Science.gov

Sample records for related prenylated indole

  1. Taichunamides: Prenylated Indole Alkaloids from Aspergillus taichungensis (IBT 19404).

    PubMed

    Kagiyama, Ippei; Kato, Hikaru; Nehira, Tatsuo; Frisvad, Jens C; Sherman, David H; Williams, Robert M; Tsukamoto, Sachiko

    2016-01-18

    Seven new prenylated indole alkaloids, taichunamides A-G, were isolated from the fungus Aspergillus taichungensis (IBT 19404). Taichunamides A and B contained an azetidine and 4-pyridone units, respectively, and are likely biosynthesized from notoamide S via (+)-6-epi-stephacidin A. Taichunamides C and D contain endoperoxide and methylsulfonyl units, respectively. This fungus produced indole alkaloids containing an anti-bicyclo[2.2.2]diazaoctane core, whereas A. protuberus and A. amoenus produced congeners with a syn-bicyclo[2.2.2]diazaoctane core. Plausible biosynthetic pathways to access these cores within the three species likely arise from an intramolecular hetero Diels-Alder reaction. PMID:26644336

  2. Indole prenyltransferases from fungi: a new enzyme group with high potential for the production of prenylated indole derivatives.

    PubMed

    Steffan, N; Grundmann, A; Yin, W-B; Kremer, A; Li, S-M

    2009-01-01

    Prenylated indole derivatives are hybrid natural products containing both aromatic and isoprenoid moieties and are widely spread in plants, fungi and bacteria. Some of these complex natural products, e.g. the ergot alkaloids ergotamine and fumigaclavine C as well as the diketopiperazine derivative fumitremorgin C and its biosynthetic precursors tryprostatin A and B, show a wide range of biological and pharmacological activities. Prenyl transfer reactions catalysed by prenyltransferases represent key steps in the biosynthesis of these compounds and often result in formation of products which possess biological activities distinct from their non-prenylated precursors. Recently, a series of putative indole prenyltransferase genes could be identified in the genome sequences of different fungal strains including Aspergillus fumigatus. The gene products show significant sequence similarities to dimethylallyltryptophan synthases from fungi. We have cloned and overexpressed six of these genes, fgaPT1, fgaPT2, ftmPT1, ftmPT2, 7-dmats and cdpNPT from A. fumigatus in E. coli and S. cerevisiae. The overproduced enzymes were characterised biochemically. Three additional prenyltransferases, DmaW-Cs, TdiB and MaPT were identified and characterised in a Clavicipitalean fungus, Aspergillus nidulans and Malbranchea aurantiaca, respectively. Sequence analysis and alignments with known aromatic prenyltransferases as well as phylogenetic analysis revealed that these enzymes belong to a new group of "aromatic prenyltransferases". They differ clearly from membrane-bound aromatic prenyltransferases from different sources and soluble prenyltransferases from bacteria. The characterised enzymes are soluble proteins, catalyse different prenyl transfer reactions on indole moieties of various substrates and do not require divalent metal ions for their enzymatic reactions. All of the enzymes accepted only dimethylallyl diphosphate as prenyl donor. On the other hand, they showed broad substrate

  3. Diastereodivergent Reverse Prenylation of Indole and Tryptophan Derivatives: Total Synthesis of Amauromine, Novoamauromine, and epi-Amauromine.

    PubMed

    Müller, Jonas M; Stark, Christian B W

    2016-04-01

    A regio- and stereoselective reverse prenylation of indole and tryptophan derivatives is presented. All four possible stereoisomers are accessible through this iridium-catalyzed reaction. The stereoselectivity is controlled by a chiral phosphoramidite ligand in combination with an achiral borane additive and can be switched by changing the nature of the borane. One enantiomer of the ligand is thus sufficient to prepare all possible isomers. The synthetic potential of this method was demonstrated by a short total synthesis of amauromine and its two natural diastereomers. PMID:26969898

  4. Facile Installation of 2-Reverse Prenyl Functionality into Indoles by a Tandem N-Alkylation-Aza-Cope Rearrangement Reaction and Its Application in Synthesis.

    PubMed

    Chen, Xiaobei; Fan, Huaqiang; Zhang, Shilei; Yu, Chenguang; Wang, Wei

    2016-01-11

    An unprecedented tandem N-alkylation-ionic aza-Cope (or Claisen) rearrangement-hydrolysis reaction of readily available indolyl bromides with enamines is described. Due to the complicated nature of the two processes, an operationally simple N-alkylation and subsequent microwave-irradiated ionic aza-Cope rearrangement-hydrolysis process has been uncovered. The tandem reaction serves as a powerful approach to the preparation of synthetically and biologically important, but challenging, 2-reverse quaternary-centered prenylated indoles with high efficiency. Notably, unusual nonaromatic 3-methylene-2,3-dihydro-1H-indole architectures, instead of aromatic indoles, are produced. Furthermore, the aza-Cope rearrangement reaction proceeds highly regioselectively to give the quaternary-centered reverse prenyl functionality, which often produces a mixture of two regioisomers by reported methods. The synthetic value of the resulting nonaromatic 3-methylene-2,3-dihydro-1H-indole architectures has been demonstrated as versatile building blocks in the efficient synthesis of structurally diverse 2-reverse prenylated indoles, such as indolines, indole-fused sultams and lactams, and the natural product bruceolline D. PMID:26586470

  5. Multi-Site Prenylation of 4-Substituted Tryptophans by Dimethylallyltryptophan Synthase

    PubMed Central

    Rudolf, Jeffrey D.; Wang, Hong; Poulter, C. Dale

    2013-01-01

    The aromatic prenyltransferase dimethylallyltryptophan synthase in Claviceps purpurea catalyzes the normal prenylation of tryptophan at C4 of the indole nucleus in the first committed step of ergot alkaloid biosynthesis. 4-Methyltryptophan is a competitive inhibitor of the enzyme that has been used in kinetic studies. Upon investigation of background activity during incubations of 4-methyltryptophan with dimethylallyl diphosphate, we found that the analogue was an alternate substrate, which gave four products. The structures of three of these compounds were established by 1H NMR and 2D NMR studies and revealed that dimethylallyltryptophan synthase catalyzed both normal and reverse prenylation at C3 of the indole ring and normal prenylation of N1. Similarly, 4-methoxytryptophan was an alternate substrate, giving normal prenylation at C5 as the major product. 4-Aminotryptophan, another alternate substrate, gave normal prenylation at C5 and C7. The ability of dimethylallyltryptophan synthase to prenylate at five different sites on the indole nucleus, with normal and reverse prenylation at one of the sites, is consistent with a dissociative electrophilic alkylation of the indole ring where orientation of the substrates within the active site and substituent electronic effects determine the position and type of prenylation. These results suggest a common mechanism for prenylation of tryptophan by all of the members of the structurally related dimethylallyltryptophan synthase family. PMID:23301871

  6. Relative Contributions of Prenylation and Postprenylation Processing in Cryptococcus neoformans Pathogenesis.

    PubMed

    Esher, Shannon K; Ost, Kyla S; Kozubowski, Lukasz; Yang, Dong-Hoon; Kim, Min Su; Bahn, Yong-Sun; Alspaugh, J Andrew; Nichols, Connie B

    2016-01-01

    Prenyltransferase enzymes promote the membrane localization of their target proteins by directing the attachment of a hydrophobic lipid group at a conserved C-terminal CAAX motif. Subsequently, the prenylated protein is further modified by postprenylation processing enzymes that cleave the terminal 3 amino acids and carboxymethylate the prenylated cysteine residue. Many prenylated proteins, including Ras1 and Ras-like proteins, require this multistep membrane localization process in order to function properly. In the human fungal pathogen Cryptococcus neoformans, previous studies have demonstrated that two distinct forms of protein prenylation, farnesylation and geranylgeranylation, are both required for cellular adaptation to stress, as well as full virulence in animal infection models. Here, we establish that the C. neoformans RAM1 gene encoding the farnesyltransferase β-subunit, though not strictly essential for growth under permissive in vitro conditions, is absolutely required for cryptococcal pathogenesis. We also identify and characterize postprenylation protease and carboxyl methyltransferase enzymes in C. neoformans. In contrast to the prenyltransferases, deletion of the genes encoding the Rce1 protease and Ste14 carboxyl methyltransferase results in subtle defects in stress response and only partial reductions in virulence. These postprenylation modifications, as well as the prenylation events themselves, do play important roles in mating and hyphal transitions, likely due to their regulation of peptide pheromones and other proteins involved in development. IMPORTANCE Cryptococcus neoformans is an important human fungal pathogen that causes disease and death in immunocompromised individuals. The growth and morphogenesis of this fungus are controlled by conserved Ras-like GTPases, which are also important for its pathogenicity. Many of these proteins require proper subcellular localization for full function, and they are directed to cellular membranes

  7. Relative Contributions of Prenylation and Postprenylation Processing in Cryptococcus neoformans Pathogenesis

    PubMed Central

    Esher, Shannon K.; Ost, Kyla S.; Kozubowski, Lukasz; Yang, Dong-Hoon; Kim, Min Su; Bahn, Yong-Sun; Nichols, Connie B.

    2016-01-01

    ABSTRACT Prenyltransferase enzymes promote the membrane localization of their target proteins by directing the attachment of a hydrophobic lipid group at a conserved C-terminal CAAX motif. Subsequently, the prenylated protein is further modified by postprenylation processing enzymes that cleave the terminal 3 amino acids and carboxymethylate the prenylated cysteine residue. Many prenylated proteins, including Ras1 and Ras-like proteins, require this multistep membrane localization process in order to function properly. In the human fungal pathogen Cryptococcus neoformans, previous studies have demonstrated that two distinct forms of protein prenylation, farnesylation and geranylgeranylation, are both required for cellular adaptation to stress, as well as full virulence in animal infection models. Here, we establish that the C. neoformans RAM1 gene encoding the farnesyltransferase β-subunit, though not strictly essential for growth under permissive in vitro conditions, is absolutely required for cryptococcal pathogenesis. We also identify and characterize postprenylation protease and carboxyl methyltransferase enzymes in C. neoformans. In contrast to the prenyltransferases, deletion of the genes encoding the Rce1 protease and Ste14 carboxyl methyltransferase results in subtle defects in stress response and only partial reductions in virulence. These postprenylation modifications, as well as the prenylation events themselves, do play important roles in mating and hyphal transitions, likely due to their regulation of peptide pheromones and other proteins involved in development. IMPORTANCE Cryptococcus neoformans is an important human fungal pathogen that causes disease and death in immunocompromised individuals. The growth and morphogenesis of this fungus are controlled by conserved Ras-like GTPases, which are also important for its pathogenicity. Many of these proteins require proper subcellular localization for full function, and they are directed to cellular

  8. Four new minor brominated indole related alkaloids with antibacterial activities from Laurencia similis.

    PubMed

    Li, Mei-Chen; Sun, Wen-Shuang; Cheng, Wei; Liu, Dong; Liang, Hong; Zhang, Qing-Ying; Lin, Wen-Han

    2016-08-01

    Four new minor brominated indole related alkaloids (one indoles, 1, one 1,3-dihydro-indole-2-one, 2, one carbazole, 3, and one 2-carbonylamino-benzoate, 4) were isolated and identified from Laurencia similis by extensive chromatographic and spectrometric methods. Among them, 1 and 2 were the first example of naturally occurring indole with 3-benzyl group and 1,3-dihydro-indole-2-one with 2-isopropylidene group, respectively, whereas 3 and 4 were the first carbazole alkaloids and 2-carbonylamino-benzoate, respectively, isolated from the genus Laurencia. Moreover, 1 showed the most potent antibacterial activity against seven bacterial strains with MIC values ranging from 2 to 8μg/mL. PMID:27318539

  9. Biomimetic Synthesis of Moschamine-Related Indole Alkaloids via Iron-Catalyzed Selectively Oxidative Radical Coupling.

    PubMed

    Liang, Kangjiang; Yang, Jing; Tong, Xiaogang; Shang, Wenbin; Pan, Zhiqiang; Xia, Chengfeng

    2016-03-18

    An iron-catalyzed oxidative radical coupling reaction was developed to selectively construct indolofuran or bisphenolic indole cores, which exist in two types of moschamine-related indole alkaloids. Both (+)-decursivine and 4,4″-bis(N-feruloyl)serotonin were biomimetically synthesized by using coupling reactions. The proposed reassignment of the structure of montamine as 4,4″-bis(N-feruloyl)serotonin was excluded. PMID:26949004

  10. Single prenyl-binding site on protein prenyl transferases

    PubMed Central

    Desnoyers, Luc; Seabra, Miguel C.

    1998-01-01

    Three distinct protein prenyl transferases, one protein farnesyl transferase (FTase) and two protein geranylgeranyl transferases (GGTase), catalyze prenylation of many cellular proteins. One group of protein substrates contains a C-terminal CAAX motif (C is Cys, A is aliphatic, and X is a variety of amino acids) in which the single cysteine residue is modified with either farnesyl or geranylgeranyl (GG) by FTase or GGTase type-I (GGTase-I), respectively. Rab proteins constitute a second group of substrates that contain a C-terminal double-cysteine motif (such as XXCC in Rab1a) in which both cysteines are geranylgeranylated by Rab GG transferase (RabGGTase). Previous characterization of CAAX prenyl transferases showed that the enzymes form stable complexes with their prenyl pyrophosphate substrates, acting as prenyl carriers. We developed a prenyl-binding assay and show that RabGGTase has a prenyl carrier function similar to the CAAX prenyl transferases. Stable RabGGTase:GG pyrophosphate (GGPP), FTase:GGPP, and GGTase-I:GGPP complexes show 1:1 (enzyme:GGPP) stoichiometry. Chromatographic analysis of prenylated products after single turnover reactions by using isolated RabGGTase:GGPP complex revealed that Rab is mono-geranylgeranylated. This study establishes that all three protein prenyl transferases contain a single prenyl-binding site and suggests that RabGGTase transfers two GG groups to Rabs in independent and consecutive reactions. PMID:9770475

  11. Novel prenyl bibenzyls from the New Zealand liverwort Marsupidium epiphytum.

    PubMed

    Toyota, Masao; Omatsu, Ikuko; Braggins, John; Asakawa, Yoshinori

    2011-01-01

    The ether extract of the New Zealand liverwort Marsupidium epiphytum gave four new prenyl bibenzyl derivatives, along with a known prenyl bibenzyl derivative which has been isolated from the Ecuadorian liverwort Lethocolea glossophylla; their structures were determined by 2D-NMR spectrum. The chemical constituents of Marsupidium epiphytum are highly characteristic since they elaborate dihydrooxepin type compounds and prenyl type bibenzyls. These structures are closely related to those found in Radula spp. (Radulaceae), although bibenzyls with two prenyl groups have not been isolated from the Radula spp. Although Marsupidium spp. are different from Radula spp. morphologically, the constituents are closely related. This is the first example of isolation of prenyl bibenzyl derivatives from M. epiphytum, a species which has not previously been investigated phytochemically. PMID:21467678

  12. Prenylated indolediketopiperazine peroxides and related homologues from the marine sediment-derived fungus Penicillium brefeldianum SD-273.

    PubMed

    An, Chun-Yan; Li, Xiao-Ming; Li, Chun-Shun; Xu, Gang-Ming; Wang, Bin-Gui

    2014-02-01

    Three new indolediketopiperazine peroxides, namely, 24-hydroxyverruculogen (1), 26-hydroxyverruculogen (2), and 13-O-prenyl-26-hydroxyverruculogen (3), along with four known homologues (4-7), were isolated and identified from the culture extract of the marine sediment-derived fungus Penicillium brefeldianum SD-273. Their structures were determined based on the extensive spectroscopic analysis and compound 1 was confirmed by X-ray crystallographic analysis. The absolute configuration of compounds 1-3 was determined using chiral HPLC analysis of their acidic hydrolysates. Each of the isolated compounds was evaluated for antibacterial and cytotoxic activity as well as brine shrimp (Artemia salina) lethality. PMID:24473173

  13. Prenylated Indolediketopiperazine Peroxides and Related Homologues from the Marine Sediment-Derived Fungus Penicillium brefeldianum SD-273

    PubMed Central

    An, Chun-Yan; Li, Xiao-Ming; Li, Chun-Shun; Xu, Gang-Ming; Wang, Bin-Gui

    2014-01-01

    Three new indolediketopiperazine peroxides, namely, 24-hydroxyverruculogen (1), 26-hydroxyverruculogen (2), and 13-O-prenyl-26-hydroxyverruculogen (3), along with four known homologues (4–7), were isolated and identified from the culture extract of the marine sediment-derived fungus Penicillium brefeldianum SD-273. Their structures were determined based on the extensive spectroscopic analysis and compound 1 was confirmed by X-ray crystallographic analysis. The absolute configuration of compounds 1–3 was determined using chiral HPLC analysis of their acidic hydrolysates. Each of the isolated compounds was evaluated for antibacterial and cytotoxic activity as well as brine shrimp (Artemia salina) lethality. PMID:24473173

  14. Analytical methods for quantitation of prenylated flavonoids from hops

    PubMed Central

    Nikolić, Dejan; van Breemen, Richard B.

    2013-01-01

    The female flowers of hops (Humulus lupulus L.) are used as a flavoring agent in the brewing industry. There is growing interest in possible health benefits of hops, particularly as estrogenic and chemopreventive agents. Among the possible active constituents, most of the attention has focused on prenylated flavonoids, which can chemically be classified as prenylated chalcones and prenylated flavanones. Among chalcones, xanthohumol (XN) and desmethylxanthohumol (DMX) have been the most studied, while among flavanones, 8-prenylnaringenin (8-PN) and 6-prenylnaringenin (6-PN) have received the most attention. Because of the interest in medicinal properties of prenylated flavonoids, there is demand for accurate, reproducible and sensitive analytical methods to quantify these compounds in various matrices. Such methods are needed, for example, for quality control and standardization of hop extracts, measurement of the content of prenylated flavonoids in beer, and to determine pharmacokinetic properties of prenylated flavonoids in animals and humans. This review summarizes currently available analytical methods for quantitative analysis of the major prenylated flavonoids, with an emphasis on the LC-MS and LC-MS-MS methods and their recent applications to biomedical research on hops. This review covers all methods in which prenylated flavonoids have been measured, either as the primary analytes or as a part of a larger group of analytes. The review also discusses methodological issues relating to the quantitative analysis of these compounds regardless of the chosen analytical approach. PMID:24077106

  15. Analytical methods for quantitation of prenylated flavonoids from hops.

    PubMed

    Nikolić, Dejan; van Breemen, Richard B

    2013-01-01

    The female flowers of hops (Humulus lupulus L.) are used as a flavoring agent in the brewing industry. There is growing interest in possible health benefits of hops, particularly as estrogenic and chemopreventive agents. Among the possible active constituents, most of the attention has focused on prenylated flavonoids, which can chemically be classified as prenylated chalcones and prenylated flavanones. Among chalcones, xanthohumol (XN) and desmethylxanthohumol (DMX) have been the most studied, while among flavanones, 8-prenylnaringenin (8-PN) and 6-prenylnaringenin (6-PN) have received the most attention. Because of the interest in medicinal properties of prenylated flavonoids, there is demand for accurate, reproducible and sensitive analytical methods to quantify these compounds in various matrices. Such methods are needed, for example, for quality control and standardization of hop extracts, measurement of the content of prenylated flavonoids in beer, and to determine pharmacokinetic properties of prenylated flavonoids in animals and humans. This review summarizes currently available analytical methods for quantitative analysis of the major prenylated flavonoids, with an emphasis on the LC-MS and LC-MS-MS methods and their recent applications to biomedical research on hops. This review covers all methods in which prenylated flavonoids have been measured, either as the primary analytes or as a part of a larger group of analytes. The review also discusses methodological issues relating to the quantitative analysis of these compounds regardless of the chosen analytical approach. PMID:24077106

  16. Synthesis of fully protected, reverse N-prenylated (2S,3R)-3-hydroxytryptophan, a unique building block of the cyclomarins.

    PubMed

    Barbie, Philipp; Kazmaier, Uli

    2015-09-21

    Reverse N-prenylated 3-hydroxytryptophan, the rather exotic amino acid of the cyclomarins, is obtained in enantio- and diastereomerically pure and fully protected form by a combination of a highly stereoselective addition of a zincated indole toward protected serinal and subsequent palladium-catalyzed N-prenylation. PMID:26229033

  17. Biochemical Characterization of Indole Prenyltransferases

    PubMed Central

    Yu, Xia; Liu, Yan; Xie, Xiulan; Zheng, Xiao-Dong; Li, Shu-Ming

    2012-01-01

    The putative prenyltransferase gene ACLA_031240 belonging to the dimethylallyltryptophan synthase superfamily was identified in the genome sequence of Aspergillus clavatus and overexpressed in Escherichia coli. The soluble His-tagged protein EAW08391 was purified to near homogeneity and used for biochemical investigation with diverse aromatic substrates in the presence of different prenyl diphosphates. It has shown that in the presence of dimethylallyl diphosphate (DMAPP), the recombinant enzyme accepted very well simple indole derivatives with l-tryptophan as the best substrate. Product formation was also observed for tryptophan-containing cyclic dipeptides but with much lower conversion yields. In contrast, no product formation was detected in the reaction mixtures of l-tryptophan with geranyl or farnesyl diphosphate. Structure elucidation of the enzyme products by NMR and MS analyses proved unequivocally the highly regiospecific regular prenylation at C-5 of the indole nucleus of the simple indole derivatives. EAW08391 was therefore termed 5-dimethylallyltryptophan synthase, and it filled the last gap in the toolbox of indole prenyltransferases regarding their prenylation positions. Km values of 5-dimethylallyltryptophan synthase were determined for l-tryptophan and DMAPP at 34 and 76 μm, respectively. Average turnover number (kcat) at 1.1 s−1 was calculated from kinetic data of l-tryptophan and DMAPP. Catalytic efficiencies of 5-dimethylallyltryptophan synthase for l-tryptophan at 25,588 s−1·m−1 and for other 11 simple indole derivatives up to 1538 s−1·m−1 provided evidence for its potential usage as a catalyst for chemoenzymatic synthesis. PMID:22123822

  18. Molecular Cloning and Functional Analysis of Gene Clusters for the Biosynthesis of Indole-Diterpenes in Penicillium crustosum and P. janthinellum

    PubMed Central

    Nicholson, Matthew J.; Eaton, Carla J.; Stärkel, Cornelia; Tapper, Brian A.; Cox, Murray P.; Scott, Barry

    2015-01-01

    The penitremane and janthitremane families of indole-diterpenes are abundant natural products synthesized by Penicillium crustosum and P. janthinellum. Using a combination of PCR, cosmid library screening, and Illumina sequencing we have identified gene clusters encoding enzymes for the synthesis of these compounds. Targeted deletion of penP in P. crustosum abolished the synthesis of penitrems A, B, D, E, and F, and led to accumulation of paspaline, a key intermediate for paxilline biosynthesis in P. paxilli. Similarly, deletion of janP and janD in P. janthinellum abolished the synthesis of prenyl-elaborated indole-diterpenes, and led to accumulation in the latter of 13-desoxypaxilline, a key intermediate for the synthesis of the structurally related aflatremanes synthesized by Aspergillus flavus. This study helps resolve the genetic basis for the complexity of indole-diterpene natural products found within the Penicillium and Aspergillus species. All indole-diterpene gene clusters identified to date have a core set of genes for the synthesis of paspaline and a suite of genes encoding multi-functional cytochrome P450 monooxygenases, FAD dependent monooxygenases, and prenyl transferases that catalyse various regio- and stereo- specific oxidations that give rise to the diversity of indole-diterpene products synthesized by this group of fungi. PMID:26213965

  19. Manipulation of prenylation reactions by structure-based engineering of bacterial indolactam prenyltransferases.

    PubMed

    Mori, Takahiro; Zhang, Lihan; Awakawa, Takayoshi; Hoshino, Shotaro; Okada, Masahiro; Morita, Hiroyuki; Abe, Ikuro

    2016-01-01

    Prenylation reactions play crucial roles in controlling the activities of biomolecules. Bacterial prenyltransferases, TleC from Streptomyces blastmyceticus and MpnD from Marinactinospora thermotolerans, catalyse the 'reverse' prenylation of (-)-indolactam V at the C-7 position of the indole ring with geranyl pyrophosphate or dimethylallyl pyrophosphate, to produce lyngbyatoxin or pendolmycin, respectively. Using in vitro analyses, here we show that both TleC and MpnD exhibit relaxed substrate specificities and accept various chain lengths (C5-C25) of the prenyl donors. Comparisons of the crystal structures and their ternary complexes with (-)-indolactam V and dimethylallyl S-thiophosphate revealed the intimate structural details of the enzyme-catalysed 'reverse' prenylation reactions and identified the active-site residues governing the selection of the substrates. Furthermore, structure-based enzyme engineering successfully altered the preference for the prenyl chain length of the substrates, as well as the regio- and stereo-selectivities of the prenylation reactions, to produce a series of unnatural novel indolactams. PMID:26952246

  20. Manipulation of prenylation reactions by structure-based engineering of bacterial indolactam prenyltransferases

    NASA Astrophysics Data System (ADS)

    Mori, Takahiro; Zhang, Lihan; Awakawa, Takayoshi; Hoshino, Shotaro; Okada, Masahiro; Morita, Hiroyuki; Abe, Ikuro

    2016-03-01

    Prenylation reactions play crucial roles in controlling the activities of biomolecules. Bacterial prenyltransferases, TleC from Streptomyces blastmyceticus and MpnD from Marinactinospora thermotolerans, catalyse the `reverse' prenylation of (-)-indolactam V at the C-7 position of the indole ring with geranyl pyrophosphate or dimethylallyl pyrophosphate, to produce lyngbyatoxin or pendolmycin, respectively. Using in vitro analyses, here we show that both TleC and MpnD exhibit relaxed substrate specificities and accept various chain lengths (C5-C25) of the prenyl donors. Comparisons of the crystal structures and their ternary complexes with (-)-indolactam V and dimethylallyl S-thiophosphate revealed the intimate structural details of the enzyme-catalysed `reverse' prenylation reactions and identified the active-site residues governing the selection of the substrates. Furthermore, structure-based enzyme engineering successfully altered the preference for the prenyl chain length of the substrates, as well as the regio- and stereo-selectivities of the prenylation reactions, to produce a series of unnatural novel indolactams.

  1. Manipulation of prenylation reactions by structure-based engineering of bacterial indolactam prenyltransferases

    PubMed Central

    Mori, Takahiro; Zhang, Lihan; Awakawa, Takayoshi; Hoshino, Shotaro; Okada, Masahiro; Morita, Hiroyuki; Abe, Ikuro

    2016-01-01

    Prenylation reactions play crucial roles in controlling the activities of biomolecules. Bacterial prenyltransferases, TleC from Streptomyces blastmyceticus and MpnD from Marinactinospora thermotolerans, catalyse the ‘reverse' prenylation of (−)-indolactam V at the C-7 position of the indole ring with geranyl pyrophosphate or dimethylallyl pyrophosphate, to produce lyngbyatoxin or pendolmycin, respectively. Using in vitro analyses, here we show that both TleC and MpnD exhibit relaxed substrate specificities and accept various chain lengths (C5–C25) of the prenyl donors. Comparisons of the crystal structures and their ternary complexes with (−)-indolactam V and dimethylallyl S-thiophosphate revealed the intimate structural details of the enzyme-catalysed ‘reverse' prenylation reactions and identified the active-site residues governing the selection of the substrates. Furthermore, structure-based enzyme engineering successfully altered the preference for the prenyl chain length of the substrates, as well as the regio- and stereo-selectivities of the prenylation reactions, to produce a series of unnatural novel indolactams. PMID:26952246

  2. Prenylated flavones from Artocarpus altilis.

    PubMed

    Shamaun, Shireen Shaharina; Rahmani, Mawardi; Hashim, Najihah Mohd; Ismail, Hazar Bebe Mohd; Sukari, Mohd Aspollah; Lian, Gwendoline Ee Cheng; Go, Rusea

    2010-10-01

    Six prenylated flavones, including one new compound, were isolated and identified from the stem bark extracts of Artocarpus altilis. The new prenylated flavone hydroxyartocarpin (1) was characterized as 3-(gamma,gamma-dimethylallyl)-6-isopentenyl-5,8,2',4'-tetrahydroxy-7-methoxyflavone and the known compounds were artocarpin (2), morusin (3), cycloartobiloxanthone (4), cycloartocarpin A (5) and artoindonesianin V (6). The structures of the compounds were determined by spectroscopic methods (IR, MS, (1)H-NMR and (13)C-NMR) and comparison with published data for the known compounds. PMID:20526745

  3. A simple method for simultaneous RP-HPLC determination of indolic compounds related to bacterial biosynthesis of indole-3-acetic acid.

    PubMed

    Szkop, Michał; Bielawski, Wiesław

    2013-03-01

    In this short technical report, we present a fast and simple procedure for sample preparation and a single-run Reversed Phase High Performance Liquid Chromatography (RP-HPLC) determination of seven indoles (indole-3-acetic acid, indole-3-acetamide, indole-3-acetonitrile, indole-3-ethanol, indole-3-lactic acid, tryptamine and tryptophan) in bacterial culture supernatants. The separation of the analytes, after a single centrifugal filtration clean-up step, was performed using a gradient elution on a symmetry C8 column followed by fluorimetric detection (λ(ex) = 280/λ(em) = 350 nm). The calibration curves were linear for all of the studied compounds over the concentration range of 0.0625-125 μg mL(-1) (r ( 2 ) ≥ 0.998) and the limits of detection were below 0.015 μg mL(-1). The applicability of the method was confirmed by analysis of Pseudomonas putida culture supernatants. PMID:23111785

  4. Palladium-Catalyzed Oxidative Sulfenylation of Indoles and Related Electron-Rich Heteroarenes with Aryl Boronic Acids and Elemental Sulfur.

    PubMed

    Li, Jianxiao; Li, Chunsheng; Yang, Shaorong; An, Yanni; Wu, Wanqing; Jiang, Huanfeng

    2016-09-01

    An efficient and convenient palladium-catalyzed C-H bond oxidative sulfenylation of indoles and related electron-rich heteroarenes with aryl boronic acids and elemental sulfur has been described. This procedure provides a useful and direct approach for the assembly of a wide range of structurally diverse 3-sulfenylheteroarenes with moderate to excellent yields from simple and readily available starting materials. Moreover, this synthetic protocol is suitable for N-protected and unprotected indoles. Notably, the construction of two C-S bonds in one step was also achieved in this transformation. PMID:27500941

  5. Synthetic approaches to the bicyclo[2.2.2]diazaoctane ring system common to the paraherquamides, stephacidins and related prenylated indole alkaloids.

    PubMed

    Miller, Kenneth A; Williams, Robert M

    2009-11-01

    The bicyclo[2.2.2]diazaoctane ring system is common to a number of highly biologically active secondary metabolites isolated from numerous species of fungi. In this tutorial review, we describe the varied synthetic approaches that have been employed to construct this ring system in the course of recent total synthesis endeavors, and this review should be of interest to synthetic organic chemists and natural product chemists. Detailed herein are a number of synthetic disconnections including intramolecular S(N)2' cyclizations, biomimetic Diels-Alder reactions, radical cyclizations, and cationic cascade reactions. PMID:19847349

  6. Measurements of serotonin and related indoles using capillary electrophoresis with multiphoton-induced hyperluminescence.

    PubMed

    Gostkowski, M L; Wei, J; Shear, J B

    1998-07-01

    We report the use of multiphoton-excited photochemistry to generate highly fluorescent products from hydroxyindoles fractionated in submicron capillary electrophoresis channels. In this approach, the near-infrared (750 nm) output from a modelocked titanium:sapphire laser is focused at the outlet of a 0.6-micron i.d. capillary, producing pulse intensities of approximately 10(12) W cm-2 within a femtoliter focal volume. Hydroxyindole molecules migrating through the outlet aperture of the capillary intersect the beam focus, where absorption of three to four photons (approximately 1.65 eV photon-1) initiates a photobleaching reaction. The resultant hydroxyindole photoproducts produce broadband visible emission (lambdamax approximately 500 nm) when excited with two additional near-IR photons and appear substantially more resistant to photobleaching than the parent hydroxyindoles. This multiphoton-induced conversion of analytes to hyperluminescent derivatives thus offers a more sensitive approach than UV fluorescence for detecting extremely small quantities of material. Mixtures of the hydroxyindoles serotonin (5-hydroxytryptamine), 5-hydroxytryptophan, and 5-hydroxyindole acetic acid are reliably characterized (relative error approximately 10%) in 100 s, with detection limits as low as approximately 70 zmol (approximately 42,000 molecules). The sensitivity of this measurement strategy improves on the best previously reported results for capillary separations of indoles by more than one order of magnitude. PMID:9657885

  7. Diurnal profiles of melatonin synthesis-related indoles, catecholamines and their metabolites in the duck pineal organ.

    PubMed

    Lewczuk, Bogdan; Ziółkowska, Natalia; Prusik, Magdalena; Przybylska-Gornowicz, Barbara

    2014-01-01

    This study characterizes the diurnal profiles of ten melatonin synthesis-related indoles, the quantitative relations between these compounds, and daily variations in the contents of catecholamines and their metabolites in the domestic duck pineal organ. Fourteen-week-old birds, which were reared under a 12L:12D cycle, were killed at two-hour intervals. The indole contents were measured using HPLC with fluorescence detection, whereas the levels of catecholamines and their metabolites were measured using HPLC with electrochemical detection. All indole contents, except for tryptophan, showed significant diurnal variations. The 5-hydroxytryptophan level was approximately two-fold higher during the scotophase than during the photophase. The serotonin content increased during the first half of the photophase, remained elevated for approximately 10 h and then rapidly decreased in the middle of the scotophase. N-acetylserotonin showed the most prominent changes, with a more than 15-fold increase at night. The melatonin cycle demonstrated only an approximately 5-fold difference between the peak and nadir. The 5-methoxytryptamine content was markedly elevated during the scotophase. The 5-hydroxyindole acetic acid, 5-hydroxytryptophol, 5-methoxyindole acetic acid and 5-methoxytryptophol profiles were analogous to the serotonin rhythm. The norepinephrine and dopamine contents showed no significant changes. The DOPA, DOPAC and homovanillic acid levels were higher during the scotophase than during the photophase. Vanillylmandelic acid showed the opposite rhythm, with an elevated level during the daytime. PMID:25032843

  8. Diurnal Profiles of Melatonin Synthesis-Related Indoles, Catecholamines and Their Metabolites in the Duck Pineal Organ

    PubMed Central

    Lewczuk, Bogdan; Ziółkowska, Natalia; Prusik, Magdalena; Przybylska-Gornowicz, Barbara

    2014-01-01

    This study characterizes the diurnal profiles of ten melatonin synthesis-related indoles, the quantitative relations between these compounds, and daily variations in the contents of catecholamines and their metabolites in the domestic duck pineal organ. Fourteen-week-old birds, which were reared under a 12L:12D cycle, were killed at two-hour intervals. The indole contents were measured using HPLC with fluorescence detection, whereas the levels of catecholamines and their metabolites were measured using HPLC with electrochemical detection. All indole contents, except for tryptophan, showed significant diurnal variations. The 5-hydroxytryptophan level was approximately two-fold higher during the scotophase than during the photophase. The serotonin content increased during the first half of the photophase, remained elevated for approximately 10 h and then rapidly decreased in the middle of the scotophase. N-acetylserotonin showed the most prominent changes, with a more than 15-fold increase at night. The melatonin cycle demonstrated only an approximately 5-fold difference between the peak and nadir. The 5-methoxytryptamine content was markedly elevated during the scotophase. The 5-hydroxyindole acetic acid, 5-hydroxytryptophol, 5-methoxyindole acetic acid and 5-methoxytryptophol profiles were analogous to the serotonin rhythm. The norepinephrine and dopamine contents showed no significant changes. The DOPA, DOPAC and homovanillic acid levels were higher during the scotophase than during the photophase. Vanillylmandelic acid showed the opposite rhythm, with an elevated level during the daytime. PMID:25032843

  9. Prenylated benzophenones from Triadenum japonicum.

    PubMed

    Oya, Atsushi; Tanaka, Naonobu; Kusama, Taishi; Kim, Sang-Yong; Hayashi, Shigeki; Kojoma, Mareshige; Hishida, Atsuyuki; Kawahara, Nobuo; Sakai, Kanae; Gonoi, Tohru; Kobayashi, Jun'ichi

    2015-02-27

    Six new prenylated benzophenones, (-)-nemorosonol (1) and trijapins A-E (2-6), were isolated from the aerial parts of Triadenum japonicum. (-)-Nemorosonol (1) and trijapins A-C (2-4) have a common tricyclo[4.3.1.0(3,7)]decane skeleton, while 1 is an enantiomer of (+)-nemorosonol previously isolated from Clusia nemorosa. The absolute configuration of (-)-nemorosonol (1) was assigned by ECD spectroscopy. Trijapins A-C (2-4) are analogues of 1 possessing an additional tetrahydrofuran ring. Trijapins D (5) and E (6) are prenylated benzophenones with a 1,2-dioxane moiety and a hydroperoxy group, respectively. (-)-Nemorosonol (1) exhibited antimicrobial activity against Escherichia coli (MIC, 8 μg/mL), Staphylococcus aureus (MIC, 16 μg/mL), Bacillus subtilis (MIC, 16 μg/mL), Micrococcus luteus (MIC, 32 μg/mL), Aspergillus niger (IC50, 16 μg/mL), Trichophyton mentagrophytes (IC50, 8 μg/mL), and Candida albicans (IC50, 32 μg/mL), while trijapin D (5) showed antimicrobial activity against C. albicans (IC50, 8 μg/mL). PMID:25602977

  10. Indole-3-carbinol protects against cisplatin-induced acute nephrotoxicity: role of calcitonin gene-related peptide and insulin-like growth factor-1

    PubMed Central

    El-Naga, Reem N.; Mahran, Yasmen F.

    2016-01-01

    Nephrotoxicity associated with the clinical use of the anticancer drug cisplatin is a limiting problem. Thus, searching for new protective measures is required. Indole-3-carbinol is a powerful anti-oxidant, anti-inflammatory and anti-tumor agent. The present study aimed to investigate the potential protective effect of indole-3-carbinol against cisplatin-induced acute nephrotoxicity in rats. Rats were pre-treated with 20 mg/kg indole-3-carbinol orally before giving cisplatin (7 mg/kg). Cisplatin-induced acute nephrotoxicity was demonstrated where relative kidney weight, BUN and serum creatinine were significantly increased. Increased oxidative stress was evident in cisplatin group where GSH and SOD tissue levels were significantly depleted. Also, lipid peroxidation and NOX-1 were increased as compared to the control. Additionally, renal expression of pro-inflammatory mediators was induced by cisplatin. Cisplatin-induced cell death was shown by increased caspase-3 and decreased expression of EGF, IGF-1 and IGF-1 receptor. Nephrotoxicity, oxidative stress, inflammation and apoptotic effects induced by cisplatin were significantly ameliorated by indole-3-carbinol pre-treatment. Besides, the role of CGRP in cisplatin-induced nephrotoxicity was explored. Furthermore, cisplatin cytotoxic activity was significantly enhanced by indole-3-carbinol pre-treatment in vitro. In conclusion, indole-3-carbinol provides protection against cisplatin-induced nephrotoxicity. Also, reduced expression of CGRP may play a role in the pathogenesis of cisplatin-induced renal injury. PMID:27417335

  11. Indole-3-carbinol protects against cisplatin-induced acute nephrotoxicity: role of calcitonin gene-related peptide and insulin-like growth factor-1.

