Articles de revues : « Diterpeni »

1

Pruteanu, Elena, Vladilena Gîrbu, Nicon Ungur, Leentje Persoons, Dirk Daelemans, Philippe Renaud et Veaceslav Kulcițki. « Preparation of Antiproliferative Terpene-Alkaloid Hybrids by Free Radical-Mediated Modification of ent-Kauranic Derivatives ». Molecules 26, n^o 15 (28 juillet 2021) : 4549. http://dx.doi.org/10.3390/molecules26154549.

Texte intégral

Résumé :

A convenient strategy for molecular editing of available ent-kauranic natural scaffolds has been developed based on radical mediated C–C bond formation. Iodine atom transfer radical addition (ATRA) followed by rapid ionic elimination and radical azidoalkylation were investigated. Both reactions involve radical addition to the exo-methylenic double bond of the parent substrate. Easy transformations of the obtained adducts lead to extended diterpenes of broad structural diversity and artificial diterpene-alkaloid hybrids possessing lactam and pyrrolidine pharmacophores. The cytotoxicity of selected diterpenic derivatives was examined by in vitro testing on several tumor cell lines. The terpene-alkaloid hybrids containing N-heterocycles with unprecedented spiro-junction have shown relevant cytotoxicity and promising selectivity indexes. These results represent a solid basis for following research on the synthesis of such derivatives based on available natural product templates.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Tazawa, Shigemi, Yasuko Arai, Sho Hotta, Taichi Mitsui, Hiroshi Nozaki et Kenji Ichihara. « Discovery of a Novel Diterpene in Brown Propolis from the State of Parana, Brazil ». Natural Product Communications 11, n^o 2 (février 2016) : 1934578X1601100. http://dx.doi.org/10.1177/1934578x1601100218.

Texte intégral

Résumé :

Propolis is a resinous substance collected by honeybees from certain plant sources. The components of propolis depend on the vegetation of the area in which apiculture is practiced. In Brazil, there are several types of propolis including ‘green,’ ‘red’ and ‘brown'. Brazilian brown propolis from the state of Parana characteristically includes diterpenes, and we discovered a novel clerodane diterpene, rel-(5 S,6 S,8 R,9 R,10 S,18 R,19 S)-18,19-epoxy-2-oxocleroda-3,12( E),14-triene-6,18,19-triol 18,19-diacetate 6-benzoate (3) and five known diterpenes (1, 2, 4, 5 and 6). The chemical structure of the novel diterpene 3 was determined using 1D- and 2D-NMR spectroscopic analyses. Furthermore, the activities of the isolated diterpenes on growth inhibition of several human cancer cell lines (LNCaP, MCF-7, DLD-1 and A549) were evaluated in vitro; diterpene 3 exhibited a potent inhibition of cell growth, and its activity was approximately 15 times higher than that of the other diterpenes.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Yazdiniapour, Zeinab, Mohammad Hossein Sohrabi, Newsha Motinia, Behzad Zolfaghari, Pegah Mehdifar, Mustafa Ghanadian et Virginia Lanzotti. « Diterpenoids from Euphorbia gedrosiaca as Potential Anti-Proliferative Agents against Breast Cancer Cells ». Metabolites 13, n^o 2 (3 février 2023) : 225. http://dx.doi.org/10.3390/metabo13020225.

Texte intégral

Résumé :

Isolated diterpenes from various species of Euphorbia are important compounds for drug discovery with a broad spectrum of structures and biological effects. In this study, Euphorbia gedrosiaca, one of the endemic species of Iran, was analyzed in terms of the presence and structural determination of diterpenoid compounds. They were extracted with dichloromethane/acetone (2:1) from aerial parts of this plant and purified by chromatographic methods such as MPLC and HPLC. Four premyrsinane compounds and one myrsinane diterpene were isolated from Euphorbia gedrosiaca. They were characterized by extensive 1D and 2D NMR and HRMS analyses. Additionally, their activities were evaluated against two breast cancer cell lines, MDA-MB-231 and MCF-7, by MTT proliferation assay. They exhibited cytotoxic effects in a dose-dependent manner with promising results, which can help to find possible therapeutic application of diterpenoids in breast cancer treatment.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Alicandri, Enrica, Stefano Covino, Bartolomeo Sebastiani, Anna Rita Paolacci, Maurizio Badiani, Francesco Manti, Carmelo Peter Bonsignore, Agostino Sorgonà et Mario Ciaffi. « Diterpene Resin Acids and Olefins in Calabrian Pine (Pinus nigra subsp. laricio (Poiret) Maire) Oleoresin : GC-MS Profiling of Major Diterpenoids in Different Plant Organs, Molecular Identification and Expression Analysis of Diterpene Synthase Genes ». Plants 10, n^o 11 (5 novembre 2021) : 2391. http://dx.doi.org/10.3390/plants10112391.

Texte intégral

Résumé :

A quali-quantitative analysis of diterpenoid composition in tissues obtained from different organs of Pinus nigra subsp. laricio (Poiret) Maire (Calabrian pine) was carried out. Diterpene resin acids were the most abundant diterpenoids across all the examined tissues. The same nine diterpene resin acids were always found, with the abietane type prevailing on the pimarane type, although their quantitative distribution was found to be remarkably tissue-specific. The scrutiny of the available literature revealed species specificity as well. A phylogeny-based approach allowed us to isolate four cDNAs coding for diterpene synthases in Calabrian pine, each of which belonging to one of the four groups into which the d3 clade of the plants’ terpene synthases family can be divided. The deduced amino acid sequences allowed predicting that both monofunctional and bifunctional diterpene synthases are involved in the biosynthesis of diterpene resin acids in Calabrian pine. Transcript profiling revealed differential expression across the different tissues and was found to be consistent with the corresponding diterpenoid profiles. The isolation of the complete genomic sequences and the determination of their exon/intron structures allowed us to place the diterpene synthase genes from Calabrian pine on the background of current ideas on the functional evolution of diterpene synthases in Gymnosperms.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Li, Fang-Ru, Xiaoxu Lin, Qian Yang, Ning-Hua Tan et Liao-Bin Dong. « Efficient production of clerodane and ent-kaurane diterpenes through truncated artificial pathways in Escherichia coli ». Beilstein Journal of Organic Chemistry 18 (21 juillet 2022) : 881–88. http://dx.doi.org/10.3762/bjoc.18.89.

Texte intégral

Résumé :

The clerodane and ent-kaurane diterpenoids are two typical categories of diterpenoid natural products with complicated polycyclic carbon skeletons and significant pharmacological activities. Despite exciting advances in organic chemistry, access to these skeletons is still highly challenging. Using synthetic biology to engineer microbes provides an innovative alternative to bypass synthetic challenges. In this study, we constructed two truncated artificial pathways to efficiently produce terpentetriene and ent-kaurene, two representative clerodane and ent-kaurane diterpenes, in Escherichia coli. Both pathways depend on the exogenous addition of isoprenoid alcohol to reinforce the supply of IPP and DMAPP via two sequential phosphorylation reactions. Optimization of these constructs provided terpentetriene and ent-kaurene titers of 66 ± 4 mg/L and 113 ± 7 mg/L, respectively, in shake-flask fermentation. The truncated pathways to overproduce clerodane and ent-kaurane skeletons outlined here may provide an attractive route to prepare other privileged diterpene scaffolds.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Reddy, Priyanka, Kathryn Guthridge, Simone Vassiliadis, Joanne Hemsworth, Inoka Hettiarachchige, German Spangenberg et Simone Rochfort. « Tremorgenic Mycotoxins : Structure Diversity and Biological Activity ». Toxins 11, n^o 5 (27 mai 2019) : 302. http://dx.doi.org/10.3390/toxins11050302.

