- An orsellinic acid glucoside from Syzygium aromatica
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The buds of Syzygium aromatica yielded two triterpenoid acids, oleanolic acid and crategolic acid, and a new phenolic glucoside, orsellinic-2-O-β-D- glucopyranoside, from its methanolic extract. The structure was elucidated by spectroscopic methods and acid hydrolysis.
- Charles, Reena,Garg, Shri Niwas,Kumar, Sushil
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- CRUSTINIC ACID, A TRIDEPSIDE FROM UMBILICARIA CRUSTULOSA
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The structure of crustinic acid extracted from Umbilicaria crustulosa has been elucidated as 4,6-dihydroxy-3-carboxy-2-methylphenyl lecanorate by spectroscopic and chemical means.Key Word Index - Umbilicaria crustulosa; Umbilicariaceae; crustinic acid; tridepside; lichen substance.
- Huneck, S.,Porzel, A.,Schmidt, J.,Feige, G. B.,Posner, B.
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- Synthesis, biological, and photophysical studies of molecular rotor-based fluorescent inhibitors of the trypanosome alternative oxidase
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We have recently reported on the development and trypanocidal activity of a class of inhibitors of Trypanosome Alternative Oxidase (TAO) that are targeted to the mitochondrial matrix by coupling to lipophilic cations via C14 linkers to enable optimal interaction with the enzyme's active site. This strategy resulted in a much-enhanced anti-parasite effect, which we ascribed to the greater accumulation of the compound at the location of the target protein, i.e. the mitochondrion, but to date this localization has not been formally established. We therefore synthesized a series of fluorescent analogues to visualize accumulation and distribution within the cell. The fluorophore chosen, julolidine, has the remarkable extra feature of being able to function as a viscosity sensor and might thus additionally act as a probe of the cellular glycerol that is expected to be produced when TAO is inhibited. Two series of fluorescent inhibitor conjugates incorporating a cationic julolidine-based viscosity sensor were synthesized and their photophysical and biological properties were studied. These probes display a red emission, with a high signal-to-noise ratio (SNR), using both single- and two-photon excitation. Upon incubation with T. brucei and mammalian cells, the fluorescent inhibitors 1a and 2a were taken up selectively in the mitochondria as shown by live-cell imaging. Efficient partition of 1a in functional isolated (rat liver) mitochondria was estimated to 66 ± 20% of the total. The compounds inhibited recombinant TAO enzyme in the submicromolar (1a, 2c, 2d) to low nanomolar range (2a) and were effective against WT and multidrug-resistant trypanosome strains (B48, AQP1-3 KO) in the submicromolar range. Good selectivity (SI > 29) over mammalian HEK cells was observed. However, no viscosity-related shift could be detected, presumably because the glycerol was produced cytosolically, and released through aquaglyceroporins, whereas the probe was located, virtually exclusively, in the trypanosome's mitochondrion.
- Cueto-Díaz, Eduardo J.,Ebiloma, Godwin U.,Alfayez, Ibrahim A.,Ungogo, Marzuq A.,Lemgruber, Leandro,González-García, M. Carmen,Giron, Maria D.,Salto, Rafael,Fueyo-González, Francisco José,Shiba, Tomoo,González-Vera, Juan A.,Ruedas Rama, Maria José,Orte, Angel,de Koning, Harry P.,Dardonville, Christophe
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- Kolbe-Schmitt type reaction under ambient conditions mediated by an organic base
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The combined use of an organic base for resorcinols realized a Kolbe-Schmitt type reaction under ambient conditions. When resorcinols (3-hydroxyphenol derivatives) were treated with DBU under a carbon dioxide atmosphere, nucleophilic addition to carbon dioxide proceeded to afford the corresponding salicylic acid derivatives in high yields.