    PubMed

    El-Naga, Reem N; Mahran, Yasmen F

    2016-01-01

    Nephrotoxicity associated with the clinical use of the anticancer drug cisplatin is a limiting problem. Thus, searching for new protective measures is required. Indole-3-carbinol is a powerful anti-oxidant, anti-inflammatory and anti-tumor agent. The present study aimed to investigate the potential protective effect of indole-3-carbinol against cisplatin-induced acute nephrotoxicity in rats. Rats were pre-treated with 20 mg/kg indole-3-carbinol orally before giving cisplatin (7 mg/kg). Cisplatin-induced acute nephrotoxicity was demonstrated where relative kidney weight, BUN and serum creatinine were significantly increased. Increased oxidative stress was evident in cisplatin group where GSH and SOD tissue levels were significantly depleted. Also, lipid peroxidation and NOX-1 were increased as compared to the control. Additionally, renal expression of pro-inflammatory mediators was induced by cisplatin. Cisplatin-induced cell death was shown by increased caspase-3 and decreased expression of EGF, IGF-1 and IGF-1 receptor. Nephrotoxicity, oxidative stress, inflammation and apoptotic effects induced by cisplatin were significantly ameliorated by indole-3-carbinol pre-treatment. Besides, the role of CGRP in cisplatin-induced nephrotoxicity was explored. Furthermore, cisplatin cytotoxic activity was significantly enhanced by indole-3-carbinol pre-treatment in vitro. In conclusion, indole-3-carbinol provides protection against cisplatin-induced nephrotoxicity. Also, reduced expression of CGRP may play a role in the pathogenesis of cisplatin-induced renal injury. PMID:27417335

  12. Synthesis and biological activities of aminopyrimidyl-indoles structurally related to meridianins.

    PubMed

    Akue-Gedu, Rufine; Debiton, Eric; Ferandin, Yoan; Meijer, Laurent; Prudhomme, Michelle; Anizon, Fabrice; Moreau, Pascale

    2009-07-01

    The synthesis of new meridianin derivatives substituted at the C-5 position of the 2-aminopyrimidine ring by various aryl groups and substituted or not by a methyl group on the indole nitrogen is described. These compounds were tested for their kinase inhibitory potencies toward five kinases (CDK5/p25, CK1delta/epsilon, GSK-3alpha/beta, Dyrk1A and Erk2) as well as their in vitro antiproliferative activities toward a human fibroblast primary culture and two human solid cancer cell lines (MCF-7 and PA 1). PMID:19477650

  13. Ste24p Mediates Proteolysis of Both Isoprenylated and Non-prenylated Oligopeptides.

    PubMed

    Hildebrandt, Emily R; Arachea, Buenafe T; Wiener, Michael C; Schmidt, Walter K

    2016-07-01

    Rce1p and Ste24p are integral membrane proteins involved in the proteolytic maturation of isoprenylated proteins. Extensive published evidence indicates that Rce1p requires the isoprenyl moiety as an important substrate determinant. By contrast, we report that Ste24p can cleave both isoprenylated and non-prenylated substrates in vitro, indicating that the isoprenyl moiety is not required for substrate recognition. Steady-state enzyme kinetics are significantly different for prenylated versus non-prenylated substrates, strongly suggestive of a role for substrate-membrane interaction in protease function. Mass spectroscopy analyses identify a cleavage preference at bonds where P1' is aliphatic in both isoprenylated and non-prenylated substrates, although this is not necessarily predictive. The identified cleavage sites are not at a fixed distance position relative to the C terminus. In this study, the substrates cleaved by Ste24p are based on known isoprenylated proteins (i.e. K-Ras4b and the yeast a-factor mating pheromone) and non-prenylated biological peptides (Aβ and insulin chains) that are known substrates of the M16A family of soluble zinc-dependent metalloproteases. These results establish that the substrate profile of Ste24p is broader than anticipated, being more similar to that of the M16A protease family than that of the Rce1p CAAX protease with which it has been functionally associated. PMID:27129777

  14. Site-directed Mutagenesis Switching a Dimethylallyl Tryptophan Synthase to a Specific Tyrosine C3-Prenylating Enzyme*

    PubMed Central

    Fan, Aili; Zocher, Georg; Stec, Edyta; Stehle, Thilo; Li, Shu-Ming

    2015-01-01

    The tryptophan prenyltransferases FgaPT2 and 7-DMATS (7-dimethylallyl tryptophan synthase) from Aspergillus fumigatus catalyze C4- and C7-prenylation of the indole ring, respectively. 7-DMATS was found to accept l-tyrosine as substrate as well and converted it to an O-prenylated derivative. An acceptance of l-tyrosine by FgaPT2 was also observed in this study. Interestingly, isolation and structure elucidation revealed the identification of a C3-prenylated l-tyrosine as enzyme product. Molecular modeling and site-directed mutagenesis led to creation of a mutant FgaPT2_K174F, which showed much higher specificity toward l-tyrosine than l-tryptophan. Its catalytic efficiency toward l-tyrosine was found to be 4.9-fold in comparison with that of non-mutated FgaPT2, whereas the activity toward l-tryptophan was less than 0.4% of that of the wild-type. To the best of our knowledge, this is the first report on an enzymatic C-prenylation of l-tyrosine as free amino acid and altering the substrate preference of a prenyltransferase by mutagenesis. PMID:25477507

  15. Humudifucol and Bioactive Prenylated Polyphenols from Hops (Humulus lupulus cv. "Cascade").

    PubMed

    Forino, Martino; Pace, Simona; Chianese, Giuseppina; Santagostini, Laura; Werner, Markus; Weinigel, Christina; Rummler, Silke; Fico, Gelsomina; Werz, Oliver; Taglialatela-Scafati, Orazio

    2016-03-25

    Humulus lupulus (hop plant) has long been used in traditional medicine as a sedative and antimicrobial agent. More recently, attention has been devoted to the phytoestrogenic activity of the plant extracts as well as to the anti-inflammatory and chemopreventive properties of the prenylated chalcones present. In this study, an Italian sample of H. lupulus cv. "Cascade" has been investigated and three new compounds [4-hydroxycolupulone (6), humudifucol (7) and cascadone (8)] have been purified and identified by means of NMR spectroscopy along with four known metabolites. Notably, humudifucol (7) is the first prenylated dimeric phlorotannin discovered in nature. Because structurally related phloroglucinols from natural sources were found previously to inhibit microsomal prostaglandin E2 synthase (mPGES)-1 and 5-lipoxygenase (5-LO), the isolated compounds were evaluated for their bioactivity against these pro-inflammatory target proteins. The prenylated chalcone xanthohumol inhibited both enzymes at low μM concentrations. PMID:26918635

  16. Statin Treatment Increases Lifespan and Improves Cardiac Health in Drosophila by Decreasing Specific Protein Prenylation

    PubMed Central

    Spindler, Stephen R.; Li, Rui; Dhahbi, Joseph M.; Yamakawa, Amy; Mote, Patricia; Bodmer, Rolf; Ocorr, Karen; Williams, Renee T.; Wang, Yinsheng; Ablao, Kenneth P.

    2012-01-01

    Statins such as simvastatin are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and standard therapy for the prevention and treatment of cardiovascular diseases in mammals. Here we show that simvastatin significantly increased the mean and maximum lifespan of Drosophila melanogaster (Drosophila) and enhanced cardiac function in aging flies by significantly reducing heart arrhythmias and increasing the contraction proportion of the contraction/relaxation cycle. These results appeared independent of internal changes in ubiquinone or juvenile hormone levels. Rather, they appeared to involve decreased protein prenylation. Simvastatin decreased the membrane association (prenylation) of specific small Ras GTPases in mice. Both farnesyl (L744832) and type 1 geranylgeranyl transferase (GGTI-298) inhibitors increased Drosophila lifespan. These data are the most direct evidence to date that decreased protein prenylation can increase cardiac health and lifespan in any metazoan species, and may explain the pleiotropic (non-cholesterol related) health effects of statins. PMID:22737247

  17. Properties of Rab5 N-terminal domain dictate prenylation of C-terminal cysteines.

    PubMed Central

    Sanford, J C; Pan, Y; Wessling-Resnick, M

    1995-01-01

    Rab5 is a Ras-related GTP-binding protein that is post-translationally modified by prenylation. We report here that an N-terminal domain contained within the first 22 amino acids of Rab5 is critical for efficient geranylgeranylation of the protein's C-terminal cysteines. This domain is immediately upstream from the "phosphate binding loop" common to all GTP-binding proteins and contains a highly conserved sequence recognized among members of the Rab family, referred to here as the YXYLFK motif. A truncation mutant that lacks this domain (Rab5(23-215) fails to become prenylated. However, a chimeric peptide with the conserved motif replacing cognate Rab5 sequence (MAYDYLFKRab5(23-215) does become post-translationally modified, demonstrating that the presence of this simple six amino acid N-terminal element enables prenylation at Rab5's C-terminus. H-Ras/Rab5 chimeras that include the conserved YXYLFK motif at the N-terminus do not become prenylated, indicating that, while this element may be necessary for prenylation of Rab proteins, it alone is not sufficient to confer properties to a heterologous protein to enable substrate recognition by the Rab geranylgeranyl transferase. Deletion analysis and studies of point mutants further reveal that the lysine residue of the YXYLFK motif is an absolute requirement to enable geranylgeranylation of Rab proteins. Functional studies support the idea that this domain is not required for guanine nucleotide binding since prenylation-defective mutants still bind GDP and are protected from protease digestion in the presence of GTP gamma S. We conclude that the mechanism of Rab geranylgeranylation involves key elements of the protein's tertiary structure including a conserved N-terminal amino acid motif (YXYLFK) that incorporates a critical lysine residue. Images PMID:7749197

  18. Parallel analysis of volatile fatty acids, indole, skatole, phenol, and trimethylamine from waste-related source environments.

    PubMed

    Rahman, Md Mahmudur; Kim, Ki-Hyun

    2013-11-01

    An experimental technique based on sorbent tube-thermal desorption-gas chromatography (ST-TD-GC) was investigated for the simultaneous determination of a cluster of eight volatile odorants (propionic acid, n-butyric acid, i-valeric acid, n-valeric acid, trimethylamine, phenol, indole, and skatole) and a reference compound (benzene). Calibration was made by direct injection of a liquid working standard (L-WS) into a quartz tube packed with three bed sorbent (Tenax TA, Carbopack B, and Carbopack X). To assess the relative performance between different detector systems, a comparative analysis was made using both mass spectrometry (MS) and a flame ionization detector (FID) with the aid of a TD system. In the TD-GC-MS analysis, calibration results were evaluated in two different modes, namely total ion chromatogram (TIC) and extracted ion chromatogram (EIC). In both FID and MS, the elution order of investigated odorants complied with the retention time index (RTI) values for the polar column with a coefficient of determination (R(2)) at or above 0.99. As a means to validate our detection approach, environmental samples from a bathroom and manhole (vacuum samples) as well as cat stool and wastewater (headspace samples) were also collected. The ST-TD method tested for the concurrent analysis of diverse odorants allowed us to measure a list of offensive odorants from those samples. PMID:24070624

  19. Five new prenylated chalcones from Desmodium renifolium.

    PubMed

    Li, Yan-Ping; Yang, Yu-Chun; Li, Yin-Ke; Jiang, Zhi-Yong; Huang, Xiang-Zhong; Wang, Wei-Guang; Gao, Xue-Mei; Hu, Qiu-Fen

    2014-06-01

    Five unusual new prenylated chalcones, renifolins D-H (1-5), were isolated from whole Desmodium renifolium plants. All of their structures were determined by spectroscopic methods including 1D and 2D NMR. All of the isolates were evaluated for cytotoxicity using five tumor cell lines. Compounds 2 and 3 exhibited cytotoxicity against A549 cells, with IC50 values of 2.8 and 2.2 μM, respectively. PMID:24704553

  20. Breast cancer cell targeting by prenylation inhibitors elucidated in living animals with a bioluminescence reporter

    PubMed Central

    Chinault, Sharon L.; Prior, Julie L.; Kaltenbronn, Kevin M.; Penly, Anya; Weilbaecher, Katherine N.; Piwnica-Worms, David; Blumer, Kendall J.

    2013-01-01

    Purpose Inhibitors of protein prenylation, including prenyltransferase inhibitors and aminobisphosphonates such as zoledronic acid, are being investigated intensively as therapeutics in cancer and other diseases. Determining whether prenylation inhibitors directly or indirectly target tumor and/or host cells is key to understanding therapeutic mechanisms. Experimental Design To determine which cell types can be targeted directly by distinct classes of prenylation inhibitors in vivo, we describe herein the development and implementation of a sensitive and pharmacologically specific bioluminescence-based imaging reporter that is inducible by prenylation inhibitors. Results In mouse xenograft models of breast cancer using reporter-bearing mammary fat pad- or bone-localized tumor cells, we show that a prenyltransferase inhibitor robustly induces reporter activity in vivo. In contrast, zoledronic acid, a bone-associated aminobisphosphonate that exerts adjuvant chemotherapeutic activity in breast cancer patients, fails to induce reporter activity in tumor cells of either model. Conclusions Whereas a prenyltransferase inhibitor can directly target breast cancer cells in vivo, zoledronic acid and related aminobisphosphonates are likely to exert anti-tumor activity indirectly by targeting host cells. Accordingly, these findings shift attention toward the goal of determining which host cell types are targeted directly by aminobisphosphonates to exert adjuvant chemotherapeutic activity. PMID:22693355

  1. Interaction of prenylated chalcones and flavanones from common hop with phosphatidylcholine model membranes.

    PubMed

    Wesołowska, Olga; Gąsiorowska, Justyna; Petrus, Joanna; Czarnik-Matusewicz, Bogusława; Michalak, Krystyna

    2014-01-01

    Common hop (Humulus lupulus) constitutes a source of numerous prenylated chalcones such as xanthohumol (XH) and flavanones such as 8-prenylnaringenin (8-PN) and isoxanthohumol (IXH). Range of their biological activities includes estrogenic, anti-inflammatory, anti-infective, anti-cancer, and antioxidant activities. The aim of the present work was to characterize the influence of prenylated polyphenols on model 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) membranes by means of differential scanning calorimetry (DSC), fluorescence and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopies. All studied compounds intercalated into DPPC bilayers and decreased its melting temperature as recorded by DSC, Laurdan and Prodan fluorescence, and ATR-FTIR. Polyphenols interacted mainly with glycerol backbone and acyl chain region of membrane. Magnitude of the induced effect correlated both with lipophilicity and molecular shape of the studied compounds. Elbow-shaped 8-PN and IXH were locked at polar-apolar region with their prenyl chains penetrating into hydrophobic part of the bilayer, while relatively planar XH molecule adopted linear shape that resulted in its deeper insertion into hydrophobic region. Additionally, by means of DSC and Laurdan fluorescence IXH was demonstrated to induce lateral phase separation in DPPC bilayers in gel-like state. It was assumed that IXH-rich and IXH-poor microdomains appeared within membrane. Present work constitutes the first experimental report describing interactions of prenylated hop polyphenols with phospholipid model membranes. PMID:24060562

  2. Structures of RabGGTase-substrate/product complexes provide insights into the evolution of protein prenylation.

    PubMed

    Guo, Zhong; Wu, Yao-Wen; Das, Debapratim; Delon, Christine; Cramer, Janinna; Yu, Shen; Thuns, Sandra; Lupilova, Nataliya; Waldmann, Herbert; Brunsveld, Luc; Goody, Roger S; Alexandrov, Kirill; Blankenfeldt, Wulf

    2008-09-17

    Post-translational isoprenylation of proteins is carried out by three related enzymes: farnesyltransferase, geranylgeranyl transferase-I, and Rab geranylgeranyl transferase (RabGGTase). Despite the fact that the last one is responsible for the largest number of individual protein prenylation events in the cell, no structural information is available on its interaction with substrates and products. Here, we present structural and biophysical analyses of RabGGTase in complex with phosphoisoprenoids as well as with the prenylated peptides that mimic the C terminus of Rab7 GTPase. The data demonstrate that, unlike other protein prenyl transferases, both RabGGTase and its substrate RabGTPases completely 'outsource' their specificity for each other to an accessory subunit, the Rab escort protein (REP). REP mediates the placement of the C terminus of RabGTPase into the active site of RabGGTase through a series protein-protein interactions of decreasing strength and selectivity. This arrangement enables RabGGTase to prenylate any cysteine-containing sequence. On the basis of our structural and thermodynamic data, we propose that RabGGTase has evolved from a GGTase-I-like molecule that 'learned' to interact with a recycling factor (GDI) that, in turn, eventually gave rise to REP. PMID:18756270

  3. Farnesol-mediated shift in the metabolic origin of prenyl groups used for protein prenylation in plants.

    PubMed

    Huchelmann, Alexandre; Brahim, Mathieu Semir; Gerber, Esther; Tritsch, Denis; Bach, Thomas J; Hemmerlin, Andréa

    2016-08-01

    Little is known about how plant cells regulate the exchange of prenyl diphosphates between the two compartmentalized isoprenoid biosynthesis pathways. Prenylation of proteins is a suitable model to study such interactions between the plastidial methylerythritol phosphate (MEP) and the cytosolic mevalonate (MVA) pathways because prenyl moieties used to modify proteins rely on both origins. Tobacco cells expressing a prenylatable GFP were treated with specific MEP and/or MVA pathways inhibitors to block the formation of prenyl diphosphates and therefore the possibility to modify the proteins. Chemical complementation assays using prenyl alcohol precursors restore the prenylation. Indeed, geranylgeraniol (C20 prenyl alcohol) and to a lesser but significant level C15-farnesol restored the prenylation of a protein bearing a geranylgeranylation CaaX motif, which under standard conditions is modified by a MEP-derived prenyl group. However, the restoration takes place in different ways. While geranylgeraniol operates directly as a metabolic precursor, the C15-prenyl alcohol functions indirectly as a signal that leads to shift the metabolic origin of prenyl groups in modified proteins, here from the plastidial MEP pathway in favor of the cytosolic MVA pathway. Furthermore, farnesol interferes negatively with the MEP pathway in an engineered Escherichia coli strain synthesizing isoprenoids either starting from MVA or from MEP. Following the cellular uptake of a fluorescent analog of farnesol, we showed its close interaction with tobacco plastids and modification of plastid homeostasis. As a consequence, in tobacco farnesol supposedly inhibits the plastidial MEP pathway and activates the cytosolic MVA pathway, leading to the shift in the metabolic origin and thereby acts as a potential regulator of crosstalk between the two pathways. Together, those results suggest a new role for farnesol (or a metabolite thereof) as a central molecule for the regulation of isoprenoid

  4. Prenyl Ethers: Novel Fungal Volatiles Formed by Penicillium digitatum.

    PubMed

    Amrein, Thomas M; Frey, Peter; Meier, Roberto; Baumann, Heidi; Tanner, Miriam; Gassenmeier, Klaus F

    2014-10-01

    Prenyl ethyl ether (PEE) was previously described as the cause for a solvent-like off-note in ground hazelnuts, but its origin remained unclear. Investigations were carried out by analytical groups of Coop and Givaudan over four years to elucidate this phenomenon. From mouldy citrus fruits a strain of Penicillium digitatum was isolated and found to form PEE. Formation on citrus and other fruits was prominent and contributed to the particular smell of decayed fruits. Several strains of P. digitatum formed PEE, while other fungal species did not. In contrast to citrus fruit, prenyl methyl ether (PME) was formed as dominant prenyl ether on hazelnuts while only small amounts of PEE were found. PME has not been previously described as volatile metabolite of fungi or as a food-taint. Spiking experiments with deuterated ethanol showed that the ethyl group is likely incorporated into PEE via the aldehyde form. On hazelnuts strongly decayed by P. digitatum yet another prenyl ether was tentatively identified: Prenyl isopropyl ether. Prenyl ethers present a novel group of volatile metabolites of P. digitatum. They are likely typical for this species and have not been described before. Prenyl ethers seem to play a significant role in the smell of food decayed by P. digitatum and should be considered in cases of off-notes and taints. PMID:25437159

  5. Cytotoxic prenylated bibenzyls and flavonoids from Macaranga kurzii.

    PubMed

    Yang, Da-Song; Wei, Jian-Guo; Peng, Wei-Bing; Wang, Shuang-Mei; Sun, Chen; Yang, Yong-Ping; Liu, Ke-Chun; Li, Xiao-Li

    2014-12-01

    One unique prenylated bibenzyl, kurzphenol A (1), two new prenylated flavonoids, kurzphenols B and C (2 and 3), as well as fourteen known compounds (4-17) were isolated from the twigs of Macaranga kurzii. Compound 1 was the first example of prenylated bibenzyl which possesses a benzofuran ring. All the known compounds were isolated from M. kurzii for the first time. Their structures were elucidated on the basis of extensive spectroscopic interpretation. Compounds 1-17 were tested for their cytotoxicity against A-549 and Hep G2 cancer cell lines and showed IC50 values in the range of 9.76-30.14 μg/mL. PMID:25446044

  6. Marine Indole Alkaloids.

    PubMed

    Netz, Natalie; Opatz, Till

    2015-08-01

    Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed. PMID:26287214

  7. Marine Indole Alkaloids

    PubMed Central

    Netz, Natalie; Opatz, Till

    2015-01-01

    Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed. PMID:26287214

  8. A new prenylated biflavonoid from the leaves of Garcinia dulcis.

    PubMed

    Saelee, Arun; Phongpaichit, Souwalak; Mahabusarakam, Wilawan

    2015-01-01

    A new prenylated biflavonoid, named dulcisbiflavonoid A, together with five biflavonoids were isolated from the leaves of Garcinia dulcis. Their structures were elucidated by analysing their spectroscopic data, especially 1D and 2D NMR. PMID:25675112

  9. Pharmacokinetics of Prenylated Hop Phenols in Women Following Oral Administration of a Standardized Extract of Hops

    PubMed Central

    van Breemen, Richard B.; Yuan, Yang; Banuvar, Suzanne; Shulman, Lee P.; Qiu, Xi; Alvarenga, René F. Ramos; Chen, Shao-Nong; Dietz, Birgit M.; Bolton, Judy L.; Pauli, Guido F.; Krause, Elizabeth; Viana, Marlos; Nikolic, Dejan

    2014-01-01

    SCOPE Women seeking alternatives to hormone replacement therapy for menopausal symptoms often try botanical dietary supplements containing extracts of hops (Humulus lupulus L.). Hops contain 8-prenylnaringenin (8-PN), a potent phytoestrogen, the related flavanones 6-prenylnaringenin (6-PN) and isoxanthohumol (IX), and the prenylated chalcone xanthohumol (XN). METHODS AND RESULTS After chemically and biologically standardizing an extract of spent hops to these marker compounds, an escalating dose study was carried out in menopausal women to evaluate safety and pharmacokinetics. 8-PN, 6-PN, IX, and XN, sex hormones, and prothrombin time (PT/INR) were determined in blood samples and/or 24-h urine samples. There was no effect on sex hormones or blood clotting. The maximum serum concentrations of the prenylated phenols were dose-dependent and were reached from 2 to 7 h, indicating slow absorption. The marker compounds formed glucuronides that were found in serum and urine. Secondary peaks at 5 h in the serum concentration-time curves indicated enterohepatic recirculation. The serum concentration-time curves indicated demethylation of IX to form 8-PN and cyclization of XN to IX. Slow absorption and enterohepatic recirculation contributed to half-lives exceeding 20 h. CONCLUSION This human study indicated long half-lives of the estrogenic and proestrogenic prenylated phenols in hops but no acute toxicity. PMID:25045111

  10. Geranylgeranyl Diphosphate Synthase Modulates Fetal Lung Branching Morphogenesis Possibly through Controlling K-Ras Prenylation.

    PubMed

    Jia, Wen-Jun; Jiang, Shan; Tang, Qiao-Li; Shen, Di; Xue, Bin; Ning, Wen; Li, Chao-Jun

    2016-06-01

    G proteins play essential roles in regulating fetal lung development, and any defects in their expression or function (eg, activation or posttranslational modification) can lead to lung developmental malformation. Geranylgeranyl diphosphate synthase (GGPPS) can modulate protein prenylation that is required for protein membrane-anchoring and activation. Here, we report that GGPPS regulates fetal lung branching morphogenesis possibly through controlling K-Ras prenylation during fetal lung development. GGPPS was continuously expressed in lung epithelium throughout whole fetal lung development. Specific deletion of geranylgeranyl diphosphate synthase 1 (Ggps1) in lung epithelium during fetal lung development resulted in neonatal respiratory distress syndrome-like disease. The knockout mice died at postnatal day 1 of respiratory failure, and the lungs showed compensatory pneumonectasis, pulmonary atelectasis, and hyaline membranes. Subsequently, we proved that lung malformations in Ggps1-deficient mice resulted from the failure of fetal lung branching morphogenesis. Further investigation revealed Ggps1 deletion blocked K-Ras geranylgeranylation and extracellular signal-related kinase 1 or 2/mitogen-activated protein kinase signaling, which in turn disturbed fibroblast growth factor 10 regulation on fetal lung branching morphogenesis. Collectively, our data suggest that GGPPS is essential for maintaining fetal lung branching morphogenesis, which is possibly through regulating K-Ras prenylation. PMID:27106761

  11. Fungal endophytes of Catharanthus roseus enhance vindoline content by modulating structural and regulatory genes related to terpenoid indole alkaloid biosynthesis

    PubMed Central

    Pandey, Shiv S.; Singh, Sucheta; Babu, C. S. Vivek; Shanker, Karuna; Srivastava, N. K.; Shukla, Ashutosh K.; Kalra, Alok

    2016-01-01

    Not much is known about the mechanism of endophyte-mediated induction of secondary metabolite production in Catharanthus roseus. In the present study two fungal endophytes, Curvularia sp. CATDLF5 and Choanephora infundibulifera CATDLF6 were isolated from the leaves of the plant that were found to enhance vindoline content by 229–403%. The isolated endophytes did not affect the primary metabolism of the plant as the maximum quantum efficiency of PSII, net CO2 assimilation, plant biomass and starch content of endophyte-inoculated plants was similar to endophyte-free control plants. Expression of terpenoid indole alkaloid (TIA) pathway genes, geraniol 10-hydroxylase (G10H), tryptophan decarboxylase (TDC), strictosidine synthase (STR), 16-hydoxytabersonine-O-methyltransferase (16OMT), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT) were upregulated in endophyte-inoculated plants. Endophyte inoculation upregulated the expression of the gene for transcriptional activator octadecanoid-responsive Catharanthus AP2-domain protein (ORCA3) and downregulated the expression of Cys2/His2-type zinc finger protein family transcriptional repressors (ZCTs). The gene for the vacuolar class III peroxidase (PRX1), responsible for coupling vindoline and catharanthine, was upregulated in endophyte-inoculated plants. These endophytes may enhance vindoline production by modulating the expression of key structural and regulatory genes of vindoline biosynthesis without affecting the primary metabolism of the host plant. PMID:27220774

  12. Fungal endophytes of Catharanthus roseus enhance vindoline content by modulating structural and regulatory genes related to terpenoid indole alkaloid biosynthesis.

    PubMed

    Pandey, Shiv S; Singh, Sucheta; Babu, C S Vivek; Shanker, Karuna; Srivastava, N K; Shukla, Ashutosh K; Kalra, Alok

    2016-01-01

    Not much is known about the mechanism of endophyte-mediated induction of secondary metabolite production in Catharanthus roseus. In the present study two fungal endophytes, Curvularia sp. CATDLF5 and Choanephora infundibulifera CATDLF6 were isolated from the leaves of the plant that were found to enhance vindoline content by 229-403%. The isolated endophytes did not affect the primary metabolism of the plant as the maximum quantum efficiency of PSII, net CO2 assimilation, plant biomass and starch content of endophyte-inoculated plants was similar to endophyte-free control plants. Expression of terpenoid indole alkaloid (TIA) pathway genes, geraniol 10-hydroxylase (G10H), tryptophan decarboxylase (TDC), strictosidine synthase (STR), 16-hydoxytabersonine-O-methyltransferase (16OMT), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT) were upregulated in endophyte-inoculated plants. Endophyte inoculation upregulated the expression of the gene for transcriptional activator octadecanoid-responsive Catharanthus AP2-domain protein (ORCA3) and downregulated the expression of Cys2/His2-type zinc finger protein family transcriptional repressors (ZCTs). The gene for the vacuolar class III peroxidase (PRX1), responsible for coupling vindoline and catharanthine, was upregulated in endophyte-inoculated plants. These endophytes may enhance vindoline production by modulating the expression of key structural and regulatory genes of vindoline biosynthesis without affecting the primary metabolism of the host plant. PMID:27220774

  13. The Vinylguaiacol/Indole or VGI ("Veggie") Ratio: A Novel Molecular Parameter to Evaluate the Relative Contributions of Terrestrial and Aquatic Organic Matter to Sediments

    NASA Astrophysics Data System (ADS)

    Kruge, M. A.; Olsen, K. K.; Slusarczyk, J.; Gomez, E.

    2010-12-01

    The organic matter (OM) fraction of estuarine sediments is often distinctive and thus diagnostically useful in determinations of sedimentary provenance. Among the most fundamental distinctions to be made is that between terrestrial and aquatic OM. To supplement the parameters commonly used for this purpose (e.g., C/N and stable isotope ratios), we proposed the Vinylguaiacol/Indole or VGI ("Veggie") ratio, defined as [vinylguaiacol / (indole + vinylguaiacol)] using data produced by analytical pyrolysis-gas chromatography/mass spectrometry of dried, homogenized sediment samples. The ratio employs the peak areas of these two compounds on the mass chromatograms of their molecular ions (m/z 150 and 117). Major pyrolysis products of terrestrial plant lignin include a variety of methoxyphenols, notably 4-vinylguaiacol. In contrast, aquatic algae and bacteria characteristically produce distinctive organonitrogen compounds upon pyrolysis, particularly indole, derived from the amino acid tryptophan. The end member VGI ratio value of 1.00 is obtained for reference land plant matter, including the marsh plants Phragmites and Spartina, as well as maple and pine wood. The end member value of 0.00 is obtained for cultured microbes, including Escherichia coli and the cyanobacterium Anacystis. Vinylguaiacol and indole are commonly detected in Recent sediment pyrolyzates. We hypothesized that their relative quantities therein should be proportional to the relative contributions of land plant and microbial OM, respectively. Samples taken from Spartina peat marshes at the mouths of major rivers (Housatonic and Connecticut) entering Long Island Sound, wetlands behind the barrier island at Cape May (NJ), and a Phragmites-dominated tidal marsh along the Hackensack River (NJ) have high (> 0.8) VGI ratio values. Sediments collected within the Newark Bay (NJ) estuary from the lower Passaic and Hackensack Rivers and the Arthur Kill show mixed terrestrial and aquatic OM signatures (VGI from 0

  14. Biosynthesis of Fungal Indole Alkaloids

    PubMed Central

    Xu, Wei; Gavia, Diego J.; Tang, Yi

    2014-01-01

    This review provides a summary of recent research advances in elucidating the biosynthesis of fungal indole alkaloids. Different strategies used to incorporate and derivatize the indole/indoline moieties in various families of fungal indole alkaloids will be discussed, including tryptophan-containing nonribosomal peptides and polyketide-nonribosomal peptide hybrids; and alkaloids derived from other indole building blocks. This review also includes discussion regarding the downstream modifications that generate chemical and structural diversity among indole alkaloids. PMID:25180619

  15. Prenylated Dihydrochalcones from Artocarpus altilis as Antiausterity Agents.

    PubMed

    Nguyen, Mai Thanh Thi; Nguyen, Nhan Trung; Awale, Suresh

    2015-01-01

    Human pancreatic cancer cell lines have remarkable tolerance to nutrition starvation, which enables them to survive under a tumor microenvironment. A novel antiausterity strategy in anticancer drug discovery led to the discovery of agents that preferentially inhibit the survival of cancer cells under low nutrient conditions. Artocarpus altilis (Family: Moraceae) is commonly referred to as breadfruit, traditionally for the treatment of many diseases. Many prenylated flavonoid and prenylated chalocones together with their cancer cell cytotoxicity were reported from this plant. This chapter briefly summarizes the constituents, biosynthesis, cytotoxicity, and antiausterity activity on PANC-1 human pancreatic cancer cell line of A. altilis. PMID:26298457

  16. UV-Photoelectron Spectroscopy of BN Indoles: Experimental and Computational Electronic Structure Analysis

    PubMed Central

    2015-01-01

    We present a comprehensive electronic structure analysis of two BN isosteres of indole using a combined UV-photoelectron spectroscopy (UV-PES)/computational chemistry approach. Gas-phase He I photoelectron spectra of external BN indole I and fused BN indole II have been recorded, assessed by density functional theory calculations, and compared with natural indole. The first ionization energies of these indoles are natural indole (7.9 eV), external BN indole I (7.9 eV), and fused BN indole II (8.05 eV). The computationally determined molecular dipole moments are in the order: natural indole (2.177 D) > fused BN indole II (1.512 D) > external BN indole I (0.543 D). The λmax in the UV–vis absorption spectra are in the order: fused BN indole II (292 nm) > external BN indole I (282 nm) > natural indole (270 nm). The observed relative electrophilic aromatic substitution reactivity of the investigated indoles with dimethyliminium chloride as the electrophile is as follows: fused BN indole II > natural indole > external BN indole I, and this trend correlates with the π-orbital coefficient at the 3-position. Nucleus-independent chemical shifts calculations show that the introduction of boron into an aromatic 6π-electron system leads to a reduction in aromaticity, presumably due to a stronger bond localization. Trends and conclusions from BN isosteres of simple monocyclic aromatic systems such as benzene and toluene are not necessarily translated to the bicyclic indole core. Thus, electronic structure consequences resulting from BN/CC isosterism will need to be evaluated individually from system to system. PMID:25089659

  17. Expression, purification and crystallization of an indole prenyltransferase from Aspergillus fumigatus

    PubMed Central

    Chen, Jing; Morita, Hiroyuki; Kato, Ryohei; Noguchi, Hiroshi; Sugio, Shigetoshi; Abe, Ikuro

    2012-01-01

    CdpNPT from Aspergillus fumigatus is a dimethylallyltryptophan synthase/indole prenyltransferase that catalyzes reverse prenylation at position N1 of tryptophan-containing cyclic dipeptides. Residues 38–440 of CdpNPT were expressed in Escherichia coli and crystallized using the sitting-drop vapour-diffusion and microseeding techniques. The crystals belonged to space group P212121, with unit-cell parameters a = 84.4, b = 157.1, c = 161.8 Å, α = β = γ = 90.0°. PMID:22442243

  18. Seven 3-methylidene-1H-indol-2(3H)-ones related to the multiple-receptor tyrosine kinase inhibitor sunitinib.

    PubMed

    Spencer, John; Chowdhry, Babur Z; Hamid, Samiyah; Mendham, Andrew P; Male, Louise; Coles, Simon J; Hursthouse, Michael B

    2010-02-01

    The solid-state structures of a series of seven substituted 3-methylidene-1H-indol-2(3H)-one derivatives have been determined by single-crystal X-ray diffraction and are compared in detail. Six of the structures {(3Z)-3-(1H-pyrrol-2-ylmethylidene)-1H-indol-2(3H)-one, C(13)H(10)N(2)O, (2a); (3Z)-3-(2-thienylmethylidene)-1H-indol-2(3H)-one, C(13)H(9)NOS, (2b); (3E)-3-(2-furylmethylidene)-1H-indol-2(3H)-one monohydrate, C(13)H(9)NO(2).H(2)O, (3a); 3-(1-methylethylidene)-1H-indol-2(3H)-one, C(11)H(11)NO, (4a); 3-cyclohexylidene-1H-indol-2(3H)-one, C(14)H(15)NO, (4c); and spiro[1,3-dioxane-2,3'-indolin]-2'-one, C(11)H(11)NO(3), (5)} display, as expected, intermolecular hydrogen bonding (N-H...O=C) between the 1H-indol-2(3H)-one units. However, methyl 3-(1-methylethylidene)-2-oxo-2,3-dihydro-1H-indole-1-carboxylate, C(13)H(13)NO(3), (4b), a carbamate analogue of (4a) lacking an N-H bond, displays no intermolecular hydrogen bonding. The structure of (4a) contains three molecules in the asymmetric unit, while (4b) and (4c) both contain two independent molecules. PMID:20124685

  19. Exercising Regiocontrol in Palladium-Catalyzed Asymmetric Prenylations and Geranylation: Unifying Strategy Towards Flustramines A and B

    PubMed Central

    Malhotra, Sushant; Chan, Walter H.

    2011-01-01

    Palladium-catalyzed asymmetric prenylation of oxindoles to selectively afford either the prenyl or the reverse prenyl product has been demonstrated. Control of regioselectivity in this transformation is governed by choice of ligand, solvent, and halide additive. The resulting prenylated and reverse prenylated products have been transformed into ent-flustramides and ent-flustramines A and B. Additionally, control in regio- and diastereoselectivity has been obtained using π-geranylpalladium complexes. PMID:21520958

  20. Unified Approach to the Spiro(pyrrolidinyl-oxindole) and Hexahydropyrrolo[2,3-b]indole Alkaloids: Total Syntheses of Pseudophrynamines 270 and 272A.