Texte intégral

Résumé :

Indole-diterpenes are an important class of chemical compounds which can be unique to different fungal species. The highly complex lolitrem compounds are confined to Epichloë species, whilst penitrem production is confined to Penicillium spp. and Aspergillus spp. These fungal species are often present in association with pasture grasses, and the indole-diterpenes produced may cause toxicity in grazing animals. In this review, we highlight the unique structural variations of indole-diterpenes that are characterised into subgroups, including paspaline, paxilline, shearinines, paspalitrems, terpendoles, penitrems, lolitrems, janthitrems, and sulpinines. A detailed description of the unique biological activities has been documented where even structurally related compounds have displayed unique biological activities. Indole-diterpene production has been reported in two classes of ascomycete fungi, namely Eurotiomycetes (e.g., Aspergillus and Penicillium) and Sordariomycetes (e.g., Claviceps and Epichloë). These compounds all have a common structural core comprised of a cyclic diterpene skeleton derived from geranylgeranyl diphosphate (GGPP) and an indole moiety derived from tryptophan. Structure diversity is generated from the enzymatic conversion of different sites on the basic indole-diterpene structure. This review highlights the wide-ranging biological versatility presented by the indole-diterpene group of compounds and their role in an agricultural and pharmaceutical setting.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Ye, Ke, et Hong-lian Ai. « Pimarane Diterpenes from Fungi ». Pharmaceuticals 15, n^o 10 (20 octobre 2022) : 1291. http://dx.doi.org/10.3390/ph15101291.

Texte intégral

Résumé :

Pimarane diterpenes are a kind of tricyclic diterpene, generally isolated from plant and fungi. In nature, fungi distribute widely and there are nearly two to three million species. They provide many secondary metabolites, including pimarane diterpenes, with novel skeletons and bioactivities. These natural products from fungi have the potential to be developed into clinical medicines. Herein, the structures and bioactivities of 197 pimarane diterpenes are summarized and the biosynthesis and pharmacological researches of pimarane diterpenes are introduced. This review may be useful improving the understanding of pimarane diterpenes from fungi.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Liu, Zhang, Wu, Chen, Li, Dai et Wang. « Four New ent-Kaurane Diterpene Glycosides from Isodon henryi ». Molecules 24, n^o 15 (27 juillet 2019) : 2736. http://dx.doi.org/10.3390/molecules24152736.

Texte intégral

Résumé :

To obtain diterpene glycosides from an aqueous extract of the aerial parts of Isodon henryi and further investigate their cytotoxicities, in this study, a total of seven compounds were isolated, including six ent-kaurane diterpene glycosides (1–6) and one diterpene aglycon (7). Among the seven ent-kaurane diterpenes obtained, four were novel compounds, including ent-7,20-epoxy- kaur-16-en-1α,6β,7β,15β-tetrahydroxyl-11-O-β-d-glucopyranoside (1), ent-7,20-epoxy-kaur-16-en- 6β,7β,14β,15β-tetrahydroxyl-1-O-β-d-glucopyranoside (2), ent-7,20-epoxy-kaur-16-en-6β,7β,15β- trihydroxyl-1-O-β-d-glucopyranoside (3), and ent-7,20-epoxy-kaur-16-en-7β,11β,14α,15β-tetrahydr- oxyl-6-O-β-d-glucopyranoside (4), and three were isolated from this plant for the first time (5–7). Their structures were elucidated by utilizing spectroscopic methods and electronic circular dichroism analyses. Furthermore, the cytotoxicities of all seven compounds were investigated in four human cancer cell lines, including A2780, BGC-823, HCT-116, and HepG2. The IC50 values of these diterpenes ranged from 0.18 to 2.44 mM in the tested cell lines. In addition, the structure–cytotoxicity relationship of diterpene glycosides was also evaluated to study the effect of glycosylation on the cytotoxicity of diterpene compounds.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Eren, Fatma Hulyam, et Halit Tanju Besler. « Bioactive diterpenes (cafestol and kahweol) in Turkish coffees : Impact of roasting ». International Food Research Journal 29, n^o 2 (1 avril 2022) : 328–37. http://dx.doi.org/10.47836/ifrj.29.2.11.

Texte intégral

Résumé :

While the cholesterol-raising effect of coffee has been ascribed to the presence of diterpenes, they have also been shown to present favourable health effects. Boiled-type coffees show slightly higher levels of diterpenes than those made with other brewing methods. However, there is considerable controversy regarding the effect of roasting on the contents of the diterpenes cafestol and kahweol. Therefore, the aim of the present work was to measure the contents of these diterpenes in Turkish coffees, and to determine how they are influenced by roasting. The samples used were 16 roasted and ready-ground Turkish coffees sold in supermarkets in the Turkish Republic of Northern Cyprus. The cafestol and kahweol contents of the coffee samples were analysed using liquid-liquid extraction followed by HPLC-DAD. The lipid contents of commercially roasted and ground Turkish coffee samples varied in the range of 14.32 ± 0.09 to 15.60 ± 0.09 g/100 g. The lipid contents of brewed Turkish coffee samples varied from 318 ± 2.00 to 571 ± 4.30 mg/100 mL. When compared within each commercial brand, dark roasted ground Turkish coffee samples had higher lipid contents. The average diterpene content in one cup of Turkish coffee sample was between 2.69 ± 0.28 and 13.58 ± 0.88 mg. The ranges of cafestol and kahweol contents in a cup were 1.4 ± 0.21 - 6.9 ± 0.65 mg and 1.28 ± 0.07 - 6.68 ± 0.28 mg, respectively. Within products of the same brand, the highest amount of oil was observed in dark roasted Turkish coffee beverages, and no significant differences were found in total diterpene, cafestol, and kahweol contents in coffee beverages among the different roasting levels. It is recommended that future studies perform more detailed investigations of the effect of roasting on the diterpene contents in Turkish coffees, and the impact of preparation parameters, as well as the presence of diterpene-derived compounds.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Wollenweber, Eckhard, Marion Dörr, Marco Dörsam, Abu El-Hamed Hassan, Ahmed A. Ahmed, M. F. Hegazy et Klaus-Peter Zeller. « Flavonoids and Terpenoids from the Resinous Exudates of Madia Species (Asteraceae, Helenieae) ». Zeitschrift für Naturforschung C 58, n^o 3-4 (1 avril 2003) : 153–60. http://dx.doi.org/10.1515/znc-2003-3-401.

Texte intégral

Résumé :

The resinous material accumulated on aerial parts of Madia species is shown to consist mainly of diterpenes, containing a series of flavonoid aglycones. A6- and/or 8-O-substitution is characteristic for many of these flavonoids. Three known rare diterpenes were found and the structure elucidation of a diterpene with a new carbon skeleton, named madiaol, is reported.

Styles APA, Harvard, Vancouver, ISO, etc.

11

García, Abraham, Teresa Ramírez-Apan, J. Antonio Cogordan et Guillermo Delgado. « Absolute configuration assignments by experimental and theoretical approaches of ent-labdane- and cis-ent-clerodane-type diterpenes isolated from Croton glabellus ». Canadian Journal of Chemistry 84, n^o 12 (1 décembre 2006) : 1593–602. http://dx.doi.org/10.1139/v06-164.

