4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (1) and 2Z,4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (5) was accomplished by organometallic coupling followed by introduction of the doubly unsaturated amide moiety. The distribution of these two amides in accessions of the nine species of Echinacea was determined. Full article

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48 KiB

Open AccessArticle

A Simple and Cost Effective Synthesis of 3,11-Dimethylnonacosan-2-one, A Female Sex Pheromone of the German Cockroach

by Kwang–Chan Ahn, Jae–Chul Jung and Oee–Sook Park

Molecules 2006, 11(10), 751-757; https://doi.org/10.3390/11100751 - 12 Oct 2006

Cited by 3 | Viewed by 9053

Abstract

A convenient synthesis of 3,11-dimethylnonacosan-2-one (1) is described. Our strategy involves the use of well known C–alkylation and ethyl acetoacetate synthesis reactions as key steps. We expect that this method will prove to be useful for large scale preparation of 1 and modification [...] Read more.

A convenient synthesis of 3,11-dimethylnonacosan-2-one (1) is described. Our strategy involves the use of well known C–alkylation and ethyl acetoacetate synthesis reactions as key steps. We expect that this method will prove to be useful for large scale preparation of 1 and modification of dimethylnonacosanones. Full article

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96 KiB

Open AccessArticle

A Simple Synthesis of 2-Thiohydantoins

by Zerong Daniel Wang, Samia O. Sheikh and Yulu Zhang

Molecules 2006, 11(10), 739-750; https://doi.org/10.3390/11100739 - 2 Oct 2006

Cited by 74 | Viewed by 14066

Abstract

2-Thiohydantoin derivatives are produced by heating a mixture of thiourea and an α-amino acid. The method described offers the advantages of simplicity, low cost, easy work-up and scalability. Full article

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83 KiB

Open AccessArticle

Sulfated Zirconia-Catalyzed Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones (DHPMs) Under Solventless Conditions: Competitive Multicomponent Biginelli vs. Hantzsch Reactions

by Deyanira Angeles-Beltrán, Leticia Lomas-Romero, Victor H. Lara-Corona, Eduardo González-Zamora and Guillermo Negrón-Silva

Molecules 2006, 11(10), 731-738; https://doi.org/10.3390/11100731 - 2 Oct 2006

Cited by 46 | Viewed by 11378

Abstract

The catalytic ability of ZrO₂/SO₄^2- to promote solventless three-componentcondensation reactions of a diversity of aromatic aldehydes, urea or thoiurea and ethylacetoacetate was studied. Products resulting from Hantzsch and/or Biginelli multi-component reactions are obtained in the presence of solid acid [...] Read more.

The catalytic ability of ZrO₂/SO₄^2- to promote solventless three-componentcondensation reactions of a diversity of aromatic aldehydes, urea or thoiurea and ethylacetoacetate was studied. Products resulting from Hantzsch and/or Biginelli multi-component reactions are obtained in the presence of solid acid catalysts using the samereactants but different temperature conditions. The sulfated zirconia catalyst can berecovered and recycled in subsequent reactions with a gradual decrease of activity. Full article

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Molecules, Volume 11, Issue 10 (October 2006) – 10 articles , Pages 731-826

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