    PubMed

    De, Subhadip; Das, Mrinal Kanti; Bhunia, Subhajit; Bisai, Alakesh

    2015-12-01

    The first enantioselective total syntheses of architecturally interesting prenylated pyrroloindole alkaloids, (-)-pseudophrynamines 272A (3d) and 270 (3b), have been achieved starting from enantioenriched 2-oxindoles having all-carbon quaternary stereocenters. A common strategy involving a thio-urea catalyzed aldol reaction is employed for the total synthesis of both spiro(pyrrolidinyl-oxindole) and hexahydropyrrolo[2,3-b]indole alkaloids. PMID:26600374

  1. Effect of S(-) perillic acid on protein prenylation and arterial smooth muscle cell proliferation.

    PubMed

    Ferri, N; Arnaboldi, L; Orlandi, A; Yokoyama, K; Gree, R; Granata, A; Hachem, A; Paoletti, R; Gelb, M H; Corsini, A

    2001-12-15

    A number of proteins post-translationally modified by the covalent attachment of mevalonate-derived isoprene groups farnesol (FOH) or geranylgeraniol (GGOH), play a role in cell proliferation. For this reason, protein farnesyltransferase (PFTase) and protein geranylgeranyltransferases (PGGTases) I and II have gained attention as novel targets for the development of antiproliferative agents. Monoterpenes [limonene, perillic acid (PA) and its derivatives] have been shown to inhibit cell growth and protein prenylation in cancer cells. In the present study, we evaluated the effect of S(-) PA on diploid rat aorta smooth muscle cell (SMC) proliferation as related to protein prenylation. S(-) PA (1-3.5 mM) decreased, in a concentration-dependent manner, rat SMC proliferation as evaluated by cell counting and DNA synthesis. Morphological criteria and flow cytometry analysis excluded the induction of apoptosis as a potential antiproliferative mechanism of S(-) PA on SMC and confirmed a block of the cell cycle progression in G(0)/G(1) phase. The antiproliferative effect of S(-) PA could not be prevented by the addition of mevalonate, FOH, and GGOH to the culture medium and was independent of cholesterol biosynthesis. Densitometric analysis of fluorographed gels, after sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the cell lysates, further supported that S(-) PA (1-3.5 mM), under the same experimental conditions, concentration-dependently inhibited FOH (up to 70%) and GGOH (up to 70%) incorporation into cellular proteins. We provide evidence that S(-) PA affects protein prenylation, an effect that may contribute to its inhibition of SMC proliferation. PMID:11755117

  2. Novel prenyl-linked benzophenone substrate analogues of mycobacterial mannosyltransferases

    PubMed Central

    2004-01-01

    PPM (polyprenol monophosphomannose) has been shown to act as a glycosyl donor in the biosynthesis of the Man (mannose)-rich mycobacterial lipoglycans LM (lipomannan) and LAM (lipoarabinomannan). The Mycobacterium tuberculosis PPM synthase (Mt-Ppm1) catalyses the transfer of Man from GDP-Man to polyprenyl phosphates. The resulting PPM then serves as a donor of Man residues leading to the formation of an α(1→6)LM intermediate through a PPM-dependent α(1→6)mannosyltransferase. In the present study, we prepared a series of ten novel prenyl-related photoactivatable probes based on benzophenone with lipophilic spacers replacing several internal isoprene units. These probes were excellent substrates for the recombinant PPM synthase Mt-Ppm1/D2 and, on photoactivation, several inhibited its activity in vitro. The protection of the PPM synthase activity by a ‘natural’ C75 polyprenyl acceptor during phototreatment is consistent with probe-mediated photoinhibition occurring via specific covalent modification of the enzyme active site. In addition, the unique mannosylated derivatives of the photoreactive probes were all donors of Man residues, through a PPM-dependent mycobacterial α(1→6)mannosyltransferase, to a synthetic Manp(1→6)-Manp-O-C10:1 disaccharide acceptor (where Manp stands for mannopyranose). Photoactivation of probe 7 led to striking-specific inhibition of the M. smegmatis α(1→6)mannosyltransferase. The present study represents the first application of photoreactive probes to the study of mycobacterial glycosyltransferases involved in LM and LAM biosynthesis. These preliminary findings suggest that the probes will prove useful in investigating the polyprenyl-dependent steps of the complex biosynthetic pathways to the mycobacterial lipoglycans, aiding in the identification of novel glycosyltransferases. PMID:15202931

  3. Prenylation has a compound specific effect on the estrogenicity of naringenin and genistein.

    PubMed

    Kretzschmar, Georg; Zierau, Oliver; Wober, Jannette; Tischer, Sandra; Metz, Peter; Vollmer, Günter

    2010-01-01

    A variety of plant derived substances, so-called phytoestrogens (PEs), although structurally not related to steroids, produce effects similar to the mammalian estradiol. However, little is known so far about the structural requirements which determine PE activities. Taking into consideration that prenylation reactions are relatively common in plant secondary metabolism, the activity of a set of three PE derivatives of genistein and naringenin, namely genistein, 8-prenylgenistein (8PG), 6-(1,1-dimethylallyl)genistein (6DMAG), naringenin, 8-prenylnaringenin (8PN) and 6-(1,1-dimethylallyl)naringenin (6DMAN) was compared regarding structure-estrogenicity relationships in three functionally different estrogen receptor assays. Strong estrogenic activities were recorded for 6DMAN and 8PN in all assays used, while the parent compound naringenin showed only very weak estrogenicity. In contrast, in the case of genistein derivatives, only genistein itself exhibited estrogenic activity in a yeast based assay. In MVLN breast cancer cells, a bioluminescent MCF-7-derived cell line, the estrogenic activity of all three genistein derivatives was similar. Studying alkaline phosphatase activity in Ishikawa endometrial cancer cells as an estrogenic response marker revealed a similar pattern of estrogenicity of the genistein derivatives compared to the yeast based assay although a slight estrogenic effect of 6DMAG and 8PG was apparent. In summary, this study demonstrates that prenylation often found in plant secondary metabolism differentially modifies estrogenic properties of PEs depending on the basic structure of the respective PE. PMID:19733663

  4. Mistrafficking of prenylated proteins causes retinitis pigmentosa 2

    PubMed Central

    Zhang, Houbin; Hanke-Gogokhia, Christin; Jiang, Li; Li, Xiaobo; Wang, Pu; Gerstner, Cecilia D.; Frederick, Jeanne M.; Yang, Zhenglin; Baehr, Wolfgang

    2015-01-01

    The retinitis pigmentosa 2 polypeptide (RP2) functions as a GTPase-activating protein (GAP) for ARL3 (Arf-like protein 3), a small GTPase. ARL3 is an effector of phosphodiesterase 6 Δ (PDE6D), a prenyl-binding protein and chaperone of prenylated protein in photoreceptors. Mutations in the human RP2 gene cause X-linked retinitis pigmentosa (XLRP) and cone-rod dystrophy (XL-CORD). To study mechanisms causing XLRP, we generated an RP2 knockout mouse. The Rp2h−/− mice exhibited a slowly progressing rod-cone dystrophy simulating the human disease. Rp2h−/− scotopic a-wave and photopic b-wave amplitudes declined at 1 mo of age and continued to decline over the next 6 mo. Prenylated PDE6 subunits and G-protein coupled receptor kinase 1 (GRK1) were unable to traffic effectively to the Rp2h−/− outer segments. Mechanistically, absence of RP2 GAP activity increases ARL3-GTP levels, forcing PDE6D to assume a predominantly “closed” conformation that impedes binding of lipids. Lack of interaction disrupts trafficking of PDE6 and GRK1 to their destination, the photoreceptor outer segments. We propose that hyperactivity of ARL3-GTP in RP2 knockout mice and human patients with RP2 null alleles leads to XLRP resembling recessive rod-cone dystrophy.—Zhang, H., Hanke-Gogokhia, C., Jiang, L., Li, X., Wang, P., Gerstner, C. D., Frederick, J. M., Yang, Z., Baehr, W. Mistrafficking of prenylated proteins causes retinitis pigmentosa 2. PMID:25422369

  5. Discovery of prenylated flavonoids with dual activity against influenza virus and Streptococcus pneumoniae

    PubMed Central

    Grienke, Ulrike; Richter, Martina; Walther, Elisabeth; Hoffmann, Anja; Kirchmair, Johannes; Makarov, Vadim; Nietzsche, Sandor; Schmidtke, Michaela; Rollinger, Judith M.

    2016-01-01

    Influenza virus neuraminidase (NA) is the primary target for influenza therapeutics. Severe complications are often related to secondary pneumonia caused by Streptococcus pneumoniae (pneumococci), which also express NAs. Recently, a NA-mediated lethal synergism between influenza A viruses and pneumococci was described. Therefore, dual inhibitors of both viral and bacterial NAs are expected to be advantageous for the treatment of influenza. We investigated the traditional Chinese herbal drug sāng bái pí (mulberry root bark) as source for anti-infectives. Two prenylated flavonoid derivatives, sanggenon G (4) and sanggenol A (5) inhibited influenza A viral and pneumococcal NAs and, in contrast to the approved NA inhibitor oseltamivir, also planktonic growth and biofilm formation of pneumococci. Evaluation of 27 congeners of 5 revealed a correlation between the degree of prenylation and bioactivity. Abyssinone-V 4′-methyl ether (27) inhibited pneumococcal NA with IC50 = 2.18 μM, pneumococcal growth with MIC = 5.63 μM, and biofilm formation with MBIC = 4.21 μM, without harming lung epithelial cells. Compounds 5 and 27 also disrupt the synergism between influenza A virus and pneumococcal NA in vitro, hence functioning as dual-acting anti-infectives. The results warrant further studies on whether the observed disruption of this synergism is transferable to in vivo systems. PMID:27257160

  6. Discovery of prenylated flavonoids with dual activity against influenza virus and Streptococcus pneumoniae.

    PubMed

    Grienke, Ulrike; Richter, Martina; Walther, Elisabeth; Hoffmann, Anja; Kirchmair, Johannes; Makarov, Vadim; Nietzsche, Sandor; Schmidtke, Michaela; Rollinger, Judith M

    2016-01-01

    Influenza virus neuraminidase (NA) is the primary target for influenza therapeutics. Severe complications are often related to secondary pneumonia caused by Streptococcus pneumoniae (pneumococci), which also express NAs. Recently, a NA-mediated lethal synergism between influenza A viruses and pneumococci was described. Therefore, dual inhibitors of both viral and bacterial NAs are expected to be advantageous for the treatment of influenza. We investigated the traditional Chinese herbal drug sāng bái pí (mulberry root bark) as source for anti-infectives. Two prenylated flavonoid derivatives, sanggenon G (4) and sanggenol A (5) inhibited influenza A viral and pneumococcal NAs and, in contrast to the approved NA inhibitor oseltamivir, also planktonic growth and biofilm formation of pneumococci. Evaluation of 27 congeners of 5 revealed a correlation between the degree of prenylation and bioactivity. Abyssinone-V 4'-methyl ether (27) inhibited pneumococcal NA with IC50 = 2.18 μM, pneumococcal growth with MIC = 5.63 μM, and biofilm formation with MBIC = 4.21 μM, without harming lung epithelial cells. Compounds 5 and 27 also disrupt the synergism between influenza A virus and pneumococcal NA in vitro, hence functioning as dual-acting anti-infectives. The results warrant further studies on whether the observed disruption of this synergism is transferable to in vivo systems. PMID:27257160

  7. Evaluation of alkyne-modified isoprenoids as chemical reporters of protein prenylation

    PubMed Central

    DeGraw, Amanda J.; Palsuledesai, Charuta; Ochocki, Joshua D.; Dozier, Jonathan K.; Lenevich, Stepan; Rashidian, Mohammad; Distefano, Mark D.

    2010-01-01

    Protein prenyltransferases catalyze the attachment of C15 (farnesyl) and C20 (geranylgeranyl) groups to proteins at specific sequences localized at or near the C-termini of specific proteins. Determination of the specific protein prenyltransferase substrates affected by the inhibition of these enzymes is critical for enhancing knowledge of the mechanism of such potential drugs. Here we investigate the utility of alkyne-containing isoprenoid analogues for chemical proteomics experiments by showing that these compounds readily penetrate mammalian cells in culture and become incorporated into proteins that are normally prenylated. Derivatization via Cu(I) catalyzed Click reaction with a fluorescent azide reagent allows the proteins to be visualized and their relative levels to be analyzed. Simultaneous treatment of cells with these probes and inhibitors of prenylation reveals decreases in the levels of some but not all of the labeled proteins. Two-dimensional electrophoretic separation of these labeled proteins followed by mass spectrometric analysis allowed several labeled proteins to be unambiguously identified. Docking experiments and DFT calculations suggest that the substrate specificity of PFTase may vary depending on whether azide- or alkyne-based isoprenoid analogues are employed. These results demonstrate the utility of alkyne-containing analogues for chemical proteomic applications. PMID:21040496

  8. Caged Protein Prenyltransferase Substrates: Tools for Understanding Protein Prenylation

    SciTech Connect

    DeGraw, Amanda J.; Hast, Michael A.; Xu, Juhua; Mullen, Daniel; Beese, Lorena S.; Barany, George; Distefano, Mark D.

    2010-11-15

    Originally designed to block the prenylation of oncogenic Ras, inhibitors of protein farnesyltransferase currently in preclinical and clinical trials are showing efficacy in cancers with normal Ras. Blocking protein prenylation has also shown promise in the treatment of malaria, Chagas disease and progeria syndrome. A better understanding of the mechanism, targets and in vivo consequences of protein prenylation are needed to elucidate the mode of action of current PFTase (Protein Farnesyltransferase) inhibitors and to create more potent and selective compounds. Caged enzyme substrates are useful tools for understanding enzyme mechanism and biological function. Reported here is the synthesis and characterization of caged substrates of PFTase. The caged isoprenoid diphosphates are poor substrates prior to photolysis. The caged CAAX peptide is a true catalytically caged substrate of PFTase in that it is to not a substrate, yet is able to bind to the enzyme as established by inhibition studies and X-ray crystallography. Irradiation of the caged molecules with 350 nm light readily releases their cognate substrate and their photolysis products are benign. These properties highlight the utility of those analogs towards a variety of in vitro and in vivo applications.

  9. A Soluble, magnesium-independent prenyltransferase catalyzes reverse and regular C-prenylations and O-prenylations of aromatic substrates

    PubMed Central

    Haagen, Yvonne; Unsöld, Inge; Westrich, Lucia; Gust, Bertolt; Richard, Stéphane B.; Noel, Joseph P.; Heide, Lutz

    2010-01-01

    Fnq26 from Streptomyces cinnamonensis DSM 1042 is a new member of the recently identified CloQ/Orf2 class of prenyltransferases. The enzyme was overexpressed in E. coli and purified to apparent homogeneity, resulting in a soluble, monomeric protein of 33.2 kDa. The catalytic activity of Fnq26 is independent of the presence of Mg2+ or other divalent metal ions. With flaviolin (2,5,7-trihydroxy-1,4-naphthoquinone) as substrate, Fnq26 catalyzes the formation of a carbon–carbon-bond between C-3 (rather than C-1) of geranyl diphosphate and C-3 of flaviolin, i.e. an unusual ‘‘reverse’’ prenylation. With 1,3-dihydroxynaphthalene and 4-hydroxybenzoate as substrates Fnq26 catalyzes O-prenylations. PMID:17543953

  10. Type-I Prenyl Protease Function Is Required in the Male Germline of Drosophila melanogaster

    PubMed Central

    Adolphsen, Katie; Amell, Amanda; Havko, Nathan; Kevorkian, Sara; Mears, Kyle; Neher, Hayley; Schwarz, Dietmar; Schulze, Sandra R.

    2012-01-01

    Many proteins require the addition of a hydrophobic prenyl anchor (prenylation) for proper trafficking and localization in the cell. Prenyl proteases play critical roles in modifying proteins for membrane anchorage. The type I prenyl protease has a defined function in yeast (Ste24p/Afc1p) where it modifies a mating pheromone, and in humans (Zmpste24) where it has been implicated in a disease of premature aging. Despite these apparently very different biological processes, the type I prenyl protease gene is highly conserved, encoded by a single gene in a wide range of animal and plant groups. A notable exception is Drosophila melanogaster, where the gene encoding the type I prenyl protease has undergone an unprecedented series of duplications in the genome, resulting in five distinct paralogs, three of which are organized in a tandem array, and demonstrate high conservation, particularly in the vicinity of the active site of the enzyme. We have undertaken targeted deletion to remove the three tandem paralogs from the genome. The result is a male fertility defect, manifesting late in spermatogenesis. Our results also show that the ancestral type I prenyl protease gene in Drosophila is under strong purifying selection, while the more recent replicates are evolving rapidly. Our rescue data support a role for the rapidly evolving tandem paralogs in the male germline. We propose that potential targets for the male-specific type I prenyl proteases include proteins involved in the very dramatic cytoskeletal remodeling events required for spermatid maturation. PMID:22690372

  11. Inhibition of protein prenylation down-regulates signalling by inflammatory mediators in human keratinocytes.

    PubMed

    Alaei, P; MacNulty, E E; Ryder, N S

    1996-05-01

    Several inflammatory mediators have been shown to activate phospholipase C in human keratinocytes via GTP-binding protein-coupled receptors. Since GTP-binding proteins are prenylated proteins, we have examined the role of prenylation in signal transduction in HaCaT keratinocytes. Indirect inhibition of prenylation with the HMG CoA reductase inhibitors fluvastatin or compactin decreased bradykinin-stimulated inositol 1,4,5-triphosphate generation. This effect was abolished by mevalonic acid but not by serum, indicating a requirement for a non-sterol metabolite for signal generation. The BK response was also inhibited by zaragozic acids B and C, known inhibitors of prenyl protein transferases. These results suggest that protein prenylation may be a novel therapeutic target in dermatological conditions where an up-regulation of the inositol lipid pathway has been demonstrated. PMID:8630058

  12. Glucose enhances indolic glucosinolate biosynthesis without reducing primary sulfur assimilation

    PubMed Central

    Miao, Huiying; Cai, Congxi; Wei, Jia; Huang, Jirong; Chang, Jiaqi; Qian, Hongmei; Zhang, Xin; Zhao, Yanting; Sun, Bo; Wang, Bingliang; Wang, Qiaomei

    2016-01-01

    The effect of glucose as a signaling molecule on induction of aliphatic glucosinolate biosynthesis was reported in our former study. Here, we further investigated the regulatory mechanism of indolic glucosinolate biosynthesis by glucose in Arabidopsis. Glucose exerted a positive influence on indolic glucosinolate biosynthesis, which was demonstrated by induced accumulation of indolic glucosinolates and enhanced expression of related genes upon glucose treatment. Genetic analysis revealed that MYB34 and MYB51 were crucial in maintaining the basal indolic glucosinolate accumulation, with MYB34 being pivotal in response to glucose signaling. The increased accumulation of indolic glucosinolates and mRNA levels of MYB34, MYB51, and MYB122 caused by glucose were inhibited in the gin2-1 mutant, suggesting an important role of HXK1 in glucose-mediated induction of indolic glucosinolate biosynthesis. In contrast to what was known on the function of ABI5 in glucose-mediated aliphatic glucosinolate biosynthesis, ABI5 was not required for glucose-induced indolic glucosinolate accumulation. In addition, our results also indicated that glucose-induced glucosinolate accumulation was due to enhanced sulfur assimilation instead of directed sulfur partitioning into glucosinolate biosynthesis. Thus, our data provide new insights into molecular mechanisms underlying glucose-regulated glucosinolate biosynthesis. PMID:27549907

  13. Glucose enhances indolic glucosinolate biosynthesis without reducing primary sulfur assimilation.

    PubMed

    Miao, Huiying; Cai, Congxi; Wei, Jia; Huang, Jirong; Chang, Jiaqi; Qian, Hongmei; Zhang, Xin; Zhao, Yanting; Sun, Bo; Wang, Bingliang; Wang, Qiaomei

    2016-01-01

    The effect of glucose as a signaling molecule on induction of aliphatic glucosinolate biosynthesis was reported in our former study. Here, we further investigated the regulatory mechanism of indolic glucosinolate biosynthesis by glucose in Arabidopsis. Glucose exerted a positive influence on indolic glucosinolate biosynthesis, which was demonstrated by induced accumulation of indolic glucosinolates and enhanced expression of related genes upon glucose treatment. Genetic analysis revealed that MYB34 and MYB51 were crucial in maintaining the basal indolic glucosinolate accumulation, with MYB34 being pivotal in response to glucose signaling. The increased accumulation of indolic glucosinolates and mRNA levels of MYB34, MYB51, and MYB122 caused by glucose were inhibited in the gin2-1 mutant, suggesting an important role of HXK1 in glucose-mediated induction of indolic glucosinolate biosynthesis. In contrast to what was known on the function of ABI5 in glucose-mediated aliphatic glucosinolate biosynthesis, ABI5 was not required for glucose-induced indolic glucosinolate accumulation. In addition, our results also indicated that glucose-induced glucosinolate accumulation was due to enhanced sulfur assimilation instead of directed sulfur partitioning into glucosinolate biosynthesis. Thus, our data provide new insights into molecular mechanisms underlying glucose-regulated glucosinolate biosynthesis. PMID:27549907

  14. Indole and 7-hydroxyindole diminish Pseudomonas aeruginosa virulence.

    PubMed

    Lee, Jintae; Attila, Can; Cirillo, Suat L G; Cirillo, Jeffrey D; Wood, Thomas K

    2009-01-01

    Indole is an extracellular biofilm signal for Escherichia coli, and many bacterial oxygenases readily convert indole to various oxidized compounds including 7-hydroxyindole (7HI). Here we investigate the impact of indole and 7HI on Pseudomonas aeruginosa PAO1 virulence and quorum sensing (QS)-regulated phenotypes; this strain does not synthesize these compounds but degrades them rapidly. Indole and 7HI both altered extensively gene expression in a manner opposite that of acylhomoserine lactones; the most repressed genes encode the mexGHI-opmD multidrug efflux pump and genes involved in the synthesis of QS-regulated virulence factors including pyocyanin (phz operon), 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS) signal (pqs operon), pyochelin (pch operon) and pyoverdine (pvd operon). Corroborating these microarray results, indole and 7HI decreased production of pyocyanin, rhamnolipid, PQS and pyoverdine and enhanced antibiotic resistance. In addition, indole affected the utilization of carbon, nitrogen and phosphorus, and 7HI abolished swarming motility. Furthermore, 7HI reduced pulmonary colonization of P. aeruginosa in guinea pigs and increased clearance in lungs. Hence, indole-related compounds have potential as a novel antivirulence approach for the recalcitrant pathogen P. aeruginosa. PMID:21261883

  15. Inhibition of Rab prenylation by statins induces cellular glycosphingolipid remodeling.

    PubMed

    Binnington, Beth; Nguyen, Long; Kamani, Mustafa; Hossain, Delowar; Marks, David L; Budani, Monique; Lingwood, Clifford A

    2016-02-01

    Statins, which specifically inhibit HMG Co-A reductase, the rate-limiting step of cholesterol biosynthesis, are widely prescribed to reduce serum cholesterol and cardiac risk, but many other effects are seen. We now show an effect of these drugs to induce profound changes in the step-wise synthesis of glycosphingolipids (GSLs) in the Golgi. Glucosylceramide (GlcCer) was increased several-fold in all cell lines tested, demonstrating a widespread effect. Additionally, de novo or elevated lactotriaosylceramide (Lc3Cer; GlcNAcβ1-3Galβ1-4GlcCer) synthesis was observed in 70%. Western blot showed that GlcCer synthase (GCS) was elevated by statins, and GCS and Lc3Cer synthase (Lc3S) activities were increased; however, transcript was elevated for Lc3S only. Supplementation with the isoprenoid precursor, geranylgeranyl pyrophosphate (GGPP), a downstream product of HMG Co-A reductase, reversed statin-induced glycosyltransferase and GSL elevation. The Rab geranylgeranyl transferase inhibitor 3-PEHPC, but not specific inhibitors of farnesyl transferase, or geranylgeranyl transferase I, was sufficient to replicate statin-induced GlcCer and Lc3Cer synthesis, supporting a Rab prenylation-dependent mechanism. While total cholesterol was unaffected, the trans-Golgi network (TGN) cholesterol pool was dissipated and medial Golgi GCS partially relocated by statins. GSL-dependent vesicular retrograde transport of Verotoxin and cholera toxin to the Golgi/endoplasmic reticulum were blocked after statin or 3-PEHPC treatment, suggesting aberrant, prenylation-dependent vesicular traffic as a basis of glycosyltransferase increase and GSL remodeling. These in vitro studies indicate a previously unreported link between Rab prenylation and regulation of GCS activity and GlcCer metabolism. PMID:26405105

  16. Emended descriptions of indole negative and indole positive isolates of Brachyspira (Serpulina) hyodysenteriae.

    PubMed

    Fellström, C; Karlsson, M; Pettersson, B; Zimmerman, U; Gunnarsson, A; Aspan, A

    1999-12-01

    Two type/reference strains of Brachyspira (B.) hyodysenteriae, 14 Belgian and German indole negative, and 14 Belgian, German and Swedish indole positive field isolates of strongly beta-haemolytic intestinal spirochaetes were compared by pulsed-field gel electrophoresis (PFGE) patterns, biochemical reaction patterns, 16S rDNA sequences and MIC determinations of six antibacterial substances. Three tests for indole production, including a spot indole test, were compared with congruent results. All field isolates were classified as B. hyodysenteriae due to a high genetic and phenotypic similarity with the type strains. The Belgian and German indole negative isolates had identical and unique PFGE patterns for the tested restriction enzymes MluI and SalI, as well as identical 16S rDNA sequences, and they could not be differentiated by any of the methods used. Seven unique PFGE patterns were achieved from the 14 indole positive field isolates. The patterns were identical and unique for epidemiologically related isolates. Type/reference strains and isolates without known relation to other tested isolates showed unique banding patterns. The MICs of tylosin, tiamulin, erythromycin, clindamycin, carbadox and virginiamycin were determined in broth for all isolates. In contrast to Belgian and German isolates, the majority of the Swedish field isolates were susceptible to tylosin, erythromycin and clindamycin. Probable pathways of infection for some of the Swedish isolates were determined. The PFGE patterns of epidemic clones of B. hyodysenteriae remained stable for a period of up to 8 years. In vivo development of resistance to macrolide and lincosamide antibiotics due to use of tylosin was clearly indicated for two epidemic clones. PMID:10596806

  17. Prenylation of aromatic compounds, a key diversification of plant secondary metabolites.

    PubMed

    Yazaki, Kazufumi; Sasaki, Kanako; Tsurumaru, Yusuke

    2009-01-01

    Prenylation plays a major role in the diversification of aromatic natural products, such as phenylpropanoids, flavonoids, and coumarins. This biosynthetic reaction represents the crucial coupling process of the shikimate or polyketide pathway providing an aromatic moiety and the isoprenoid pathway derived from the mevalonate or methyl erythritol phosphate (MEP) pathway, which provides the prenyl (isoprenoid) chain. In particular, prenylation contributes strongly to the diversification of flavonoids, due to differences in the prenylation position on the aromatic rings, various lengths of prenyl chain, and further modifications of the prenyl moiety, e.g., cyclization and hydroxylation, resulting in the occurrence of ca. 1000 prenylated flavonoids in plants. Many prenylated flavonoids have been identified as active components in medicinal plants with biological activities, such as anti-cancer, anti-androgen, anti-leishmania, and anti-nitric oxide production. Due to their beneficial effects on human health, prenylated flavonoids are of particular interest as lead compounds for producing drugs and functional foods. However, the gene coding for prenyltransferases that catalyze the key step of flavonoid prenylation have remained unidentified for more than three decades, because of the membrane-bound nature of these enzymes. Recently, we have succeeded in identifying the first prenyltransferase gene SfN8DT-1 from Sophora flavescens, which is responsible for the prenylation of the flavonoid naringenin at the 8-position, and is specific for flavanones and dimethylallyl diphosphate (DMAPP) as substrates. Phylogenetic analysis showed that SfN8DT-1 has the same evolutionary origin as prenyltransferases for vitamin E and plastoquinone. A prenyltransferase GmG4DT from soybean, which is involved in the formation of glyceollin, was also identified recently. This enzyme was specific for pterocarpan as its aromatic substrate, and (-)-glycinol was the native substrate yielding the

  18. Flemingin-Type Prenylated Chalcones from the Sarawak Rainforest Plant Desmodium congestum.

    PubMed

    Rees, Karlee A; Bermudez, Cindy; Edwards, David J; Elliott, Alysha G; Ripen, Jovita E; Seta, Cynthia; Huang, Johnny X; Cooper, Matthew A; Fraser, James A; Yeo, Tiong Chia; Butler, Mark S

    2015-08-28

    In an ongoing program to identify new anti-infective leads, an extract derived from whole plant material of Desmodium congestum collected in the Sarawak rainforest was found to have anti-MRSA activity. Bioassay-guided isolation led to the isolation of two new prenylated chalcones, 5'-O-methyl-3-hydroxyflemingin A (1) and 5'-O-methylflemingin C (2), which were closely related to the flemingins previously isolated from various Flemingia species. Chalcones 1 and 2, which were determined to be 4:6 enantiomeric mixtures by chiral HPLC, exhibited moderate activity against a panel of Gram-positive bacteria and were also cytotoxic to the HEK293 human embryonic kidney cell line. PMID:26284978

  19. Bioassay-guided isolation of prenylated xanthones and polycyclic acylphloroglucinols from the leaves of Garcinia nujiangensis.

    PubMed

    Xia, Zheng-Xiang; Zhang, Dan-Dan; Liang, Shuang; Lao, Yuan-Zhi; Zhang, Hong; Tan, Hong-Sheng; Chen, Shi-Lin; Wang, Xin-Hong; Xu, Hong-Xi

    2012-08-24

    Bioassay-guided fractionation of the acetone extract of the leaves of Garcinia nujiangensis resulted in the isolation of two new prenylated xanthones, nujiangexanthones A (1) and B (2), three new polycyclic polyprenylated acylphloroglucinols, nujiangefolins A-C (3-5), and 10 known related analogues. The structures of compounds 1-5 were elucidated by interpretation of their spectroscopic data. Compounds 3 and 4 are unusual polycyclic polyprenylated acylphloroglucinols in which the enol hydroxy group forms a six-membered ring with a benzene ring carbon. The compounds isolated were evaluated for their cytotoxic effects against 11 cancer cell lines and immortalized MIHA normal liver cells, and the test substances demonstrated selectivity toward the cancer cells. Isojacareubin (6) was found to be the most potent cytotoxic compound of those tested. PMID:22871217

  20. Efficient microwave-assisted prenylation of pinostrobin and biological evaluation of its derivatives as antitumor agents.

    PubMed

    Poerwono, Hadi; Sasaki, Shigeru; Hattori, Yoshiyuki; Higashiyama, Kimio

    2010-04-01

    Pinostrobin (5-hydroxy-7-methoxyflavanone) obtained in relatively large amounts from fingerroot (Boesenbergia pandurata) was converted to its C-6 and C-8 prenylated derivatives. The Mitsunobu reaction, europium(III)-catalyzed Claisen-Cope rearrangement, and Claisen reaction coupled with cross-metathesis were used as the key steps. Using a sealed-vessel microwave reactor, the Mitsunobu and Claisen/Cope reactions occurred smoothly with short reaction times and in satisfactory yields. The target compounds and five new intermediary substances showed cytotoxic activity toward SK-BR-3, MCF-7, PC-3, and Colo-320DM human tumor cell lines, and all of them had significantly lower IC(50) (microM) values than pinostrobin. PMID:20219370

  1. Protein Prenylation Constitutes an Endogenous Brake on Axonal Growth.

    PubMed

    Li, Hai; Kuwajima, Takaaki; Oakley, Derek; Nikulina, Elena; Hou, Jianwei; Yang, Wan Seok; Lowry, Emily Rhodes; Lamas, Nuno Jorge; Amoroso, Mackenzie Weygandt; Croft, Gist F; Hosur, Raghavendra; Wichterle, Hynek; Sebti, Said; Filbin, Marie T; Stockwell, Brent; Henderson, Christopher E

    2016-07-12

    Suboptimal axonal regeneration contributes to the consequences of nervous system trauma and neurodegenerative disease, but the intrinsic mechanisms that regulate axon growth remain unclear. We screened 50,400 small molecules for their ability to promote axon outgrowth on inhibitory substrata. The most potent hits were the statins, which stimulated growth of all mouse- and human-patient-derived neurons tested, both in vitro and in vivo, as did combined inhibition of the protein prenylation enzymes farnesyltransferase (PFT) and geranylgeranyl transferase I (PGGT-1). Compensatory sprouting of motor axons may delay clinical onset of amyotrophic lateral sclerosis (ALS). Accordingly, elevated levels of PGGT1B, which would be predicted to reduce sprouting, were found in motor neurons of early- versus late-onset ALS patients postmortem. The mevalonate-prenylation pathway therefore constitutes an endogenous brake on axonal growth, and its inhibition provides a potential therapeutic approach to accelerate neuronal regeneration in humans. PMID:27373155

  2. Protein prenylation is required for aldosterone-stimulated Na+ transport.

    PubMed

    Blazer-Yost, B L; Hughes, C L; Nolan, P L

    1997-06-01

    Aldosterone stimulation of transcellular Na+ flux in polarized epithelial cells is dependent on at least one transmethylation reaction, but the substrate of this signaling step is unknown. Because it is clear that the majority of cellular protein methylation occurs in conjunction with protein prenylation, we examined the importance of prenylation to aldosterone-stimulated Na+ transport in the A6 cell line. Lovastatin, an inhibitor of the first committed step of the mevalonate pathway, inhibits the natriferic effect of aldosterone but does not inhibit insulin-stimulated Na+ flux. The addition of a farnesyl group does not appear to be involved in aldosterone's action. Neither alpha-hydroxyfarne-sylphosphonic acid, an inhibitor of farnesyl:protein transferase, nor N-acetyl-S-farnesyl-L-cysteine, an inhibitor of farnesylated protein methylation, inhibits the hormone-induced increase in Na+ transport. In contrast, N-acetyl-S-geranyl-geranyl-L-cysteine, an inhibitor of geranylgeranyl protein methylation, completely abolishes the aldosterone-induced increase in Na+ flux with no effect on insulin-mediated Na+ transport or cellular protein content. These data indicate that methylation of a geranylgeranylated protein is involved in aldosterone's natriferic action. PMID:9227422

  3. Regiospecific synthesis of prenylated flavonoids by a prenyltransferase cloned from Fusarium oxysporum.

    PubMed

    Yang, Xiaoman; Yang, Jiali; Jiang, Yueming; Yang, Hongshun; Yun, Ze; Rong, Weiliang; Yang, Bao

    2016-01-01

    Due to their impressive pharmaceutical activities and safety, prenylated flavonoids have a high potent to be applied as medicines and nutraceuticals. Biocatalysis is an effective technique to synthesize prenylated flavonoids. The major concern of this technique is that the microbe-derived prenyltransferases usually have poor regiospecificity and generate multiple prenylated products. In this work, a highly regiospecific prenyltransferase (FoPT1) was found from Fusarium oxysporum. It could recognize apigenin, naringenin, genistein, dihydrogenistein, kampferol, luteolin and hesperetin as substrates, and only 6-C-prenylated flavonoids were detected as the products. The catalytic efficiency of FoPT1 on flavonoids was in a decreasing order with hesperetin >naringenin >apigenin >genistein >luteolin >dihydrogenistein >kaempferol. Chalcones, flavanols and stilbenes were not active when acting as the substrates. 5,7-Dihydroxy and 4-carbonyl groups of flavonid were required for the catalysis. 2,3-Alkenyl was beneficial to the catalysis whereas 3-hydroxy impaired the prenylation reaction. Docking studies simulated the prenyl transfer reaction of FoPT1. E186 was involved in the formation of prenyl carbonium ion. E98, F89, F182, Y197 and E246 positioned apigenin for catalysis. PMID:27098599

  4. Characterization of prenyl protein transferase enzymes in a human keratinocyte cell line.

    PubMed

    MacNulty, E E; Ryder, N S

    1996-02-01

    Prenylation is a post-translational modification of proteins that involves the attachment of an isoprenoid group derived from mevalonic acid, either 15-carbon farnesyl or 20-carbon geranylgeranyl, to a specific carboxy-terminal domain of acceptor proteins. Three prenyl transferase enzymes have been identified so far. In this paper we report the presence of two prenyl transferases in the HaCaT human keratinocyte cell line. Chromatography of a cytosolic extract from these cells resolved a farnesyl protein transferase (FPT) and geranylgeranyl protein transferase-I (GGPT-I) whose activities were measured using a novel peptide-based assay. Both enzymes were inhibited dose dependently by zaragozic acids A and C. Zaragozic acid C was more active towards the FPT than GGPT-I while zaragozic acid A inhibited both enzymes with similar potency. Incubation of HaCaT cell homogenates with [3H] prenyl precursors resulted in the labelling of a number of proteins which was increased when the cells were pretreated with an inhibitor of hydroxymethylglutaryl CoA reductase. Given the role of prenylated proteins in proliferative and inflammatory processes, our finding that prenyl transferases capable of prenylating endogenous substrates are also present in keratinocytes suggests that these enzymes might provide novel therapeutic targets of dermatological importance. PMID:8605230

  5. Regiospecific synthesis of prenylated flavonoids by a prenyltransferase cloned from Fusarium oxysporum

    PubMed Central

    Yang, Xiaoman; Yang, Jiali; Jiang, Yueming; Yang, Hongshun; Yun, Ze; Rong, Weiliang; Yang, Bao

    2016-01-01

    Due to their impressive pharmaceutical activities and safety, prenylated flavonoids have a high potent to be applied as medicines and nutraceuticals. Biocatalysis is an effective technique to synthesize prenylated flavonoids. The major concern of this technique is that the microbe-derived prenyltransferases usually have poor regiospecificity and generate multiple prenylated products. In this work, a highly regiospecific prenyltransferase (FoPT1) was found from Fusarium oxysporum. It could recognize apigenin, naringenin, genistein, dihydrogenistein, kampferol, luteolin and hesperetin as substrates, and only 6-C-prenylated flavonoids were detected as the products. The catalytic efficiency of FoPT1 on flavonoids was in a decreasing order with hesperetin >naringenin >apigenin >genistein >luteolin >dihydrogenistein >kaempferol. Chalcones, flavanols and stilbenes were not active when acting as the substrates. 5,7-Dihydroxy and 4-carbonyl groups of flavonid were required for the catalysis. 2,3-Alkenyl was beneficial to the catalysis whereas 3-hydroxy impaired the prenylation reaction. Docking studies simulated the prenyl transfer reaction of FoPT1. E186 was involved in the formation of prenyl carbonium ion. E98, F89, F182, Y197 and E246 positioned apigenin for catalysis. PMID:27098599

  6. The multifaceted roles of the interspecies signalling molecule indole in Agrobacterium tumefaciens.

    PubMed

    Lee, Jin-Hyung; Kim, Yong-Guy; Baek, Kwang-Hyun; Cho, Moo Hwan; Lee, Jintae

    2015-04-01

    Bacteria utilize signal molecules to ensure their survival in environmental niches, and indole is an interspecies and interkingdom signalling molecule, which is widespread in the natural environment. In this study, we sought to identify novel roles of indole in soil-borne bacterium Agrobacterium tumefaciens. Agrobacterium tumefaciens was found not to synthesize indole and to degrade it rapidly. The addition of exogenous indole dose-dependently inhibited A. tumefaciens growth and decreased its motility. Surprisingly, indole markedly increased A. tumefaciens biofilm formation on polystyrene, glass and nylon membrane surfaces and enhanced its antibiotic tolerance. Transcriptional analysis showed that indole markedly up-regulated several biofilm-related (celA, cheA, exoR, phoB, flgE, fliR and motA), stress-related genes (clpB, dnaK, gsp, gyrB, marR and soxR) and efflux genes (emrA, norM, and Atu2551) in A. tumefaciens, which partially explained the increased biofilm formation and antibiotic tolerance. In contrast, the plant auxin indole-3-acetic acid did not affect biofilm formation, antibiotic tolerance or gene expression. Interestingly, indole was found to exhibit several similarities with antibiotics, as it inhibited the growth of non-indole-producing bacteria, whereas these bacteria countered its effects by rapidly degrading indole, and by enhancing biofilm formation and antibiotic tolerance. PMID:25040348

  7. Novel prenylated bichalcone and chalcone from Humulus lupulus and their quinone reductase induction activities.

    PubMed

    Yu, Liyan; Zhang, Fuxian; Hu, Zhijuan; Ding, Hui; Tang, Huifang; Ma, Zhongjun; Zhao, Xiaofeng

    2014-03-01

    A new prenylated chalcone xanthohumol M (1), a novel prenylated bichalcone humulusol (2) and six known chalcones (3-8) were found from Humulus lupulus. Their structures were determined by spectroscopic methods. All the chalcones' electrophilic abilities were assessed by GSH (glutathione) rapid screening, and their QR (quinone reductase) induction activities were evaluated using hepa 1c1c7 cells. The results of electrophilic assay and QR induction activity assay were quite well. New compounds 1 and 2, along with some known prenylated chalcones, displayed certain QR induction activity. PMID:24397993

  8. Concurrent profiling of indole-3-acetic acid, abscisic acid, and cytokinins and structurally related purines by high-performance-liquid-chromatography tandem electrospray mass spectrometry

    PubMed Central

    2012-01-01

    Background Cytokinins (CKs) are a group of plant growth regulators that are involved in several plant developmental processes. Despite the breadth of knowledge surrounding CKs and their diverse functions, much remains to be discovered about the full potential of CKs, including their relationship with the purine salvage pathway, and other phytohormones. The most widely used approach to query unknown facets of CK biology utilized functional genomics coupled with CK metabolite assays and screening of CK associated phenotypes. There are numerous different types of assays for determining CK quantity, however, none of these methods screen for the compendium of metabolites that are necessary for elucidating all roles, including purine salvage pathway enzymes in CK metabolism, and CK cross-talk with other phytohormones. Furthermore, all published analytical methods have drawbacks ranging from the required use of radiolabelled compounds, or hazardous derivatization reagents, poor sensitivity, lack of resolution between CK isomers and lengthy run times. Results In this paper, a method is described for the concurrent extraction, purification and analysis of several CKs (freebases, ribosides, glucosides, nucleotides), purines (adenosine monophosphate, inosine, adenosine, and adenine), indole-3-acetic acid, and abscisic acid from hundred-milligram (mg) quantities of Arabidopsis thaliana leaf tissue. This method utilizes conventional Bieleski solvents extraction, solid phase purification, and is unique because of its diverse range of detectable analytes, and implementation of a conventional HPLC system with a fused core column that enables good sensitivity without the requirement of a UHPLC system. Using this method we were able to resolve CKs about twice as fast as our previous method. Similarly, analysis of adenosine, indole-3-acetic acid, and abscisic acid, was comparatively rapid. A further enhancement of the method was the utilization of a QTRAP 5500 mass analyzer, which

  9. Studies on the synthesis and opioid agonistic activities of mitragynine-related indole alkaloids: discovery of opioid agonists structurally different from other opioid ligands.