Texte intégral

Résumé :

The bioassay-guided fractionation of the moderately cytotoxic extract from Croton glabellus resulted in the isolation of bioactive compounds, which were characterized as austroinulin (2), 6-O-acetylaustroinulin (3), the acetonide artifact of 2 (4), and 3-O-methylkaempferol (9). In addition, a new natural cis-ent-clerodane lactone diterpene named marrubiagenin (1), trans-dehydrocrotonin (6), the epimeric mixture of cajucarinolide (7/8), and 5,7,3′,4′-tetrahydroxy-3-methoxyflavonoid (10) were also characterized and identified as nonbioactive compounds. The structures of all compounds were determined by analyses of their physical and spectroscopic data and by comparison with those reported in the literature. The absolute configuration assignment of 3 was carried out by means of the modified Mosher method and by the experimental and theoretical circular dichroism method establishing that 3 belongs to the ent-labdane diterpene series. Furthermore, the absolute configuration of 1 was established by analysis of its chiroptical properties concluding that 1 belongs to the cis-ent-clerodane diterpene series.Key words: Croton glabellus, ent-labdane-type diterpenes, cis-ent-clerodane-type diterpenes, circular dichroism, TD-DFT.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Vaccaro, Mariacarmela, Vivian Ocampo Bernal, Nicola Malafronte, Nunziatina De Tommasi et Antonietta Leone. « High Yield of Bioactive Abietane Diterpenes in Salvia sclarea Hairy Roots by Overexpressing Cyanobacterial DXS or DXR Genes ». Planta Medica 85, n^o 11/12 (26 avril 2019) : 973–80. http://dx.doi.org/10.1055/a-0895-5878.

Texte intégral

Résumé :

AbstractAbietane diterpenoids, containing a quinone moiety, are synthesized in the roots of several Salvia species. Promising cytotoxicity and antiproliferative activities have been reported for these compounds in various cell and animal models. We have recently shown that aethiopinone, an o-naphto-quinone diterpene, produced in the roots of different Salvia species, is selectively cytotoxic against the A375 melanoma cell line. To enhance the synthesis of this abietane diterpenoid, we have engineered the plastidial 2-C-methyl-D-erythritol 4-phosphate-derived isoprenoid pathway in Salvia sclarea hairy roots by ectopic expression and plastid targeting of cyanobacterial genes encoding the 1-deoxy-D-xylulose 5-phosphate synthase or 1-deoxy-D-xylulose-5-phosphate reductoisomerase gene, the first two enzymatic steps of the plastidial MEP pathway, from which plant diterpenes primarily derive. Plastid-targeted expression of 1-deoxy-D-xylulose 5-phosphate synthase and 1-deoxy-D-xylulose-5-phosphate reductoisomerase proteins significantly enhanced the yield of aethiopinone by a 3-fold and about 6-fold increase, respectively. The accumulation of other abietane-type diterpenes (ferruginol, salvipisone, and carnosic acid), with interesting antiproliferative activity, was also increased. Compared to our previous data obtained by overexpressing the plant orthologous 1-deoxy-D-xylulose 5-phosphate synthase and 1-deoxy-D-xylulose-5-phosphate reductoisomerase genes in S. sclarea hairy roots, the results presented here confirm that the bacterial 1-deoxy-D-xylulose-5-phosphate reductoisomerase enzyme plays a major role than the DXS enzyme in the biosynthetic pathway of this class of compounds and that its ectopic expression does not conflict with active hairy root growth, resulting in a balanced trade-off between the transgenic hairy root final biomass and the increased content of o-naphto-quinone diterpenes, with interesting biological activities.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Avelar-Freitas, Bethânia Alves, Karine Beatriz Costa, Marcelo Ottoni, Alyson Torres de Barros, Patrícia Machado de Oliveira, Roqueline Rodrigues Silva et Gustavo Eustáquio Alvim Brito Melo. « Citotoxicidade e Ação Antioxidante de uma Fração Extraída da Planta Plectranthus neochilus (Boldo-gambá) ». Ensaios e Ciência : C. Biológicas, Agrárias e da Saúde 22, n^o 2 (25 janvier 2019) : 85. http://dx.doi.org/10.17921/1415-6938.2018v22n2p85-89.

Texte intégral

Résumé :

Plectranthus neochilus é uma erva aromática conhecida popularmente como boldo-gambá, usada na medicina popular para tratar dispepsia e insuficiência hepática, usada também com efeito analgésico e anti-inflamatório. Tendo em vista o uso popular da planta, torna-se importante a investigação farmacológica dos compostos isolados de P.neochilus. A avaliação da Citotoxicidade em plantas é de extrema importância para posterior utilização em medicamentos. O objetivo deste trabalho é avaliar concentrações não citotóxicas de 1,6-di-O-acetil-9-deoxiforscolina um composto isolado análogo a forscolina oriundo do extrato hidroalcoólico das folhas e caules de P.neochilus e avaliar se este diterpeno possuicapacidade antioxidante. Para o teste de citotoxicidade foi utilizado o ensaio de viabilidade com sangue total, foi feita a coleta de sangue de 5 voluntários hígidos, e confeccionadas 6 culturas, sendo a primeira controle a segunda um controle de DMSO, que foi utilizado como solvente para o diterpeno e 4 culturas em concentrações diferentes do diterpeno, 40, 20, 10 e 5μg/ml, seguiu-se o protocolo de lise de hemácias com cloreto de amônio e marcou-se com azul de tripan, posteriormente, foi feita a leitura por citometria de fluxo. Também foi analisada a capacidadeantioxidante do diterpeno por meio da determinação do poder de redução do íon ferro, FRAP (do inglês Ferric Reducing Antioxidant Power) em que é analisada a produção do íon Fe2+ a partir da redução do íon Fe3+ presente no complexo 2,4,6-tripiridil-s-triazina (TPTZ). Quando o ocorre a redução, há alteração de cor na solução, a avaliação é realizada por espectrofotômetro em comprimento de onda de 593 nm. Os resultados demonstraram que nas concentrações testadas, 40, 20, 10 e 5 μg/ml o diterpeno extraído da planta P. neochilus não apresentou citotoxicidade seletiva a nenhuma população leucocitária avaliada (linfócitos, monócitos e neutrófilos) e ainda apresentou grande capacidadeantioxidante. Mais estudos devem ser realizados evidenciando os potenciais farmacológicos da planta P. neochilus, bem como de substâncias isoladas a partir de extratos da planta.Palavras-chave: Diterepeno. Citotoxidade. antioxidanteAbstractPlectranthus neochilus is an aromatic herb popularly known as boldo- opossum, used in folk medicine to treat dyspepsia and hepatic insufficiency, also used as analgesic and anti-inflammatory. In view of the popular use of the plant, it becomes important the pharmacological investigation of the compounds isolated from P.neochilus. The evaluation of plant cytotoxicity is of extreme importance for subsequent use in medicinal products. The objective of this study is to evaluate non-cytotoxic concentrations of 1,6-di-O-acetyl-9-deoxyphosphine an isolated compound analogous to forskolin from the hydroalcoholic extract of P.neochilus leaves and stems and to evaluate whether this diterpene has antioxidant capacity. For the cytotoxicity test, the whole blood viability assay was performed, blood was collected from 5 healthy volunteers, and 6 cultures were made, the second control being a DMSO control, which is the diterpene solvent and 4 cultures at different concentrations of diterpene, 40, 20, 10 and 5 μg / ml, followed by the protocol of red blood cell lysis with ammonium chloride and labeled with tripan blue, and then read by flow cytometry. The antioxidant capacity of diterpene was also analyzed by means of the determination of the iron ion reductionpower (FRAP) in which Fe2 + ion production is analyzed from the Fe3 + ion present in complex 2, 4,6-tripyridyl-s-triazine (TPTZ). When the reduction occurs there is a color change in the solution, turning to an intense purple, the evaluation is performed by spectrophotometer at wavelength of 593 nm. The results demonstrated that at the tested concentrations, 40, 20, 10 and 5 μg / ml diterpene extracted from the plant P. neochilus did not present selective cytotoxicity to any leukocyte population evaluated (lymphocytes, monocytes and neutrophils) andstill presented a great antioxidant capacity. Further studies should be performed evidencing the pharmacological potentials of the plant P. neochilus, as well as of substances isolated from extracts of the plant.Keywords: Diterpene, cytotoxicity, antioxidant .