- Sadamitsu, Yuta,Okumura, Akira,Saito, Kodai,Yamada, Tohru
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supporting information
p. 9837 - 9840
(2019/08/20)
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- Hansforesters A-M, polyesters from the sponge-associated fungus Hansfordia sinuosae with antibacterial activities
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Bioassay-guided fractionation and chromatographic separation of a sponge-derived fungus Hansfordia sinuosae, resulted in the isolation of thirteen new polyesters namely hansforesters A-M (1-13), along with five known analogues involving ascotrichalactone A, ascotrichester B, 15G256π, 6R-hydroxymellein, and (?)orthosporin. The structures of the new compounds were determined through extensive spectroscopic analysis, in addition to the chemical conversion for the configurational assignment. The polyesters incorporating the motifs of orsellinic acid, 2,4-dihydroxy-6-acetonylbenzoic acid, and orcinotriol were found from nature for the first time. Hansforester A (1) and ascotrichalactone A exhibited potent inhibition against a panel of bacterial strains, including the agricultural pathogenic bacteria, Pseudomonas lachrymans, Agrobacterium tumefaciens, Xanthomonas vesicatoria, and Ralstonia solanacearum, with the MIC values of 15.6 μM, and the human infected bacterium Staphylococcus aureus with the MIC values of 3.9 μM. These findings suggested that hansforester A and ascotrichalactone A are the potential leads to be developed as the antibacterial agents for the treatment of agriculture bacterial pathogens.
- Wu, Zehong,Liu, Dong,Huang, Jian,Proksch, Peter,Zhu, Kui,Lin, Wenhan
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p. 39756 - 39768
(2018/12/13)
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- New orsellinic acid esters from fungus chaetomium globosporum
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Seven new orsellinic acid esters, 1-7, and four known compounds were isolated from the solid, fermented rice culture of Chaetomium globosporum (cib-132). Their structures were elucidated by 1D- and 2D-NMR spectra, and the relative configuration of compoun
- Xu, Guo-Bo,Wang, Ni-Ni,Bao, Jin-Ku,Yang, Tao,Li, Guo-You
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p. 151 - 159
(2014/02/14)
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- Assembly of melleolide antibiotics involves a polyketide synthase with cross-coupling activity
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Summary Little is known about polyketide biosynthesis in mushrooms (basidiomycota). In this study, we investigated the iterative type I polyketide synthase (PKS) ArmB of the tree pathogen Armillaria mellea, a producer of cytotoxic melleolides (i.e., polyketides esterified with various sesquiterpene alcohols). Heterologously produced ArmB showed orsellinic acid (OA) synthase activity in vitro. Further, we demonstrate cross-coupling activity of ArmB, which forms OA esters with various alcohols. Using a tricyclic Armillaria sesquiterpene alcohol, we reconstituted the biosynthesis of melledonol. Intermolecular transesterification reactions may represent a general mechanism of fungal PKSs to create structural diversity of small molecules. Phylogenetic network construction of thioesterase domains of both basidiomycetes and ascomycetes suggests that the fungal nonreducing PKS family has likely evolved from an ancient OA synthase and has gained versatility by adopting Claisen-like cyclase or transferase activity.
- Lackner, Gerald,Bohnert, Markus,Wick, Jonas,Hoffmeister, Dirk
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p. 1101 - 1106
(2013/10/01)
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- Protoilludance Norsesquiterpenoid Esters and Uses Thereof
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Disclosed herein are novel protoilludane norsesquiterpenoid ester compounds isolated from mycelium of Armillaria mellea that are useful for treating tumors or proliferative diseases such as breast cancers, lung cancers, colon cancers or leukemia.
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- Total synthesis of graphislactone G
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We present a total synthesis of the fungal natural product graphislactone G, a chlorinated resorcylic lactone. The key step is a Suzuki coupling used for the construction of the central biaryl bond. Graphislactone G was prepared in 13 steps with 22% yield
- Cudaj, Judith,Podlech, Joachim
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supporting information; experimental part
p. 3092 - 3094
(2010/07/18)
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- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
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- Radical-scavenging activity of orsellinates
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Lichens are an important source of phenolic compounds and have been intensively investigated for their biological and pharmacological activities. Lecanoric acid (1), a lichen depside, was isolated from a Parmotrema tinctorum specimen and treated with alcohols to produce orsellinic acid (2) and orsellinates (3) to (9) (2,4-dihydroxy-6-n-methyl benzoates). Free radical scavenging activity of methyl (3), ethyl (4), n-propyl (5), n-butyl (6), iso-propyl (7), sec-butyl (8), tert-butyl (9) orsellinates was evaluated using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) method. Results showed that chain elongation of methyl (3) to n-butyl (6) causes a rise in the antioxidant activity. However, iso-propyl (7) and tert-butyl (9) were more active than the correspondent linear compounds, although sec-butyl (8) was less active among the chain ramified compounds. All the orsellinates were less active than lecanoric acid (1) and orsellinic acid (2). Orcinol (10) and resorcinol (11) were also determined for comparison with activities of orsellinates. Gallic acid (12) was used as control.