    PubMed

    Takayama, Hiromitsu; Ishikawa, Hayato; Kurihara, Mika; Kitajima, Mariko; Aimi, Norio; Ponglux, Dhavadee; Koyama, Fumi; Matsumoto, Kenjiro; Moriyama, Tomoyuki; Yamamoto, Leonard T; Watanabe, Kazuo; Murayama, Toshihiko; Horie, Syunji

    2002-04-25

    Mitragynine (1) is a major alkaloidal component in the Thai traditional medicinal herb, Mitragyna speciosa, and has been proven to exhibit analgesic activity mediated by opioid receptors. By utilizing this natural product as a lead compound, synthesis of some derivatives, evaluations of the structure-activity relationship, and surveys of the intrinsic activities and potencies on opioid receptors were performed with guinea pig ileum. The affinities of some compounds for mu-, delta-, and kappa-receptors were determined in a receptor binding assay. The essential structural moieties in the Corynanthe type indole alkaloids for inducing the opioid agonistic activity were also clarified. The oxidative derivatives of mitragynine, i.e., mitragynine pseudoindoxyl (2) and 7-hydroxymitragynine (12), were found as opioid agonists with higher potency than morphine in the experiment with guinea pig ileum. In addition, 2 induced an analgesic activity in the tail flick test in mice. PMID:11960505

  10. A prenylated xanthone with antimicrobial activity from the seeds of Symphonia globulifera.

    PubMed

    Ngouela, Silvère; Ndjakou, Bruno Lenta; Tchamo, Diderot Noungoue; Zelefack, Fabien; Tsamo, Etienne; Connolly, Joseph Donald

    2005-01-01

    A prenylated xanthone has been isolated from the seeds of Symphonia globulifera together with the known compounds sitosterol and oleanolic acid. The structure of the new compound was elucidated by spectroscopic methods. PMID:15700641

  11. Cytotoxic prenylated xanthones from the pericarps of Garcinia mangostana.

    PubMed

    Xu, Zeng; Huang, Lei; Chen, Xiao-Hong; Zhu, Xiao-Feng; Qian, Xiao-Jun; Feng, Gong-Kan; Lan, Wen-Jian; Li, Hou-Jin

    2014-01-01

    Bioassay-guided fractionation of an ethanol extract of the pericarps of Garcinia mangostana led to the isolation of two new prenylated xanthones, named 1,3,7-trihydroxy-2-(3-methyl-2-butenyl)-8-(3-hydroxy-3-methylbutyl)-xanthone (1) and 1,3,8-trihydroxy-2-(3-methyl-2-butenyl)-4-(3-hydroxy-3-methylbutanoyl)-xanthone (2), together with the five known compounds garcinones C (3) and D (4), gartanin (5), xanthone I (6), and γ-mangostin (7). Their structures were elucidated primarily based on MS and NMR data. Compounds 1-7 showed significant cytotoxic activities against various human cancer cell lines. PMID:24509722

  12. α-Glucosidase Inhibitory Prenylated Anthranols from Harungana madagascariensis.

    PubMed

    Johnson, Oluwatosin O; Zhao, Ming; Gunn, Jordan; Santarsiero, Bernard D; Yin, Zhi-Qi; Ayoola, Gloria A; Coker, H A B; Che, Chun-Tao

    2016-01-22

    Four new prenylated anthranols, harunganols C-F (1-4), along with kenganthranol A (5), harunganin (6), and ferruginin A (7), were identified from the leaves of Harungana madagascariensis. The structures of compounds 2, 5, and 7 were confirmed by single-crystal X-ray diffraction analysis. Compound 1 is a unique symmetrical anthranol dimer connected via a CH2 group. Compound 4 possesses a unique C-10 hemiketal group. All anthranols were evaluated for their α-glucosidase inhibitory activities. They displayed a higher potency compared to acarbose except for 3 and 4. In particular, harunganol C (1) showed an IC50 value of 1.2 μM. PMID:26727375

  13. Prenylated flavonoids from Desmodium caudatum and evaluation of their anti-MRSA activity.

    PubMed

    Sasaki, Hisako; Kashiwada, Yoshiki; Shibata, Hirofumi; Takaishi, Yoshihisa

    2012-10-01

    Seven prenylated flavonoids and a prenylated chromanochroman derivative, together with eight known flavonoids, were isolated from roots of Desmodium caudatum. The 15 structures were elucidated by extensive spectroscopic analyses. The antibacterial activity of many of other compounds was evaluated against methicillin-resistant Staphylococcus aureus (MRSA: COL and 5) by a disc diffusion method, and the minimum inhibitory concentrations (MICs) to MRSA were determined. PMID:22800912

  14. Modification of Prenylated Stilbenoids in Peanut (Arachis hypogaea) Seedlings by the Same Fungi That Elicited Them: The Fungus Strikes Back.

    PubMed

    Aisyah, Siti; Gruppen, Harry; Slager, Mathijs; Helmink, Bianca; Vincken, Jean-Paul

    2015-10-28

    Aspergillus oryzae and Rhizopus oryzae were compared for inducing the production of prenylated stilbenoids in peanut seedlings. The fungus was applied at two different time points: directly after soaking (day 1) or after 2 days of germination (day 3). Aspergillus- and Rhizopus-elicited peanut seedlings accumulated an array of prenylated stilbenoids, with overlap in compounds induced, but also with compounds specific to the fungal treatment. The differences were confirmed to be due to modification of prenylated stilbenoids by the fungus itself. Each fungus appeared to deploy different strategies for modification. The content of prenylated stilbenoids modified by fungi accounted for around 8% to 49% (w/w) of total stilbenoids. The contents of modified prenylated stilbenoids were higher when the fungus was applied on day 1 instead of day 3. Altogether, type of fungus and time point of inoculation appeared to be crucial parameters for optimizing accumulation of prenylated stilbenoids in peanut seedlings. PMID:26458982

  15. Effects of indole on drug resistance and virulence of Salmonella enterica serovar Typhimurium revealed by genome-wide analyses

    PubMed Central

    2012-01-01

    Background Many Gram-positive and Gram-negative bacteria produce large quantities of indole as an intercellular signal in microbial communities. Indole demonstrated to affect gene expression in Escherichia coli as an intra-species signaling molecule. In contrast to E. coli, Salmonella does not produce indole because it does not harbor tnaA, which encodes the enzyme responsible for tryptophan metabolism. Our previous study demonstrated that E. coli-conditioned medium and indole induce expression of the AcrAB multidrug efflux pump in Salmonella enterica serovar Typhimurium for inter-species communication; however, the global effect of indole on genes in Salmonella remains unknown. Results To understand the complete picture of genes regulated by indole, we performed DNA microarray analysis of genes in the S. enterica serovar Typhimurium strain ATCC 14028s affected by indole. Predicted Salmonella phenotypes affected by indole based on the microarray data were also examined in this study. Indole induced expression of genes related to efflux-mediated multidrug resistance, including ramA and acrAB, and repressed those related to host cell invasion encoded in the Salmonella pathogenicity island 1, and flagella production. Reduction of invasive activity and motility of Salmonella by indole was also observed phenotypically. Conclusion Our results suggest that indole is an important signaling molecule for inter-species communication to control drug resistance and virulence of S. enterica. PMID:22632036

  16. The Importance of the Prenyl Group in the Activities of Osthole in Enhancing Bone Formation and Inhibiting Bone Resorption In Vitro

    PubMed Central

    Zhai, Yuan-Kun; Pan, Ya-Lei; Niu, Yin-Bo; Li, Chen-Rui; Wu, Xiang-Long; Fan, Wu-Tu; Lu, Ting-Li; Mei, Qi-Bing; Xian, Cory J.

    2014-01-01

    Osteoporosis treatment always aimed at keeping the balance of bone formation and bone resorption. Recently, prenyl group in natural products has been proposed as an active group to enhance the osteogenesis process. Osthole has both the prenyl group and bone-protective activities, but the relationship is still unknown. In this study we found that osthole exerted a potent ability to promote proliferation and osteogenic function of rat bone marrow stromal cells and osteoblasts, including improved cell viability, alkaline phosphatase activity, enhanced secretion of collagen-I, bone morphogenetic protein-2, osteocalcin and osteopontin, stimulated mRNA expression of insulin-like growth factor-1, runt-related transcription factor-2, osterix, OPG (osteoprotegerin), RANKL (receptor activator for nuclear factor-κB ligand), and the ratio of OPG/RANKL, as well as increasing the formation of mineralized nodules. However, 7-methoxycoumarin had no obvious effects. Osthole also inhibited osteoclastic bone resorption to a greater extent than 7-methoxycoumarin, as shown by a lower tartrate-resistant acid phosphatase activity and lower number and smaller area of resorption pits. Our findings demonstrate that osthole could be a potential agent to stimulate bone formation and inhibit bone resorption, and the prenyl group plays an important role in these bone-protective effects. PMID:25147567

  17. Relationship between indole production and differentiation of Klebsiella species: indole-positive and -negative isolates of Klebsiella determined to be clonal.

    PubMed Central

    Maslow, J N; Brecher, S M; Adams, K S; Durbin, A; Loring, S; Arbeit, R D

    1993-01-01

    Klebsiellae are an important cause of nosocomial infections. The two clinically relevant species, Klebsiella pneumoniae and Klebsiella oxytoca, are differentiated by the ability to produce indole from tryptophan, K. oxytoca being indole positive. We report here the detailed biochemical and molecular analysis of two isolates of Klebsiella, cultured from the same urine specimen, that differed only in their ability to produce indole. The two isolates were identical as determined by ribotyping and pulsed-field gel electrophoresis, and they differed from 10 epidemiologically unrelated strains. Probing with the Escherichia coli tryptophanase operon, tna, revealed seven restriction fragment length polymorphisms (RFLP) among the 12 strains. The two index strains had identical RFLP; no single RFLP could account for all of the indole-positive or -negative strains. Thus, the identification of epidemiologically related strains of Klebsiella differing only in indole production may warrant further examination to determine whether the strains are clonal. Images PMID:8370726

  18. Environmental factors affecting indole metabolism under anaerobic conditions

    SciTech Connect

    Madsen, E.L.; Francis, A.J.; Bollag, J.M.

    1988-01-01

    The influence of physiological and environmental factors on the accumulation of oxindole during anaerobic indole metabolism was investigated by high-performance liquid chromatography. Under methanogenic conditions, indole was temporarily converted to oxindole in stoichiometric amounts in media inoculated with three freshwater sediments and an organic soil. In media inoculated with methanogenic sewage sludge, the modest amounts of oxindole detected at 35/sup 0/C reached higher concentrations and persisted longer when the incubation temperature was decreased from 35 to 15/sup 0/C. Also, decreasing the concentration of sewage sludge used as an inoculum from 50 to 1% caused an increase in the accumulation of oxindole from 10 to 75% of the indole added. Under denitrifying conditions, regardless of the concentration or source of the inoculum, oxindole appeared in trace amounts but did not accumulate during indole metabolism. In addition, denitrifying consortia which previously metabolized indole degraded oxindole with no lag period. Our data suggest that oxindole accumulation under methanogenic, but not under denitrifying conditions is caused by differences between relative rates of oxindole production and destruction.

  19. Toxic effects of brominated indoles and phenols on zebrafish embryos.

    PubMed

    Kammann, U; Vobach, M; Wosniok, W

    2006-07-01

    Organobromine compounds in the marine environment have been the focus of growing attention in past years. In contrast to anthropogenic brominated flame retardants, other brominated compounds are produced naturally, e.g., by common polychaete worms and algae. Brominated phenols and indoles assumed to be of biogenic origin have been detected in water and sediment extracts from the German Bight. These substances as well as some of their isomers have been tested with the zebrafish embryo test and were found to cause lethal as well as nonlethal malformations. The zebrafish test was able to detect a log K(OW)-related toxicity for bromophenols, suggesting nonpolar narcosis as a major mode of action. Different effect patterns could be observed for brominated indoles and bromophenols. The comparison of effective concentrations in the zebrafish embryo test with the concentrations determined in water samples suggests the possibility that brominated indoles may affect early life stages of marine fish species in the North Sea. PMID:16418895

  20. Synthesis of phenanthrene derivatives through the net [5+5]-cycloaddition of prenylated carbene complexes with 2-alkynylbenzaldehyde derivatives

    PubMed Central

    Menon, Suneetha; Sinha-Mahapatra, Dilip

    2007-01-01

    The reaction of prenylated carbene complexes and 2-alkynylbenzoyl derivatives has been investigated. Phenanthrene derivatives are produced if iodine is added prior to product isolation. Under these conditions alkyl migration reactions occur to form the observed products. The product yields are considerably higher using bis(prenylated) species owing to an increase in the effective molarity of dienophilic entities. PMID:18769535

  1. Chemoenzymatic syntheses of prenylated aromatic small molecules using Streptomyces prenyltransferases with relaxed substrate specificities

    PubMed Central

    Kumano, Takuto; Richard, Stéphane B.; Noel, Joseph P.; Nishiyama, Makoto; Kuzuyama, Tomohisa

    2010-01-01

    NphB is a soluble prenyltransferase from Streptomyces sp. strain CL190 that attaches a geranyl group to a 1,3,6,8-tetrahydroxynaphthalene-derived polyketide during the biosynthesis of anti-oxidant naphterpin. Here we report multiple chemoenzymatic syntheses of various prenylated compounds from aromatic substrates including flavonoids using two prenyltransferases NphB and SCO7190, a NphB homolog from Streptomyces coelicolor A3(2), as biocatalysts. NphB catalyzes carbon–carbon-based and carbon–oxygen-based geranylation of a diverse collection of hydroxyl-containing aromatic acceptors. Thus, this simple method using the prenyltransferases can be used to explore novel prenylated aromatic compounds with biological activities. Kinetic studies with NphB reveal that the prenylation reaction follows a sequential ordered mechanism. PMID:18682327

  2. Synthesis of prenylated benzaldehydes and their use in the synthesis of analogues of licochalcone A.

    PubMed

    Kromann, Hasse; Larsen, Mogens; Boesen, Thomas; Schønning, Kristian; Nielsen, Simon Feldbaek

    2004-11-01

    In this paper, a general applicable synthesis of prenylated aromatic compounds exemplified by prenylated benzaldehydes starting from readily available acetophenones is described. The synthesized benzaldehydes are used to prepare a number of novel analogues of Licochalcone A, a known antibacterial compound, and for the exploration of the pharmacophoric elements that are essential for the antibacterial activity. It is shown that the hydroxyl group in the A ring is essential for the activity and that the hydroxyl group in the B ring has no influence on the antibacterial effect of Licochalcone A. Furthermore, it is shown that the prenyl group at the position 5 of the B ring also has a dominating influence on the activity. This aliphatic group can be replaced by other lipophilic long chained substituents in order to maintain the activity. PMID:15501549

  3. Prenylated flavonoids and resveratrol derivatives isolated from Artocarpus communis with the ability to overcome TRAIL resistance.

    PubMed

    Toume, Kazufumi; Habu, Tadashi; Arai, Midori A; Koyano, Takashi; Kowithayakorn, Thaworn; Ishibashi, Masami

    2015-01-23

    In a screening program on natural products that can abrogate tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) resistance, four new prenylated flavonoid and resveratrol derivatives (1-4) were isolated from Artocarpus communis, together with eight known prenylflavonoids (5-12). The structures of 1-4 were elucidated spectroscopically. Pannokin D [corrected] (1) (2 μM) and artonin E (5) (3 μM) potently exhibited the ability to overcome TRAIL resistance. Artonin E (5) induced caspase-dependent apoptosis in combination with TRAIL, increased caspase 3/7 activity, and enhanced the protein levels of p53 and DR5. Moreover, this substance decreased cell viability in combination with TRAIL and enhanced the protein levels of DR5, and these effects were mediated by increases in the production of ROS (reactive oxygen species). Thus, artonin E (5) was found to induce extrinsic apoptotic cell death by the ROS- and p53-mediated up-regulation of DR5 expression in AGS cells. PMID:25537111

  4. Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus), Prevents Platelet Activation in Human Platelets

    PubMed Central

    Lee, Ye-Ming; Hsieh, Kuo-Hsien; Lu, Wan-Jung; Chou, Hsiu-Chu; Chou, Duen-Suey; Lien, Li-Ming; Sheu, Joen-Rong; Lin, Kuan-Hung

    2012-01-01

    Xanthohumol is the principal prenylated flavonoid in the hop plant (Humulus lupulus L.). Xanthohumol was found to be a very potent cancer chemopreventive agent through regulation of diverse mechanisms. However, no data are available concerning the effects of xanthohumol on platelet activation. The aim of this paper was to examine the antiplatelet effect of xanthohumol in washed human platelets. In the present paper, xanthohumol exhibited more-potent activity in inhibiting platelet aggregation stimulated by collagen. Xanthohumol inhibited platelet activation accompanied by relative [Ca2+]i mobilization, thromboxane A2 formation, hydroxyl radical (OH●) formation, and phospholipase C (PLC)γ2, protein kinase C (PKC), mitogen-activated protein kinase (MAPK), and Akt phosphorylation. Neither SQ22536, an inhibitor of adenylate cyclase, nor ODQ, an inhibitor of guanylate cyclase, reversed the xanthohumol-mediated inhibitory effect on platelet aggregation. Furthermore, xanthohumol did not significantly increase nitrate formation in platelets. This study demonstrates for the first time that xanthohumol possesses potent antiplatelet activity which may initially inhibit the PI3-kinase/Akt, p38 MAPK, and PLCγ2-PKC cascades, followed by inhibition of the thromboxane A2 formation, thereby leading to inhibition of [Ca2+]i and finally inhibition of platelet aggregation. Therefore, this novel role of xanthohumol may represent a high therapeutic potential for treatment or prevention of cardiovascular diseases. PMID:22611436

  5. Host-Mediated Post-Translational Prenylation of Novel Dot/Icm-Translocated Effectors of Legionella Pneumophila

    PubMed Central

    Price, Christopher T. D.; Jones, Snake C.; Amundson, Karen E.; Kwaik, Yousef Abu

    2010-01-01

    The Dot/Icm type IV translocated Ankyrin B (AnkB) effector of Legionella pneumophila is modified by the host prenylation machinery that anchors it into the outer leaflet of the Legionella-containing vacuole (LCV), which is essential for biological function of the effector in vitro and in vivo. Prenylation involves the covalent linkage of an isoprenoid lipid moiety to a C-terminal CaaX motif in eukaryotic proteins enabling their anchoring into membranes. We show here that the LCV harboring an ankB null mutant is decorated with prenylated proteins in a Dot/Icm-dependent manner, indicating that other LCV membrane-anchored proteins are prenylated. In silico analyses of four sequenced L. pneumophila genomes revealed the presence of eleven other genes that encode proteins with a C-terminal eukaryotic CaaX prenylation motif. Of these eleven designated Prenylated effectors of Legionella (Pel), seven are also found in L. pneumophila AA100. We show that six L. pneumophila AA100 Pel proteins exhibit distinct cellular localization when ectopically expressed in mammalian cells and this is dependent on action of the host prenylation machinery and the conserved cysteine residue of the CaaX motif. Although inhibition of the host prenylation machinery completely blocks intra-vacuolar proliferation of L. pneumophila, it only had a modest effect on intracellular trafficking of the LCV. Five of the Pel proteins are injected into human macrophages by the Dot/Icm type IV translocation system of L. pneumophila. Taken together, the Pel proteins are novel Dot/Icm-translocated effectors of L. pneumophila that are post-translationally modified by the host prenylation machinery, which enables their anchoring into cellular membranes, and the prenylated effectors contribute to evasion of lysosomal fusion by the LCV. PMID:21687755

  6. Tuning the Lewis acid phenol [Formula: see text]-prenylation as a molecular diversity tool.

    PubMed

    Jäger, Sebastián N; Porta, Exequiel O J; Labadie, Guillermo R

    2016-05-01

    A diversity-oriented approach for the synthesis of various structurally different prenylated alcohols from readily accessible and common precursors was developed. With varying approaches, this article describes some successful examples of a Friedel-Crafts alkylation using methoxyphenols and different prenyl alcohols (geraniol and (E,E)-farnesol). We demonstrated that just by varying the stoichiometry of the Lewis acid used, the course of the reaction can be shifted to produce the alkylated or the cyclized product. Eighteen unique products were obtained with good isolated yields by direct alkylation with or without a consecutive [Formula: see text]-cationic cyclization. PMID:26525879

  7. Five new prenylated stilbenes from the root bark of Lonchocarpus chiricanus.

    PubMed

    Ioset, J R; Marston, A; Gupta, M P; Hostettmann, K

    2001-06-01

    Besides the known compounds longistylines C (1), D (2), and 3,5-dimethoxystilbene (5), five new prenylated stilbenes, named chiricanines A--E (3, 4, 6--8), have been isolated from the root bark of Lonchocarpus chiricanus. Their structures were resolved on the basis of spectrometric methods including (1)H, (13)C, and 2D NMR experiments and mass spectrometry. Compound 3 was the only prenylated stilbene to demonstrate antifungal effects against Cladosporium cucumerinum. Four of the isolated compounds showed toxic properties against larvae of the yellow fever-transmitting mosquito Aedes aegypti. Compound 5 was found to be as potent as rotenone in larvicidal dilution tests. PMID:11421729

  8. Prenylation of Rab8 GTPase by type I and type II geranylgeranyl transferases.

    PubMed

    Wilson, A L; Erdman, R A; Castellano, F; Maltese, W A

    1998-08-01

    Rab GTPases are post-translationally modified by addition of geranylgeranyl moieties to carboxyl-terminal cysteine residues. For Rab proteins ending with xxCC xCxC and CCxx motifs this modification is catalysed by geranylgeranyltransferase type II (GGTaseII), and is entirely dependent on the Rab substrate being bound to Rab escort protein (REP). Several Rab proteins contain carboxyl-terminal CaaL prenylation motifs typical of members of the Rho family, which are modified in a REP-independent manner by geranylgeranyltransferase type I (GGTaseI). The present studies show that one such Rab protein (Rab8), which ends with a CVLL motif, is uniquely able to serve as a substrate for either REP/GGTaseII or GGTaseI in cell-free assays. The modification of Rab8 by GGTaseI did not require REP, indicating that a REP-induced conformational change is not essential for exposure of the Rab carboxyl-terminal cysteine prenylation site. To determine whether one enzyme plays a predominant role in Rab8 prenylation in vivo, the incorporation of [3H]mevalonate into Rab8 was measured in human embryonal kidney 293 cells under conditions where the activity of GGTaseI, but not GGTaseII, was blocked by the peptidomimetic inhibitor GGTI-298. The GGTaseI inhibitor did not prevent prenylation of either overexpressed Myc-tagged Rab8 or endogenous Rab8, whereas prenylation of a known GGTaseI substrate with the same carboxyl-terminal motif, Cdc42Hs, was completely blocked. To rule out the possibility that the apparent prenylation of Rab8 by GGTaseII occurs only when GGTaseI activity is eliminated, metabolic labelling studies were carried out in the absence of the GGTaseI inhibitor, using a REP-binding-deficient Rab8 construct (Y78D) that cannot serve as a substrate for GGTaseII, but is indistinguishable from wild-type Rab8 as a substrate for GGTaseI. Prenylation of the Y78D mutant was reduced by 60-70% in intact cells, consistent with the conclusion that the majority of Rab8 is prenylated by the

  9. Prenylation of Rab8 GTPase by type I and type II geranylgeranyl transferases.

    PubMed Central

    Wilson, A L; Erdman, R A; Castellano, F; Maltese, W A

    1998-01-01

    Rab GTPases are post-translationally modified by addition of geranylgeranyl moieties to carboxyl-terminal cysteine residues. For Rab proteins ending with xxCC xCxC and CCxx motifs this modification is catalysed by geranylgeranyltransferase type II (GGTaseII), and is entirely dependent on the Rab substrate being bound to Rab escort protein (REP). Several Rab proteins contain carboxyl-terminal CaaL prenylation motifs typical of members of the Rho family, which are modified in a REP-independent manner by geranylgeranyltransferase type I (GGTaseI). The present studies show that one such Rab protein (Rab8), which ends with a CVLL motif, is uniquely able to serve as a substrate for either REP/GGTaseII or GGTaseI in cell-free assays. The modification of Rab8 by GGTaseI did not require REP, indicating that a REP-induced conformational change is not essential for exposure of the Rab carboxyl-terminal cysteine prenylation site. To determine whether one enzyme plays a predominant role in Rab8 prenylation in vivo, the incorporation of [3H]mevalonate into Rab8 was measured in human embryonal kidney 293 cells under conditions where the activity of GGTaseI, but not GGTaseII, was blocked by the peptidomimetic inhibitor GGTI-298. The GGTaseI inhibitor did not prevent prenylation of either overexpressed Myc-tagged Rab8 or endogenous Rab8, whereas prenylation of a known GGTaseI substrate with the same carboxyl-terminal motif, Cdc42Hs, was completely blocked. To rule out the possibility that the apparent prenylation of Rab8 by GGTaseII occurs only when GGTaseI activity is eliminated, metabolic labelling studies were carried out in the absence of the GGTaseI inhibitor, using a REP-binding-deficient Rab8 construct (Y78D) that cannot serve as a substrate for GGTaseII, but is indistinguishable from wild-type Rab8 as a substrate for GGTaseI. Prenylation of the Y78D mutant was reduced by 60-70% in intact cells, consistent with the conclusion that the majority of Rab8 is prenylated by the

  10. Structural basis for the promiscuous biosynthetic prenylation of aromatic natural products

    PubMed Central

    Kuzuyama, Tomohisa; Noel, Joseph P.; Richard, Stéphane B.

    2010-01-01

    The anti-oxidant naphterpin is a natural product containing a polyketide-based aromatic core with an attached 10-carbon geranyl group derived from isoprenoid (terpene) metabolism1–3. Hybrid natural products such as naphterpin that contain 5-carbon (dimethylallyl), 10-carbon (geranyl) or 15-carbon (farnesyl) isoprenoid chains possess biological activities distinct from their non-prenylated aromatic precursors4. These hybrid natural products represent new anti-microbial, anti-oxidant, anti-inflammatory, anti-viral and anti-cancer compounds. A small number of aromatic prenyltransferases (PTases) responsible for prenyl group attachment have only recently been isolated and characterized5,6. Here we report the gene identification, biochemical characterization and high-resolution X-ray crystal structures of an architecturally novel aromatic PTase, Orf2 from Streptomyces sp. strain CL190, with substrates and substrate analogues bound. In vivo, Orf2 attaches a geranyl group to a 1,3,6,8-tetra-hydroxynaphthalene-derived polyketide during naphterpin biosynthesis. In vitro, Orf2 catalyses carbon–carbon-based and carbon–oxygen-based prenylation of a diverse collection of hydroxyl-containing aromatic acceptors of synthetic, microbial and plant origin. These crystal structures, coupled with in vitro assays, provide a basis for understanding and potentially manipulating the regio-specific prenylation of aromatic small molecules using this structurally unique family of aromatic PTases. PMID:15959519

  11. Isolation and synthesis of antibacterial prenylated acylphloroglu-cinols from Psorothamnus fremontii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antibacterial assay-guided fractionation of the methanol extract of the native American plant Psorothamnus fremontii followed by structure elucidation afforded three prenylated acylphloroglucinol derivatives, psorothatins A-C (1-3). They feature a unique a,ß-epoxyketone functionality and an a,ß-hydr...

  12. Alteration of protein prenylation promotes spermatogonial differentiation and exhausts spermatogonial stem cells in newborn mice

    PubMed Central

    Diao, Fan; Jiang, Chen; Wang, Xiu-Xing; Zhu, Rui-Lou; Wang, Qiang; Yao, Bing; Li, Chao-Jun

    2016-01-01

    Spermatogenesis in adulthood depends on the successful neonatal establishment of the spermatogonial stem cell (SSC) pool and gradual differentiation during puberty. The stage-dependent changes in protein prenylation in the seminiferous epithelium might be important during the first round of spermatogenesis before sexual maturation, but the mechanisms are unclear. We have previous found that altered prenylation in Sertoli cells induced spermatogonial apoptosis in the neonatal testis, resulting in adult infertility. Now we further explored the role of protein prenylation in germ cells, using a conditional deletion of geranylgeranyl diphosphate synthase (Ggpps) in embryonic stage and postmeiotic stage respectively. We observed infertility of Ggpps−/− Ddx4-Cre mice that displayed a Sertoli-cell-only syndrome phenotype, which resulted from abnormal spermatogonial differentiation and SSC depletion during the prepubertal stage. Analysis of morphological characteristics and cell-specific markers revealed that spermatogonial differentiation was enhanced from as early as the 7th postnatal day in the first round of spermatogenesis. Studies of the molecular mechanisms indicated that Ggpps deletion enhanced Rheb farnesylation, which subsequently activated mTORC1 and facilitated spermatogonial differentiation. In conclusion, the prenylation balance in germ cells is crucial for spermatogonial differentiation fate decision during the prepubertal stage, and the disruption of this process results in primary infertility. PMID:27374985

  13. Three new prenylated isoflavonoids from the root bark of Erythrina vogelii.

    PubMed

    Atindehou, K K; Queiroz, E F; Terreaux, C; Traore, D; Hostettmann, K

    2002-02-01

    Phytochemical investigation of the CH2Cl2 extract of Erythrina vogelii led to the isolation of five isoflavonoids. Three prenylated isoflavonoids are new natural compounds. The isolation of the antifungal compounds was monitored by inhibition of the growth of Cladosporium cucumerinum in a direct TLC bioautographic assay. The structures of these compounds were elucidated by spectroscopic techniques. PMID:11859477

  14. Antiparasitic activity of prenylated benzoic acid derivatives from Piper species.

    PubMed

    Flores, Ninoska; Jiménez, Ignacio A; Giménez, Alberto; Ruiz, Grace; Gutiérrez, David; Bourdy, Genevieve; Bazzocchi, Isabel L

    2009-03-01

    Fractionation of dichloromethane extracts from the leaves of Piper heterophyllum and P. aduncum afforded three prenylated hydroxybenzoic acids, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid, 3-[(2E,6E,10E)-11-carboxy-13-hydroxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl]-4,5-dihydroxybenzoic acid and 3-[(2E,6E,10E)-11-carboxy-14-hydroxy-3,7,15-trimethyl-2,6,10,15-hexadecatetraenyl]-4,5-dihydroxybenzoic acid, along with the known compounds, 4,5-dihydroxy-3-(E,E,E-11-formyl-3,7,15-trimethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid (arieianal), 3,4-dihydroxy-5-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 4-hydroxy-3-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid, 4-hydroxy-3-(3,7-dimethyl-2,6-octadienyl)benzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid. Their structures were elucidated on the basis of spectroscopic data, including homo- and heteronuclear correlation NMR experiments (COSY, HSQC and HMBC) and comparison with data reported in the literature. Riguera ester reactions and optical rotation measurements established the compounds as racemates. The antiparasitic activity of the compounds were tested against three strains of Leishmania spp., Trypanosoma cruzi and Plasmodium falciparum. The results showed that 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid exhibited potent and selective activity against L. braziliensis (IC(50) 6.5 microg/ml), higher that pentamidine used as control. Moreover, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl- 2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid showed moderate antiplasmodial (IC(50) 3.2 microg/ml) and trypanocidal (16.5 microg/ml) activities, respectively. PMID:19361822

  15. The prenyl group contributes to activities of phytoestrogen 8-prenynaringenin in enhancing bone formation and inhibiting bone resorption in vitro.

    PubMed

    Ming, Lei-Guo; Lv, Xiang; Ma, Xiao-Ni; Ge, Bao-Feng; Zhen, Ping; Song, Peng; Zhou, Jian; Ma, Hui-Ping; Xian, Cory J; Chen, Ke-Ming

    2013-03-01

    Previous studies have found that 8-prenylflavonoids have a higher osteogenic activity than do flavonoids, which suggested that the 8-prenyl group may play an active role in bone-protective properties. To address this hypothesis, activities of 8-prenylnaringenin (PNG) and naringenin (NG) in osteoblast and osteoclast differentiation and function were compared in vitro. PNG was found to have a stronger ability than NG to improve osteoblast differentiation and osteogenic function in cultured rat calvarial osteoblasts, as demonstrated by levels of alkaline phosphatase activity, osteocalcin, calcium deposition, and the number and area of mineralized bone nodules, as well as mRNA expression of osteogenesis-related genes Bmp-2, OSX, and Runx-2. In addition, although expression of osteoclastogenic inducer receptor activator of nuclear factor kappa-B ligand (RANKL) was not affected, that of osteoclastogenesis inhibitor osteoprotegerin (OPG) and consequently the OPG/RANKL ratio were increased, more potently by PNG than NG. PNG was also found to have a higher potency than NG in inhibiting the osteoclast formation in rabbit bone marrow cells and their resorptive activity, as revealed by lower numbers of osteoclasts formed, lower numbers and areas of bone resorption pits, and lower mRNA expression levels of tartrate-resistant acid phosphatase and cathepsin K. Furthermore, PNG induced apoptosis of mature osteoclasts at a higher degree and at an earlier time than did NG. These results indicate that the 8-prenyl group plays an important role and contributes to the higher bone-protective activity of PNG in comparison with NG. PMID:23389955

  16. Intracellular oxygen determined by respiration regulates localization of Ras and prenylated proteins

    PubMed Central

    Kim, A; Davis, R; Higuchi, M

    2015-01-01

    Reduction of mitochondrial DNA (mtDNA) content induces the reduction of oxidative phosphorylation and dependence on fermentative glycolysis, that is, the Warburg effect. In aggressive prostate cancer (PCa), the reduction of mtDNA reduces oxygen consumption, increases intracellular oxygen concentration, and induces constitutive activation of Ras. Many essential proteins for cell death, growth, differentiation, and development, such as Ras, require prenylation for subcellular localization and activation. Prenylation of a protein is defined as the attachment of isoprenoids to a cysteine residue at or near the C-terminus. 3-Hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR) produces isoprenoids, and is posttranslationally regulated by oxygen. We investigated a critical role of intracellular oxygen in membrane localization of prenylated proteins. Localization of prenylated proteins (H-Ras, prelamin A/C, and Rab5a) was observed in poorly differentiated PCa (PC-3) and well-differentiated PCa (LNCaP) cells. PC-3 cells exhibited high intracellular oxygen concentration, and H-Ras, prelamin A/C, and Rab5a were localized to various membranes (Golgi and plasma membrane, nuclear membrane, and early endosomes, respectively). Remarkably, exogenous hypoxia (0.2% O2) in PC-3 cells induced intracellular hypoxia and changed the localization of the prenylated proteins. H-Ras and Rab5a were translocated to cytosol, and prelamin A/C was in the nucleus forming an abnormal nuclear envelope. The localization was reversed by mevalonate indicating the involvement of mevalonate pathway. In contrast, in LNCaP cells, exhibiting low intracellular oxygen concentration, H-Ras and Rab5a were localized in the cytosol, and prelamin A/C was inside the nucleus forming an inadequate nuclear envelope. Exogenous hyperoxia (40% O2) increased the intracellular oxygen concentration and induced Ras translocation from cytosol to the membrane. Prelamin A/C was translocated to the nuclear membrane and formed a

  17. Strongly Acidic Auxin Indole-3-Methanesulfonic Acid

    PubMed Central

    Cohen, Jerry D.; Baldi, Bruce G.; Bialek, Krystyna

    1985-01-01

    A radiochemical synthesis is described for [14C]indole-3-methanesulfonic acid (IMS), a strongly acidic auxin analog. Techniques were developed for fractionation and purification of IMS using normal and reverse phase chromatography. In addition, the utility of both Fourier transform infrared spectrometry and fast atom bombardment mass spectrometry for analysis of IMS has been demonstrated. IMS was shown to be an active auxin, stimulating soybean hypocotyl elongation, bean first internode curvature, and ethylene production. IMS uptake by thin sections of soybean hypocotyl was essentially independent of solution pH and, when applied at a 100 micromolar concentration, IMS exhibited a basipetal polarity in its transport in both corn coleoptile and soybean hypocotyl sections. [14C]IMS should, therefore, be a useful compound to study fundamental processes related to the movement of auxins in plant tissues and organelles. PMID:16664007

  18. The use of chemometrics to study multifunctional indole alkaloids from Psychotria nemorosa (Palicourea comb. nov.). Part II: Indication of peaks related to the inhibition of butyrylcholinesterase and monoamine oxidase-A.

    PubMed

    Klein-Júnior, Luiz C; Viaene, Johan; Tuenter, Emmy; Salton, Juliana; Gasper, André L; Apers, Sandra; Andries, Jan P M; Pieters, Luc; Henriques, Amélia T; Vander Heyden, Yvan

    2016-09-01

    Psychotria nemorosa is chemically characterized by indole alkaloids and displays significant inhibitory activity on butyrylcholinesterase (BChE) and monoamine oxidase-A (MAO-A), both enzymes related to neurodegenerative disorders. In the present study, 43 samples of P. nemorosa leaves were extracted and fractionated in accordance to previously optimized methods (see Part I). These fractions were analyzed by means of UPLC-DAD and assayed for their BChE and MAO-A inhibitory potencies. The chromatographic fingerprint data was first aligned using correlation optimized warping and Principal Component Analysis to explore the data structure was performed. Multivariate calibration techniques, namely Partial Least Squares (PLS1), PLS2 and Orthogonal Projections to Latent Structure (O-PLS1), were evaluated for modelling the activities as a function of the fingerprints. Since the best results were obtained with O-PLS1 model (RMSECV=9.3 and 3.3 for BChE and MAO-A, respectively), the regression coefficients of the model were analyzed and plotted relative to the original fingerprints. Four peaks were indicated as multifunctional compounds, with the capacity to impair both BChE and MAO-A activities. In order to confirm these results, a semi-prep HPLC technique was used and a fraction containing the four peaks was purified and evaluated in vitro. It was observed that the fraction exhibited an IC50 of 2.12μgmL(-1) for BChE and 1.07μgmL(-1) for MAO-A. These results reinforce the prediction obtained by O-PLS1 modelling. PMID:27511709

  19. The glucosinolate breakdown product indole-3-carbinol acts as an auxin antagonist in roots of Arabidopsis thaliana.

    PubMed

    Katz, Ella; Nisani, Sophia; Yadav, Brijesh S; Woldemariam, Melkamu G; Shai, Ben; Obolski, Uri; Ehrlich, Marcelo; Shani, Eilon; Jander, Georg; Chamovitz, Daniel A

    2015-05-01

    The glucosinolate breakdown product indole-3-carbinol functions in cruciferous vegetables as a protective agent against foraging insects. While the toxic and deterrent effects of glucosinolate breakdown on herbivores and pathogens have been studied extensively, the secondary responses that are induced in the plant by indole-3-carbinol remain relatively uninvestigated. Here we examined the hypothesis that indole-3-carbinol plays a role in influencing plant growth and development by manipulating auxin signaling. We show that indole-3-carbinol rapidly and reversibly inhibits root elongation in a dose-dependent manner, and that this inhibition is accompanied by a loss of auxin activity in the root meristem. A direct interaction between indole-3-carbinol and the auxin perception machinery was suggested, as application of indole-3-carbinol rescues auxin-induced root phenotypes. In vitro and yeast-based protein interaction studies showed that indole-3-carbinol perturbs the auxin-dependent interaction of Transport Inhibitor Response (TIR1) with auxin/3-indoleacetic acid (Aux/IAAs) proteins, further supporting the possibility that indole-3-carbinol acts as an auxin antagonist. The results indicate that chemicals whose production is induced by herbivory, such as indole-3-carbinol, function not only to repel herbivores, but also as signaling molecules that directly compete with auxin to fine tune plant growth and development. PMID:25758811

  20. An evaluation of synthetic indole derivatives as inhibitors of monoamine oxidase.

    PubMed

    Chirkova, Zhanna V; Kabanova, Mariya V; Filimonov, Sergey I; Abramov, Igor G; Petzer, Anél; Petzer, Jacobus P; Suponitsky, Kyrill Yu

    2016-05-01

    In a recent study we have shown that several indole-5,6-dicarbonitrile derivatives are potent inhibitors of human monoamine oxidase (MAO) A and B. To expand on these results and to further determine structure-activity relationships (SARs) for MAO inhibition by this chemical class, the present study investigates the MAO inhibition properties of additional indole-5,6-dicarbonitriles and related indole-5,6-dicarboxylic acid and pyrrolo[3,4-f]indole-5,7-dione derivatives. Among the active compounds two pyrrolo[3,4-f]indole-5,7-dione derivatives inhibited MAO-A (4g) and MAO-B (4d) with IC50 values of 0.250 and 0.581μM, respectively. In general indole-5,6-dicarbonitriles, however, exhibit higher MAO inhibition potencies while indole-5,6-dicarboxylic acids are weak MAO inhibitors. Active MAO inhibitors such as 4g and 4d may be used as leads for the development of drugs for the treatment of disease states such as Parkinson's disease and depression. MAO inhibitors are also under investigation as potential agents for the treatment of prostate cancer, certain types of cardiomyopathies and Alzheimer's disease. PMID:27020523

  1. Characterization of a Novel Phenol Hydroxylase in Indoles Biotranformation from a Strain Arthrobacter sp. W1

    PubMed Central

    Li, Xinliang; Zhang, Xuwang; Zhou, Jiti

    2012-01-01

    Background Indigoids, as popular dyes, can be produced by microbial strains or enzymes catalysis. However, the new valuable products with their transformation mechanisms, especially inter-conversion among the intermediates and products have not been clearly identified yet. Therefore, it is necessary to investigate novel microbial catalytic processes for indigoids production systematically. Findings A phenol hydroxylase gene cluster (4,606 bp) from Arthrobacter sp. W1 (PHw1) was obtained. This cluster contains six components in the order of KLMNOP, which exhibit relatively low sequence identities (37–72%) with known genes. It was suggested that indole and all the tested indole derivatives except for 3-methylindole were transformed to various substituted indigoid pigments, and the predominant color products derived from indoles were identified by spectrum analysis. One new purple product from indole, 2-(7-oxo-1H-indol-6(7H)-ylidene) indolin-3-one, should be proposed as the dimerization of isatin and 7-hydroxylindole at the C-2 and C-6 positions. Tunnel entrance and docking studies were used to predict the important amino acids for indoles biotransformation, which were further proved by site-directed mutagenesis. Conclusions/Significance We showed that the phenol hydroxylase from genus Arthrobacter could transform indoles to indigoids with new chemical compounds being produced. Our work should show high insights into understanding the mechanism of indigoids bio-production. PMID:23028517

  2. Fecal Indole as a Biomarker of Susceptibility to Cryptosporidium Infection.

    PubMed

    Chappell, Cynthia L; Darkoh, Charles; Shimmin, Lawrence; Farhana, Naveed; Kim, Do-Kyun; Okhuysen, Pablo C; Hixson, James

    2016-08-01

    Cryptosporidium causes significant diarrhea worldwide, especially among children and immunocompromised individuals, and no effective drug treatment is currently available for those who need it most. In this report, previous volunteer infectivity studies have been extended to examine the association between fecal indole and indole-producing (IP) gut microbiota on the outcome of a Cryptosporidium infection. Fecal indole concentrations (FICs) of 50 subjects and 19 taxa of common gut microbiota, including six IP taxa (11 subjects) were determined in stool samples collected before and after a challenge with Cryptosporidium oocysts. At the baseline, the mean FIC (± the standard deviation) was 1.66 ± 0.80 mM in those who became infected after a challenge versus 3.20 ± 1.23 mM in those who remained uninfected (P = 0.0001). Only 11.1% of the subjects with a FIC of >2.5 mM became infected after a challenge versus 65.2% of the subjects with a FIC of <2.5 mM. In contrast, the FICs of infected subjects at the baseline or during diarrhea were not correlated with infection intensity or disease severity. The relative abundances (percent) of Escherichia coli, Bacillus spp., and Clostridium spp. were greater ≥2.5-fold in volunteers with a baseline FIC of >2.5 mM, while those of Bacteroides pyogenes, B. fragilis, and Akkermansia muciniphila were greater in those with a baseline FIC of <2.5 mM. These data indicate that some IP bacteria, or perhaps indole alone, can influence the ability of Cryptosporidium to establish an infection. Thus, preexisting indole levels in the gut join the oocyst dose and immune status as important factors that determine the outcome of Cryptosporidium exposure. PMID:27245413

  3. Simultaneous extraction and HPLC determination of 3-indole butyric acid and 3-indole acetic acid in pea plant by using ionic liquid-modified silica as sorbent.