Styles APA, Harvard, Vancouver, ISO, etc.

14

Kurzrock, T., et K. Speer. « DITERPENES AND DITERPENE ESTERS IN COFFEE ». Food Reviews International 17, n^o 4 (30 novembre 2001) : 433–50. http://dx.doi.org/10.1081/fri-100108532.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

15

Lai, Guo-Fang, Xian-You Wang, Yi-Fen Wang, Jian-Xin Cao, Shi-De Luo et Peng Ju. « Diterpenes and Diterpene Glucosides fromPhlogacanthus curviflorus ». Helvetica Chimica Acta 92, n^o 3 (mars 2009) : 470–80. http://dx.doi.org/10.1002/hlca.200800274.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

16

Prakash, Indra, Gil Ma, Cynthia Bunders, Krishna P. Devkota, Romila D. Charan, Catherine Ramirez, Tara M. Snyder et Christopher Priedemann. « A New Diterpene Glycoside : 15α-Hydroxy-Rebaudioside M Isolated from Stevia rebaudiana ». Natural Product Communications 10, n^o 7 (juillet 2015) : 1934578X1501000. http://dx.doi.org/10.1177/1934578x1501000705.

Texte intégral

Résumé :

In a continued search for novel diterpenoid glycosides, we recently isolated and characterized a Rebaudioside M derivative with a hydroxyl group at position 15 in the central diterpene core from an extract of Stevia rebaudiana Bertoni. Here we report the complete structure elucidation of 15α-hydroxy-Rebaudioside M (2) on the basis of NMR (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D TOCSY, NOESY) and mass spectral data. Steviol glycoside with a hydroxyl group at C-15 in the central diterpene core has not been previously reported.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Soto, H., J. Rovirosa et A. San-Martín. « A New Diterpene from Dictyota crenulata ». Zeitschrift für Naturforschung B 58, n^o 8 (1 août 2003) : 795–98. http://dx.doi.org/10.1515/znb-2003-0812.

Texte intégral

Résumé :

Chemical analysis of the brown alga Dictyota crenulata, family Dictyotaceae, collected at Easter Island, yielded a new diterpene. The structure was determined on the basis of spectroscopic evidence. The insecticidal activity of two diterpenes towards the tomato moth Tuta absolute (Povolny) was tested.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Scotti, Luciana, Marcus T. Scotti, Hamilton Ishiki, Francisco J. B. M. Junior, Paula F. dos Santos, Josean F. Tavares et Marcelo S. da Silva. « Prediction of Anticancer Activity of Diterpenes Isolated from the Paraiban Flora through a PLS Model and Molecular Surfaces ». Natural Product Communications 9, n^o 5 (mai 2014) : 1934578X1400900. http://dx.doi.org/10.1177/1934578x1400900503.

Texte intégral

Résumé :

The aim of this work was to predict the anticancer potential of 3 atisane, and 3 trachylobane diterpene compounds extracted from the roots of Xylopia langsdorffiana. The prediction of anticancer activity as expressed against PC-3 tumor cells was made using a PLS model built with 26 diterpenes in the training set. Significant statistical measures were obtained. The six investigated diterpenes were applied to the model and their activities against PC-3 cells were calculated. All the diterpenes were active, with atisane diterpenes showing the higher pIC50 values. In human prostate carcinoma PC-3 cells, the apoptosis mechanism is related to an inhibition of IKK/NF-κB. Antioxidant potential implies a greater electronic molecular atmosphere (increased donor electron capacity), which can reduce radical reactivity, and facilitate post donation charge accommodation. Molecular surfaces indicated a much greater electronic cloud over atisane diterpenes.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Shen, Yong, Wen-Juan Liang, Ya-Na Shi, Edward J. Kennelly et Da-Ke Zhao. « Structural diversity, bioactivities, and biosynthesis of natural diterpenoid alkaloids ». Natural Product Reports 37, n^o 6 (2020) : 763–96. http://dx.doi.org/10.1039/d0np00002g.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

20

Villamizar, José E., José Juncosa, Jean Pittelaud, Madeleyn Hernández, Nieves Canudas, Eleonora Tropper, Franklin Salazar et Juan Fuentes. « Facile Access to Labdane-type Diterpenes : Synthesis of Coronarin C, Zerumin B, Labda-8(17), 13(14)-dien-15,16-olide and derivatives from (+)-manool ». Journal of Chemical Research 2007, n^o 6 (juin 2007) : 342–46. http://dx.doi.org/10.3184/030823407x225527.

Texte intégral

Résumé :

A practical method for the synthesis of optically active labdane-type diterpenes from (+)-manool 8, is described. We prepared the natural labdane-type diterpene 5 via key intermediate peroxide 9 and coronarin C 1, compound 8 and zerumin B 6 via a furan photosensitised oxygenation reactions.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Bankova, V., M. C. Marcucci, S. Simova, N. Nikolova, A. Kujumgiev et S. Popov. « Antibacterial Diterpenic Acids from Brazilian Propolis ». Zeitschrift für Naturforschung C 51, n^o 5-6 (1 juin 1996) : 277–80. http://dx.doi.org/10.1515/znc-1996-5-602.

Texte intégral

Résumé :

Abstract Four labdane-type diterpenic acids and syringaldehyde were isolated and identified from Brazilian propolis. A ll the compounds exhibit antibacterial activity. The diterpenes, found for the first time in propolis, are typical for some Araucaria species and thus indicate a possible plant source of Brazilian propolis.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Tang, Dai-Hui, Ding Ma, Hang Cheng, Yong-Li Li et Liang Xu. « A bio-inspired synthetic route to the core ring systems of Spiraea atisine-type diterpenoid alkaloids and related diterpenes ». Organic & ; Biomolecular Chemistry 14, n^o 9 (2016) : 2716–22. http://dx.doi.org/10.1039/c6ob00053c.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

23

Toyomasu, Tomonobu, Matthew R. Shenton et Kazunori Okada. « Evolution of Labdane-Related Diterpene Synthases in Cereals ». Plant and Cell Physiology 61, n^o 11 (18 août 2020) : 1850–59. http://dx.doi.org/10.1093/pcp/pcaa106.

Texte intégral

Résumé :

Abstract Gibberellins (GAs) are labdane-related diterpenoid phytohormones that regulate various aspects of higher plant growth. A biosynthetic intermediate of GAs is ent-kaurene, a tetra-cyclic diterpene that is produced through successive cyclization of geranylgeranyl diphosphate catalyzed by the two distinct monofunctional diterpene synthases—ent-copalyl diphosphate synthase (ent-CPS) and ent-kaurene synthase (KS). Various homologous genes of the two diterpene synthases have been identified in cereals, including rice (Oryza sativa), wheat (Triticum aestivum) and maize (Zea mays), and are believed to have been derived from GA biosynthetic ent-CPS and KS genes through duplication and neofunctionalization. They play roles in specialized metabolism, giving rise to diverse labdane-related diterpenoids for defense because a variety of diterpene synthases generate diverse carbon-skeleton structures. This review mainly describes the diterpene synthase homologs that have been identified and characterized in rice, wheat and maize and shows the evolutionary history of various homologs in rice inferred by comparative genomics studies using wild rice species, such as Oryza rufipogon and Oryza brachyantha. In addition, we introduce labdane-related diterpene synthases in bryophytes and gymnosperms to illuminate the macroscopic evolutionary history of diterpene synthases in the plant kingdom—bifunctional enzymes possessing both CPS and KS activities are present in bryophytes; gymnosperms possess monofunctional CPS and KS responsible for GA biosynthesis and also possess bifunctional diterpene synthases facilitating specialized metabolism for defense.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Muñoz, Marcelo A., Aurelio San-Martín et Pedro Joseph-Nathan. « Vibrational Circular Dichroism Absolute Configuration of 9,12-Cyclomulin-13-ol, a Diterpene from Azorella and Laretia Species ». Natural Product Communications 10, n^o 8 (août 2015) : 1934578X1501000. http://dx.doi.org/10.1177/1934578x1501000805.