- Lopes, Thiago Inacio Barros,Coelho, Roberta Gomes,Yoshida, Nidia Cristiane,Honda, Neli Kika
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experimental part
p. 1551 - 1554
(2009/09/06)
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- Chemical study on Garhwal Himalayan Lichen: Usnea emidotteries
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Usnea species are medicinally important, so we take unexplored species, Usnea emidotteris. Seven components 2-hydroxy-3-methoxy-4, 6-dimethyl ethyl benzoate, 2, 4-dihydro-xy-3, 6-dimethyl ethyl benzoate, 2-hydroxy-4-methoxy-3, 6-dimethylbezoic acid, usnic
- Rawat,Shukla, Vertika,Negi, Sandeep,Pant
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p. 2566 - 2570
(2007/10/03)
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- Total synthesis of CRM646-A and -B, two fungal glucuronides with potent heparinase inhibition activities
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CRM646-A (1) and -B (2), two fungal glucuronides with a dimeric 2,4-dihydroxy-6-alkylbenzoic acid (orcinol p-depside) aglycone showing significant heparinase and telomerase inhibition activities, were synthesized for the first time. The successful approac
- Wang, Ping,Zhang, Zhaojun,Yu, Biao
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p. 8884 - 8889
(2007/10/03)
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- TOTAL SYNTHESIS OF DAURICHROMENIC ACID
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The present invention provides a method to prepare 2H-benzo[6]pyrans, such as the anti-HIV natural product daurichromenic acid (1a), by microwave-assisted tandem aldol reaction of a phenolic enolate followed by intramolecular SN2' type cyclization to form the 2H-benzo[6]pyran core structure.
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Page 2/2; 10
(2008/06/13)
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- Total Synthesis of the Highly Potent Anti-HIV Natural Product Daurichromenic Acid along with Its Two Chromane Derivatives, Rhododaurichromanic Acids A and B
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(Equation presented) The highly potent anti-HIV natural product daurichromenic acid was successfully synthesized in only five steps with 49% overall yield. The key step in the synthetic strategy involves a microwave-assisted tandem condensation and intramolecular SN2′- type cyclization to form the 2H-benzopyran core structure.
- Kang, Ying,Mei, Yan,Du, Yuguo,Jin, Zhendong
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p. 4481 - 4484
(2007/10/03)
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- Total synthesis of everninomicin 13,384-1 - Part 1: Retrosynthetic analysis and synthesis of the A1B(A)C fragment
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In this first of a series of four articles we introduce everninomicin 13,384-1 (1), a powerful antibiotic effective against drug resistant bacteria, as a target for total synthesis and discuss its retrosynthetic analysis. From the three defined fragments required for the synthesis (2: A1B(A)C fragment; 4: DE fragment; 5: FGHA2 fragment), we describe herein two approaches to the A1B(A)C block. The first strategy relied on an olefin metathesis reaction to construct a common intermediate for rings B and C, but was faced with final protecting group problems. The second, and successful approach, involved a 1,2-phenylsulfeno migration and a sulfur directed glycosidation procedure to link rings B and C, as well as an acyl fluoride intermediate to install the sterically hindered aryl ester moiety (ring A1). The final stages of the synthesis of the required 2-phenylseleno glycosyl fluoride 2 required introduction of a phenylseleno group at C-1 of ring C followed by a novel, DAST-promoted 1,2-migration to produce the desired 2-β-phenylseleno glycosyl fluoride moiety.
- Nicolaou,Rodriguez, Rosa Maria,Mitchell, Helen J.,Suzuki, Hideo,Fylaktakidou, Konstantina C.,Baudoin, Olivier,Van Delft, Floris L.
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p. 3095 - 3115
(2007/10/03)
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- Total synthesis of everninomicin 13,384-1 - Part 1: Synthesis of the A1B(A)C fragment
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The powerful antibiotic everninomicin 13,384-1 (1, Ziracin) has been prepared for the first time through a total synthesis. The (1 → 1-disaccharide and the two orthoesters of this target molecule were introduced by new methodologies using a tin acetal and 1,2-phenylseleno migrations. The reaction sequence also relies on stereoselective glycosidations and subtle manipulations of protecting groups. In addition to the introduction of new synthetic methodologies, this total synthesis should allow the preparation of combinatorial libraries of semisynthetic analogues of this highly promising antibiotic for biological screening purposes.
- Nicolaou,Mitchell, Helen J.,Suzuki, Hideo,Rodriguez, Rosa Maria,Baudoin, Olivier,Fylaktakidou, Konstantina C.