    PubMed

    Sheikhian, Leila; Bina, Sedigheh

    2016-01-15

    In this study, ionic liquid-modified silica was used as sorbent for simultaneous extraction and preconcentration of 3-indole butyric acid and 3-indole acetic acid in pea plants. The effect of some parameters such as pH and ionic strength of sample solution, amount of sorbent, flow rate of aqueous sample solution and eluent solution, concentration of eluent solution, and temperature were studied for each hormone solution. Percent extraction of 3-indole butyric acid and 3-indole acetic acid was strongly affected by pH of aqueous sample solution. Ionic strength of aqueous phase and temperature showed no serious effects on extraction efficiency of studied plant hormones. Obtained breakthrough volume was 200mL for each of studied hormones. Preconcentration factor for spectroscopic and chromatographic determination of studied hormones was 100 and 4.0×10(3) respectively. Each solid sorbent phase was reusable for almost 10 times of extraction/stripping procedure. Relative standard deviations of extraction/stripping processes of 3-indole butyric acid and 3-indole acetic acid were 2.79% and 3.66% respectively. The calculated limit of detections for IBA and IAA were 9.1×10(-2)mgL(-1) and 1.6×10(-1)mgL(-1) respectively. PMID:26701202

  4. Nucleoplasmic localization of prelamin A: implications for prenylation-dependent lamin A assembly into the nuclear lamina.

    PubMed Central

    Lutz, R J; Trujillo, M A; Denham, K S; Wenger, L; Sinensky, M

    1992-01-01

    The synthesis of the nuclear lamina protein lamin A requires the prenylation-dependent processing of its precursor protein, prelamin A. Unlike p21ras, which undergoes similar initial posttranslational modifications, maturation of lamin A results in the proteolytic removal of the prenylated portion of the molecule. We have used an in vitro prenylation system to demonstrate the nature of the prenyl substituent on prelamin A to be a farnesyl group. Further, the in vitro farnesylation of prelamin A requires an intact cysteine-aliphatic-aliphatic-other (CAAX) amino acid sequence motif at its carboxyl terminus. The effect of blocking the prenylation of prelamin A on its localization and assembly into the nuclear lamina was investigated by indirect immunofluorescence. Expression of wild-type prelamin A in lovastatin-treated cells showed that nonprenylated prelamin A accumulated as nucleoplasmic particles. Upon addition of mevalonate to lovastatin-treated cells, the wild-type lamin A was incorporated into the lamina within 3 hr. Expression of a mutant lamin A in which the carboxyl-terminal 21 amino acids were deleted resulted in a lamin molecule that was directly assembled into the lamina. These results indicate that the carboxyl-terminal peptide of prelamin A blocks its proper assembly into the nuclear lamina and that the prenylation-initiated removal of this peptide can occur in the nucleus. Images PMID:1557405

  5. Prenylation differentially inhibits insulin-dependent immediate early gene mRNA expression.

    PubMed

    Franklin, J Lee; Amsler, Maggie O; Messina, Joseph L

    2016-06-01

    Increased activity of prenyl transferases is observed in pathological states of insulin resistance, diabetes, and obesity. Thus, functional inhibitors of farnesyl transferase (FTase) and geranylgeranyl transferase (GGTase) may be promising therapeutic treatments. We previously identified insulin responsive genes from a rat H4IIE hepatoma cell cDNA library, including β-actin, EGR1, Pip92, c-fos, and Hsp60. In the present study, we investigated whether acute treatment with FTase and GGTase inhibitors would alter insulin responsive gene initiation and/or elongation rates. We observed differential regulation of insulin responsive gene expression, suggesting a differential sensitivity of these genes to one or both of the specific protein prenylation inhibitors. PMID:27086854

  6. Prenylated flavonoids from the roots of Desmodium caudatum and evaluation of their antifungal activity.

    PubMed

    Sasaki, Hisako; Kashiwada, Yoshiki; Shibatav, Hirofumi; Takaishi, Yoshihisa

    2012-11-01

    Two new prenylated flavonoids (1, 4) and two new prenylated C-methyl-flavonoids (6, 7), together with four known flavonoids (2, 3, 5, 8), were isolated from the roots of Desmodium caudatum. The structures of the new compounds were elucidated by extensive spectroscopic analyses including 1D-, 2D-NMR and MS. The antifungal activities of five compounds (1, 2, 4, 6, 8) as well as nine flavonoids (9-17) previously isolated from this plant against Aspergillus niger, Penicillium sp., Rhizopus sp., and Trichophyton sp. were evaluated. Compound 6 showed potent antifungal activity against Trichophyton sp. with a minimum inhibitory concentration (MIC) value of 1.95 µg/mL. PMID:23059627

  7. Detoxification of Indole by an Indole-Induced Flavoprotein Oxygenase from Acinetobacter baumannii.

    PubMed

    Lin, Guang-Huey; Chen, Hao-Ping; Shu, Hung-Yu

    2015-01-01

    Indole, a derivative of the amino acid tryptophan, is a toxic signaling molecule, which can inhibit bacterial growth. To overcome indole-induced toxicity, many bacteria have developed enzymatic defense systems to convert indole to non-toxic, water-insoluble indigo. We previously demonstrated that, like other aromatic compound-degrading bacteria, Acinetobacter baumannii can also convert indole to indigo. However, no work has been published investigating this mechanism. Here, we have shown that the growth of wild-type A. baumannii is severely inhibited in the presence of 3.5 mM indole. However, at lower concentrations, growth is stable, implying that the bacteria may be utilizing a survival mechanism to oxidize indole. To this end, we have identified a flavoprotein oxygenase encoded by the iifC gene of A. baumannii. Further, our results suggest that expressing this recombinant oxygenase protein in Escherichia coli can drive indole oxidation to indigo in vitro. Genome analysis shows that the iif operon is exclusively present in the genomes of A. baumannii and Pseudomonas syringae pv. actinidiae. Quantitative PCR and Western blot analysis also indicate that the iif operon is activated by indole through the AraC-like transcriptional regulator IifR. Taken together, these data suggest that this species of bacteria utilizes a novel indole-detoxification mechanism that is modulated by IifC, a protein that appears to be, at least to some extent, regulated by IifR. PMID:26390211

  8. Detoxification of Indole by an Indole-Induced Flavoprotein Oxygenase from Acinetobacter baumannii

    PubMed Central

    Lin, Guang-Huey; Chen, Hao-Ping; Shu, Hung-Yu

    2015-01-01

    Indole, a derivative of the amino acid tryptophan, is a toxic signaling molecule, which can inhibit bacterial growth. To overcome indole-induced toxicity, many bacteria have developed enzymatic defense systems to convert indole to non-toxic, water-insoluble indigo. We previously demonstrated that, like other aromatic compound-degrading bacteria, Acinetobacter baumannii can also convert indole to indigo. However, no work has been published investigating this mechanism. Here, we have shown that the growth of wild-type A. baumannii is severely inhibited in the presence of 3.5 mM indole. However, at lower concentrations, growth is stable, implying that the bacteria may be utilizing a survival mechanism to oxidize indole. To this end, we have identified a flavoprotein oxygenase encoded by the iifC gene of A. baumannii. Further, our results suggest that expressing this recombinant oxygenase protein in Escherichia coli can drive indole oxidation to indigo in vitro. Genome analysis shows that the iif operon is exclusively present in the genomes of A. baumannii and Pseudomonas syringae pv. actinidiae. Quantitative PCR and Western blot analysis also indicate that the iif operon is activated by indole through the AraC-like transcriptional regulator IifR. Taken together, these data suggest that this species of bacteria utilizes a novel indole-detoxification mechanism that is modulated by IifC, a protein that appears to be, at least to some extent, regulated by IifR. PMID:26390211

  9. Unusual cyclic terpenoids with terminal pendant prenyl moieties: from occurrence to synthesis.

    PubMed

    Kulcitki, Veaceslav; Harghel, Petru; Ungur, Nicon

    2014-12-01

    The paper reviews the known examples of cyclic terpenoids produced from open chain polyenic precursors by an "unusual" biosynthetic pathway, involving selective electrophilic attack on an internal double bond followed by cyclization. The resulting compounds possess cyclic backbones with pendant terminal prenyl groups. Synthetic approaches applied for the synthesis of such specifically functionalized compounds are also discussed, as well as biological activity of reported representatives. PMID:25118808

  10. Six new prenylated acetophenone derivatives from the leaves of Acronychia oligophlebia.

    PubMed

    Yang, Xian; Zhang, Yu-Bo; Wu, Zhong-Nan; Zhang, Xiang-Qiang; Jiang, Jian-Wei; Li, Yao-Lan; Wang, Guo-Cai

    2015-09-01

    Six new prenylated acetophenone derivatives were isolated from the leaves of Acronychia oligophlebia. The chemical structures of them were elucidated by extensive analysis of spectroscopic data (IR, UV, HRESIMS, 1D and 2D NMR). The cytotoxic activity of the isolates was evaluated against MCF-7 cells. Among these compounds, 2 and 6 exhibited mild cytotoxic activity with IC50 values of 33.5 and 25.6 μM, respectively. PMID:26160157

  11. Cytotoxic and leishmanicidal properties of garcinielliptone FC, a prenylated benzophenone from Platonia insignis.

    PubMed

    Costa Júnior, Joaquim S; de Almeida, Antonia Amanda Cardoso; de Barros Falcão Ferraz, Alexandre; Rossatto, Raíssa Rebés; Silva, Teresinha G; Silva, Paulo B N; Militão, Gardenia C G; das Graças Lopes Citó, Antonia Maria; Santana, Lorena Citó Lopes Resende; de Amorim Carvalho, Fernando Aécio; Freitas, Rivelilson M

    2013-03-01

    Garcinielliptone FC (GFC), a natural prenylated benzophenone, was extracted from Platonia insignis Mart. (Clusiaceae), a native plant commonly known as bacuri and used in traditional Brazilian medicine for the treatment of skin diseases. The aim of this study was to evaluate the cytotoxic and leishmanicidal effects of GFC using in vitro models. The experimental data demonstrated that the polyisoprenylated benzophenone GFC possesses cytotoxic and leishmanicidal activities. PMID:22708546

  12. Four new prenylated flavonoids and xanthones from the root bark of Artocarpus nobilis.

    PubMed

    Jayasinghe, U L B; Samarakoon, T B; Kumarihamy, B M M; Hara, N; Fujimoto, Y

    2008-01-01

    Chemical investigation of the n-butanol extract from the methanol extract of the root bark of Artocarpus nobilis furnished four new prenylated flavonoids together with artonin E 2'-methylether (4), isoartonin E 2'-methylether (5), dihydroisoartonin E 2'-methylether (6), artonin V 2'-methylether (7), artobiloxanthone (1), artonin E (2) and cycloartobiloxanthone (3). All these compounds showed strong radical scavenging properties towards DPPH radical. PMID:17855020

  13. Interactions of Indole Derivatives with β-Cyclodextrin: A Quantitative Structure-Property Relationship Study

    PubMed Central

    Šoškić, Milan; Porobić, Ivana

    2016-01-01

    Retention factors for 31 indole derivatives, most of them with auxin activity, were determined by high-performance liquid chromatography, using bonded β-cyclodextrin as a stationary phase. A three-parameter QSPR (quantitative structure-property relationship) model, based on physico-chemical and structural descriptors was derived, which accounted for about 98% variations in the retention factors. The model suggests that the indole nucleus occupies the relatively apolar cavity of β-cyclodextrin while the carboxyl group of the indole -3-carboxylic acids makes hydrogen bonds with the hydroxyl groups of β-cyclodextrin. The length and flexibility of the side chain containing carboxyl group strongly affect the binding of these compounds to β-cyclodextrin. Non-acidic derivatives, unlike the indole-3-carboxylic acids, are poorly retained on the column. A reasonably well correlation was found between the retention factors of the indole-3-acetic acids and their relative binding affinities for human serum albumin, a carrier protein in the blood plasma. A less satisfactory correlation was obtained when the retention factors of the indole derivatives were compared with their affinities for auxin-binding protein 1, a plant auxin receptor. PMID:27124734

  14. Interactions of Indole Derivatives with β-Cyclodextrin: A Quantitative Structure-Property Relationship Study.

    PubMed

    Šoškić, Milan; Porobić, Ivana

    2016-01-01

    Retention factors for 31 indole derivatives, most of them with auxin activity, were determined by high-performance liquid chromatography, using bonded β-cyclodextrin as a stationary phase. A three-parameter QSPR (quantitative structure-property relationship) model, based on physico-chemical and structural descriptors was derived, which accounted for about 98% variations in the retention factors. The model suggests that the indole nucleus occupies the relatively apolar cavity of β-cyclodextrin while the carboxyl group of the indole -3-carboxylic acids makes hydrogen bonds with the hydroxyl groups of β-cyclodextrin. The length and flexibility of the side chain containing carboxyl group strongly affect the binding of these compounds to β-cyclodextrin. Non-acidic derivatives, unlike the indole-3-carboxylic acids, are poorly retained on the column. A reasonably well correlation was found between the retention factors of the indole-3-acetic acids and their relative binding affinities for human serum albumin, a carrier protein in the blood plasma. A less satisfactory correlation was obtained when the retention factors of the indole derivatives were compared with their affinities for auxin-binding protein 1, a plant auxin receptor. PMID:27124734

  15. Degradation of indole by Alcaligenes spec.

    PubMed

    Claus, G; Kutzner, H J

    1983-01-01

    Alcaligenes spec. strain In 3 was isolated from an enrichment culture with indole inoculated with activated sludge. The organism was able to grow with indole as sole source of carbon and nitrogen. During growth with this substrate indigo and anthranilate accumulated in the culture broth. By measurement of the oxidation of intermediates (O(2)-uptake) and determination of the activity of enzymes responsible for ring cleavage the following pathway for indole degradation could be established: indole → indoxyl → isatin → anthranilate → gentisate → maleyl pyruvate → fumaryl pyruvate → fumarate + pyruvate. - Alcaligenes spec. strain In 3 was also able to grow with various aromatic compounds; these were degraded by ortho- or meta-cleavage or via the gentisinic acid pathway. PMID:23194589

  16. Evidence for Prenylation-Dependent Targeting of a Ykt6 SNARE in Plasmodium falciparum

    PubMed Central

    Ayong, Lawrence; DaSilva, Thiago; Mauser, Jennifer; Allen, Charles M.; Chakrabarti, Debopam

    2011-01-01

    Ykt6 proteins are the most versatile fusogens in eukaryotic cells, and the only SNAREs that can be both prenylated and acylated at a C-terminal CAAX motif. Unlike yeast and mammalian cells where a single Ykt6 gene is expressed, the Plasmodium falciparum genome encodes two Ykt6 proteins. We have investigated the expression and prenylation of the Ykt6 orthologue, PfYkt6.1in intra-erythrocytic stages of P. falciparum. PfYkt6.1 localized to the parasite Golgi and other unidentified cytoplasmic compartments, and was partly cytosolic (~50% in early trophozoites). The membrane-association of PfYkt6.1 was dependent on presence of a conserved C-terminal CAAX motif (CCSIM). By expressing full-length and mutant proteins in Escherichia coli, we have shown that PfYkt6.1 indeed serves as substrate for prenylation by P. falciparum farnesyltransferases. Surprisingly, PfYkt6.1 could also be geranylgeranylated by parasite extracts independent of the C-terminal amino acid residue. Deletion of the CAAX motif inhibited both farnesylation and geranylgeranylation activities. Additionally, the PfYkt6.1 heptapeptide KQCCSIM, corresponding to the C-terminal CAAX sequence, inhibited the parasite farnesyltransferase activity with an IC50 of 1 µM. Our findings underscore the importance of CAAX motif-derived peptidomimetics for antimalarial drug development. PMID:21075148

  17. Rhodium-catalyzed pyridannulation of indoles with diazoenals: a direct approach to pyrido[1,2-a]indoles.

    PubMed

    Dawande, Sudam Ganpat; Lad, Bapurao Sudam; Prajapati, Sunitkumar; Katukojvala, Sreenivas

    2016-06-28

    A novel rhodium catalyzed pyridannulation of 3-substituted indoles with diazoenals furnished privileged pyrido[1,2-a]indoles. The reaction is proposed to involve a [4 + 2]-annulation of the diacceptor rhodium enalcarbenoid via C-2 functionalization of the indole. The utility of the methodology was demonstrated with a short synthesis of the tetrahydropyrido[1,2-a]indole core, present in a large number of biologically important polycyclic indole alkaloids. PMID:26964882

  18. Indoles in edible members of the Cruciferae.

    PubMed

    Wall, M E; Taylor, H; Perera, P; Wani, M C

    1988-01-01

    Antimutagenic fractions from collards yielded indole-3-carboxaldehyde [4] and traces of indole-3-acetonitrile [2]. The compounds had no antimutagenic activity. An analytical procedure for various indoles in plants was developed based on reversed-phase hplc. The indoles studied included the 3-carbinol 1, the acetonitrile 2, the carboxaldehyde 4, the 3-carboxylic acid 5, and the 3-acetic acid 6. Many Cruciferae and non-Cruciferae were analyzed. The latter did not contain measurable quantities of these compounds. In the case of the Cruciferae--with the exception of collards, which consistently indicated the presence of the aldehyde 4--major indole found was the nitrile 2. Although a particularly careful search for the carbinol 1 was conducted, only trace levels were noted. A review of the literature indicates that the content and occurrence of this indole in plants have been heavily overestimated. Because of the low levels found in the Cruciferae, our studies indicate that the role of the compound as a dietary factor may be questionable. PMID:3373222

  19. Degradation of substituted indoles by an indole-degrading methanogenic consortium

    SciTech Connect

    Jidong Gu; Berry, D.F. )

    1991-09-01

    Degradation of indole-degrading methanogenic consortium enriched from sewage sludge proceeded through a two-step hydroxylation pathway yielding oxindole and isatin. The ability of this consortium to hydroxylate and subsequently degrade-substituted indoles was investigated. Of the substituted indoles tested, the consortium was able to transform or degrade 3-methylindole, and 3-indolyl acetate. Oxindole, 3-methyloxindole, and indoxyl were identified as metabolites of indole, 3-methylindole, and 3-indolyl acetate degradation, respectively. Isatin (indole-2, 3-dione) was produced as an intermediate when the acetate degradation, respectively, Isatin (indole-2,3-dione) was produced as an intermediate when the consortium was amended with oxindole, providing evidence that degradation of indole proceeded through successive hydroxylation of the 2- and 3-positions prior to ring cleavage between the C-2 and C-3 atoms on the pyrrole ring of indole. The presence of a methyl group ({emdash}CH{sub 3}) at either the 1- or 2-position of indole inhibited the initial hydroxylation reaction. The substituted indole, 3-methylindole, was hydroxylated in the 2-position but not in the 3 position and could not be further metabolized through the oxindole-isatin pathway. Indoxyl (indole-3-one), the deacetylated product of 3-indolyl acetate, was not hydroxylated in the 2-position and thus was not further metabolized by the consortium. When an H atom or electron-donating group (i.e., {emdash}CH{sub 3}) was present at the 3-position, hydroxylation proceeded at the 2-position, but the presence of electron-withdrawing substituent groups (i.e., {emdash}OH or {emdash}COOH) at the 3-position inhibited hydroxylation.

  20. Synthesis of pharmacologically active indoles.

    PubMed

    Hishmat, O H; Ebeid, M Y; Nakkady, S S; Fathy, M M; Mahmoud, S S

    1999-06-01

    Formylation of 6-methoxy-1-methyl and 5-methyl,2,3-diphenyl-1H-indole (Ib and IX) gave the 5- and 6- carboxaldehyde derivatives (II and X) respectively, which were treated with ethyl cyanoacetate to form the corresponding 2-cyano-3-substituted acrylic acid ethyl ester (III and XI). The latter compounds reacted with hydrazine hydrate, urea and thiourea to form the corresponding 5-amino-4-substituted 2,4,dihydropyrazol-3- one (IV), 6-indolyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile s (V and XII) and 6-indolyl-4-oxo-2-thixo-1,2,3,4-tetrahydropyrimidine-5-ca rbonitriles (VI and XIII). Reaction of the 5- and 6-carboxaldehyde derivatives with malononitrile afforded the 2-substituted malononitrile derivatives (VII and XIV). VII and XIV reacted readilly with aromatic ketones to give the 2-amino4,6-disubstituted nicotinonitriles (VIII a,b and XVa,b). The biological activity of compounds Ia, Ib, II, III, IX and X was tested for antiinflammatory, ulcerogenic and antispasmodic activities. PMID:10464975

  1. Catalytic functionalization of indoles in a new dimension.

    PubMed

    Bandini, Marco; Eichholzer, Astrid

    2009-01-01

    140 years ago Adolf von Baeyer proposed the structure of a heteroaromatic compound which revolutionized organic and medical chemistry: indole. After more than a century, indole itself and the complexity of naturally occurring indole derivatives continue to inspire and influence developments in synthetic chemistry. In particular, the ubiquitous presence of indole rings in pharmaceuticals, agrochemicals, and functional materials are testament to the ever increasing interest in the design of mild and efficient synthetic routes to functionalized indole derivatives. This Review emphasizes the achievements in the selective catalytic functionalization of indoles (C-C bond-forming processes) over the last four years. PMID:19946913

  2. Production of prenylated flavonoids in tomato fruits expressing a prenyltransferase gene from Streptomyces coelicolor A3(2).

    PubMed

    Koeduka, T; Shitan, N; Kumano, T; Sasaki, K; Sugiyama, A; Linley, P; Kawasaki, T; Ezura, H; Kuzuyama, T; Yazaki, K

    2011-03-01

    Flavonoids are natural compounds found in many plants, including the important fruit crop, tomato. Prenylated flavonoids consist of a large group of compounds, which often exhibit antitumour, antibacterial and/or anti-androgen activities. In this study, we engineered the biosynthesis of prenylated flavonoids using a Streptomyces prenyltransferase HypSc (SCO7190) possessing broad-range substrate specificity, in tomato as a host plant. LC/MS/MS analysis demonstrated the generation of 3'-dimethylallyl naringenin in tomato fruits when recombinant HypSc protein was targeted to the plastids, whereas the recombinant protein hardly produced this compound in vitro. This is the first report confirming the accumulation of a prenylated flavonoid using a bacterial prenyltransferase in transgenic plants, and our results suggest that the product specificities of prenyltransferases can be significantly influenced by the host plant. PMID:21309988

  3. Prenylated xanthones from mangosteen as promising cholinesterase inhibitors and their molecular docking studies.

    PubMed

    Khaw, K Y; Choi, S B; Tan, S C; Wahab, H A; Chan, K L; Murugaiyah, V

    2014-09-25

    Garcinia mangostana is a well-known tropical plant found mostly in South East Asia. The present study investigated acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of G. mangostana extract and its chemical constituents using Ellman's colorimetric method. Cholinesterase inhibitory-guided approach led to identification of six bioactive prenylated xanthones showing moderate to potent cholinesterases inhibition with IC50 values of lower than 20.5 μM. The most potent inhibitor of AChE was garcinone C while γ-mangostin was the most potent inhibitor of BChE with IC50 values of 1.24 and 1.78 μM, respectively. Among the xanthones, mangostanol, 3-isomangostin, garcinone C and α-mangostin are AChE selective inhibitors, 8-deoxygartanin is a BChE selective inhibitor while γ-mangostin is a dual inhibitor. Preliminary structure-activity relationship suggests the importance of the C-8 prenyl and C-7 hydroxy groups for good AChE and BChE inhibitory activities. The enzyme kinetic studies indicate that both α-mangostin and garcinone C are mixed-mode inhibitors, while γ-mangostin is a non-competitive inhibitor of AChE. In contrast, both γ-mangostin and garcinone C are uncompetitive inhibitors, while α-mangostin is a mixed-mode inhibitor of BChE. Molecular docking studies revealed that α-mangostin, γ-mangostin and garcinone C interacts differently with the five important regions of AChE and BChE. The nature of protein-ligand interactions is mainly hydrophobic and hydrogen bonding. These bioactive prenylated xanthones are worthy for further investigations. PMID:25172794

  4. Isolation and characterization of a dual prenylated Rab and VAMP2 receptor.

    PubMed

    Martincic, I; Peralta, M E; Ngsee, J K

    1997-10-24

    Rab GTPases have been implicated in intracellular vesicle trafficking. Using the yeast two-hybrid screen, we have isolated a rat clone that interacts with Rab3A as well as with Rab1. The gene encodes a 20.6-kDa protein with two extensive hydrophobic domains and is broadly expressed in all tissues. This protein binds to prenylated Rab GTPases but not to other small Ras-like GTPases such as the Rho/Rac family. This prenylated Rab acceptor (PRA1) also binds specifically to the synaptic vesicle protein VAMP2 (or synaptobrevin II) but shows no affinity for VAMP1 or cellubrevin in both the yeast two-hybrid system and in vitro binding assays. This specificity resides, in part, in the proline-rich domain of VAMP2 as a chimera containing this domain of VAMP2 fused to VAMP1 is able to bind to PRA1. The transmembrane domain of VAMP2 is also essential as its deletion abolished binding to PRA1. Replacement of the deleted VAMP2 transmembrane domain by a CAAX prenylation signal can not restore binding to PRA1. This interaction is therefore distinct from that required for VAMP2 binding to either syntaxin or both syntaxin and SNAP-25. Deletion analysis on PRA1 indicates that the critical Rab- and VAMP2-interacting residues reside in two regions: the amino-terminal residues 30-54 and the extreme carboxyl-terminal domain. This dual Rab and VAMP2 binding characteristic suggests that PRA1 may serve to link these two protein families in the control of vesicle docking and fusion. PMID:9341137

  5. Quality of Life is Similar between Long-term Survivors of Indolent and Aggressive Non-Hodgkin Lymphoma.

    PubMed

    Beaven, Anne W; Samsa, Greg; Zimmerman, Sheryl; Smith, Sophia K

    2016-07-01

    Differences in quality of life (QOL) of long-term survivors of aggressive or indolent subtypes of non-Hodgkin lymphoma (NHL) have not been frequently evaluated. We assessed these differences by analyzing results of a large QOL survey of long-term NHL survivors. We hypothesized that the incurable nature of indolent NHL would relate to worse QOL in long-term survivors while the potentially cured long-term survivors of aggressive lymphoma would have better QOL. We found that QOL was similar between the two groups. Results suggest that patients with indolent NHL are coping well with their disease, yet experience some overall feelings of life threat. PMID:27379565

  6. Indoles: Industrial, Agricultural and Over-the-Counter Uses

    NASA Astrophysics Data System (ADS)

    Barden, Timothy C.

    Indole-containing compounds are best known for their medicinal properties in the pharmaceutical industry. Although to a lesser degree, the indole motif none-the-less appears in many significant products across the entire chemical industry. This chapter describes the role that indole plays in a more commodity setting and provides examples illustrating these uses.

  7. Photophysics of indole-2-carboxylic acid (I2C) and indole-5-carboxylic acid (I5C): heavy atom effect.

    PubMed

    Kowalska-Baron, Agnieszka; Gałęcki, Krystian; Wysocki, Stanisław

    2013-12-01

    In this study the effect of carboxylic group substitution in the 2 and 5 position of indole ring on the photophysics of the parent indole chromophore has been studied. The photophysical parameters crucial in triplet state decay mechanism of aqueous indole-2-carboxylic acid (I2C) and indole-5-carboxylic acid (I5C) have been determined applying our previously proposed methodology based on the heavy atom effect and fluorescence and phosphorescence decay kinetics [Kowalska-Baron et al., 2012]. The determined time-resolved phosphorescence spectra of I2C and I5C are red-shifted as compared to that of the parent indole. This red-shift was especially evident in the case of I2C and may indicate the possibility of hydrogen bonded complex formation incorporating carbonyl CO, the NH group of I2C and, possibly, surrounding water molecules. The possibility of the excited state charge transfer process and the subsequent electronic charge redistribution in such a hydrogen bonded complex may also be postulated. The resulting stabilization of the I2C triplet state is manifested by its relatively long phosphorescence lifetime in aqueous solution (912 μs). The relatively short phosphorescence lifetime of I5C (56 μs) may be the consequence of more effective ground-state quenching of I5 C triplet state. This hypothesis may be strengthened by the significantly larger value of the determined rate constant of I5C triplet state quenching by its ground-state (4.4 × 10(8)M(-1)s(-1)) as compared to that for indole (6.8 × 10(7)M(-1)s(-1)) and I2C (2.3 × 10(7)M(-1)s(-1)). The determined bimolecular rate constant for triplet state quenching by iodide [Formula: see text] is equal to 1 × 10(4)M(-1)s(-1); 6 × 10(3)M(-1)s(-1) and 2.7 × 10(4)M(-1)s(-1) for indole, I2 C and I5 C, respectively. In order to obtain a better insight into iodide quenching of I2C and I5C triplet states in aqueous solution, the temperature dependence of the bimolecular rate constants for iodide quenching of the

  8. Chemistry and biology of new marine alkaloids from the indole and annelated indole series.

    PubMed

    Aygün, Alparslan; Pindur, Ulf

    2003-07-01

    Chemistry and biology of marine natural products from the indole and annelated indole series have become an attractive research field for development of new pharmacological lead substances. In the past years some of the isolated natural organic compounds were synthesized by chemists and evaluated with great enthusiasm to find new lead natural compounds against different diseases. In this review the latest results for new compounds including isolation, biological evaluation, synthetic pathways and some retrosynthetic analyses are summarized. PMID:12678805

  9. A new indole alkaloid from Ervatamia yunnanensis.

    PubMed

    Jin, Yong-Sheng; Du, Jing-Ling; Chen, Hai-Sheng; Jin, Li; Liang, Shuang

    2010-01-01

    The stems of Ervatamia yunnanensis have afforded a new indole alkaloid, ervataine (1), whose structure was determined by spectroscopic analysis. Five known compounds, ibogaine (2) coronaridine (3), heyneanine (4), voacangine hydroxyindolenine (5) and coronaridine hydroxyindolenine (6), were also isolated. PMID:19647051

  10. Rho-A prenylation and signaling link epithelial homeostasis to intestinal inflammation

    PubMed Central

    López-Posadas, Rocío; Becker, Christoph; Günther, Claudia; Tenzer, Stefan; Amann, Kerstin; Billmeier, Ulrike; Atreya, Raja; Fiorino, Gionata; Vetrano, Stefania; Danese, Silvio; Ekici, Arif B.; Wirtz, Stefan; Thonn, Veronika; Watson, Alastair J.M.; Brakebusch, Cord; Bergö, Martin; Neurath, Markus F.; Atreya, Imke

    2016-01-01

    Although defects in intestinal barrier function are a key pathogenic factor in patients with inflammatory bowel diseases (IBDs), the molecular pathways driving disease-specific alterations of intestinal epithelial cells (IECs) are largely unknown. Here, we addressed this issue by characterizing the transcriptome of IECs from IBD patients using a genome-wide approach. We observed disease-specific alterations in IECs with markedly impaired Rho-A signaling in active IBD patients. Localization of epithelial Rho-A was shifted to the cytosol in IBDs, and inflammation was associated with suppressed Rho-A activation due to reduced expression of the Rho-A prenylation enzyme geranylgeranyltransferase-I (GGTase-I). Functionally, we found that mice with conditional loss of Rhoa or the gene encoding GGTase-I, Pggt1b, in IECs exhibit spontaneous chronic intestinal inflammation with accumulation of granulocytes and CD4+ T cells. This phenotype was associated with cytoskeleton rearrangement and aberrant cell shedding, ultimately leading to loss of epithelial integrity and subsequent inflammation. These findings uncover deficient prenylation of Rho-A as a key player in the pathogenesis of IBDs. As therapeutic triggering of Rho-A signaling suppressed intestinal inflammation in mice with GGTase-I–deficient IECs, our findings suggest new avenues for treatment of epithelial injury and mucosal inflammation in IBD patients. PMID:26752649

  11. Rho-A prenylation and signaling link epithelial homeostasis to intestinal inflammation.

    PubMed

    López-Posadas, Rocío; Becker, Christoph; Günther, Claudia; Tenzer, Stefan; Amann, Kerstin; Billmeier, Ulrike; Atreya, Raja; Fiorino, Gionata; Vetrano, Stefania; Danese, Silvio; Ekici, Arif B; Wirtz, Stefan; Thonn, Veronika; Watson, Alastair J M; Brakebusch, Cord; Bergö, Martin; Neurath, Markus F; Atreya, Imke

    2016-02-01

    Although defects in intestinal barrier function are a key pathogenic factor in patients with inflammatory bowel diseases (IBDs), the molecular pathways driving disease-specific alterations of intestinal epithelial cells (IECs) are largely unknown. Here, we addressed this issue by characterizing the transcriptome of IECs from IBD patients using a genome-wide approach. We observed disease-specific alterations in IECs with markedly impaired Rho-A signaling in active IBD patients. Localization of epithelial Rho-A was shifted to the cytosol in IBDs, and inflammation was associated with suppressed Rho-A activation due to reduced expression of the Rho-A prenylation enzyme geranylgeranyltransferase-I (GGTase-I). Functionally, we found that mice with conditional loss of Rhoa or the gene encoding GGTase-I, Pggt1b, in IECs exhibit spontaneous chronic intestinal inflammation with accumulation of granulocytes and CD4+ T cells. This phenotype was associated with cytoskeleton rearrangement and aberrant cell shedding, ultimately leading to loss of epithelial integrity and subsequent inflammation. These findings uncover deficient prenylation of Rho-A as a key player in the pathogenesis of IBDs. As therapeutic triggering of Rho-A signaling suppressed intestinal inflammation in mice with GGTase-I-deficient IECs, our findings suggest new avenues for treatment of epithelial injury and mucosal inflammation in IBD patients. PMID:26752649

  12. Prenylated 2-arylbenzofuran derivatives with potent antioxidant properties from Chlorophora regia (Moraceae).

    PubMed

    Kyekyeku, James Oppong; Kusari, Souvik; Adosraku, Reimmel Kwame; Zühlke, Sebastian; Spiteller, Michael

    2016-01-01

    Extracts of Chlorophora regia are frequently used in Ghana in traditional medicine. There is, however, no reported data on the chemical composition of the plant. Comprehensive phytochemical investigation of the stem bark of C. regia resulted in the isolation of three new prenylated 2-arylbenzofuran derivatives, regiafuran A-C (1-3), and one new prenylated flavonol (4), together with fifteen known compounds (5-19). Their structures were elucidated by combined spectroscopic analysis of their NMR and HRESI-MS(n) data. Compounds 1, 2, 5, 9 and 15 exhibited remarkable free radical scavenging properties with IC50 values of 1.9 μg/ml, 2.4 μg/ml, 2.2 μg/ml, 2.1 μg/ml and 1.8 μg/ml, respectively, compared to the standard trolox (IC50 1.1 μg/ml). The isolated compounds did not, however, show any anti-inflammatory potential when tested using a PGE2 (prostaglandin E2) competitive enzyme immunoassay. PMID:26592854

  13. Farnesylation or geranylgeranylation? Efficient assays for testing protein prenylation in vitro and in vivo

    PubMed Central

    Benetka, Wolfgang; Koranda, Manfred; Maurer-Stroh, Sebastian; Pittner, Fritz; Eisenhaber, Frank

    2006-01-01

    Background Available in vitro and in vivo methods for verifying protein substrates for posttranslational modifications via farnesylation or geranylgeranylation (for example, autoradiography with 3H-labeled anchor precursors) are time consuming (weeks/months), laborious and suffer from low sensitivity. Results We describe a new technique for detecting prenyl anchors in N-terminally glutathione S-transferase (GST)-labeled constructs of target proteins expressed in vitro in rabbit reticulocyte lysate and incubated with 3H-labeled anchor precursors. Alternatively, hemagglutinin (HA)-labeled constructs expressed in vivo (in cell culture) can be used. For registration of the radioactive marker, we propose to use a thin layer chromatography (TLC) analyzer. As a control, the protein yield is tested by Western blotting with anti-GST- (or anti-HA-) antibodies on the same membrane that has been previously used for TLC-scanning. These protocols have been tested with Rap2A, v-Ki-Ras2 and RhoA (variant RhoA63L) including the necessary controls. We show directly that RasD2 is a farnesylation target. Conclusion Savings in time for experimentation and the higher sensitivity for detecting 3H-labeled lipid anchors recommend the TLC-scanning method with purified GST- (or HA-) tagged target proteins as the method of choice for analyzing their prenylation capabilities in vitro and in vivo and, possibly, also for studying the myristoyl and palmitoyl posttranslational modifications. PMID:16507103

  14. Prenylated polyphenolic compounds from Glycyrrhiza iconica and their antimicrobial and antioxidant activities.

    PubMed

    Kırmızıbekmez, Hasan; Uysal, Görkem Berk; Masullo, Milena; Demirci, Fatih; Bağcı, Yavuz; Kan, Yüksel; Piacente, Sonia

    2015-06-01

    A new prenylated isoflavan, iconisoflavan (1), and a new prenylated isoflav-3-ene, iconisoflaven (2) were isolated from the roots of Glycyrrhiza iconica together with four known ones namely (3S)-licoricidin (3), licorisoflavan A (4), topazolin (5) and glycycoumarin (6). The structures were elucidated on the basis of extensive spectroscopic analysis including 1D and 2D NMR as well as HR-MS. Furthermore, the absolute configurations of compounds 1, 3 and 4 were established by electronic circular dichroism (ECD). All the isolated compounds (1-6) were evaluated for their in vitro antimicrobial activities against five pathogenic bacteria and one yeast (Candida albicans) using an in vitro microdilution method. Compounds 1 and 3-5 displayed significant activity against Salmonella typhimurium ATCC 13311 with MIC values ranging from 2 to 8 μg/mL. Additionally, all compounds were screened for their in vitro free radical scavenging activities using an in vitro microdilution DPPH assay spectrofotometrically. The tested compounds exhibited IC50 values in the range of 0.18-0.56 mg/mL, suggesting an activity comparable with that of ascorbic acid (IC50: 0.07 mg/mL). To the best of our knowledge, the present study constitutes the first phytochemical and bioactivity investigation on G. iconica. PMID:25963162

  15. Globulixanthones C, D and E: three prenylated xanthones with antimicrobial properties from the root bark of Symphonia globulifera.