Texte intégral

Résumé :

The absolute configuration of the diterpenoid 9,12-cyclomulin-13-ol (1), a constituent of Azorella and Laretia species, has been established by vibrational circular dichroism spectroscopy in combination with density functional theory calculations. The obtained normal diterpene absolute configuration confirms that of azorellanol (2), which was determined by single crystal X-ray diffraction.

Styles APA, Harvard, Vancouver, ISO, etc.

25

Liu, Xiao-Yu, et Yong Qin. « Enabling syntheses of diterpenoid alkaloids and related diterpenes by an oxidative dearomatization/Diels–Alder cycloaddition strategy ». Natural Product Reports 34, n^o 9 (2017) : 1044–50. http://dx.doi.org/10.1039/c7np00033b.

Texte intégral

Résumé :

Recent accomplishments in the total syntheses of diterpenoid alkaloids and their biosynthetically associated diterpenes have highly relied on an oxidative dearomatization/Diels–Alder cycloaddition strategy, and are highlighted in this article.

Styles APA, Harvard, Vancouver, ISO, etc.

26

Torrenegra, Ruben, Jorge Robles, Reiner Waibel, Matthias Löwel et Hans Achenbach. « Diterpenes and diterpene xylosides from Conyza trihecatactis ». Phytochemistry 35, n^o 1 (décembre 1993) : 195–99. http://dx.doi.org/10.1016/s0031-9422(00)90533-8.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

27

Vassallo, Antonio, Ammar Bader, Alessandra Braca, Angela Bisio, Luca Rastrelli, Francesco De Simone et Nunziatina De Tommasi. « Secondary Metabolites from the Roots of Salvia Palaestina Bentham ». Natural Product Communications 3, n^o 12 (décembre 2008) : 1934578X0800301. http://dx.doi.org/10.1177/1934578x0800301205.

Texte intégral

Résumé :

Two new sesquiterpenes (1–2), and one diterpene (3) were isolated from the roots of Salvia palaestina Bentham (Lamiaceae), together with eight known diterpenes and two triterpenes. Their structures were elucidated by 1D and 2D NMR spectroscopy, including 1D-TOCSY, DQF-COSY, ROESY, HSQC, and HMBC experiments, as well as ESIMS and chemical analysis.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Suciati, Lynette K. Lambert et Mary J. Garson. « Structures and Anatomical Distribution of Oxygenated Diterpenes in the Australian Nudibranch Chromodoris reticulata ». Australian Journal of Chemistry 64, n^o 6 (2011) : 757. http://dx.doi.org/10.1071/ch11036.

Texte intégral

Résumé :

The structures and stereochemistry of six new diterpenes (1–6), two of which contain cyclic imine functionality, have been deduced by 2D NMR spectroscopy. The anatomical distribution of these, and of 17 other diterpenes (7–23) that were also isolated, has been investigated. The known compound aplyroseol-2 (14) was the major compound in the mantle tissue along with some dialdehydes, while the linear furan ambliofuran (7) was the only diterpene found solely in the internal organs. The presence of lactone-acetal-hemiacetal functionality in many of the isolated compounds is a consequence of the reactive dialdehydes present in the mollusc.

Styles APA, Harvard, Vancouver, ISO, etc.

29

White, Andrew M., Ariyanti S. Dewi, Karen L. Cheney, Anne E. Winters, Joanne T. Blanchfield et Mary J. Garson. « Oxygenated Diterpenes from the Indo-Pacific Nudibranchs Goniobranchus splendidus and Ardeadoris egretta ». Natural Product Communications 11, n^o 7 (juillet 2016) : 1934578X1601100. http://dx.doi.org/10.1177/1934578x1601100714.

Texte intégral

Résumé :

Five new diterpenes (1-5), each with a highly oxygenated spongian framework, were characterized from an organic extract of a specimen of the nudibranch Goniobranchus splendidus collected from Eastern Australia. The new diterpene 7α-hydroxydendrillol-3 (6) was identified from specimens of Ardeodoris egretta. The structures and relative configurations of the six new metabolites have been elucidated by analysis of their spectroscopic data.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Rosselli, Sergio, Antonella Maria Maggio, Gabriella Bellone, Carmen Formisano, Felice Senatore et Maurizio Bruno. « A New Irregular Diterpenoid of Biogenetic Interest from the Flowers of Magydaris Tomentosa (Desf.) DC. (Apiaceae) ». Natural Product Communications 2, n^o 1 (janvier 2007) : 1934578X0700200. http://dx.doi.org/10.1177/1934578x0700200102.

Texte intégral

Résumé :

A new irregular acyclic diterpene, magytomol acetate (2), has been isolated from the light petroleum extract of the flowers of Magydaris tomentosa (Desf.) DC. (Apiaceae) and its structure has been elucidated by means of extensive spectroscopic experiments. The new compound can be considered the acetyl derivative of the biogenetic precursor of other irregular diterpenes isolated from other species belonging to the family Apiaceae.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Malafronte, Anna, Fabrizio Dal Piaz, Giuseppina Cioffi, Alessandra Braca, Antonella Leone et Nunziatina De Tommasi. « Secondary Metabolites from the Aerial Parts of Salvia Aethiopis L ». Natural Product Communications 3, n^o 6 (juin 2008) : 1934578X0800300. http://dx.doi.org/10.1177/1934578x0800300610.

Texte intégral

Résumé :

Three new sesterterpenes (1–3), and one new diterpene (4) were isolated from the aerial parts of Salvia aethiopis L. (Lamiaceae), together with two known sesterterpenes, and four diterpenes. Their structural elucidation was accomplished by extensive spectroscopic methods including 1D (1H, 13C, 13C DEPT, TOCSY, NOESY) and 2D NMR experiments (DQF-COSY, HSQC, HMBC, ROESY), as well as ESIMS and chemical analysis.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Rédei, Dóra, Norbert Kúsz, Gréta Sátori, Annamária Kincses, Gabriella Spengler, Katalin Burián, Zoltán Barina et Judit Hohmann. « Bioactive Segetane, Ingenane, and Jatrophane Diterpenes from Euphorbia taurinensis ». Planta Medica 84, n^o 09/10 (19 mars 2018) : 729–35. http://dx.doi.org/10.1055/a-0589-0525.

Texte intégral

Résumé :

AbstractA novel segetane (1) and jatrophane diterpene (2), together with five known diterpenoids possessing segetane (3), jatrophane (4), and ingenane skeletons (5 – 7), were isolated from the methanol extract of Euphorbia taurinensis All. The structure elucidation of the compounds was performed by means of extensive spectroscopic analysis, including HRESIMS and 1D (1H, J-modulated spin-echo carbon experiment) and 2D (HSQC, HMBC, COSY, NOESY) NMR experiments. The multidrug resistance reversing and cytotoxic effects of five diterpenes (1, 4 – 7) were studied on the L5178 mouse lymphoma cell line using rhodamine 123 accumulation and the MTT cell viability assay. Segetane and jatrophane diterpenes had no cytotoxic activity on the sensitive parent and multidrug resistance cells, while ingenane diterpenes showed a cytotoxic effect on both cell lines. Ingenanes 6 and 7 and segetane 1 demonstrated the remarkable multidrug resistance modulating effect at 20 µM.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Gondal, Humaira Y., Muhammad Nisar et Muhammad I. Choudhary. « Antileishmanial Activity of Diterpene lactones from Suregada multiflora and Their Semisynthetic Derivatives ». Current Bioactive Compounds 16, n^o 1 (20 février 2020) : 53–57. http://dx.doi.org/10.2174/1573407214666180516101031.

