Nagelamides A−H, New Dimeric Bromopyrrole Alkaloids from Marine Sponge <i>Agelas</i> Species

Endo, Tadashi; Tsuda, Masashi; Okada, Tadashi; Mitsuhashi, Shinya; Shima, Hiroshi; Kikuchi, Kunimi; Mikami, Yuzuru; Fromont, Jane; Kobayashi, Jun’ichi

doi:10.1021/np034077n

Cited by 111 publications

(127 citation statements)

References 22 publications

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“…Such studies are important due to the fact that the determination of the structure of large molecules of natural origin is frequently difficult. An example is benzosceptrin [19,20] isolated from Agelas sp, which was synthesized to confirm its putative molecular structure. However, the spectrum of the synthetic compound differs slightly from the spectra of the compound of natural origin [21].…”

Section: Introductionmentioning

confidence: 99%

Conformational Preferences of 2-Acylpyrroles in Light of FT-IR and DFT Studies

Dubis

2014

J Phys Chem Biophys

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2-carboxylic acids [3] and corresponding esters [4]. Pyrrole-2-carboxylates are also useful substrates for the preparation of more complex pyrrole containing systems [5] such as ketorolac, a drug with anti-inflammatory and analgesic properties [6]. It is noted that the 2-acylpyrrole motif is widespread in nature. There are many examples of 2-acylpyrrole based molecules (Figure 1) with various biological activities [7,8]. Representative examples are pyoluteorin and pyrrolomycin D, secondary metabolites produced by marine Conformational Preferences of 2-Acylpyrroles in Light of FT-IR and DFT StudiesAlina T Dubis* Institute of Chemistry, University of Białystok, Hurtowa 1, Poland AbstractConformations of alpha-substituted pyrroles have been effectively studied using spectroscopic methods assisted by theoretical calculations developed in the recent decade. The question of how to effectively study the conformation of 2-acylpyrrole no longer remains unanswered. The detailed spectroscopic studies conducted in the last decade and interpreted on the basis of theoretical calculations provide a satisfactory answer to that question. Based on the Density Functional Theory (DFT) calculations of conformational properties of 2-acylpyrroles, for which two stable rotameric forms were predicted, syn and anti-conformers have been studied either by experimental or theoretical methods. The family of 2-acylpyrroles have both a proton donor N-H group and a proton acceptor C=O group. This structure favors the formation of doubly hydrogen-bonded cyclic dimers connected by two N-H...O=C bonds. The tendency to form cyclic dimers stabilizes the syn-conformation. Due to these properties 2-acylpyrroles can be used as structural models for the conformational analysis of peptides.This review summarizes recent investigations of conformations of 2-acylpyrroles, with a particular emphasis on the hydrogen bonds forming within these systems. The influence of 2-substitution on different aspects of stability of these molecular systems and the usefulness of infrared spectroscopy supported by theoretical calculations in H-bonds and conformational studies are discussed. Among the molecular properties hydrogen bond energy, structural characteristics such as C=O bond length of dimers and unique spectral features of 2-acylpyrroles that can be used to predict and investigate the conformation and structure of proteins are considered.Graphical abstract. The potential energy diagram of 2-acylpyrroles as a function of the dihedral angle pyrrole ringcarbonyl group of bond rotation. Most stable conformer syn converts to conformer anti via the transition state TS1; less stable conformer anti converts to conformer syn via the transition state TS2. conformational research and can greatly support experimental work with quite good accuracy. Among the most useful parameters are geometrical parameters, relative conformational energies, barriers to internal rotation and vibrational frequencies for each conformer. Journal of Physical Chemistry & BiophysicsEnergy differ...

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Section: Introductionmentioning

confidence: 99%

Conformational Preferences of 2-Acylpyrroles in Light of FT-IR and DFT Studies

Dubis

2014

J Phys Chem Biophys

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“…In 1993, Scheuer and co-workers reported the structure of palauamine (1, Scheme 1), [7] an architecturally interesting alkaloid from the same family. Since then, the pyrroleimidazole alkaloid family (Scheme 2) has been steadily growing, with the isolation of many analogues of sceptrin (3)(4)(5)(6)(7), [8] the ageliferins (8)(9)(10), [9] the nagelamides (11-13), [10] the axinellamines (14)(15)(16)(17), [11] massadine (18), [12] the styloguanidines (19)(20)(21)(22), [13] the konbuacidins (23 and 24), [14] brominated palauamines (26 and 27), [7b] and the stunning tetrameric stylissadines (28 and 29). [15] Recently, the structure of palauamine was called into question and was revised based on a combination of advanced spectroscopic analysis, computation, and even biosynthetic considerations.…”

Section: Introductionmentioning

confidence: 99%

The Pursuit of Palau'amine

et al. 2007

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Since its discovery in 1993, the marine natural product palau'amine has intrigued natural product chemists. Its exotic molecular architecture and purported bioactivity made it an ideal target for synthesis. However, as the years went by and related marine alkaloids were isolated, a skeptical eye was cast on the structure of palau'amine; recently these suspicions were confirmed and the structure of palau'amine revised. This Minireview gives a careful overview of the structural revision and its ramifications to both its biogenesis and total synthesis.

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“…(Endo et al, 2004). Nagelamide G exhibited antibacterial activity against M. luteus, B. subtilis and E. coli, but weakly inhibited protein phosphatase 2 A (IC 50 = 13 μM), thus suggesting that this enzyme may not be the main molecular target responsible for the antibacterial activity of this compound.…”

Section: Fig 6d Anthelminthic and Antibacterial Compoundsmentioning

confidence: 96%

Biologically active compounds from natural and marine natural organisms with antituberculosis, antimalarial, leishmaniasis, trypanosomiasis, anthelmintic, antibacterial, antifungal, antiprotozoal, and antiviral activities

Asif¹

2016

TANG [HUMANITAS MEDICINE]

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The biologically active compounds derived from different natural organisms such as animals, plants, and microorganisms like algae, fungi, bacteria and merine organisms. These natural compounds possess diverse biological activities like anthelmintic, antibacterial, antifungal, antimalarial, antiprotozoal, antituberculosis, and antiviral activities. These biological active compounds were acted by variety of molecular targets and thus may potentially contribute to several pharmacological classes. The synthesis of natural products and their analogues provides effect of structural modifications on the parent compounds which may be useful in the discovery of potential new drug molecules with different biological activities. Natural organisms have developed complex chemical defense systems by repelling or killing predators, such as insects, microorganisms, animals etc. These defense systems have the ability to produce large numbers of diverse compounds which can be used as new drugs. Thus, research on natural products for novel therapeutic agents with broad spectrum activities and will continue to provide important new drug molecules.

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Nagelamides A−H, New Dimeric Bromopyrrole Alkaloids from Marine Sponge Agelas Species

Cited by 111 publications

References 22 publications

Conformational Preferences of 2-Acylpyrroles in Light of FT-IR and DFT Studies

Conformational Preferences of 2-Acylpyrroles in Light of FT-IR and DFT Studies

The Pursuit of Palau'amine

Biologically active compounds from natural and marine natural organisms with antituberculosis, antimalarial, leishmaniasis, trypanosomiasis, anthelmintic, antibacterial, antifungal, antiprotozoal, and antiviral activities

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