    PubMed

    Nkengfack, Augustin E; Mkounga, Pierre; Meyer, Michele; Fomum, Zacharias T; Bodo, Bernard

    2002-09-01

    Two prenylated xanthone derivatives, named globulixanthones C and D and one bis-xanthone, designated globulixanthone E, have been isolated from the root bark of Symphonia globulifera. The structures of these compounds were elucidated by a detailed spectroscopic analysis. They have been shown to exhibit in vitro significant antimicrobial activity against a range of micro-organisms. PMID:12169313

  16. Stem cell transplantation for indolent lymphoma and chronic lymphocytic leukemia

    PubMed Central

    Gribben, John G; Hosing, Chitra; Maloney, David G.

    2012-01-01

    The indolent lymphomas, including chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) remain incurable with standard therapy. Autologous hematopoietic stem cell transplantation (HSCT[JHA1]) is feasible and has low treatment related mortality in follicular lymphoma, but there are questions relating to optimal timing of the procedure, conditioning regimen and late effects. Myeloablative allogeneic HSCT is associated with high treatment related morbidity and mortality, few late relapses, but is applicable to only a small number of patients. The major focus of HSCT in these lymphomas has been with reduced intensity conditioning (RIC) allogeneic HSCT, which is applicable to the age distribution of these diseases and which exploit the graft versus lymphoma effect in these diseases. Steps to further decrease the morbidity and mortality of the RIC HSCT and in particular to reduce the incidence of chronic extensive graft versus host disease while maintaining tumor control remain the major focus. Many potential treatments are available for indolent lymphomas and CLL, and appropriate patient selection and the timing of HSCT remain controversial. The use of HSCT must always be weighed against the risk of the underlying disease, particularly in a setting where improvements in treatment are leading to improved outcome. PMID:21195313

  17. An herbivore elicitor activates the gene for indole emission in maize

    PubMed Central

    Frey, Monika; Stettner, Cornelia; Paré, Paul W.; Schmelz, Eric A.; Tumlinson, James H.; Gierl, Alfons

    2000-01-01

    Maize and a variety of other plant species release volatile compounds in response to herbivore attack that serve as chemical cues to signal natural enemies of the feeding herbivore. N-(17-hydroxylinolenoyl)-l-glutamine is an elicitor component that has been isolated and chemically characterized from the regurgitant of the herbivore-pest beet armyworm. This fatty acid derivative, referred to as volicitin, triggers the synthesis and release of volatile components, including terpenoids and indole in maize. Here we report on a previously unidentified enzyme, indole-3-glycerol phosphate lyase (IGL), that catalyzes the formation of free indole and is selectively activated by volicitin. IGL's enzymatic properties are similar to BX1, a maize enzyme that serves as the entry point to the secondary defense metabolites DIBOA and DIMBOA. Gene-sequence analysis indicates that Igl and Bx1 are evolutionarily related to the tryptophan synthase alpha subunit. PMID:11106389

  18. Identification and biochemical characterization of an Arabidopsis indole-3-acetic acid glucosyltransferase.

    PubMed

    Jackson, R G; Lim, E K; Li, Y; Kowalczyk, M; Sandberg, G; Hoggett, J; Ashford, D A; Bowles, D J

    2001-02-01

    Biochemical characterization of recombinant gene products following a phylogenetic analysis of the UDP-glucosyltransferase (UGT) multigene family of Arabidopsis has identified one enzyme (UGT84B1) with high activity toward the plant hormone indole-3-acetic acid (IAA) and three related enzymes (UGT84B2, UGT75B1, and UGT75B2) with trace activities. The identity of the IAA conjugate has been confirmed to be 1-O-indole acetyl glucose ester. A sequence annotated as a UDP-glucose:IAA glucosyltransferase (IAA-UGT) in the Arabidopsis genome and expressed sequence tag data bases given its similarity to the maize iaglu gene sequence showed no activity toward IAA. This study describes the first biochemical analysis of a recombinant IAA-UGT and provides the foundation for future genetic approaches to understand the role of 1-O-indole acetyl glucose ester in Arabidopsis. PMID:11042207

  19. On the positional and orientational order of water and methanol around indole: a study on the microscopic origin of solubility.

    PubMed

    Henao, Andres; Johnston, Andrew J; Guàrdia, Elvira; McLain, Sylvia E; Pardo, Luis Carlos

    2016-08-17

    Although they are both highly polar liquids, there are a number of compounds, such as many pharmaceuticals, which show vastly different solubilities in methanol compared with water. From theories of the hydrophobic effect, it might be predicted that this enhanced solubility is due to association between drugs and the less polar -CH3 groups on methanol. In this work, detailed analysis on the atomic structural interactions between water, methanol and the small molecule indole - which is a precursor to many drugs and is sparingly soluble in water yet highly soluble in methanol - reveal that indole preferentially interacts with both water and methanol via electrostatic interactions rather than with direction interactions to the -CH3 groups. The presence of methanol hydrogen bonds with π electrons of the benzene ring of indole can explain the increase in solubility of indole in methanol relative to water. In addition, the excess entropy calculations performed here suggest that this solvation is enthalpically rather than entropically driven. PMID:27489172

  20. Substituted indoles as HIV-1 non-nucleoside reverse transcriptase inhibitors: a patent evaluation (WO2015044928).

    PubMed

    Li, Xiao; Gao, Ping; Zhan, Peng; Liu, Xinyong

    2016-05-01

    The invention described in this patent (WO2015044928) is related to compounds based on the substituted indole scaffold, their synthetic process and application to inhibit HIV-1 replication as non-nucleoside reverse transcriptase inhibitors (NNRTIs). Some of the newly claimed compounds presented improved potency against wild-type (WT) HIV-1 strain in comparison to previously disclosed indole-based NNRTIs and were also shown to be effective against common resistant HIV-1 strains. In light of their novel structural characteristics, simple synthetic route and improved anti-HIV activity, these compounds deserve further study as promising NNRTIs. PMID:26742549

  1. Hobartine: a tetracyclic indole alkaloid extracted from Aristotelia chilensis (maqui).

    PubMed

    Paz Robles, Cristian; Badilla Vidal, Natalia; Suarez, Sebastián; Baggio, Ricardo

    2014-11-01

    The natural compound hobartine {systematic name: (1R)-3-[(1S,5S)-(4,4,8-trimethylbicyclo[3.3.1]non-7-en-2-yl)methyl]-2,3-dihydro-1H-indole}, C20H26N2, (I), is an indole alkaloid isolated from Aristotelia chilensis as part of a study of secondary metabolites from Chilean flora. The colourless compound has a tetracyclic structure closely related to the strongly coloured polymorphic structures discussed in Paz et al. [Acta Cryst. (2013), C69, 1509-1512] and Watson et al. [Acta Cryst. (1989), C45, 1322-1324]. The main differences reside in the absence of a keto group in (I) compared with the previous structures, as well as an endo double bond in (I) contrasting with the exo double bond found in the previous structures. The supramolecular structure of (I) in strongly related to the twofold screw axis, around which isolated chains build up, internally linked by an N-H···N hydrogen bond which is the only significant intermolecular interaction present in the structure. PMID:25370110

  2. Induced production of 1-methoxy-indol-3-ylmethyl glucosinolate by jasmonic acid and methyl jasmonate in sprouts and leaves of pak choi (Brassica rapa ssp. chinensis).

    PubMed

    Wiesner, Melanie; Hanschen, Franziska S; Schreiner, Monika; Glatt, Hansruedi; Zrenner, Rita

    2013-01-01

    Pak choi plants (Brassica rapa ssp. chinensis) were treated with different signaling molecules methyl jasmonate, jasmonic acid, linolenic acid, and methyl salicylate and were analyzed for specific changes in their glucosinolate profile. Glucosinolate levels were quantified using HPLC-DAD-UV, with focus on induction of indole glucosinolates and special emphasis on 1-methoxy-indol-3-ylmethyl glucosinolate. Furthermore, the effects of the different signaling molecules on indole glucosinolate accumulation were analyzed on the level of gene expression using semi-quantitative realtime RT-PCR of selected genes. The treatments with signaling molecules were performed on sprouts and mature leaves to determine ontogenetic differences in glucosinolate accumulation and related gene expression. The highest increase of indole glucosinolate levels, with considerable enhancement of the 1-methoxy-indol-3-ylmethyl glucosinolate content, was achieved with treatments of sprouts and mature leaves with methyl jasmonate and jasmonic acid. This increase was accompanied by increased expression of genes putatively involved in the indole glucosinolate biosynthetic pathway. The high levels of indole glucosinolates enabled the plant to preferentially produce the respective breakdown products after tissue damage. Thus, pak choi plants treated with methyl jasmonate or jasmonic acid, are a valuable tool to analyze the specific protection functions of 1-methoxy-indole-3-carbinole in the plants defense strategy in the future. PMID:23873294

  3. Induced Production of 1-Methoxy-indol-3-ylmethyl Glucosinolate by Jasmonic Acid and Methyl Jasmonate in Sprouts and Leaves of Pak Choi (Brassica rapa ssp. chinensis)

    PubMed Central

    Wiesner, Melanie; Hanschen, Franziska S.; Schreiner, Monika; Glatt, Hansruedi; Zrenner, Rita

    2013-01-01

    Pak choi plants (Brassica rapa ssp. chinensis) were treated with different signaling molecules methyl jasmonate, jasmonic acid, linolenic acid, and methyl salicylate and were analyzed for specific changes in their glucosinolate profile. Glucosinolate levels were quantified using HPLC-DAD-UV, with focus on induction of indole glucosinolates and special emphasis on 1-methoxy-indol-3-ylmethyl glucosinolate. Furthermore, the effects of the different signaling molecules on indole glucosinolate accumulation were analyzed on the level of gene expression using semi-quantitative realtime RT-PCR of selected genes. The treatments with signaling molecules were performed on sprouts and mature leaves to determine ontogenetic differences in glucosinolate accumulation and related gene expression. The highest increase of indole glucosinolate levels, with considerable enhancement of the 1-methoxy-indol-3-ylmethyl glucosinolate content, was achieved with treatments of sprouts and mature leaves with methyl jasmonate and jasmonic acid. This increase was accompanied by increased expression of genes putatively involved in the indole glucosinolate biosynthetic pathway. The high levels of indole glucosinolates enabled the plant to preferentially produce the respective breakdown products after tissue damage. Thus, pak choi plants treated with methyl jasmonate or jasmonic acid, are a valuable tool to analyze the specific protection functions of 1-methoxy-indole-3-carbinole in the plants defense strategy in the future. PMID:23873294

  4. Indoles - A promising scaffold for drug development.

    PubMed

    Sravanthi, T V; Manju, S L

    2016-08-25

    Generally, heterocycles occupy a prominent place in chemistry due to their wide range of applications in the fields of drug design, photochemistry, agrochemicals, dyes and so on. Among them, indole scaffolds have been found in most of the important synthetic drug molecules and paved a faithful way to develop effective targets. Privileged structures bind to multiple receptors with high affinity, thus aiding the development of novel biologically active compounds. Among the indole class of compounds, 2-arylindoles appear to be a most promising lead for drug development. The derivatives of 2-arylindoles exhibits antibacterial, anticancer, anti-oxidants, anti-inflammatory, anti-diabetic, antiviral, antiproliferative, antituberculosis activity, etc. This article would provide a clear knowledge on the wide-ranging biological activities of 2-arylindoles over the past two decades, which would be beneficial for the designing of more potent drug targets in order to compete with the existing drugs. PMID:27237590

  5. Obinutuzumab for the treatment of indolent lymphoma.

    PubMed

    Edelmann, Jennifer; Gribben, John G

    2016-08-01

    Obinutuzumab is a humanized, type II anti-CD20 monoclonal antibody designed for strong induction of direct cell death and antibody-dependent cell-mediated cytotoxicity. The Phase III GADOLIN trial tested the clinical efficacy of obinutuzumab plus bendamustine followed by obinutuzumab monotherapy in rituximab-refractory indolent non-Hodgkin lymphoma versus treatment with bendamustine alone. It demonstrated significantly longer progression-free survival for the obinutuzumab-containing regimen in this difficult to treat patient group. Based on the results of this trial, US FDA approval was most recently granted for obinutuzumab in the treatment of follicular lymphoma that has relapsed after or was refractory to a rituximab-containing regimen. This article summarizes the available data on chemistry, pharmacokinetics, clinical efficacy and safety of obinutuzumab in the treatment of indolent non-Hodgkin lymphoma. PMID:27117452

  6. Indole-like Trk receptor antagonists.

    PubMed

    Tammiku-Taul, Jaana; Park, Rahel; Jaanson, Kaur; Luberg, Kristi; Dobchev, Dimitar A; Kananovich, Dzmitry; Noole, Artur; Mandel, Merle; Kaasik, Allen; Lopp, Margus; Timmusk, Tõnis; Karelson, Mati

    2016-10-01

    The virtual screening for new scaffolds for TrkA receptor antagonists resulted in potential low molecular weight drug candidates for the treatment of neuropathic pain and cancer. In particular, the compound (Z)-3-((5-methoxy-1H-indol-3-yl)methylene)-2-oxindole and its derivatives were assessed for their inhibitory activity against Trk receptors. The IC50 values were computationally predicted in combination of molecular and fragment-based QSAR. Thereafter, based on the structure-activity relationships (SAR), a series of new compounds were designed and synthesized. Among the final selection of 13 compounds, (Z)-3-((5-methoxy-1-methyl-1H-indol-3-yl)methylene)-N-methyl-2-oxindole-5-sulfonamide showed the best TrkA inhibitory activity using both biochemical and cellular assays and (Z)-3-((5-methoxy-1-methyl-1H-indol-3-yl)methylene)-2-oxindole-5-sulfonamide was the most potent inhibitor of TrkB and TrkC. PMID:27318978

  7. Xanthohumol, a prenylated chalcone from beer hops, acts as an α-glucosidase inhibitor in vitro.

    PubMed

    Liu, Ming; Yin, Hua; Liu, Ge; Dong, Jianjun; Qian, Zhonghua; Miao, Jinlai

    2014-06-18

    Xanthohumol (XN) is a unique prenylated flavonoid in hops (Humulus lupulus L.) and beer. XN alleviates hyperglycemia and has potential usage in the treatment of type 2 diabetes. In the present study, a series of in vitro experiments were performed to investigate whether XN was an effective inhibitor of α-glucosidase. The results showed that XN inhibited α-glucosidase in a reversible and noncompetitive manner, with an IC50 value of 8.8 μM and that XN inhibited the release of glucose from the maltose in the apical side of the Caco-2 cell monolayer. Fluorescence and circular dichroism spectra results indicated that XN directly bound to α-glucosidase and induced minor conformational changes of the enzyme. These results demonstrated that XN is a promising α-glucosidase inhibitor, which therefore could be used as functional food to alleviate postprandial hyperglycemia and as a potential candidate for the development of an antidiabetic agent. PMID:24897556

  8. Cytotoxic and anti-inflammatory prenylated benzoylphloroglucinols and xanthones from the twigs of Garcinia esculenta.

    PubMed

    Zhang, Hong; Zhang, Dan-Dan; Lao, Yuan-Zhi; Fu, Wen-Wei; Liang, Shuang; Yuan, Qing-Hong; Yang, Ling; Xu, Hong-Xi

    2014-07-25

    Five new prenylated benzoylphloroglucinol derivatives, garciesculentones A-E (1-5), a new xanthone, garciesculenxanthone A (6), and 15 known compounds were isolated from the petroleum ether extract and the EtOAc-soluble fraction of a 80% (v/v) EtOH extract of Garcinia esculenta. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopic analysis and mass spectrometry. Experimental and calculated ECD and a convenient modified Mosher's method were used to determine the absolute configurations. The cytotoxicity of these compounds were evaluated by MTT assay against three human cancer cell lines (HepG2, MCF-7, and MDA-MB-231) and against normal hepatic cells (HL-7702). In addition, these isolates were evaluated for their inhibitory effects on interferon-γ plus lipopolysaccharide-induced nitric oxide production in RAW264.7 cells. PMID:24960143

  9. Prenylated benzoylphloroglucinols and xanthones from the leaves of Garcinia oblongifolia with antienteroviral activity.

    PubMed

    Zhang, Hong; Tao, Ling; Fu, Wen-Wei; Liang, Shuang; Yang, Yi-Fu; Yuan, Qing-Hong; Yang, Da-Jian; Lu, Ai-Ping; Xu, Hong-Xi

    2014-04-25

    An acetone extract of the leaves of Garcinia oblongifolia showed antiviral activity against enterovirus 71 (EV71) using a cytopathic effect inhibition assay. Bioassay-guided fractionation yielded 12 new prenylated benzoylphloroglucinols, oblongifolins J-U (1-12), and five known compounds. The structures of 1-12 were elucidated by spectroscopic analysis including 1D- and 2D-NMR and mass spectrometry methods. The absolute configurations were determined by a combination of a Mosher ester procedure carried out in NMR tubes and ECD calculations. Compared to ribavirin (IC50 253.1 μM), compounds 1, 4, and 13 exhibited significant anti-EV71 activity in vitro, with IC50 values of 31.1, 16.1, and 12.2 μM, respectively. In addition, the selectivity indices of these compounds were 1.5, 2.4, and 3.0 in African green monkey kidney (Vero) cells, respectively. PMID:24679044

  10. Biosynthesis of Neocarazostatin A Reveals the Sequential Carbazole Prenylation and Hydroxylation in the Tailoring Steps.

    PubMed

    Huang, Sheng; Elsayed, Somayah Sameer; Lv, Meinan; Tabudravu, Jioji; Rateb, Mostafa E; Gyampoh, Roland; Kyeremeh, Kwaku; Ebel, Rainer; Jaspars, Marcel; Deng, Zixin; Yu, Yi; Deng, Hai

    2015-12-17

    Neocarazostatin A (NZS) is a bacterial alkaloid with promising bioactivities against free radicals, featuring a tricyclic carbazole nucleus with a prenyl moiety at C-6 of the carbazole ring. Here, we report the discovery and characterization of the biosynthetic pathway of NZS through genome mining and gene inactivation. The in vitro assays characterized two enzymes: NzsA is a P450 hydroxylase and NzsG is a new phytoene-synthase-like prenyltransferase (PTase). This is the first reported native PTase that specifically acts on the carbazole nucleus. Finally, our in vitro reconstituted experiment demonstrated a coupled reaction catalyzed by NzsG and NzsA tailoring the NZS biosynthesis. PMID:26670080

  11. Cytotoxic prenylated flavones from the stem and root bark of Daphne giraldii.

    PubMed

    Sun, Qian; Wang, Di; Li, Fei-Fei; Yao, Guo-Dong; Li, Xue; Li, Ling-Zhi; Huang, Xiao-Xiao; Song, Shao-Jiang

    2016-08-15

    Three new prenylated flavones (1-3), along with three known analogues (4-6), were isolated from the stem and root bark of Daphne giraldii. Their structures were determined by comprehensive NMR and HRESIMS spectroscopic data analyses. The absolute configurations of compounds 2 and 3 were assigned by optical rotation comparison, CD and [Rh2(OCOCF3)4]-induced CD spectral methods. The in vitro cytotoxicity experiments carried out involving five cancer cell lines (U251, A549, HepG2, MCF-7 and Bcap37) showed that 2 markedly inhibited the proliferation of all tested cells with IC50 values ranging from 4.26 to 20.82μM. The preliminary structure-activity relationships of these flavones are discussed. In addition, compound 2 was found to effectively induce apoptosis in HepG2 cells according to a flow cytometry analysis. PMID:27400887

  12. Antimicrobial prenylated benzoylphloroglucinol derivatives and xanthones from the leaves of Garcinia goudotiana.

    PubMed

    Mahamodo, Sania; Rivière, Céline; Neut, Christel; Abedini, Amin; Ranarivelo, Heritiana; Duhal, Nathalie; Roumy, Vincent; Hennebelle, Thierry; Sahpaz, Sevser; Lemoine, Amélie; Razafimahefa, Dorothée; Razanamahefa, Bakonirina; Bailleul, François; Andriamihaja, Bakolinirina

    2014-06-01

    Bioassay-guided fractionation using antimicrobial assay of the crude acetonic extract of Garcinia goudotiana leaves and of its five partitions led to the isolation of two new prenylated benzoylphloroglucinol derivatives, goudotianone 1 (1) and goudotianone 2 (2), in addition to two known compounds including one xanthone, 1,3,7-trihydroxy-2-isoprenylxanthone (3), and one triterpenoid, friedelin (4). Their structures were elucidated on the basis of different spectroscopic methods, including extensive 1D- and 2D-NMR spectroscopy and mass spectrometry. The crude acetonic extract, the methylene chloride and ethyl acetate partitions, and some tested compounds isolated from this species (1-3) demonstrated selective significant antimicrobial activities against Gram-positive bacteria, in particular Staphylococcus lugdunensis, Enterococcus faecalis and Mycobacterium smegmatis. The potential cytotoxic activities of these extracts and compounds were evaluated against human colon carcinoma HT29 and human fetal lung fibroblast MRC5 cells. PMID:24690454

  13. Structural Complexity, Differential Response to Infection, and Tissue Specificity of Indolic and Phenylpropanoid Secondary Metabolism in Arabidopsis Roots1[w

    PubMed Central

    Bednarek, Paweł; Schneider, Bernd; Svatoš, Aleš; Oldham, Neil J.; Hahlbrock, Klaus

    2005-01-01

    Levels of indolic and phenylpropanoid secondary metabolites in Arabidopsis (Arabidopsis thaliana) leaves undergo rapid and drastic changes during pathogen defense, yet little is known about this process in roots. Using Arabidopsis wild-type and mutant root cultures as an experimental system, and the root-pathogenic oomycete, Pythium sylvaticum, for infections, we analyzed the aromatic metabolite profiles in soluble extracts from uninfected and infected roots, as well as from the surrounding medium. A total of 16 indolic, one heterocyclic, and three phenylpropanoid compounds were structurally identified by mass spectrometry and nuclear magnetic resonance analyses. Most of the indolics increased strongly upon infection, whereas the three phenylpropanoids decreased. Concomitant increases in both indolic and phenylpropanoid biosynthetic mRNAs suggested that phenylpropanoids other than those examined here in “soluble extracts” were coinduced with the indolics. These and previous results indicate that roots differ greatly from leaves with regard to the nature and relative abundance of all major soluble phenylpropanoid constituents. For indolics, by contrast, our data reveal far-reaching similarities between roots and leaves and, beyond this comparative aspect, provide an insight into this highly diversified yet under-explored metabolic realm. The data point to metabolic interconnections among the compounds identified and suggest a partial revision of the previously proposed camalexin pathway. PMID:15923335

  14. Indole generates quiescent and metabolically active Escherichia coli cultures.

    PubMed

    Chen, Chih-Chin; Walia, Rupali; Mukherjee, Krishna J; Mahalik, Subhashree; Summers, David K

    2015-04-01

    An inherent problem with bacterial cell factories used to produce recombinant proteins or metabolites is that resources are channeled into unwanted biomass as well as product. Over several years, attempts have been made to increase efficiency by unlinking biomass and product generation. One example was the quiescent cell (Q-Cell) expression system that generated non-growing but metabolically active Escherichia coli by over-expressing a regulatory RNA (Rcd) in a defined genetic background. Although effective at increasing the efficiency with which resources are converted to product, the technical complexity of the Rcd-based Q-Cell system limited its use. We describe here an alternative method for generating Q-Cells by the direct addition of indole, or related indole derivatives, to the culture medium of an E. coli strain carrying defined mutations in the hns gene. This simple and effective approach is shown to be functional in both shake-flask and fermenter culture. The cells remain metabolically active and analysis of their performance in the fermenter suggests that they may be particularly suitable for the production of cellular metabolites. PMID:25594833

  15. Unprecedented Utilization of Pelargonidin and Indole for the Biosynthesis of Plant Indole Alkaloids

    PubMed Central

    Warskulat, Anne‐Christin; Tatsis, Evangelos C.; Dudek, Bettina; Kai, Marco; Lorenz, Sybille

    2016-01-01

    Abstract Nudicaulins are a group of indole alkaloid glycosides responsible for the color of yellow petals of Papaver nudicaule (Iceland poppy). The unique aglycone scaffold of these alkaloids attracted our interest as one of the most unusual flavonoid‐indole hybrid structures that occur in nature. Stable isotope labeling experiments with sliced petals identified free indole, but not tryptamine or l‐tryptophan, as one of the two key biosynthetic precursors of the nudicaulin aglycone. Pelargonidin was identified as the second key precursor, contributing the polyphenolic unit to the nudicaulin molecule. This finding was inferred from the temporary accumulation of pelargonidin glycosides in the petals during flower bud development and a drop at the point in time when nudicaulin levels start to increase. The precursor‐directed incorporation of cyanidin into a new 3′‐hydroxynudicaulin strongly supports the hypothesis that anthocyanins are involved in the biosynthesis of nudicaulins. PMID:26670055

  16. Synthesis of New Functionalized Indoles Based on Ethyl Indol-2-carboxylate.

    PubMed

    Boraei, Ahmed T A; El Ashry, El Sayed H; Barakat, Assem; Ghabbour, Hazem A

    2016-01-01

    Successful alkylations of the nitrogen of ethyl indol-2-carboxylate were carried out using aq. KOH in acetone. The respective N-alkylated acids could be obtained without separating the N-alkylated esters by increasing the amount of KOH and water. The use of NaOMe in methanol led to transesterification instead of the alkylation, while the use of NaOEt led to low yields of the N-alkylated acids. Hydrazinolysis of the ester gave indol-2-carbohydrazide which then was allowed to react with different aromatic aldehydes and ketones in ethanol catalyzed by acetic acid. Indol-2-thiosemicarbazide was used in a heterocyclization reaction to form thiazoles. The new structures were confirmed using NMR, mass spectrometry and X-ray single crystal analysis. PMID:26978331

  17. Unprecedented Utilization of Pelargonidin and Indole for the Biosynthesis of Plant Indole Alkaloids.

    PubMed

    Warskulat, Anne-Christin; Tatsis, Evangelos C; Dudek, Bettina; Kai, Marco; Lorenz, Sybille; Schneider, Bernd

    2016-02-15

    Nudicaulins are a group of indole alkaloid glycosides responsible for the color of yellow petals of Papaver nudicaule (Iceland poppy). The unique aglycone scaffold of these alkaloids attracted our interest as one of the most unusual flavonoid-indole hybrid structures that occur in nature. Stable isotope labeling experiments with sliced petals identified free indole, but not tryptamine or l-tryptophan, as one of the two key biosynthetic precursors of the nudicaulin aglycone. Pelargonidin was identified as the second key precursor, contributing the polyphenolic unit to the nudicaulin molecule. This finding was inferred from the temporary accumulation of pelargonidin glycosides in the petals during flower bud development and a drop at the point in time when nudicaulin levels start to increase. The precursor-directed incorporation of cyanidin into a new 3'-hydroxynudicaulin strongly supports the hypothesis that anthocyanins are involved in the biosynthesis of nudicaulins. PMID:26670055

  18. Analysis of several iridoid and indole precursors of terpenoid indole alkaloids with a single HPLC run.

    PubMed

    Dagnino, D; Schripsema, J; Verpoorte, R

    1996-06-01

    An isocratic HPLC system is described which allows the separation of the iridoid and indole precursors of terpenoid indole alkaloids, which are present in a single crude extract. The system consists of a column of LiChrospher 60 RP select B 5 microm, 250 x 4 mm (Merck) with an eluent of 1% formic acid-acetonitrile-trichloroacetic acid (100:10:0.25, v:v:w) at a flow of 1.2 ml/min. In the suspension cultures of Catharanthus roseus secologanin and tryptophan were detected. in the cultures of Tabernaemontana divaricata loganin, tryptophan, and tryptamine accumulated. PMID:17252445

  19. Binary stress induces an increase in indole alkaloid biosynthesis in Catharanthus roseus.

    PubMed

    Zhu, Wei; Yang, Bingxian; Komatsu, Setsuko; Lu, Xiaoping; Li, Ximin; Tian, Jingkui

    2015-01-01

    Catharanthus roseus is an important medicinal plant, which produces a variety of indole alkaloids of significant pharmaceutical relevance. In the present study, we aimed to investigate the potential stress-induced increase of indole alkaloid biosynthesis in C. roseus using proteomic technique. The contents of the detectable alkaloids ajmalicine, vindoline, catharanthine, and strictosidine in C. roseus were significantly increased under binary stress. Proteomic analysis revealed that the abundance of proteins related to tricarboxylic acid cycle and cell wall was largely increased; while, that of proteins related to tetrapyrrole synthesis and photosynthesis was decreased. Of note, 10-hydroxygeraniol oxidoreductase, which is involved in the biosynthesis of indole alkaloid was two-fold more abundant in treated group compared to the control. In addition, mRNA expression levels of genes involved in the indole alkaloid biosynthetic pathway indicated an up-regulation in their transcription in C. roseus under UV-B irradiation. These results suggest that binary stress might negatively affect the process of photosynthesis in C. roseus. In addition, the induction of alkaloid biosynthesis appears to be responsive to binary stress. PMID:26284098

  20. Binary stress induces an increase in indole alkaloid biosynthesis in Catharanthus roseus

    PubMed Central

    Zhu, Wei; Yang, Bingxian; Komatsu, Setsuko; Lu, Xiaoping; Li, Ximin; Tian, Jingkui

    2015-01-01

    Catharanthus roseus is an important medicinal plant, which produces a variety of indole alkaloids of significant pharmaceutical relevance. In the present study, we aimed to investigate the potential stress-induced increase of indole alkaloid biosynthesis in C. roseus using proteomic technique. The contents of the detectable alkaloids ajmalicine, vindoline, catharanthine, and strictosidine in C. roseus were significantly increased under binary stress. Proteomic analysis revealed that the abundance of proteins related to tricarboxylic acid cycle and cell wall was largely increased; while, that of proteins related to tetrapyrrole synthesis and photosynthesis was decreased. Of note, 10-hydroxygeraniol oxidoreductase, which is involved in the biosynthesis of indole alkaloid was two-fold more abundant in treated group compared to the control. In addition, mRNA expression levels of genes involved in the indole alkaloid biosynthetic pathway indicated an up-regulation in their transcription in C. roseus under UV-B irradiation. These results suggest that binary stress might negatively affect the process of photosynthesis in C. roseus. In addition, the induction of alkaloid biosynthesis appears to be responsive to binary stress. PMID:26284098

  1. Aerobic palladium(II)-catalyzed dehydrogenation of cyclohexene-1-carbonyl indole amides: an indole-directed aromatization.

    PubMed

    Kandukuri, Sandeep R; Oestreich, Martin

    2012-10-01

    A palladium(II)-catalyzed oxidative dehydrogenation of cyclohexene-1-carbonyl indole amides yielding the corresponding benzoylindoles is reported. The new aromatization is also applied to functionalized indoles such as tryptamine and tryptophan. The tethered indole is likely acting as a directing group for allylic C-H bond activation, and there is evidence for a mechanism proceeding through 1,3-diene formation followed by aromatization. PMID:22950832

  2. A heteromeric membrane-bound prenyltransferase complex from hop catalyzes three sequential aromatic prenylations in the bitter acid pathway.

    PubMed

    Li, Haoxun; Ban, Zhaonan; Qin, Hao; Ma, Liya; King, Andrew J; Wang, Guodong

    2015-03-01

    Bitter acids (α and β types) account for more than 30% of the fresh weight of hop (Humulus lupulus) glandular trichomes and are well known for their contribution to the bitter taste of beer. These multiprenylated chemicals also show diverse biological activities, some of which have potential benefits to human health. The bitter acid biosynthetic pathway has been investigated extensively, and the genes for the early steps of bitter acid synthesis have been cloned and functionally characterized. However, little is known about the enzyme(s) that catalyze three sequential prenylation steps in the β-bitter acid pathway. Here, we employed a yeast (Saccharomyces cerevisiae) system for the functional identification of aromatic prenyltransferase (PT) genes. Two PT genes (HlPT1L and HlPT2) obtained from a hop trichome-specific complementary DNA library were functionally characterized using this yeast system. Coexpression of codon-optimized PT1L and PT2 in yeast, together with upstream genes, led to the production of bitter acids, but no bitter acids were detected when either of the PT genes was expressed by itself. Stepwise mutation of the aspartate-rich motifs in PT1L and PT2 further revealed the prenylation sequence of these two enzymes in β-bitter acid biosynthesis: PT1L catalyzed only the first prenylation step, and PT2 catalyzed the two subsequent prenylation steps. A metabolon formed through interactions between PT1L and PT2 was demonstrated using a yeast two-hybrid system, reciprocal coimmunoprecipitation, and in vitro biochemical assays. These results provide direct evidence of the involvement of a functional metabolon of membrane-bound prenyltransferases in bitter acid biosynthesis in hop. PMID:25564559

  3. Butyrophilin 3A1 Plays an Essential Role in Prenyl Pyrophosphate Stimulation of Human Vγ2Vδ2 T Cells

    PubMed Central

    Wang, Hong; Henry, Olivier; Distefano, Mark D.; Wang, Yen-Chih; Räikkönen, Johanna; Mönkkönen, Jukka; Tanaka, Yoshimasa; Morita, Craig T.

    2013-01-01

    Most human γδ T cells express Vγ2Vδ2 TCRs and play important roles in microbial and tumor immunity. Vγ2Vδ2 T cells are stimulated by self- and foreign prenyl pyrophosphate intermediates in isoprenoid synthesis. However, little is known about the molecular basis for this stimulation. We find that a mAb specific for butyrophilin 3 (BTN3)/CD277 immunoglobulin superfamily proteins mimics prenyl pyrophosphates. The 20.1 mAb stimulated Vγ2Vδ2 T cell clones regardless of their functional phenotype or developmental origin, and selectively expanded blood Vγ2Vδ2 T cells. The γδ TCR mediates 20.1 mAb stimulation because IL-2 is released by β- Jurkat cells transfected with Vγ2Vδ2 TCRs. 20.1 stimulation was not due to isopentenyl pyrophosphate (IPP) accumulation because 20.1 treatment of APC did not increase IPP levels. In addition, stimulation was not inhibited by statin treatment, which blocks IPP production. Importantly, small interfering RNA knockdown of BTN3A1 abolished stimulation by IPP that could be restored by re-expression of BTN3A1 but not by BTN3A2 or BTN3A3. Rhesus monkey and baboon APC presented HMBPP and 20.1 to human Vγ2Vδ2 T cells despite amino acid differences in BTN3A1 that localize to its outer surface. This suggests that the conserved inner and/or top surfaces of BTN3A1 interact with its counterreceptor. Although no binding site exists on the BTN3A1 extracellular domains, a model of the intracellular B30.2 domain predicts a basic pocket on its binding surface. However, BTN3A1 did not preferentially bind a photoaffinity prenyl pyrophosphate. Thus, BTN3A1 is required for stimulation by prenyl pyrophosphates but does not bind the intermediates with high affinity. PMID:23833237

  4. Identification of New Metabolites of Bacterial Transformation of Indole by Gas Chromatography-Mass Spectrometry and High Performance Liquid Chromatography

    PubMed Central

    Arora, Pankaj Kumar

    2014-01-01

    Arthrobacter sp. SPG transformed indole completely in the presence of an additional carbon source. High performance liquid chromatography and gas chromatography-mass spectrometry detected indole-3-acetic acid, indole-3-glyoxylic acid, and indole-3-aldehyde as biotransformation products. This is the first report of the formation of indole-3-acetic acid, indole-3-glyoxylic acid, and indole-3-aldehyde from indole by any bacterium. PMID:25548566

  5. 2-Prenylated m-dimethoxybenzenes as potent inhibitors of 15-lipo-oxygenase: inhibitory mechanism and SAR studies.

    PubMed

    Jabbari, Atena; Sadeghian, Hamid; Salimi, Alireza; Mousavian, Mina; Seyedi, Seyed M; Bakavoli, Mehdi

    2016-09-01

    15-lipo-oxygenases are one of the iron-containing proteins capable of performing peroxidation of unsaturated fatty acids in animals and plants. The critical role of enzymes in the formation of inflammations, sensitivities, and some cancers has been demonstrated in mammals. The importance of enzymes has led to the development of mechanistic studies, product analysis, and synthesis of inhibitors. In this study, a series of allyl and prenyl dimethoxybenzenes were synthesized and their inhibitory potency against soybean 15-Lipo-oxygenase (L1; EC 1,13,11,12) was determined. Among the synthetic compounds, 2,6-dimethoxy-1-isopentenyl-4-methylbenzene, 2,6-dimethoxy-1-geranyl-4-methylbenzene, and 2,6-dimethoxy-1-farnesyl-4-methylbenzene showed the most potent inhibitory activity with IC50 values of 7.6, 5.3, and 0.52 μm, respectively. For some of the compounds, SAR studies showed acceptable relationship between inhibitory potency and enzyme-ligand interactions. Radical scavenging assessment results apart from the SAR studies indicate that electronic properties are the major factors for lipo-oxygenase inhibition potency of the mentioned compounds. Based on the theoretical studies, it was suggested that CH…O intramolecular hydrogen bond between ortho-methoxy oxygen and methine hydrogen atoms is one of the major factors in the stability of 2,6-dimethoxyallyl(or prenyl)benzenes radical via the planarity fixation between phenyl and allyl (or prenyl) pi orbitals. PMID:27113261

  6. Indole compounds may be promising medicines for ulcerative colitis.

    PubMed

    Sugimoto, Shinya; Naganuma, Makoto; Kanai, Takanori

    2016-09-01

    Indole compounds are extracted from indigo plants and have been used as blue or purple dyes for hundreds of years. In traditional Chinese medicine, herbal agents in combination with Qing-Dai (also known as indigo naturalis) have been used to treat patients with ulcerative colitis (UC) and to remedy inflammatory conditions. Recent studies have noted that indole compounds can be biosynthesized from tryptophan metabolites produced by various enzymes derived from intestinal microbiota. In addition to their action on indole compounds, the intestinal microbiota produce various tryptophan metabolites that mediate critical functions through distinct pathways and enzymes. Furthermore, some indole compounds, such as indigo and indirubin, act as ligands for the aryl hydrocarbon receptor. This signaling pathway stimulates mucosal type 3 innate lymphoid cells to produce interleukin-22, which induces antimicrobial peptide and tight junction molecule production, suggesting a role for indole compounds during the mucosal healing process. Thus, indole compounds may represent a novel treatment strategy for UC patients. In this review, we describe the origin and function of this indole compound-containing Chinese herb, as well as the drug development of indole compounds. PMID:27160749

  7. Palladium-catalysed direct C-2 methylation of indoles.

    PubMed

    Tu, Daoquan; Cheng, Xiuzhi; Gao, Yadong; Yang, Panpan; Ding, Yousong; Jiang, Chao

    2016-08-21

    A direct C-2 methylation reaction of indoles bearing a readily removable N-2-pyrimidyl moiety as a site-specific directing group has been developed with a palladium catalyst. This reaction relied on the use of KF to promote efficient methylation. A moderate to good yield was achieved in a range of indole substrates. PMID:27424955

  8. Gold(I)-Catalyzed Hydroarylation of Allenes with Indoles

    PubMed Central

    Toups, Kristina L.; Liu, Gordon T.; Widenhoefer, Ross A.

    2010-01-01

    Reaction of a monosubstituted, 1,3-disubstituted, or tetrasubstituted allene with various indoles catalyzed by a 1:1 mixture of a gold(I) N-heterocyclic carbene complex and AgOTf at room temperature leads to hydroarylation with formation of 3-allyl-indoles in modest to good yield. PMID:20305794

  9. Gold(I)-Catalyzed Hydroarylation of Allenes with Indoles

    PubMed Central

    Toups, Kristina L.; Liu, Gordon T.; Widenhoefer, Ross A.