Texte intégral

Résumé :

Background: There is a general lack of effective and economical chemotherapeutic agents for the treatment of widely prevalent leishmanias. To develop locally available, low cost alternative therapy, a series of diterpene lactones isolated from Suregada multiflora and their semisynthetic derivatives have been evaluated against the protozoan parasite Leishmania. Methods: A series of diterpene lactones were isolated from methanolic extract of Suregada multiflora. Major constituents were further derivatized through chemical and microbial transformations. Antileishmanial activity of structurally diverse diterpene lactones was performed by testing them in vitro against L. donovani promastigotes. All compounds were also tested for their cytotoxic effects by the brine shrimp bioassay. Results: Among all compounds evaluated in current studies, natural diterpenes Gelomulide A (1) and G (2) were found significantly active with IC50 values below 20µg/ml. While, among synthesized derivatives; compounds 5, 9 and 10 were found more potent with IC50 value 17.49, 18.38 and 17.81µg/ml, respectively. None of these compounds showed cytotoxic effects in the brine shrimp bioassay (LC50> 300). Conclusion: A new class of diterpene lactones was identified as potential antileshmanial agent. The structural diversity of natural and semisynthetic diterpene lactones, helped to rationalize structure– activity relationships. Activity of these diterpene lactones owed to C-8/14 epoxide along with unsubstituted C-1. Keto group at C-1 always lower the activity unless it is in α, β-unsaturated form. Presence of acetyl group at C-3 and 6 usually augmented the antileishmanila potential

Styles APA, Harvard, Vancouver, ISO, etc.

34

Hou, Yong, Meiying Chen, Zhaocui Sun, Guoxu Ma, Deli Chen, Haifeng Wu, Junshan Yang, Yihang Li et Xudong Xu. « The Biosynthesis Related Enzyme, Structure Diversity and Bioactivity Abundance of Indole-Diterpenes : A Review ». Molecules 27, n^o 20 (13 octobre 2022) : 6870. http://dx.doi.org/10.3390/molecules27206870.

Texte intégral

Résumé :

Indole diterpenes are a large class of secondary metabolites produced by fungi, possessing a cyclic diterpenoid backbone and an indole moiety. Novel structures and important biological activity have made indole diterpenes one of the focuses of synthetic chemists. Although the discovery, identification, structural diversity, biological activity and especially structure–activity relationship of indole diterpenes have been reported in some papers in recent years, they are absent of a systematic and comprehensive analysis, and there is no elucidation of enzymes related to this kind of natural product. Therefore, it is necessary to summarize the relevant reports to provide new perspectives for the following research. In this review, for the first time, the function of related synthases and the structure–activity relationship of indole diterpenes are expounded, and the recent research advances of them are emphasized.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Liu, Yixi, C. Houston Wiedle, Peggy J. Brodie, Martin W. Callmander, R. Rakotondrajaona, Etienne Rakotobe, Vincent E. Rasamison et David G. I. Kingston. « Antiproliferative Diterpenes from a Malleastrum sp. from the Madagascar dry forest [1] ». Natural Product Communications 10, n^o 9 (septembre 2015) : 1934578X1501000. http://dx.doi.org/10.1177/1934578x1501000905.

Texte intégral

Résumé :

An ethanol extract of leaves of the plant species Malleastrum sp. collected in northern Madagascar afforded the new clerodane diterpene 18-oxo-cleroda-3,13-dien-16,15-olide (1), together with the three known clerodane diterpenes 16,18-dihydroxykolavenic acid lactone (2), solidagolactone (3) and (-)-kolavenol (4), and the known labdane diterpene 3-oxo-ent-Iabda-8(17),13-dien-15,16-olide (5). Compounds 1, 3, and 4 showed moderate antiproliferative activities against the A2780 ovarian cancer cell line, with the IC50 values of 3.01 ± 0.8, 7.84 ± 0.2, and 17.9 ± 3 μM, respectively. The structure elucidations of all compounds were carried out based on analysis of NMR and mass spectroscopic data. The relative stereochemistry of compound 1 was determined by NOESY NMR spectrum.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Katavic, Peter L., Pinus Jumaryatno, John N. A. Hooper, Joanne T. Blanchfield et Mary J. Garson. « Oxygenated Terpenoids from the Australian Sponges Coscinoderma matthewsi and Dysidea sp., and the Nudibranch Chromodoris albopunctata ». Australian Journal of Chemistry 65, n^o 5 (2012) : 531. http://dx.doi.org/10.1071/ch12010.

Texte intégral

Résumé :

The isolation and structure elucidation of seven new oxygenated terpenoids and eight known terpene metabolites from marine invertebrates collected at the Inner Gneerings Reef, South East Queensland, is discussed. Investigation of the sponge Coscinoderma matthewsi yielded an epoxylactone derivative (1) of the known furanoterpene tetradehydrofurospongin-1 (2). A chemical investigation of the dissected nudibranch Chromodoris albopunctata provided the new oxygenated diterpenes 12α-acetoxyspongian-16-one (10), 20-acetoxyspongian-16-one (12), 20-oxyspongian-16-one propionate (13) and 12α,20-dioxyspongian-16-one dipropionate (14) in conjunction with three other known diterpene metabolites, while two new chromodorolides, D (17) and E (18), in addition to four known diterpenes were isolated from a Dysidea sp.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Katavic, Peter L., Pinus Jumaryatno, John N. A. Hooper, Joanne T. Blanchfield et Mary J. Garson. « Note of clarification about : Oxygenated Terpenoids from the Australian Sponges Coscinoderma matthewsi and Dysidea sp., and the Nudibranch Chromodoris albopunctata [vol. 65, pp. 531–538] ». Australian Journal of Chemistry 66, n^o 11 (2013) : 1461. http://dx.doi.org/10.1071/ch12010_nc.

Texte intégral

Résumé :

The isolation and structure elucidation of seven new oxygenated terpenoids and eight known terpene metabolites from marine invertebrates collected at the Inner Gneerings Reef, South East Queensland, is discussed. Investigation of the sponge Coscinoderma matthewsi yielded an epoxylactone derivative (1) of the known furanoterpene tetradehydrofurospongin-1 (2). A chemical investigation of the dissected nudibranch Chromodoris albopunctata provided the new oxygenated diterpenes 12?-acetoxyspongian-16-one (10), 20-acetoxyspongian-16-one (12), 20-oxyspongian-16-one propionate (13) and 12?,20-dioxyspongian-16-one dipropionate (14) in conjunction with three other known diterpene metabolites, while two new chromodorolides, D (17) and E (18), in addition to four known diterpenes were isolated from a Dysidea sp.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Yuan, Xiao-Hong, Bo-Gang Li, Xiu-Yun Zhang, Hua-Yi Qi, Min Zhou et Guo-Lin Zhang. « Two Diterpenes and Three Diterpene Glucosides fromPhlogacanthus curviflorus ». Journal of Natural Products 68, n^o 1 (janvier 2005) : 86–89. http://dx.doi.org/10.1021/np0497999.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

39

Grote, Daniela, Hesham S. M. Soliman, Kamel H. Shaker, Mohamed Hamza et Karlheinz Seifert. « Cembranoid diterpenes and a briarane diterpene from corals ». Natural Product Research 20, n^o 3 (mars 2006) : 285–91. http://dx.doi.org/10.1080/14786410500087657.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

40

Koch-Heitzmann, Isabella, et Wulf Schultze. « Untersuchungen an Kalluskulturen von Melissa officinalis L., II Über wasserdampfflüchtige Diterpenkohlenwasserstoffe in nicht differenzierten Oberflächenkulturen / Investigations on Callus Cultures of Melissa officinalis L., II Votile Diterpene Hydrocarbons in Not Differentiated Static Cultures ». Zeitschrift für Naturforschung C 40, n^o 1-2 (1 février 1985) : 13–20. http://dx.doi.org/10.1515/znc-1985-1-205.