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p. 3334 - 3339
(2007/10/03)
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- Stereocontrolled synthesis of the everninomicin A1B(A)C ring framework
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A strategy based on a ring-closing olefin metathesis was used to convert divinylmethanol into 1, which served as a common precursor to activated derivatives 2 and 3. These in turn serve as precursors to the C and B carbohydrate units of the A1B
- Nicolaou,Rodriguez, Rosa M.,Mitchell, Helen J.,Van Delft, Floris L.
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p. 1874 - 1876
(2007/10/03)
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- Biologically active substances of Japanese inedible mushrooms
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As a part of our systematic investigation of biologically active substances of inedible mushrooms, we studied the chemical constituents of three Basidiomycetes fungi (Cryptoporus volvatus, Lentinellus ursinus and Paxillus atrotomentosus), five inedible Ascomycetes fungi (Daldinia concentrica, Daldinia vernicosa, Entonaema splendens, Hypoxylon truncatum and Ascoclavulina sakaii), and isolated a number of novel terpenoids, phenolics and nitrogen-containing compounds. The isolation, structural determination and biological activity of the new compounds will be discussed.
- Hashimoto, Toshihiro,Asakawa, Yoshinori
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p. 1067 - 1110
(2007/10/03)
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- Biosynthesis of the benz[a]anthraquinone antibiotic PD 116198
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The labelling pattern obtained from incorporation of a mixture of sodium [1-13C]- and [2-13C]acetates has confirmed the irregular derivation of the benz[a]anthraquinone skeleton of the angucycline antibiotic PD 116198. Subsequent incorporations of sodium [1-13C, 18O2]-, and [1-13C, 2-2H3]acetates and of 18O2 have revealed the origins of the hydrogen and oxygen atoms of the antibiotic. The possibility of a 'two-chain' biosynthesis was tested by feeding 2H-labeled orsellinates; however, no incorporation was detected. PD 116198 seems most plausibly derived by rearrangement of an initially-formed linear tetracyclic intermediate.
- Gould,Cheng
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p. 11135 - 11144
(2007/10/02)
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- Thermal Decomposition of Lichen Depsides
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The thermal decomposition of the following lichen depsides has been described: lecanoric acid, gyrophoric acid, evernic acid, perlatolic acid, planaic acid, confluentic acid, atranorin, 4-O-demethylbarbatic acid, and sekikaic acid.Main reaction products are decarboxylated compounds, phenolic units, rearranged depsides, and xanthones.Triethylammonium salts of depside carboxylic acids decompose at reasonably lower temperature than the corresponding free acids. - Keywords: Lichen Depsides, Thermal Decomposition
- Huneck, Siegfried,Schmidt, Juergen,Tabacchi, Raffaele
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p. 1283 - 1289
(2007/10/02)
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- AN INVESTIGATION OF THE BIOSYNTHESIS OF CITROMYCETIN IN PENICILLIUM FREQUENTANS USING (13)C- AND (14)C-LABELLED PRECURSORS
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Citromycetin (1) has been shown by (13)C n.m.r. to incorporate seven intact acetate units from -, -, and -acetates in accordance with a polyketide biosynthesis.The distribution of radioactivity following incorporation of malonate was consistent with the utilisation of two starter units.The following possible advanced precursors, labelled with (14)C, were not incorporated : 2,4-dihydroxy-6-methylbenzoic acid (14), 4,5,7-trihydroxyphthalide (16), and 4,7-dihydroxy-5-methylcoumarin (18).Two compounds, 2,4,5-trihydroxy-6-methylbenzoic acid (15) and triacetic acid lactone (17), were degraded to radiolabelled acetate prior to incorporation.
- Evans, Geoffrey E.,Staunton, James
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p. 755 - 762
(2007/10/02)
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- Chemical Studies on the Lichen. I. The Structure of Isolecanoric Acid, a New ortho-Depside Isolated from Parmelia tinctorum Despr.
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A new ortho-depside, isolecanoric acid was isolated from Parmelia tinctorum Despr. and 2-(2,4-dihydroxy-6-methylbenzoyloxy)-4-hydroxy-6-methylbenzoic acid was assigned to this substance from studies on the hydrolysis products and from analyses of the 1H and 13C NMR spectra.This substance is the first ortho-depside isolated from the genus Lichen.
- Sakurai, Atsushi,Goto, Yohko
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p. 1917 - 1918
(2007/10/02)
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