    2009-01-01

    Reaction of a monosubstituted, 1,3-disubstituted, or tetrasubstituted allene with various indoles catalyzed by a 1:1 mixture of a gold(I) N-heterocyclic carbene complex and AgOTf at room temperature leads to hydroarylation with formation of 3-allyl-indoles in modest to good yield. PMID:17428061

  10. A highly sensitive prenylation assay reveals in vivo effects of bisphosphonate drug on the Rab prenylome of macrophages outside the skeleton

    PubMed Central

    Ali, Naveid; Jurczyluk, Julie; Shay, Gemma; Tnimov, Zakir; Alexandrov, Kirill; Munoz, Marcia A; Skinner, Oliver P; Pavlos, Nathan J; Rogers, Michael J

    2015-01-01

    Bisphosphonate drugs such as zoledronic acid (ZOL), used for the treatment of common bone disorders, target the skeleton and inhibit bone resorption by preventing the prenylation of small GTPases in bone-destroying osteoclasts. Increasing evidence indicates that bisphosphonates also have pleiotropic effects outside the skeleton, most likely via cells of the monocyte/macrophage lineage exposed to nanomolar circulating drug concentrations. However, no effects of such low concentrations of ZOL have been reported using existing approaches. We have optimized a highly sensitive in vitro prenylation assay utilizing recombinant geranylgeranyltransferases to enable the detection of subtle effects of ZOL on the prenylation of Rab- and Rho-family GTPases. Using this assay, we found for the first time that concentrations of ZOL as low as 10nM caused inhibition of Rab prenylation in J774 macrophages following prolonged cell culture. By combining the assay with quantitative mass spectrometry we identified an accumulation of 18 different unprenylated Rab proteins in J774 cells after nanomolar ZOL treatment, with a >7-fold increase in the unprenylated form of Rab proteins associated with the endophagosome pathway (Rab1, Rab5, Rab6, Rab7, Rab11, Rab14 and Rab21). Finally, we also detected a clear effect of subcutaneous ZOL administration in vivo on the prenylation of Rab1A, Rab5B, Rab7A and Rab14 in mouse peritoneal macrophages, confirming that systemic treatment with bisphosphonate drug can inhibit prenylation in myeloid cells in vivo outside the skeleton. These observations begin a new era in defining the precise pharmacological actions of bisphosphonate drugs on the prenylation of small GTPases in vivo. PMID:26399387

  11. New pathway for the biodegradation of indole in Aspergillus niger

    SciTech Connect

    Kamath, A.; Vaidyanathan, C.S. )

    1990-01-01

    Indole and its derivatives form a class of toxic recalcitrant environmental pollutants. The growth of Aspergillus niger was inhibited by very low concentrations (0.005 to 0.02%) of indole, even when 125- to 500-fold excess glucose was present in the medium. When 0.02% indole was added, the fungus showed a lag phase for about 30 h and the uptake of glucose was inhibited. Indole was metabolized by a new pathway via indoxyl (3-hydroxyindole), N-formylanthranilic acid, anthranilic acid, 2,3-dihydroxybenzoic acid, and catechol, which was further degraded by an ortho cleavage. The enzymes N-formylanthranilate deformylase, anthranilate hydroxylase, 2,3-dihydroxybenzoate decarboxylase, and catechol dioxygenase were induced by indole as early as after 5 h of growth, and their activities were demonstrated in a cell-free system.

  12. Antifungal Indole Alkaloids from Winchia calophylla.

    PubMed

    Yang, Mei-Li; Chen, Jia; Sun, Meng; Zhang, Dong-Bo; Gao, Kun

    2016-05-01

    Ten indole alkaloids (1-10) were obtained from an antifungal extract of Winchia calophylla, of which two (2 and 4) were new. N(4)-Methyl-10-hydroxyl-desacetylakuammilin (2) was an akuammiline-type indole alkaloid. N(1)-Methyl-echitaminic acid (4) was an unusual zwitterion with a basic vincorine-type skeleton. This is the first report of 10 in W. calophylla. The structures of all of the compounds were determined based on spectroscopic data, and their bioactivities were assessed. Compound 1 showed potent activity against the plant pathogenic fungi of Penicillium italicum and Fusarium oxysporum f.sp cubens with IC50 s of 10.4 and 11.5 µM, respectively, and 3 inhibited Rhizoctonia solani with an IC50 of 11.7 µM. Compounds 2 and 4 showed weak cytotoxicity against the human leukemic cell line HL-60 in vitro with IC50 s of 51.4 and 75.3 µM, respectively. Compounds 1 and 2 displayed weak activity against acetylcholinesterase with IC50 s around 61.3 and 52.6 µM, respectively. PMID:27002397

  13. Prenylated proteins and lymphocyte proliferation: inhibition by d-limonene related monoterpenes.

    PubMed

    Schulz, S; Bühling, F; Ansorge, S

    1994-02-01

    The aim of the present study was to explore the role of post-translational isoprenoid modification of cellular proteins in the proliferation of human lymphocytes. We here report that treatment of phytohemagglutinin-stimulated peripheral blood mononuclear cells with monoterpenes including d-limonene, perillic acid and perillyl alcohol (0.5-5 mM) which selectively inhibit the isoprenylation of 21-26-kDa proteins resulted in a dose-dependent inhibition of DNA synthesis. Cell cycle analysis revealed that perillic acid arrested cells in G1 and prevented cells from entering S phase in a manner similar to that induced by the specific 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor, compactin. However, unlike compactin, the perillic acid-induced effects on lymphocyte proliferation were not prevented by addition of mevalonate. We also examined the incorporation of [3H]mevalonate into proteins in resting and phytohemagglutinin-stimulated lymphocytes during the first 30 h of culture. While in unstimulated lymphocytes radioactivity was predominantly incorporated into a cluster of 21-26-kDa proteins, mitogenic stimulation was associated with a striking increase in [3H]mevalonate incorporation into a protein (approximately 68 kDa) with migration characteristics similar to that of nuclear lamin B. Treatment of phytohemagglutinin-stimulated lymphocytes with 5 mM d-limonene, 2.5 mM perillic acid or 1.25 mM perillyl alcohol strongly suppressed [3H]mevalonate-labeling of proteins to a degree that correlated with the level of DNA synthesis inhibition. These findings suggest that those mevalonate-derived products required for lymphocyte proliferation may include one or more isoprenylated proteins and that the isoprenylation of these proteins is required for cell cycle progression. PMID:8299679

  14. Site-Specific Labeling of Protein Lysine Residues and N-Terminal Amino Groups with Indoles and Indole-Derivatives.

    PubMed

    Larda, Sacha Thierry; Pichugin, Dmitry; Prosser, Robert Scott

    2015-12-16

    Indoles and indole-derivatives can be used to site-specifically label proteins on lysine and N-terminal amino groups under mild, nondenaturing reaction conditions. Hen egg white lysozyme (HEWL) and α-lactalbumin were labeled with indole, fluoroindole, or fluoroindole-2-carboxylate via electrophilic aromatic substitutions to lysine side chain Nε- and N-terminal amino imines, formed in situ in the presence of formaldehyde. The reaction is highly site-selective, easily controlled by temperature, and does not eliminate the native charge of the protein, unlike many other common lysine-specific labeling strategies. (19)F NMR was used to monitor reaction progression, and in the case of HEWL, unique resonances for each labeled side chain could be resolved. We demonstrate that the indole tags are highly selective for primary amino groups. (19)F NMR demonstrates that each lysine exhibits a different rate of conjugation to indoles making it possible to employ these tags as a means of probing surface topology by NMR or mass spectrometry. Given the site-specificity of this tagging method, the mildness of the reaction conditions (aqueous, buffered, or unbuffered) and the low stoichiometry required for the reaction, indole-derivatives should serve as a valuable addition to the bioconjugation toolkit. We propose that labeling lysine side chains and N-terminal amino groups with indoles is a versatile and general strategy for bioconjugations with substituted indoles having broad implications for protein functionalization. PMID:26587689

  15. Cannabinoids in Disguise: Δ9-Tetrahydrocannabinol-Like Effects of Tetramethylcyclopropyl Ketone Indoles

    PubMed Central

    Wiley, Jenny L.; Marusich, Julie A.; Lefever, Timothy W.; Grabenauer, Megan; Moore, Katherine N.; Thomas, Brian F.

    2013-01-01

    Synthetic indole-derived cannabinoids have become commonly used recreational drugs and continue to be abused despite their adverse consequences. As compounds that were identified early in the epidemic (e.g., naphthoylindoles) have become legally banned, new compounds have appeared on the drug market. Two tetramethylcyclopropyl ketone indoles, UR-144 [(1-pentyl-1H-indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone] and XLR-11 [(1-(5-fluoropentyl)-1H-indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone], recently have been identified in confiscated products. These compounds are structurally related to a series of CB2-selective compounds explored by Abbott Labs. The purpose of the present study was to evaluate the extent to which UR-144 and XLR-11 shared cannabinoid effects with Δ9-tetrahydrocannabinol (Δ9-THC). Indices of in vitro and in vivo activity at cannabinoid receptors were assessed. Similar to other psychoactive cannabinoid agonists, XLR-11 and UR-144 showed low nanomolar (< 30) affinity for CB1 and CB2 receptors, activated these receptors as full agonists, and produced dose-dependent effects that were blocked by rimonabant in mice, including antinociception, hypothermia, catalepsy and suppression of locomotor activity. The potency of both compounds was several-fold greater than Δ9-THC. XLR-11 and UR-144 also substituted for Δ9-THC in a Δ9-THC discrimination procedure in mice, effects that were attenuated by rimonabant. Analysis of urine from mice treated with the compounds revealed that both were extensively metabolized, with predominant urinary excretion as glucuronide conjugates. Together, these results demonstrate that UR-144 and XLR-11 share a pharmacological profile of in vitro and in vivo effects with Δ9-THC and other abused indole-derived cannabinoids and would be predicted to produce Δ9-THC-like subjective effects in humans. PMID:23916483

  16. Surface-enhanced Raman spectroscopy study of indolic molecules adsorbed on gold colloids

    NASA Astrophysics Data System (ADS)

    Tu, Qiang; Eisen, Jonathan; Chang, Chang

    2010-03-01

    Serotonin is both a ubiquitous neurotransmitter in the central nervous system and an important immunomodulator involved in various immune responses. The ability to unambiguously detect serotonin is therefore imperative in biomedical research. However, detection of serotonin and related indoles using immunohistochemistry has been largely limited by their small molecular size and the resultant uncertainty in antibody specificity. Here we show that surface-enhanced Raman spectroscopy (SERS) can be used to detect and distinguish serotonin from its various closely related precursors and metabolites. Compared with traditional antibody-based methods, SERS is highly specific and capable of real-time detection. We also quantify the relative concentration of serotonin against a background of other indoles using SERS. We expect this optical detection method to directly benefit a variety of immune and nervous systems studies involving serotonin.

  17. Indolent infection in nonunion of the distal femur.

    PubMed

    Kim, Ji Wan; Byun, Seong-Eun; Oh, Hyoung Keun; Kim, Jung Jae

    2015-04-01

    In the treatment of nonunions of the distal femur, infection should be excluded. However, it is difficult to determine whether the nonunion is infected or not with negative history and signs of infection. The purpose of this study was to investigate indolent infection as a cause of presumptive aseptic distal femur nonunion. All presumptive aseptic distal femur nonunions treated from 1998 to 2008 were retrospectively reviewed. Any patient with suspected of having an infection clinically was excluded. Multiple tissue cultures were performed at the nonunion site. The main outcomes were to analyze the rate of positive cultures in presumptive aseptic distal femur nonunion and to compare the rate of secondary surgery in positive and negative culture groups. Of the 22 patients, 3 (13.6%) had positive culture results. The organisms cultured were Staphylococcus aureus, Staphylococcus epidermidis, and Enterobacter cloacae. The overall rate of infection was 9.1% (2/22), and one patient underwent a secondary procedure. In the open fracture group, 2 of 10 patients (20%) had positive cultures; all developed infection. In the closed fracture group, 1 of 12 patients (8.3%) had positive culture results, but Infection did not occur in the patient with a 3-week intravenous antibiotic treatment. The postoperative infection rate was 67% (2/3) in patients with positive intraoperative cultures, while 0% (0/18) in the group with negative intraoperative cultures (p<0.001). The presence of indolent infection can be verified in patients with presumptive aseptic nonunion of distal femoral fractures by obtaining intraoperative biopsy tissue cultures. Positive intraoperative culture results were related with postoperative infection. PMID:25189289

  18. A New Antimicrobial Prenylated Benzo-lactone from the Rhizome of Cissus cornifolia

    PubMed Central

    Musa, Aliyu M.; Tajuddeen, Nasir; Idris, Abdullahi Y.; Rafindadi, Abdurahman Y.; Abdullahi, Musa I.; Aliyu, Abubakar B.; Abdullahi, Mikhail S.; Ibrahim, Mohammed A.

    2015-01-01

    Background: Medicinal plants remain one of the largest reservoirs of new bioactive compounds. In this study, a new prenylated benzo-lactone (4, 6-dihydroxy-5-methoxy-3-(1, 2, 3, 4, 5-pentahydroxypentyl)-2-benzofuran-1(3H)-one) was isolated from the acetone extracts of the rhizome of Cissus cornifolia. The antimicrobial activity of the compound was evaluated against some microorganisms including Staphylococcus aureus, Salmonella typhi, and Candida albicans. Materials and Methods: The acetone extracts of the rhizome of C. cornifolia was separated and purified by various chromatographic techniques. The structure of the isolated compound was characterized by analysis of spectral data including one and two-dimensional nuclear magnetic resonance. Results: The isolated compound was characterized as (4, 6-dihydroxy-5-methoxy-3-(1, 2, 3, 4, 5-pentahydroxypentyl)-2-benzofuran-1(3H)-one), it showed activity against 6 out of 10 tested clinical isolates of some microorganisms including S. aureus, S. typhi, and C. albicans. The inhibition zones ranged between 17 mm and 25 mm. The inhibition zones observed compare favorably with the positive control used. Conclusion: The compound could serve as a lead for the development of more potent antimicrobial agent. To the best of our knowledge, this is the first report of the isolation and characterization as well as antimicrobial screening of the compound. PMID:26692751

  19. Prenylated quinolinecarboxylic acid derivative suppresses immune response through inhibition of PAK2.

    PubMed

    Ogura, Masato; Kikuchi, Haruhisa; Suzuki, Toshiyuki; Yamaki, Junko; Homma, Miwako K; Oshima, Yoshiteru; Homma, Yoshimi

    2016-04-01

    Development of new immunosuppressing agents is necessary in organ transplantation or immune diseases. Because Ppc-1 exhibits a suppressing effect on interleukin-2 (IL2) production in Jurkat cells, we synthesized and screened Ppc-1 derivatives that preserve prenylated quinolinecarboxylic acid (PQA) structure, and identified compound 18 (PQA-18) as a novel molecule with immunosuppressing effect. PQA-18 suppressed not only IL2 but also IL4, IL6, and tumor necrosis factor-α production in human peripheral lymphocytes without affecting cell viability. Two-dimensional gel electrophoresis analysis and in vitro kinase assay revealed that PQA-18 inhibits kinase activity of p21-activated kinase 2 (PAK2). Administration of PQA-18 by intraperitoneal injection suppressed the population of a subset of regulatory T cells and the immunoglobulin (Ig) production against T cell-dependent antigens in mice. Treatment with the PQA-18 ointment on Nc/Nga mice, a model of human atopic dermatitis, improved skin lesions and serum IgE levels. These results suggest that PQA-18 is a unique PAK2 inhibitor with potent immunosuppressing effects in vitro and in vivo. PQA-18 may be a valuable lead for the development of novel immunosuppressants. PMID:26827943

  20. Toxic and antifeedant activities of prenylated flavonoids isolated from Tephrosia apollinea L. against three major coleopteran pests of stored grains with reference to their structure-activity relationship.

    PubMed

    Nenaah, Gomah E

    2014-01-01

    Four prenylated flavonoids, isoglabratephrin, (+)-glabratephrin, tephroapollin-F and lanceolatin-A, were isolated from Tephrosia apollinea L. and tested against three stored grain insects. Using the filter paper bioassay, compounds showed adulticidal activity against Sitophilus oryzae (L), Rhyzopertha dominica (F) and Tribolium castaneum (Herbst) at concentrations of 0.875, 1.75 and 3.5 mg mL(- 1). At 3.5 mg mL(- 1), tephroapollin-F was the most toxic (78.6%, 64.6% and 60.7% mortality was recorded after 10 days exposure of S. oryzae, R. dominica and T. castaneum, respectively). The F1 progeny production of insects was affected after parental exposure to flavonoids, where S. oryzae was the most susceptible. A nutritional bioassay, employing a flour disc and test concentrations of 0.65, 1.3 and 2.6 mg g(- 1), revealed a significant reduction in the relative growth rate, relative consumption rate and efficiency of conversion of ingested food by all insects. The structure-activity relationship among the tested flavonoids was discussed. PMID:24980754

  1. Synthesis of indoles from pyridinium salts

    SciTech Connect

    Gromov, S.P.; Bkhaumik, M.M.; Bundel', Yu.G.

    1987-10-01

    The detailed analysis of the products of the interaction of nitropyridinium salts with ketones and alkylamines resulted in new data testifying in favor of the previously proposed scheme for the formation of indoles from pyridinium salts. The PMR spectra were taken on a Bruker WM-500 spectrometer for the compounds (IXa,b) in CDCl/sub 3/, and (IVg, i-Z) in acetone-D/sub 6/, and a Varian T-60 spectrometer for the alkylindoles (IVa,c,h) in CDCl/sub 3/, with reference to HMDS. The /sup 13/C NMR spectra were taken on a Bruker WM-250 spectrometer in CDCl/sub 3/. The mass spectra were taken on a Finnigan-4021 instrument.

  2. Cytotoxic indole alkaloids from Tabernaemontana divaricata.

    PubMed

    Bao, Mei-Fen; Yan, Ju-Ming; Cheng, Gui-Guang; Li, Xing-Yao; Liu, Ya-Ping; Li, Yan; Cai, Xiang-Hai; Luo, Xiao-Dong

    2013-08-23

    Five new vobasinyl-ibogan-type bisindole alkaloids, tabernaricatines A-E (1-5), two new monomers, tabernaricatines F and G (6 and 7), and 24 known indole alkaloids were isolated from the aerial parts of Tabernaemontana divaricata. Alkaloids 1 and 2 are the first vobasinyl-ibogan-type alkaloids possessing a six-membered ring via an ether linkage between C-17 and C-21. All compounds except for 3 were evaluated for their cytotoxicity against five human cancer cell lines; conophylline showed significant bioactivity against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cells with IC₅₀ values of 0.17, 0.35, 0.21, 1.02, and 1.49 μM, respectively. PMID:23944995

  3. Lewis Acid and Fluoroalcohol Mediated Nucleophilic Addition to the C2 Position of Indoles.

    PubMed

    Morimoto, Naoki; Morioku, Kumika; Suzuki, Hideyuki; Takeuchi, Yasuo; Nishina, Yuta

    2016-05-01

    Indole readily undergoes nucleophilic substitution at the C3 site, and many indole derivatives have been functionalized using this property. Indole also forms indolium, which allows electrophilic addition in acidic conditions, but current examples have been limited to intramolecular reactions. C2 site-selective nucleophilic addition to indole derivatives using fluoroalcohol and a Lewis acid was developed. PMID:27119318

  4. Iridium(iii)-catalyzed regioselective C7-sulfonamidation of indoles.

    PubMed

    Song, Zengqiang; Antonchick, Andrey P

    2016-06-01

    Iridium(iii)-catalyzed direct C7-sulfonamidation of indoles with sulfonyl azides is described. The developed method has good compatibility with diverse functional groups, providing various 7-amino-substituted indoles with good to excellent yields in a short time under mild reaction conditions. The key feature of the developed method is the regioselective functionalization at the C7-position of 2,3-unsubstituted indoles. Biologically active compounds can be obtained using this protocol. The application of the iridium(iii) catalyst and directing group plays a crucial role in the regioselectivity of the developed reaction. PMID:27173668

  5. Synthesis and anti-inflammatory activity of indole glucosinolates.

    PubMed

    Vo, Quan V; Trenerry, Craige; Rochfort, Simone; Wadeson, Jenny; Leyton, Carolina; Hughes, Andrew B

    2014-01-15

    The nitronate and nitrovinyl methods to synthesize indole glucosinolates (GLs) have been investigated. The results were applied to generally the most prevalent natural indole glucosinolates to synthesize 4-methoxyglucobrassicin (MGB) and neo-glucobrassicin (NGB) in moderate overall yield for the first time. The anti-inflammatory activity of the synthetic indole GLs was determined by inhibition of TNF-α secretion in LPS-stimulated THP-1 cells. The data showed that glucobrassicin (GB) exhibited higher activity than other synthetic indolyl GLs. PMID:24360830

  6. Total Syntheses of the Monoterpene Indole Alkaloids (±)-Alstilobanine A and E, and (±)-Angustilodine

    PubMed Central

    Feng, Yiqing; Majireck, Max M.

    2014-01-01

    A synthetic strategy has been developed culminating in stereoselective total syntheses of the small class of unusual monoterpenoid indole alkaloids exemplified by alstilobanine A (3) and E (2) and angustilodine (1). A pivotal step includes a novel intermolecular Michael-type addition of an indole ester dianion to a piperidine-derived nitrosoalkene to form the C15, C16 bond of the alkaloids. In addition, an application of the Romo protocol for effecting a stereoselective intramolecular nucleophile-assisted aldol-lactonization was employed, leading to a β-lactone incorporating the requisite cis-fused 2-azadecalin moiety and also setting the C15, C19, C20 relative stereochemistry of the metabolites. It was then possible to stereoselectively effect an aldolization of a dianion derived from this indole ester β-lactone intermediate with formaldehyde to introduce the requisite C16 hydroxymethyl group. Further manipulations of the system ultimately led to the three alkaloids in racemic form. PMID:24319990

  7. Determination of Endogenous Indole-3-Acetic Acid in Plagiochila arctica (Hepaticae) 1

    PubMed Central

    Law, David M.; Basile, Dominick V.; Basile, Margaret R.

    1985-01-01

    Endogenous indole-3-acetic acid (IAA) was found in axenically cultured gametophytes of the leafy liverwort, Plagiochila arctica Bryhn and Kaal., by high-performance liquid chromatography with electrochemical detection. Identification of the methylated auxin was confirmed by gas chromatography-mass spectrometry. Addition of 57 micromolar IAA to cultures increased relative production of ethylene. This is the first definitive (gas chromatography-mass spectrometry) demonstration of the natural occurrence of IAA in a bryophyte. PMID:16664164

  8. Discovery of Tertiary Amine and Indole Derivatives as Potent RORγt Inverse Agonists.

    PubMed

    Yang, Ting; Liu, Qian; Cheng, Yaobang; Cai, Wei; Ma, Yingli; Yang, Liuqing; Wu, Qianqian; Orband-Miller, Lisa A; Zhou, Ling; Xiang, Zhijun; Huxdorf, Melanie; Zhang, Wei; Zhang, Jing; Xiang, Jia-Ning; Leung, Stewart; Qiu, Yang; Zhong, Zhong; Elliott, John D; Lin, Xichen; Wang, Yonghui

    2014-01-01

    A novel series of tertiary amines as retinoid-related orphan receptor gamma-t (RORγt) inverse agonists was discovered through agonist/inverse agonist conversion. The level of RORγt inhibition can be enhanced by modulating the conformational disruption of H12 in RORγt LBD. Linker exploration and rational design led to the discovery of more potent indole-based RORγt inverse agonists. PMID:24900774

  9. Translocation of radiolabeled indole-3-acetic acid and indole-3-acetyl-myo-inositol from kernel to shoot of Zea mays L

    NASA Technical Reports Server (NTRS)

    Chisnell, J. R.; Bandurski, R. S.

    1988-01-01

    Either 5-[3H]indole-3-acetic acid (IAA) or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm of kernels of dark-grown Zea mays seedlings. The distribution of total radioactivity, radiolabeled indole-3-acetic acid, and radiolabeled ester conjugated indole-3-acetic acid, in the shoots was then determined. Differences were found in the distribution and chemical form of the radiolabeled indole-3-acetic acid in the shoot depending upon whether 5-[3H]indole-3-acetic acid or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm. We demonstrated that indole-3-acetyl-myo-inositol applied to the endosperm provides both free and ester conjugated indole-3-acetic acid to the mesocotyl and coleoptile. Free indole-3-acetic acid applied to the endosperm supplies some of the indole-3-acetic acid in the mesocotyl but essentially no indole-3-acetic acid to the coleoptile or primary leaves. It is concluded that free IAA from the endosperm is not a source of IAA for the coleoptile. Neither radioactive indole-3-acetyl-myo-inositol nor IAA accumulates in the tip of the coleoptile or the mesocotyl node and thus these studies do not explain how the coleoptile tip controls the amount of IAA in the shoot.

  10. Indole-3-Acetic Acid Biosynthesis in Colletotrichum gloeosporioides f. sp. aeschynomene

    PubMed Central

    Robinson, M.; Riov, J.; Sharon, A.

    1998-01-01

    We characterized the biosynthesis of indole-3-acetic acid by the mycoherbicide Colletotrichum gloeosporioides f. sp. aeschynomene. Auxin production was tryptophan dependent. Compounds from the indole-3-acetamide and indole-3-pyruvic acid pathways were detected in culture filtrates. Feeding experiments and in vitro assay confirmed the presence of both pathways. Indole-3-acetamide was the major pathway utilized by the fungus to produce indole-3-acetic acid in culture. PMID:9835603

  11. Oxidative Furan-to-Indole Rearrangement. Synthesis of 2-(2-Acylvinyl)indoles and Flinderole C Analogues.

    PubMed

    Makarov, Anton S; Merkushev, Anton A; Uchuskin, Maxim G; Trushkov, Igor V

    2016-05-01

    Oxidative rearrangement of 2-(2-aminobenzyl)furans affording 2-(2-acylvinyl)indoles in a stereocontrolled manner in good-to-excellent yields has been developed. Thus, (2-aminobenzyl)furans with electron-releasing alkoxy substituents in the phenyl group form only E-isomers of 2-(2-acylvinyl)indoles. Conversely, substrates without such substituents produce target products as Z-isomers exclusively. A short diastereoselective method for the transformation of the obtained 2-(2-acylvinyl)indoles into antimalarial bisindole alkaloid flinderole A-C analogues has been developed. PMID:27074535

  12. Liposome reconstitution and modulation of recombinant prenylated human Rac1 by GEFs, GDI1 and Pak1.

    PubMed

    Zhang, Si-Cai; Gremer, Lothar; Heise, Henrike; Janning, Petra; Shymanets, Aliaksei; Cirstea, Ion C; Krause, Eberhard; Nürnberg, Bernd; Ahmadian, Mohammad Reza

    2014-01-01

    Small Rho GTPases are well known to regulate a variety of cellular processes by acting as molecular switches. The regulatory function of Rho GTPases is critically dependent on their posttranslational modification at the carboxyl terminus by isoprenylation and association with proper cellular membranes. Despite numerous studies, the mechanisms of recycling and functional integration of Rho GTPases at the biological membranes are largely unclear. In this study, prenylated human Rac1, a prominent member of the Rho family, was purified in large amount from baculovirus-infected Spodoptera frugiperda insect cells using a systematic detergent screening. In contrast to non-prenylated human Rac1 purified from Escherichia coli, prenylated Rac1 from insect cells was able to associate with synthetic liposomes and to bind Rho-specific guanine nucleotide dissociation inhibitor 1 (GDI1). Subsequent liposome reconstitution experiments revealed that GDI1 efficiently extracts Rac1 from liposomes preferentially in the inactive GDP-bound state. The extraction was prevented when Rac1 was activated to its GTP-bound state by Rac-specific guanine nucleotide exchange factors (GEFs), such as Vav2, Dbl, Tiam1, P-Rex1 and TrioN, and bound by the downstream effector Pak1. We found that dissociation of Rac1-GDP from its complex with GDI1 strongly correlated with two distinct activities of especially Dbl and Tiam1, including liposome association and the GDP/GTP exchange. Taken together, our results provided first detailed insights into the advantages of the in vitro liposome-based reconstitution system to study both the integration of the signal transducing protein complexes and the mechanisms of regulation and signaling of small GTPases at biological membranes. PMID:25014207

  13. Liposome Reconstitution and Modulation of Recombinant Prenylated Human Rac1 by GEFs, GDI1 and Pak1

    PubMed Central

    Zhang, Si-Cai; Gremer, Lothar; Heise, Henrike; Janning, Petra; Shymanets, Aliaksei; Cirstea, Ion C.; Krause, Eberhard; Nürnberg, Bernd; Ahmadian, Mohammad Reza

    2014-01-01

    Small Rho GTPases are well known to regulate a variety of cellular processes by acting as molecular switches. The regulatory function of Rho GTPases is critically dependent on their posttranslational modification at the carboxyl terminus by isoprenylation and association with proper cellular membranes. Despite numerous studies, the mechanisms of recycling and functional integration of Rho GTPases at the biological membranes are largely unclear. In this study, prenylated human Rac1, a prominent member of the Rho family, was purified in large amount from baculovirus-infected Spodoptera frugiperda insect cells using a systematic detergent screening. In contrast to non-prenylated human Rac1 purified from Escherichia coli, prenylated Rac1 from insect cells was able to associate with synthetic liposomes and to bind Rho-specific guanine nucleotide dissociation inhibitor 1 (GDI1). Subsequent liposome reconstitution experiments revealed that GDI1 efficiently extracts Rac1 from liposomes preferentially in the inactive GDP-bound state. The extraction was prevented when Rac1 was activated to its GTP-bound state by Rac-specific guanine nucleotide exchange factors (GEFs), such as Vav2, Dbl, Tiam1, P-Rex1 and TrioN, and bound by the downstream effector Pak1. We found that dissociation of Rac1-GDP from its complex with GDI1 strongly correlated with two distinct activities of especially Dbl and Tiam1, including liposome association and the GDP/GTP exchange. Taken together, our results provided first detailed insights into the advantages of the in vitro liposome-based reconstitution system to study both the integration of the signal transducing protein complexes and the mechanisms of regulation and signaling of small GTPases at biological membranes. PMID:25014207

  14. NADPH oxidase activity is essential for Keap1/Nrf2-mediated induction of GCLC in response to 2-indol-3-yl-methylenequinuclidin-3-ols.

    PubMed

    Sekhar, Konjeti R; Crooks, Peter A; Sonar, Vijayakumar N; Friedman, David B; Chan, Jeff Y; Meredith, Michael J; Starnes, Joseph H; Kelton, Kathy R; Summar, Samantha R; Sasi, Soumya; Freeman, Michael L

    2003-09-01

    Glutamate cysteine ligase, the rate-limiting enzyme for the synthesis of glutathione, represents an important component of chemoprevention paradigms. GCLC and GCLM, the genes encoding glutamate cysteine ligase subunits, are induced by indoles, such as indomethacin. Novel functionalized indole analogues and other structurally related compounds were synthesized and used for a comparative structure analysis of GCLC induction. Use of mouse embryo fibroblasts null for Nrf2 (nuclear factor-erythroid 2p45-related transcription factor) and HepG2 cells overexpressing Keap1 demonstrated that indole analogue-mediated GCLC expression was regulated by Nrf2-Keap1 interactions. Indole analogues capable of inducing GCLC were found to increase NADPH oxidase activity. Indole analogues unable to induce GCLC did not increase oxidase activity. HepG2 cells transfected with FLAG/Keap1 were exposed to indomethacin, and the redox state of Keap1 cysteine residues was assessed. The data indicated that Keap1 exhibited several oxidation states that were sensitive to indomethacin treatment. These indomethacin-mediated changes in thiol oxidation states were suppressed by diphenyleneiodonium, a NADPH oxidase inhibitor. Diphenyleneiodonium also suppressed indole analogue-mediated increases in GCLC mRNA. In summary, the use of the indole analogues identified NADPH oxidase activity as a novel upstream activity regulating Nrf2/Keap1 signaling of GCLC, provided data supporting the hypothesis that Keap1 is a downstream effector for oxidase activity, and afforded in vivo data to support the hypothesis that Keap1 thiols can act as molecular sensors of reactive oxygen species. Finally, the comparative structure analysis suggests that 2-indol-3-yl-methylenequinuclidin-3-ols may represent a prototype for the development of novel chemopreventative agents able to activate Keap1/Nrf2 signaling. PMID:14500406

  15. In vivo anti-inflammatory activity of some naturally occurring O- and N-prenyl secondary metabolites.

    PubMed

    Epifano, Francesco; Genovese, Salvatore; Fiorito, Serena; della Loggia, Roberto; Tubaro, Aurelia; Sosa, Silvio

    2014-01-01

    A series of O- and N-prenyl secondary metabolites of insect, fungal, and plant origin have been evaluated for their topical anti-inflammatory activity using the Croton oil ear test in mice as a model of acute inflammation. Some of the tested compounds revealed an effect (ID50 = 0.31 divided by 0.56 micromol/cm2) comparable with that of the reference non-steroidal anti-inflammatory drug indomethacin (ID50 = 0.23 micromol/cm2). PMID:24660470

  16. Synthesis, α-glucosidase inhibitory and molecular docking studies of prenylated and geranylated flavones, isoflavones and chalcones.

    PubMed

    Sun, Hua; Li, Yashan; Zhang, Xiaoting; Lei, Yanan; Ding, Weina; Zhao, Xue; Wang, Haomeng; Song, Xiaotong; Yao, Qingwei; Zhang, Yongmin; Ma, Ying; Wang, Runling; Zhu, Tao; Yu, Peng

    2015-10-15

    Three series of prenylated and/or geranylated flavonoids were synthesized and evaluated for their α-glucosidase inhibitory activity. The 3',5'-digeranylated chalcone (16) was identified as a new α-glucosidase inhibitor whose activity (IC50=0.90 μM) was 50-fold more than that of acarbose (IC50=51.32 μM). Molecular docking studies revealed the existence of strong hydrophobic interaction and H-bonding between compound 16 and α-glucosidase's active site. The inhibitory mode analysis showed that 16 exhibited a competitive inhibitory mode. PMID:26351039

  17. Vγ2Vδ2 T Cell Receptor Recognition of Prenyl Pyrophosphates is Dependent on all Complementarity Determining Regions1

    PubMed Central

    Wang, Hong; Fang, Zhimei; Morita, Craig T.

    2010-01-01

    γδ T cells differ from αβ T cells in the antigens they recognize and their functions in immunity. While most αβ T cell receptors (TCR) recognize peptides presented by MHC class I or II, human γδ T cells expressing Vγ2Vδ2 TCRs recognize nonpeptide prenyl pyrophosphates. To define the molecular basis for this recognition, the effect of mutations in the TCR complementarity-determining regions (CDR) was assessed. Mutations in all CDR loops altered recognition and cover a large footprint. Unlike murine γδ TCR recognition of the MHC class Ib T22 protein, there was no CDR3δ motif required for recognition because only 1 residue is required. Instead, the length and sequence of CDR3γ was key. Although a potential prenyl pyrophosphate-binding site was defined by Lys109 in Jγ1.2 and Arg51 in CDR2δ, the area outlined by critical mutations is much larger. These results show that prenyl pyrophosphate recognition is primarily by germline-encoded regions of the γδ TCR, allowing a high proportion of Vγ2Vδ2 TCRs to respond. This underscores its parallels to innate immune receptors. Our results also provide strong evidence for the existence of an antigen-presenting molecule for prenyl pyrophosphates. This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript. This version of the manuscript has not yet been copyedited or subjected to editorial proofreading by The JI; hence, it may differ from the final version published in The JI (online and in print). AAI (The JI) is not liable for errors or omissions in this author-produced version of the manuscript or in any version derived from it by the U.S. National Institutes of Health or any other third party. The final, citable version of record can be found at www.jimmunol.org. PMID:20483784

  18. Solophenols B-D and solomonin: new prenylated polyphenols isolated from propolis collected from the Solomon Islands and their antibacterial activity.

    PubMed

    Inui, Saori; Hosoya, Takahiro; Shimamura, Yuko; Masuda, Shuichi; Ogawa, Takeshi; Kobayashi, Hirokazu; Shirafuji, Kenichi; Moli, Reuben Toli; Kozone, Ikuko; Shin-ya, Kazuo; Kumazawa, Shigenori

    2012-11-28

    Three new prenylated flavonoids, namely, solophenols B (1), C (2), and D (3), as well as a new prenylated stilbene, solomonin (4), were isolated from propolis collected from the Solomon Islands. In addition, 17 known compounds were identified. The structures of the new compounds were determined by a combination of methods, including mass spectrometry and NMR. These new compounds and several known compounds were tested for antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa. Most of them exhibited potent antibacterial activity. These findings may indicate that propolis from the Solomon Islands has potential applications as an ingredient in food additives or pharmaceuticals. PMID:23067056

  19. Synthesis of Substituted Benzenes via Bi(OTf)3-Mediated Intramolecular Carbonyl Allylation of α-Prenyl or α-Geranyl β-Arylketosulfones.

    PubMed

    Chang, Meng-Yang; Cheng, Yu-Chieh; Lu, Yi-Ju

    2015-06-19

    Intramolecular carbonyl allylation of α-prenyl or α-geranyl β-arylketosulfones 5 in the presence of molecule sieves (MS) affords substituted benzenes 6-7 in moderate to good yields. The facile transformation proceeds by a synthetic sequence starting with the α-prenylation or α-geranylation of 1 and the Bi(OTf)3-mediated annulation of 5 followed by a sequential desulfonative aromatization or then an intramolecular Friedel-Crafts alkylation. A plausible mechanism has been studied and proposed. PMID:26068123

  20. Immunogenic and antioxidant effects of a pathogen-associated prenyl pyrophosphate in Anopheles gambiae.

    PubMed

    Lindberg, Bo G; Merritt, Eleanor A; Rayl, Melanie; Liu, Chenxiao; Parmryd, Ingela; Olofsson, Berit; Faye, Ingrid

    2013-01-01

    Despite efficient vector transmission, Plasmodium parasites suffer great bottlenecks during their developmental stages within Anopheles mosquitoes. The outcome depends on a complex three-way interaction between host, parasite and gut bacteria. Although considerable progress has been made recently in deciphering Anopheles effector responses, little is currently known regarding the underlying microbial immune elicitors. An interesting candidate in this sense is the pathogen-derived prenyl pyrophosphate and designated phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), found in Plasmodium and most eubacteria but not in higher eukaryotes. HMBPP is the most potent stimulant known of human Vγ9Vδ2 T cells, a unique lymphocyte subset that expands during several infections including malaria. In this study, we show that Vγ9Vδ2 T cells proliferate when stimulated with supernatants from intraerythrocytic stages of Plasmodium falciparum cultures, suggesting that biologically relevant doses of phosphoantigens are excreted by the parasite. Next, we used Anopheles gambiae to investigate the immune- and redox- stimulating effects of HMBPP. We demonstrate a potent activation in vitro of all but one of the signaling pathways earlier implicated in the human Vγ9Vδ2 T cell response, as p38, JNK and PI3K/Akt but not ERK were activated in the A. gambiae 4a3B cell line. Additionally, both HMBPP and the downstream endogenous metabolite isopentenyl pyrophosphate displayed antioxidant effects by promoting cellular tolerance to hydrogen peroxide challenge. When provided in the mosquito blood meal, HMBPP induced temporal changes in the expression of several immune genes. In contrast to meso-diaminopimelic acid containing peptidoglycan, HMBPP induced expression of dual oxidase and nitric oxide synthase, two key determinants of Plasmodium infection. Furthermore, temporal fluctuations in midgut bacterial numbers were observed. The multifaceted effects observed in this

  1. Immunogenic and Antioxidant Effects of a Pathogen-Associated Prenyl Pyrophosphate in Anopheles gambiae

    PubMed Central

    Lindberg, Bo G.; Merritt, Eleanor A.; Rayl, Melanie; Liu, Chenxiao; Parmryd, Ingela; Olofsson, Berit; Faye, Ingrid

    2013-01-01

    Despite efficient vector transmission, Plasmodium parasites suffer great bottlenecks during their developmental stages within Anopheles mosquitoes. The outcome depends on a complex three-way interaction between host, parasite and gut bacteria. Although considerable progress has been made recently in deciphering Anopheles effector responses, little is currently known regarding the underlying microbial immune elicitors. An interesting candidate in this sense is the pathogen-derived prenyl pyrophosphate and designated phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), found in Plasmodium and most eubacteria but not in higher eukaryotes. HMBPP is the most potent stimulant known of human Vγ9Vδ2 T cells, a unique lymphocyte subset that expands during several infections including malaria. In this study, we show that Vγ9Vδ2 T cells proliferate when stimulated with supernatants from intraerythrocytic stages of Plasmodium falciparum cultures, suggesting that biologically relevant doses of phosphoantigens are excreted by the parasite. Next, we used Anopheles gambiae to investigate the immune- and redox- stimulating effects of HMBPP. We demonstrate a potent activation in vitro of all but one of the signaling pathways earlier implicated in the human Vγ9Vδ2 T cell response, as p38, JNK and PI3K/Akt but not ERK were activated in the A. gambiae 4a3B cell line. Additionally, both HMBPP and the downstream endogenous metabolite isopentenyl pyrophosphate displayed antioxidant effects by promoting cellular tolerance to hydrogen peroxide challenge. When provided in the mosquito blood meal, HMBPP induced temporal changes in the expression of several immune genes. In contrast to meso-diaminopimelic acid containing peptidoglycan, HMBPP induced expression of dual oxidase and nitric oxide synthase, two key determinants of Plasmodium infection. Furthermore, temporal fluctuations in midgut bacterial numbers were observed. The multifaceted effects observed in this

  2. Access to Indole Derivatives from Diaryliodonium Salts and 2-Alkynylanilines.

    PubMed

    Li, Pengfei; Weng, Yunxiang; Xu, Xianxiang; Cui, Xiuling

    2016-05-20

    An efficient, environmentally friendly, and operationally simple procedure to 1,2-disubstituted indoles from 2-alkynylanilines and diaryliodonium salts has been developed. This reaction proceeds smoothly under metal-free conditions. The products obtained could be transferred into 3,3'-diindolylmethane with DMSO catalyzed by palladium. The isotopic label experiments indicated that the methylene group in 3,3'-diindolylmethane is derived from DMSO. The diverse indoles were obtained in up to 90% yield for 28 examples. PMID:27156581

  3. Friedel-Crafts Fluoroacetylation of Indoles with Fluorinated Acetic Acids for the Synthesis of Fluoromethyl Indol-3-yl Ketones under Catalyst- and Additive-Free Conditions.