Texte intégral

Résumé :

Dehydroabietane and an other diterpene hydrocarbon, being still unidentified, were found in the steam distillates of callus cultures of Melissa officinalis. The relative proportions of these two diterpenes changed considerably during the course of a cultivation passage. With advancing age of the cells they shifted gradually towards dehydroabietane. Cultures being exposed to continuous light showed the same composition of their steam distillates as cultures which were raised in the dark.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Fraga, Braulio M., Carlo Bressa, Concepción Fernández, Pedro González, Ricardo Guillermo et Melchor G. Hernández. « Diterpenes from Sideritis infernalis and S. candicans ». Zeitschrift für Naturforschung B 63, n^o 5 (1 mai 2008) : 595–99. http://dx.doi.org/10.1515/znb-2008-0519.

Texte intégral

Résumé :

A phytochemical study of Sideritis infernalis led to the isolation of the new nor-diterpene adejone (17-nor-7α,18-dihydroxy-ent-kaur-16-one). The biosynthesis of this compound implies the decarboxylation of an epoxy-acid as the last step. In addition, three diterpenes with an ent-kaurene skeleton, episideridiol, candicandiol 7α-monoacetate and candidiol 15α-monoacetate, have been isolated from S. candicans for the first time in nature.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Chaves Lobón, Natividad, Irene Ferrer de la Cruz et Juan Alías Gallego. « Autotoxicity of Diterpenes Present in Leaves of Cistus ladanifer L. » Plants 8, n^o 2 (22 janvier 2019) : 27. http://dx.doi.org/10.3390/plants8020027.

Texte intégral

Résumé :

Cistus ladanifer has been described as an allelopathic and autoallelopathic species, and the compounds that could be involved in its autotoxicity are the flavonoids and diterpenes present in the exudate of its leaves. The aim of this study was to determine which family of compounds, either phenols or terpenes, are responsible for the autoallelopathic activity quantified in C. ladanifer. These compounds were extracted from the exudate of young leaves collected in spring and separated by column chromatography into two fractions: diterpenes and flavonoids. The obtained results showed that flavonoids, at the tested concentrations, did not have a negative effect on any of the parameters quantified in the germination process of C. ladanifer seeds. On the other hand, the germination, seedling size and seedling establishment, quantified through the germination index and rate, were negatively affected by the tested diterpene solutions. In view of the obtained results, it was concluded that the compounds involved in the autoallelopathy process of C. ladanifer are diterpenes.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Syah, Yana M., Emilio L. Ghisalberti, Brian W. Skelton et Allan H. White. « A New Class of Tricyclic Diterpenes from Eremophila georgei (Myoporaceae) ». Australian Journal of Chemistry 50, n^o 7 (1997) : 705. http://dx.doi.org/10.1071/c97043.

Texte intégral

Résumé :

The first example of a new class of tricyclic diterpenes together with two new viscidanes have been isolated from a variety ofEremophila georgei. The structures of the viscidane compounds were assigned on the basis of spectroscopic data and comparison with model compounds. The structure and relative stereochemistry of the lactone (2), which represents a new diterpene skeleton, were established by spectroscopic and X-ray crystallographic methods. The derivation of (2) from a viscidane is suggested.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Barbosa Silva Cavalcanti, Andreza, Renata Priscila Costa Barros, Vicente Carlos de Oliveira Costa, Marcelo Sobral da Silva, Josean Fechine Tavares, Luciana Scotti et Marcus Tullius Scotti. « Computer-Aided Chemotaxonomy and Bioprospecting Study of Diterpenes of the Lamiaceae Family ». Molecules 24, n^o 21 (30 octobre 2019) : 3908. http://dx.doi.org/10.3390/molecules24213908.

Texte intégral

Résumé :

Lamiaceae is one of the largest families of angiosperms and is classified into 12 subfamilies that are composed of 295 genera and 7775 species. It presents a variety of secondary metabolites such as diterpenes that are commonly found in their species, and some of them are known to be chemotaxonomic markers. The aim of this work was to construct a database of diterpenes and to use it to perform a chemotaxonomic analysis among the subfamilies of Lamiaceae, using molecular descriptors and self-organizing maps (SOMs). The 4115 different diterpenes corresponding to 6386 botanical occurrences, which are distributed in eight subfamilies, 66 genera, 639 different species and 4880 geographical locations, were added to SistematX. Molecular descriptors of diterpenes and their respective botanical occurrences were used to generate the SOMs. In all obtained maps, a match rate higher than 80% was observed, demonstrating a separation of the Lamiaceae subfamilies, corroborating with the morphological and molecular data proposed by Li et al. Therefore, through this chemotaxonomic study, we can predict the localization of a diterpene in a subfamily and assist in the search for secondary metabolites with specific structural characteristics, such as compounds with potential biological activity.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Popova, Venelina, Tanya Ivanova, Albena Stoyanova, Violeta Nikolova, Tsveta Hristeva, Velizar Gochev, Yonko Yonchev, Nikolay Nikolov et Valtcho D. Zheljazkov. « Terpenoids in the Essential Oil and Concentrated Aromatic Products Obtained from Nicotiana glutinosa L. Leaves ». Molecules 25, n^o 1 (20 décembre 2019) : 30. http://dx.doi.org/10.3390/molecules25010030.

Texte intégral

Résumé :

N. glutinosa L. is a relatively less studied Nicotiana species (Solanaceae), although there are data about its importance as a model plant in viral control studies, as a gene donor in tobacco hybridization and as a source of agents with insecticidal or fungicidal effects. The biological activities of the species were associated mostly with the presence of leaf surface metabolites, in particular diterpenes and sucrose esters. The aim of this study was to identify the chemical composition of the essential oil (EO) and two aromatic extraction products (concrete and resinoid) obtained from N. glutinosa L. leaves. GC-MS analysis identified 26 components in the EO (representing 97.3% of total oil content), which contained mostly diterpene compounds with major components manool (14.2%), sclarene (8.4%) and manoyl oxide (8.1%). The number of compounds identified in the concrete was 37 (95.5% of the total content) and the major component was the diterpene alcohol sclareol (14.2%). In the resinoid, 30 volatile components (representing 95.1% of resinoid content) were identified, with major components nicotine (32.9%), α-tocopherol (8.2%), tridecanoin (6.9%), sclareol (6.9%), and solanone (6.9%). The group of bicyclic diterpenes had the largest share in the diterpene fraction of the products (57.3%, 91.7%, and 86.3%, respectively for the EO, concrete, and resinoid). Considering the abundance of sclareol in the aromatic products, the antimicrobial activity of the pure substance was determined. Sclareol was highly effective against a set of medicinally important yeasts; Candida albicans АТСС 10231, C. glabrata ATCC 90030, C. parapsilosis clinical isolate, and C. tropicalis NBIMCC 23, while being less effective against the studied Gram-positive and Gram-negative bacteria. Data from the study on N. glutinosa aromatic products composition may be of interest to the aroma industries for their possible use in perfumery and cosmetics.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Karaoğul, Eyyüp, et M. Hakkı Alma. « Solvent-free microwave and hydro-distillation extraction of essential oils from the sawdust of pines : Correlation with heat-map ». BioResources 14, n^o 4 (28 août 2019) : 8229–40. http://dx.doi.org/10.15376/biores.14.4.8229-8240.