    PubMed

    Yao, Shun-Jiang; Ren, Zhi-Hui; Wang, Yao-Yu; Guan, Zheng-Hui

    2016-05-20

    A simple and efficient protocol for the fluoroacetylation of indoles is reported. The reaction uses fluorinated acetic acids as the fluoroacetylation reagents to synthesize diverse fluoromethyl indol-3-yl ketones in good yields under catalyst- and additive-free conditions. In addition, the only byproduct is water in this transformation. The synthetic utility of this reaction was also demonstrated by the concise synthesis of α-(trifluoromethyl)(indol-3-yl)methanol and indole-3-carboxylic acid. PMID:27101475

  4. Indole and 7-benzyloxyindole attenuate the virulence of Staphylococcus aureus.

    PubMed

    Lee, Jin-Hyung; Cho, Hyun Seob; Kim, Younghoon; Kim, Jung-Ae; Banskota, Suhrid; Cho, Moo Hwan; Lee, Jintae

    2013-05-01

    Human pathogens can readily develop drug resistance due to the long-term use of antibiotics that mostly inhibit bacterial growth. Unlike antibiotics, antivirulence compounds diminish bacterial virulence without affecting cell viability and thus, may not lead to drug resistance. Staphylococcus aureus is a major agent of nosocomial infections and produces diverse virulence factors, such as the yellow carotenoid staphyloxanthin, which promotes resistance to reactive oxygen species (ROS) and the host immune system. To identify novel antivirulence compounds, bacterial signal indole present in animal gut and diverse indole derivatives were investigated with respect to reducing staphyloxanthin production and the hemolytic activity of S. aureus. Treatment with indole or its derivative 7-benzyloxyindole (7BOI) caused S. aureus to become colorless and inhibited its hemolytic ability without affecting bacterial growth. As a result, S. aureus was more easily killed by hydrogen peroxide (H₂O₂) and by human whole blood in the presence of indole or 7BOI. In addition, 7BOI attenuated S. aureus virulence in an in vivo model of nematode Caenorhabditis elegans, which is readily infected and killed by S. aureus. Transcriptional analyses showed that both indole and 7BOI repressed the expressions of several virulence genes such as α-hemolysin gene hla, enterotoxin seb, and the protease genes splA and sspA and modulated the expressions of the important regulatory genes agrA and sarA. These findings show that indole derivatives are potential candidates for use in antivirulence strategies against persistent S. aureus infection. PMID:23318836

  5. Photoreaction of indole-containing mycotoxins to fluorescent products.

    PubMed

    Maragos, C M

    2009-06-01

    Photochemical reaction of the non-fluorescent mycotoxin cyclopiazonic acid (CPA) to fluorescent products was recently reported. Because CPA contains an indole moiety, believed to contribute to the fluorescence, it was of interest to determine whether the effect might be more generally applicable to indole-containing mycotoxins. Three indole-containing tremorgens (penitrem A, paxilline, verruculogen) that have not previously been reported to be fluorescent were rendered fluorescent by exposure to ultraviolet light in a photoreactor. Naturally fluorescent ergot alkaloids, which also contain an indole-moiety, exhibited a diminished response after exposure. This suggests that the phenomenon may be most useful for detection of indole-containing tremorgens that are non-fluorescent, rather than for the enhancement of materials that are already fluorescent, such as the ergot alkaloids. The extent to which fluorescence enhancement was seen was strongly influenced by the reaction environment, in particular the solvent used and whether cyclodextrins were present. In an HPLC format, placement of the photoreactor post-column allowed for the fluorescence detection of penitrem A, paxilline, and verruculogen. The ability to photoreact indole-containing tremorgens and detect them by fluorescence may open up new avenues for detection of these mycotoxins alone or in combination. PMID:23604981

  6. N-alkenyl indoles as useful intermediates for alkaloid synthesis.

    PubMed

    Li, Hao; Boonnak, Nawong; Padwa, Albert

    2011-11-18

    A mild cross-coupling reaction to access several N-alkenyl-substituted indoles has been developed. The coupling procedure involves treating a NH-indole with various alkenyl bromides using a combination of 10 mol % of copper(I) iodide and 20 mol % of ethylenediamine as the catalyst in dioxane at 110 °C in the presence of K(3)PO(4) as the base. When treated with acid, these unique enamines produce a dimeric product derived from a preferred protonation reaction at the enamine π-bond. A cationic cyclization reaction of the readily available 2-(2-(1H-indol-1-yl)allyl)cyclopentanol was utilized to construct tetracyclic indole derivatives with a quaternary stereocenter attached to the C(2)-position of the indole ring. An alternative strategy for selective functionalization at the C(2)-position of a N-alkenyl-substituted indole derivative that was also studied involves a radical cyclization of a xanthate derivative. The work described provides an attractive route to the tetracyclic core of some vinca alkaloids, including the tetrahydroisoquinocarbazole RS-2135. PMID:22007631

  7. Metabolic regulation of the plant hormone indole-3-acetic acid

    SciTech Connect

    Jerry D. Cohen

    2009-11-01

    The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.

  8. Regulation of the AcrAB multidrug efflux pump in Salmonella enterica serovar Typhimurium in response to indole and paraquat.

    PubMed

    Nikaido, Eiji; Shirosaka, Ikue; Yamaguchi, Akihito; Nishino, Kunihiko

    2011-03-01

    Salmonella enterica serovar Typhimurium has at least nine multidrug efflux pumps. Among these, AcrAB is constitutively expressed and is the most efficient, playing a role in both drug resistance and virulence. The acrAB locus is induced by indole, Escherichia coli-conditioned medium, and bile salts. This induction is dependent on RamA through the binding sequence in the upstream region of acrA that binds RamA. In the present study, we made a detailed investigation of the ramA and acrAB induction mechanisms in Salmonella in response to indole, a biological oxidant for bacteria. We found that acrAB and ramA induction in response to indole is dependent on RamR. However, the cysteine residues of RamR do not play a role in the induction of ramA in response to indole, and the oxidative effect of indole is therefore not related to ramA induction via RamR. Furthermore, we showed that paraquat, a superoxide generator, induces acrAB but not ramA. We further discovered that the mechanism of acrAB induction in response to paraquat is dependent on SoxS. The data indicate that there are at least two independent induction pathways for acrAB in response to extracellular signals such as indole and paraquat. We propose that Salmonella utilizes these regulators for acrAB induction in response to extracellular signals in order to adapt itself to environmental conditions. PMID:21148208

  9. Synthesis and bioactivity of secondary metabolites from marine sponges containing dibrominated indolic systems.

    PubMed

    Mollica, Adriano; Locatelli, Marcello; Stefanucci, Azzurra; Pinnen, Francesco

    2012-01-01

    Marine sponges. (e.g., Hyrtios sp., Dragmacidin sp., Aglophenia pleuma, Aplidium cyaneum, Aplidium meridianum.) produce bioactive secondary metabolites involved in their defence mechanisms. Recently it was demonstrated that several of those compounds show a large variety of biological activities against different human diseases with possible applications in medicinal chemistry and in pharmaceutical fields, especially related to the new drug development process. Researchers have focused their attention principally on secondary metabolites with anti-cancer and cytotoxic activities. A common target for these molecules is the cytoskeleton, which has a central role in cellular proliferation, motility, and profusion involved in the metastatic process associate with tumors. In particular, many substances containing brominated indolic rings such as 5,6-dibromotryptamine, 5,6-dibromo-N-methyltryptamine, 5,6-dibromo-N-methyltryptophan (dibromoabrine), 5,6-dibromo-N,N-dimethyltryptamine and 5,6-dibromo-L-hypaphorine isolated from different marine sources, have shown anti-cancer activity, as well as antibiotic and anti-inflammatory properties. Considering the structural correlation between endogenous monoamine serotonin with marine indolic alkaloids 5,6-dibromoabrine and 5,6-dibromotryptamine, a potential use of some dibrominated indolic metabolites in the treatment of depression-related pathologies has also been hypothesized. Due to the potential applications in the treatment of various diseases and the increasing demand of these compounds for biological assays and the difficult of their isolation from marine sources, we report in this review a series of recent syntheses of marine dibrominated indole-containing products. PMID:22614862

  10. Partial purification and characterization of indol-3-ylacetylglucose:myo-inositol indol-3-ylacetyltransferase (indoleacetic acid-inositol synthase)

    NASA Technical Reports Server (NTRS)

    Kesy, J. M.; Bandurski, R. S.

    1990-01-01

    A procedure is described for the purification of the enzyme indol-3-ylacetylglucose:myo-inositol indol-3-ylacetyltransferase (IAA-myo-inositol synthase). This enzyme catalyzes the transfer of indol-3-ylacetate from 1-0-indol-3-ylacetyl-beta-d-glucose to myo-inositol to form indol-3-ylacetyl-myo-inositol and glucose. A hexokinase or glucose oxidase based assay system is described. The enzyme has been purified approximately 16,000-fold, has an isoelectric point of pH 6.1 and yields three catalytically inactive bands upon acrylamide gel electrophoresis of the native protein. The enzyme shows maximum transferase activity with myo-inositol but shows some transferase activity with scyllo-inositol and myo-inosose-2. No transfer of IAA occurs with myo-inositol-d-galactopyranose, cyclohexanol, mannitol, or glycerol as acyl acceptor. The affinity of the enzyme for 1-0-indol-3-ylacetyl-beta-d-glucose is, Km = 30 micromolar, and for myo-inositol is, Km = 4 millimolar. The enzyme does not catalyze the exchange incorporation of glucose into IAA-glucose indicating the reaction mechanism involves binding of IAA glucose to the enzyme with subsequent hydrolytic cleavage of the acyl moiety by the hydroxyl of myo-inositol to form IAA myo-inositol ester.

  11. Bioactive indole alkaloids isolated from Alstonia angustifolia

    PubMed Central

    Pan, Li; Terrazas, César; Muñoz Acuña, Ulyana; Ninh, Tran Ngoc; Chai, Heebyung; Carcache de Blanco, Esperanza J.; Soejarto, Djaja D.; Satoskar, Abhay R.

    2014-01-01

    Bioassay-guided fractionation was conducted on a CHCl3-soluble extract of the stem bark of Alstonia angustifolia (Apocynaceae) collected in Vietnam using the HT-29 human colon cancer cell line, and led to the isolation of a new sarpagine-type indole alkaloid (1), together with nine known alkaloids, including four macroline-derived alkaloids (2–5), a sarpagine-type alkaloid (6), and four macroline-pleiocarpamine bisindole alkaloids (7–10). The structure of the new compound (1) was determined on the basis of spectroscopic data interpretation. Compounds 1–10 were evaluated in vitro for their NF-κB (p65) inhibitory activity against the Hela cells in an ELISA assay. The new sarpagine alkaloid, N(4)-methyltalpinine (1), was found to show significant NF-κB inhibitory activity (ED50 = 1.2 µM). Furthermore, all the isolates (1–10) were evaluated in vitro for their antileishmanial activity, and compounds (1–4, 6 and 8–10) exhibited leishmaniacidal activity against promastigotes of Leishmania mexicana. PMID:25584095

  12. Synthesis and anti-cancer activity evaluation of novel prenylated and geranylated chalcone natural products and their analogs.

    PubMed

    Wang, Hao-Meng; Zhang, Li; Liu, Jiang; Yang, Zhao-Liang; Zhao, Hong-Ye; Yang, Yao; Shen, Di; Lu, Kui; Fan, Zhen-Chuan; Yao, Qing-Wei; Zhang, Yong-Min; Teng, Yu-Ou; Peng, Yu

    2015-03-01

    Four natural chalcones bearing prenyl or geranyl groups, i.e., bavachalcone (1a), xanthoangelol (1b), isobavachalcone (1c), and isoxanthoangelol (1d) were synthesized by using a regio-selective iodination and the Suzuki coupling reaction as key steps. The first total synthesis of isoxanthoangelol (1d) was achieved in 36% overall yield. A series of diprenylated and digeranylated chalcone analogs were also synthesized by alkylation, regio-selective iodination, aldol condensation, Suzuki coupling and [1,3]-sigmatropic rearrangement. The structures of the 11 new derivatives were confirmed by (1)H NMR, (13)C NMR and HRMS. The anticancer activity of these new chalcone derivatives against human tumor cell line K562 were evaluated by MTT assay in vitro. SAR studies suggested that the 5'-prenylation/geranylation of the chalcones significantly enhance their cytotoxic activity. Among them, Bavachalcone (1a) displayed the most potent cytotoxic activity against K562 with IC50 value of 2.7 μM. The morphology changes and annexin-V/PI staining studies suggested that those chalcone derivatives inhibited the proliferation of K562 cells by inducing apoptosis. PMID:25590864

  13. Prenylated Rab acceptor 1 (PRA1) inhibits TCF/{beta}-catenin signaling by binding to {beta}-catenin

    SciTech Connect

    Kim, Jong-Tae; Cho, Mi-Young; Choi, Seung-Chul; Kim, Jung Woo; Chae, Suhn-Kee; Yoon, Do-Young; Kim, Jae Wha . E-mail: wjkim@kribb.re.kr; Lim, Jong-Seok . E-mail: jslim@sookmyung.ac.kr

    2006-10-13

    The prenylated Rab acceptor 1 (PRA1) is a ubiquitously expressed 21 kDa protein containing two transmembrane domains that possibly induce its localization to the Golgi complex. It binds to prenylated Rab GTPases and VAMP2. In this study, we report that PRA1-overexpressing cells exhibited a significantly retarded growth rate as compared to that of the mock-transfected cells, and the transcriptional activity of TCF, as evaluated by TOPflash luciferase reporter assay, was profoundly reduced in the PRA1-overexpressed cells. These intracellular functions of PRA1 were verified by introducing deletion mutant or site-directed mutants, or small interfering RNA of PRA1. In addition, the translocation of {beta}-catenin from the cytosol to the nucleus was blocked to a significant degree in the PRA1-cells, and the interaction of PRA1 and {beta}-catenin was identified by confocal microscopy and immunoprecipitation analysis. Finally, we observed that the inhibition of TCF/{beta}-catenin signaling by PRA1 is associated with ERK1/2 dephosphorylation. Therefore, our data suggest that the in vivo modulation of PRA1 may be involved in TCF/{beta}-catenin signaling, as well as cellular proliferation and tumorigenesis.

  14. Prenylated Chalcone 2 Acts as an Antimitotic Agent and Enhances the Chemosensitivity of Tumor Cells to Paclitaxel.

    PubMed

    Fonseca, Joana; Marques, Sandra; Silva, Patrícia M A; Brandão, Pedro; Cidade, Honorina; Pinto, Madalena M; Bousbaa, Hassan

    2016-01-01

    We previously reported that prenylated chalcone 2 (PC2), the O-prenyl derivative (2) of 2'-hydroxy-3,4,4',5,6'-pentamethoxychalcone (1), induced cytotoxicity of tumor cells via disruption of p53-MDM2 interaction. However, the cellular changes through which PC2 exerts its cytotoxic activity and its antitumor potential, remain to be addressed. In the present work, we aimed to (i) characterize the effect of PC2 on mitotic progression and the underlying mechanism; and to (ii) explore this information to evaluate its ability to sensitize tumor cells to paclitaxel in a combination regimen. PC2 was able to arrest breast adenocarcinoma MCF-7 and non-small cell lung cancer NCI-H460 cells in mitosis. All mitosis-arrested cells showed collapsed mitotic spindles with randomly distributed chromosomes, and activated spindle assembly checkpoint. Live-cell imaging revealed that the compound induced a prolonged delay (up to 14 h) in mitosis, culminating in massive cell death by blebbing. Importantly, PC2 in combination with paclitaxel enhanced the effect on cell growth inhibition as determined by cell viability and proliferation assays. Our findings demonstrate that the cytotoxicity induced by PC2 is mediated through antimitotic activity as a result of mitotic spindle damage. The enhancement effects of PC2 on chemosensitivity of cancer cells to paclitaxel encourage further validation of the clinical potential of this combination. PMID:27483224

  15. New Prenylated Aeruginosin, Microphycin, Anabaenopeptin and Micropeptin Analogues from a Microcystis Bloom Material Collected in Kibbutz Kfar Blum, Israel

    PubMed Central

    Elkobi-Peer, Shira; Carmeli, Shmuel

    2015-01-01

    Thirteen new and eighteen known natural products were isolated from a bloom material of an assembly of various Microcystis spp. collected in November, 2008, from a commercial fishpond near Kibbutz Kfar Blum, the Jordan Valley, Israel. The new natural products included the prenylated aeruginosin KB676 (1), microphycin KB921 (2), anabaenopeptins KB906 (3) and KB899 (4) and micropeptins KB928 (5), KB956 (6), KB970A (7), KB970B (8), KB984 (9), KB970C (10), KB1048 (11), KB992 (12) and KB1046 (13). Their structures were elucidated primarily by interpretation of their 1D and 2D nuclear magnetic resonance spectra and high-resolution mass spectrometry. Marfey’s and chiral-phase high performance liquid chromatography methods were used to determine the absolute configurations of their chiral centers. Aeruginosin KB676 (1) contains the rare (2S,3aS,6S,7aS)-Choi and is the first prenylated aeruginosin derivative described in the literature. Compounds 1 and 5–11 inhibited trypsin with sub-μM IC50s, while Compounds 11–13 inhibited chymotrypsin with sub-μM IC50s. The structures and biological activities of the new natural products and our procedures of dereplication are described. PMID:25884445

  16. The Synthesis and Pharmacological Evaluation of Adamantane-Derived Indoles: Cannabimimetic Drugs of Abuse

    PubMed Central

    2013-01-01

    Two novel adamantane derivatives, adamantan-1-yl(1-pentyl-1H-indol-3-yl)methanone (AB-001) and N-(adamtan-1-yl)-1-pentyl-1H-indole-3-carboxamide (SDB-001), were recently identified as cannabimimetic indoles of abuse. Conflicting anecdotal reports of the psychoactivity of AB-001 in humans, and a complete dearth of information about the bioactivity of SDB-001, prompted the preparation of AB-001, SDB-001, and several analogues intended to explore preliminary structure–activity relationships within this class. This study sought to elucidate which structural features of AB-001, SDB-001, and their analogues govern the cannabimimetic potency of these chemotypes in vitro and in vivo. All compounds showed similar full agonist profiles at CB1 (EC50 = 16–43 nM) and CB2 (EC50 = 29–216 nM) receptors in vitro using a FLIPR membrane potential assay, with the exception of SDB-002, which demonstrated partial agonist activity at CB2 receptors. The activity of AB-001, AB-002, and SDB-001 in rats was compared to that of Δ9-tetrahydrocannabinol (Δ9-THC) and cannabimimetic indole JWH-018 using biotelemetry. SDB-001 dose-dependently induced hypothermia and reduced heart rate (maximal dose 10 mg/kg) with potency comparable to that of Δ9-tetrahydrocannabinol (Δ9-THC, maximal dose 10 mg/kg), and lower than that of JWH-018 (maximal dose 3 mg/kg). Additionally, the changes in body temperature and heart rate affected by SDB-001 are of longer duration than those of Δ9-THC or JWH-018, suggesting a different pharmacokinetic profile. In contrast, AB-001, and its homologue, AB-002, did not produce significant hypothermic and bradycardic effects, even at relatively higher doses (up to 30 mg/kg), indicating greatly reduced potency compared to Δ9-THC, JWH-018, and SDB-001. PMID:23551277

  17. GC-MS studies on the six naphthoyl-substituted 1-n-pentyl-indoles: JWH-018 and five regioisomeric equivalents.

    PubMed

    Thaxton, Amber; Belal, Tarek S; Smith, Forrest; DeRuiter, Jack; Abdel-Hay, Karim M; Clark, C Randall

    2015-07-01

    The GC-MS properties of the synthetic cannabinoid drug of abuse 3-(1-naphthoyl)-1-pentylindole (JWH-018) and all 5 of its' regioisomeric 1-naphthoyl substituted 1-n-pentylindoles are compared in this report. These compounds have the 1-naphthoyl-group attached at each of the possible substituent positions of the indole ring. The six compounds have the same elemental composition C24H23NO and the same substituents attached to the indole ring. The electron ionization mass spectra showed equivalent regioisomeric major fragment ions resulting from cleavage of the groups attached to the central indole nucleus. The characteristic (M-17)(+) fragment ion at m/z 324 resulting from the loss of an OH group was significant in the EI-MS of 3-, 4-, 5- and 6-(1-naphthoyl)-1-pentylindole. Fragment ions occurred at m/z 127 and 155 for the naphthyl and naphthoyl cations common to all six regioisomeric substances. Indole containing fragments produced the cations at m/z 284, 270, 214 and 186. The unique fragment at m/z 141 observed in the 1,2- and 1,7-isomers resulted from a rearrangement involving the two indole substituents to yield the C10H7CH2(+) cation. The major points of EI-MS differentiation of the synthetic cannabinoid JWH-018 from the other five isomers are the high relative abundance of both the m/z 144 ion and the m/z 324 ion in the JWH-018 spectrum. GC separations on a capillary column containing a trifluoropropyl methyl polysiloxane (Rtx-200) stationary phase provided excellent resolution of these six compounds. The elution order appears related to the relative distance between the two indole substituents with the lowest retention associated with minimum distance between the groups attached to the indole nucleus. PMID:25965306

  18. Indole Glucosinolate Biosynthesis Limits Phenylpropanoid Accumulation in Arabidopsis thaliana

    PubMed Central

    2015-01-01

    Plants produce an array of metabolites (including lignin monomers and soluble UV-protective metabolites) from phenylalanine through the phenylpropanoid biosynthetic pathway. A subset of plants, including many related to Arabidopsis thaliana, synthesizes glucosinolates, nitrogen- and sulfur-containing secondary metabolites that serve as components of a plant defense system that deters herbivores and pathogens. Here, we report that the Arabidopsis thaliana reduced epidermal fluorescence5 (ref5-1) mutant, identified in a screen for plants with defects in soluble phenylpropanoid accumulation, has a missense mutation in CYP83B1 and displays defects in glucosinolate biosynthesis and in phenylpropanoid accumulation. CYP79B2 and CYP79B3 are responsible for the production of the CYP83B1 substrate indole-3-acetaldoxime (IAOx), and we found that the phenylpropanoid content of cyp79b2 cyp79b3 and ref5-1 cyp79b2 cyp79b3 plants is increased compared with the wild type. These data suggest that levels of IAOx or a subsequent metabolite negatively influence phenylpropanoid accumulation in ref5 and more importantly that this crosstalk is relevant in the wild type. Additional biochemical and genetic evidence indicates that this inhibition impacts the early steps of the phenylpropanoid biosynthetic pathway and restoration of phenylpropanoid accumulation in a ref5-1 med5a/b triple mutant suggests that the function of the Mediator complex is required for the crosstalk. PMID:25944103

  19. Low-Dose Radiotherapy in Indolent Lymphoma

    SciTech Connect

    Rossier, Christine; Schick, Ulrike; Miralbell, Raymond; Mirimanoff, Rene O.; Weber, Damien C.; Ozsahin, Mahmut

    2011-11-01

    Purpose: To assess the response rate, duration of response, and overall survival after low-dose involved-field radiotherapy in patients with recurrent low-grade lymphoma or chronic lymphocytic leukemia (CLL). Methods and Materials: Forty-three (24 women, 19 men) consecutive patients with indolent lymphoma or CLL were treated with a total dose of 4 Gy (2 x 2 Gy) using 6- 18-MV photons. The median age was 73 years (range, 39-88). Radiotherapy was given either after (n = 32; 75%) or before (n = 11; 25%) chemotherapy. The median time from diagnosis was 48 months (range, 1-249). The median follow-up period was 20 months (range, 1-56). Results: The overall response rate was 90%. Twelve patients (28%) had a complete response, 15 (35%) had a partial response, 11 (26%) had stable disease, and 5 (11%) had progressive disease. The median overall survival for patients with a positive response (complete response/partial response/stable disease) was 41 months; for patients with progressive disease it was 6 months (p = 0.001). The median time to in-field progression was 21 months (range, 0-24), and the median time to out-field progression was 8 months (range, 0-40). The 3-year in-field control was 92% in patients with complete response (median was not reached). The median time to in-field progression was 9 months (range, 0.5-24) in patients with partial response and 6 months (range, 0.6-6) in those with stable disease (p < 0.05). Younger age, positive response to radiotherapy, and no previous chemotherapy were the best factors influencing the outcome. Conclusions: Low-dose involved-field radiotherapy is an effective treatment in the management of patients with recurrent low-grade lymphoma or CLL.

  20. Development and Characterization of Monoclonal Antibodies Specific for 3-(1-naphthoyl) Indole Derivatives.

    PubMed

    Nakayama, Hiroshi; Kenjyou, Noriko; Ito, Yuji

    2016-02-01

    3-(1-naphthoyl) indole is one of the raw materials that synthesizes a synthetic cannabinoid such as 1-pentyl-3-(1-naphthoyl) indole (JWH-018) and 1-butyl-3-(1-naphthoyl) indole (JWH-073). It is important to detect the 3-(1-naphthoyl) indole derivatives rapidly, sensitively, and comprehensively. We developed two monoclonal antibodies (MAb) against 3-(1-naphthoyl) indole derivatives, named NT1 (IgG1) and NT2 (IgG1), which were possibly effective for detecting 3-(1-naphthoyl) indole derivatives. The cross-reactive ability of these MAbs was evaluated using a competitive enzyme-linked immunosorbent assay (ELISA). In the results, we found both of these antibodies recognize 3-(1-naphthoyl) indole and its derivatives. However neither of these antibodies recognize naphtoic acid, 4-methyl-naphtoic acid, and indole. Sixty to 100 nanomole per liter of 3-(1-naphthoyl) indole derivatives, such as 1-methyl-3-(1-naphthoyl) indole, 1-ethyl-3-(1-naphthoyl) indole, and 1-octyl-3-(1-naphthoyl) indole, can be detected using both of the obtained MAbs. Thus, the MAbs produced in this study could be a useful tool for the detection of 3-(1-naphthoyl) indole derivatives. PMID:26871514

  1. Synthetic small molecule GLP-1 secretagogues prepared by means of a three-component indole annulation strategy

    PubMed Central

    Chepurny, Oleg G.; Leech, Colin A.; Tomanik, Martin; DiPoto, Maria C.; Li, Hui; Han, Xinping; Meng, Qinghe; Cooney, Robert N.; Wu, Jimmy; Holz, George G.

    2016-01-01

    Rational assembly of small molecule libraries for purposes of drug discovery requires an efficient approach in which the synthesis of bioactive compounds is enabled so that numerous structurally related compounds of a similar basic formulation can be derived. Here, we describe (4 + 3) and (3 + 2) indole annulation strategies that quickly generate complex indole heterocycle libraries that contain novel cyclohepta- and cyclopenta[b]indoles, respectively. Screening of one such library comprised of these indoles identifies JWU-A021 to be an especially potent stimulator of glucagon-like peptide-1 (GLP-1) secretion in vitro. Surprisingly, JWU-A021 is also a potent stimulator of Ca2+ influx through TRPA1 cation channels (EC50 ca. 200 nM), thereby explaining its ability to stimulate GLP-1 release. Of additional importance, the available evidence indicates that JWU-A021 is one of the most potent non-electrophilic TRPA-1 channel agonists yet to be reported in the literature. PMID:27352904

  2. Synthetic small molecule GLP-1 secretagogues prepared by means of a three-component indole annulation strategy

    NASA Astrophysics Data System (ADS)

    Chepurny, Oleg G.; Leech, Colin A.; Tomanik, Martin; Dipoto, Maria C.; Li, Hui; Han, Xinping; Meng, Qinghe; Cooney, Robert N.; Wu, Jimmy; Holz, George G.

    2016-06-01

    Rational assembly of small molecule libraries for purposes of drug discovery requires an efficient approach in which the synthesis of bioactive compounds is enabled so that numerous structurally related compounds of a similar basic formulation can be derived. Here, we describe (4 + 3) and (3 + 2) indole annulation strategies that quickly generate complex indole heterocycle libraries that contain novel cyclohepta- and cyclopenta[b]indoles, respectively. Screening of one such library comprised of these indoles identifies JWU-A021 to be an especially potent stimulator of glucagon-like peptide-1 (GLP-1) secretion in vitro. Surprisingly, JWU-A021 is also a potent stimulator of Ca2+ influx through TRPA1 cation channels (EC50 ca. 200 nM), thereby explaining its ability to stimulate GLP-1 release. Of additional importance, the available evidence indicates that JWU-A021 is one of the most potent non-electrophilic TRPA-1 channel agonists yet to be reported in the literature.

  3. Synthetic small molecule GLP-1 secretagogues prepared by means of a three-component indole annulation strategy.

    PubMed

    Chepurny, Oleg G; Leech, Colin A; Tomanik, Martin; DiPoto, Maria C; Li, Hui; Han, Xinping; Meng, Qinghe; Cooney, Robert N; Wu, Jimmy; Holz, George G

    2016-01-01

    Rational assembly of small molecule libraries for purposes of drug discovery requires an efficient approach in which the synthesis of bioactive compounds is enabled so that numerous structurally related compounds of a similar basic formulation can be derived. Here, we describe (4 + 3) and (3 + 2) indole annulation strategies that quickly generate complex indole heterocycle libraries that contain novel cyclohepta- and cyclopenta[b]indoles, respectively. Screening of one such library comprised of these indoles identifies JWU-A021 to be an especially potent stimulator of glucagon-like peptide-1 (GLP-1) secretion in vitro. Surprisingly, JWU-A021 is also a potent stimulator of Ca(2+) influx through TRPA1 cation channels (EC50 ca. 200 nM), thereby explaining its ability to stimulate GLP-1 release. Of additional importance, the available evidence indicates that JWU-A021 is one of the most potent non-electrophilic TRPA-1 channel agonists yet to be reported in the literature. PMID:27352904

  4. [Occurrence of indole alkaloids among secondary metabolites of soil Aspergillus].

    PubMed

    Vinokurova, N G; Khmel'nitskaia, I I; Baskunov, B P; Arinbasarov, M U

    2003-01-01

    The occurrence of indole alkaloids among secondary fungal metabolites was studied in species of the genus Aspergillus, isolated from soils that were sampled in various regions of Russia (a total of 102 isolates of the species A. niger, A. phoenicis, A. fumigatus, A. flavus, A. versicolor, A. ustus, A. clavatus, and A. ochraceus). Clavine alkaloids were represented by fumigaclavine, which was formed by A. fumigatus. alpha-Cyclopiazonic acid was formed by isolates of A. fumigatus, A. flavus, A. versicolor, A. phoenicis, and A. clavatus. The occurrence of indole-containing diketopiperazine alkaloids was documented for isolates of A. flavus, A. fumigatus, A. clavatus, and A. ochraceus. No indole-containing metabolites were found among the metabolites of A. ustus or A. niger. PMID:12722658

  5. Conversion of indole to oxindole under methanogenic conditions

    SciTech Connect

    Berry, D.F.; Madsen, E.L.; Bollag, J.M.

    1987-01-01

    Aromatic N-heterocyclic compounds are often present in aqueous effluents associated with coal mining and processing operations. The environmental fate of these chemicals is of great concern because they are toxic and may contaminate both surface water and groundwater. Previous investigations of microbial metabolism of aromatic chemicals under aerobic and anaerobic conditions suggest that microorganisms may play a key role in determining the fate of this class of compounds. When indole was incubated under methanogenic conditions with an inoculum of sewage sludge, the chemical was metabolized within 10 days and temporary formation of an intermediate was observed. The metabolite was isolated by thin-layer chromatography and determined to be 1,3-dihydro-2H-indol-2-one (oxindole) by UV spectroscopy (lambda/sub max/, 247 nm) and mass spectrometry (m/z, 133). The methane produced (net amount) indicated nearly complete mineralization of indole.

  6. Structure of the indole-benzene dimer revisited.

    PubMed

    Biswal, Himansu S; Gloaguen, Eric; Mons, Michel; Bhattacharyya, Surjendu; Shirhatti, Pranav R; Wategaonkar, Sanjay

    2011-09-01

    The structure of the indole-benzene dimer has been investigated using experimental techniques, namely, UV spectroscopy and infrared-ultraviolet (IR/UV) double resonance spectroscopy, combined with quantum chemical calculations such as MP2 and dispersion corrected DFT methods. The red shift of the indole N-H stretch frequency in the dimer provides direct evidence that the experimentally observed indole-benzene dimer is an N-H···π bound hydrogen bonded complex. Theoretical investigations suggest that the potential energy surface (PES) of the complex is rather flat along the coordinate describing the tilt angle between the molecular planes of indole and benzene, with several minima of similar energies, namely, parallel displaced (PD), right-angle T-shaped (T), and other intermediate structures which can be categorized as tilted T-shaped (T') and tilted parallel displaced (PD') structures. Three different computational methods, namely, RI-MP2, RI-B97-D, and PBE1-DCP, are used to arrive at a new structural assignment after assessing their performance in predicting the structure of the pyrrole dimer, for which accurate experimental data are available. By comparing the computed IR spectra of PD, T, and T'/PD' structures with the experimental IR spectrum, the tilted T-shaped (T') structure was assigned to the indole-benzene dimer. The empirically dispersion-corrected functionals (RI-B97-D and PBE1-DCP) correctly reproduce the experimental IR spectrum whereas the popular post-Hartree-Fock, MP2 method gives disappointing results. These results are also in agreement with the experimental dissociation energy (D(0)) reported in the literature. The N-H stretch frequency of the indole-benzene dimer has been found to be a more pertinent parameter for the structural assignment than the dissociation energy (D(0)). PMID:21413767

  7. Indole Alkaloids from the Leaves of Nauclea officinalis.

    PubMed

    Fan, Long; Liao, Cheng-Hui; Kang, Qiang-Rong; Zheng, Kai; Jiang, Ying-Chun; He, Zhen-Dan

    2016-01-01

    Three new indole alkaloids, named naucleamide G (1), and nauclealomide B and C (5 and 6), were isolated from the n-BuOH-soluble fraction of an EtOH extract of the leaves of Nauclea officinalis, together with three known alkaloids, paratunamide C (2), paratunamide D (3) and paratunamide A (4). The structures with absolute configurations of the new compounds were identified on the basis of 1D and 2D NMR, HRESIMS, acid hydrolysis and quantum chemical circular dichroism (CD) calculation. According to the structures of isolated indole alkaloids, their plausible biosynthetic pathway was deduced. PMID:27455233

  8. Effect of Exogenous Indole-3-Acetic Acid and Indole-3-Butyric Acid on Internal Levels of the Respective Auxins and Their Conjugation with Aspartic Acid during Adventitious Root Formation in Pea Cuttings.

    PubMed

    Nordström, A C; Jacobs, F A; Eliasson, L

    1991-07-01

    The influence of exogenous indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) on the internal levels of these auxins was studied during the first 4 days of adventitious root formation in cuttings of Pisum sativum L. The quantitations were done by high performance liquid chromatography with spectrofluorometric detection. IBA, identified by combined gas chromatography-mass spectrometry (GC-MS), was found to naturally occur in this plant material. The root inducing ability of exogenous IBA was superior to that of IAA. The IAA level in the tissue increased considerably on the first day after application of IAA, but rapidly decreased again, returning to a level twice the control by day 3. The predominant metabolic route was conjugation with aspartic acid, as reflected by the increase in the level of indole-3-acetylaspartic acid. The IBA treatment resulted in increases in the levels of IBA, IAA, and indole-3-acetylaspartic acid. The IAA content rapidly returned to control levels, whereas the IBA level remained high throughout the experimental period. High amounts of indole-3-butyrylaspartic acid were found in the tissue after feeding with IBA. The identity of the conjugate was confirmed by (1)H-nuclear magnetic resonance and GC-MS. IBA was much more stable in solution than IAA. No IAA was detected after 48 hours, whereas 70% IBA was still recovered after this time. The relatively higher root inducing ability of IBA is ascribed to the fact that its level remained elevated longer than that of IAA, even though IBA was metabolized in the tissue. Adventitious root formation is discussed on the basis of these findings. PMID:16668265

  9. Avertoxins A-D, Prenyl Asteltoxin Derivatives from Aspergillus versicolor Y10, an Endophytic Fungus of Huperzia serrata.

    PubMed

    Wang, Mingzi; Sun, Mingwei; Hao, Huilin; Lu, Chunhua

    2015-12-24

    Aspergillus versicolor Y10 is an endophytic fungus isolated from Huperzia serrata, which showed inhibitory activity against acetylcholinesterase. An investigation of the chemical constituents of Y10 led to the isolation of four new prenylated asteltoxin derivatives, named avertoxins A-D (2-5), together with the known mycotoxin asteltoxin (1). In the present study, we report structure elucidation for 2-5 and the revised NMR assignments for asteltoxin and demonstrated that avertoxin B (3) is an active inhibitor against human acetylcholinesterase with the IC50 value of 14.9 μM (huperzine A as the positive control had an IC50 of 0.6 μM). In addition, the cytotoxicity of asteltoxin (1) and avertoxins A-D (2-5) against MDA-MB-231, HCT116, and HeLa cell lines was evaluated. PMID:26618211

  10. Prenylated chalcones and flavanones as inducers of quinone reductase in mouse Hepa 1c1c7 cells.

    PubMed

    Miranda, C L; Aponso, G L; Stevens, J F; Deinzer, M L; Buhler, D R

    2000-02-28

    The objective of this study was to determine if prenylchalcones (open C-ring flavonoids) and prenylflavanones from hops and beer are inducers of quinone reductase (QR) in the mouse hepatoma Hepa 1c1c7 cell line. All the prenylchalcones and prenylflavanones tested were found to induce QR but not CYP1A1 in this cell line. In contrast, the synthetic chalcone, chalconaringenin, and the flavanone, naringenin, with no prenyl or geranyl groups, were ineffective in inducing QR. The hop chalcones, xanthohumol and dehydrocycloxanthohumol hydrate, also induced QR in the Ah-receptor-defective mutant cell line, Hepa 1c1c7 bp(r)c1. Thus, the prenylflavonoids represent a new class of monofunctional inducers of QR. PMID:10737704