Texte intégral

Résumé :

The chemical compositions were investigated for pine essential oils obtained through a solvent-free microwave assistance extraction system (ME) and a conventional hydrodistillation system (HD). The essential oils of P. pinea, P. nigra, P. brutia, and P. sylvestris sawdust were analyzed by gas chromatography and mass spectroscopy (GC-MS). The main components of the pine essential oils were D-limonene (52.8% for ME and 76.6% for HD), β-caryophyllene (12.4% for ME), β-myrcene (2.89% for ME and 1.48% for HD), sesquiterpene hydrocarbons (25% for ME and 9.79% for HD), and total sesquiterpene (25.25% for ME and 9.79% for HD) for P. pinea; D-limonene (28.1% for ME and 79.2% for HD) for P. nigra; α-pinene (76.6% for ME and 77.3% for HD), diterpene hydrocarbons (94.17% for ME and 95.62% for HD), and total diterpenes (94.94% for ME and 96.3% for HD) for P. brutia; β-pinene (36.7% for ME and 42.4% for HD), terpineol, (13.8% for ME and 6.06% for HD) diterpene alcohol (26% for ME and 12.57% for HD), and total oxygenated terpenes (26% for ME and 12.57% for HD)for P. sylvestris. Moreover, the ME was able to produce more diterpene alcohols and sesquiterpene hydrocarbons while the HD showed higher potential for the diterpene hydrocarbons. According to the heat-map correlation, P. pinea showed high similarity with P. nigra, while P. sylvestris was related to P. brutia.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Maciel, M. A. M., J. K. P. C. Cortez et F. E. S. Gomes. « O gênero Croton e Aspectos Relevantes de Diterpenos Clerodanos ». Revista Fitos 2, n^o 03 (1 décembre 2006) : 54–73. http://dx.doi.org/10.32712/2446-4775.2006.59.

Texte intégral

Résumé :

O gênero Croton (Euphorbiaceae) encontra-se amplamente distribuído em todo o mundo, com concentração significativa na África, Brasil e México. As espécies Croton zambesicus Muell Arg. (África), Croton lechleri Muell Arg. (EUA) e Croton tiglium Klotzsch (Ásia), lideram as pesquisas internacionais com documentação de 58 artigos publicados em periódicos indexados. Dentre as espécies nativas do Brasil, destacam-se o Croton cajucara Benth, Croton zehntneri Pax e Hoffm. e Croton sonderianus Müll Arg. por serem os mais representativos com 86 artigos publicados. O Croton cajucara representa a espécie mais estudada do gênero, perfazendo 60 publicações inseridas em um contexto científico multidisciplinar. A fonte mais abundante de diterpenos do tipo clerodano são plantas pertencentes ao gênero Teucrium (Labiatae). No entanto, os gêneros Ajuga, Scutellaria, Clerodendrum e Croton, representam também, uma fonte rica em clerodanos. As espécies Croton schiedeanus Schlecht, Croton sonderianus e Croton cajucara Benth são exemplos a serem citados, já que nestas espécies, a ocorrência de clerodanos é abundante. Atualmente, o diterpeno do tipo 19-nor-clerodano transdesidrocrotonina (DCTN) por ter sido correlacionado com grande parte das indicações tradicionais de Croton cajucara, é um dos mais representativos desta classe de diterpeno. O presente artigo enfoca aspectos relevantes sobre o gênero Croton e os diterpenos do tipo clerodano, com enfoque especial para os resultados quimiofarmacológicos obtidos para a espécie medicinal Croton cajucara.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Janke, Ronja, Christian Görner, Max Hirte, Thomas Brück et Bernhard Loll. « The first structure of a bacterial diterpene cyclase : CotB2 ». Acta Crystallographica Section D Biological Crystallography 70, n^o 6 (23 mai 2014) : 1528–37. http://dx.doi.org/10.1107/s1399004714005513.

Texte intégral

Résumé :

Sesquiterpenes and diterpenes are a diverse class of secondary metabolites that are predominantly derived from plants and some prokaryotes. The properties of these natural products encompass antitumor, antibiotic and even insecticidal activities. Therefore, they are interesting commercial targets for the chemical and pharmaceutical industries. Owing to their structural complexity, these compounds are more efficiently accessed by metabolic engineering of microbial systems than by chemical synthesis. This work presents the first crystal structure of a bacterial diterpene cyclase, CotB2 from the soil bacteriumStreptomyces melanosporofaciens, at 1.64 Å resolution. CotB2 is a diterpene cyclase that catalyzes the cyclization of the linear geranylgeranyl diphosphate to the tricyclic cyclooctat-9-en-7-ol. The subsequent oxidation of cyclooctat-9-en-7-ol by two cytochrome P450 monooxygenases leads to bioactive cyclooctatin. Plasticity residues that decorate the active site of CotB2 have been mutated, resulting in alternative monocyclic, dicyclic and tricyclic compounds that show bioactivity. These new compounds shed new light on diterpene cyclase reaction mechanisms. Furthermore, the product of mutant CotB2W288Gproduced the new antibiotic compound (1R,3E,7E,11S,12S)-3,7,18-dolabellatriene, which acts specifically against multidrug-resistantStaphylococcus aureus. This opens a sustainable route for the industrial-scale production of this bioactive compound.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Muhammad, Ilias, Satoshi Takamatsu, Jamal Mustafa, Shabana I. Khan, Ikhlas A. Khan, Volodymyr Samoylenko, Jaber S. Mossa, Farouk S. El-Feraly et D. Chuck Dunbar. « COX-2 Inhibitory Activity of Cafestol and Analogs from Coffee Beans ». Natural Product Communications 3, n^o 1 (janvier 2008) : 1934578X0800300. http://dx.doi.org/10.1177/1934578x0800300103.

Texte intégral

Résumé :

Two kaurane diterpenes, namely cafestol (1) and kahweol (2), were isolated from hydrolyzed fraction of the fixed oil of Ethiopian Coffea arabica unroasted beans, using AgNO3-impregnated silica gel chromatography. In addition, cafestol palmitate (3) and kahweol palmitate (4), the two natural diterpene esters of C. arabica, were also synthesized. Compounds 1–4 were evaluated for anti-inflammatory activity using cyclooxygenase-2 (COX-2), cell aggregation, cell proliferation, cell adhesion, iNOS and antioxidant assays. The COX-2 inhibitory activity of cafestol (1) was found to be 20-fold more potent than kahweol (2) (IC50 value 0.25 μg/mL vs. 5.0 μg/mL), while compounds 3 and 4 were weakly active. The isolation and structure elucidation of the diterpenes 1 and 2, preparation of compounds 3 and 4, and their biological activities are presented in this paper.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Kate, Abhijeet S., Kelly Richard, Balaji Ramanathan et Russell G. Kerr. « A halogenated pseudopterane diterpene from the Bahamian octocoral Pseudopterogorgia acerosa ». Canadian Journal of Chemistry 88, n^o 4 (avril 2010) : 318–22. http://dx.doi.org/10.1139/v09-168.

Texte intégral

Résumé :

Two new pseudopteranoid diterpenes have been isolated from the gorgonian coral Pseudopterogorgia acerosa and have been characterized by NMR and mass spectrometry. These include 15-chlorodeoxypseudopterolide (1), the first halogenated pseudopterane diterpene, and 11-epi-pseudopteranol (2), an epimer of the previously described 11-pseudopteranol. In addition, six known diterpenes were also isolated from this collection including deoxypseudopterolide (3), pseudopteradiene (4), acerosolide (5), pseudopterolide-methanol adduct (6), 11-pseudopteranol (7), and isogorgiacerodiol (8). The cytotoxicity of these eight compounds towards three cancer cell lines (HeLa, PC-3, and HCT116) was assessed and the chlorinated pseudopteranoid 1 was found to have modest but selective activity against HCT116 (IC50 2.7 µmol/L), whereas its nonchlorinated derivative 3 was inactive. This indicates that the halo functionality can modify the cytotoxic activity of pseudopteranoids and potentially other classes of deterpenes.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Diterpeni »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres