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Renaissance of Natural Products Chemistry - Virtual Issue

Renaissance of Natural Products Chemistry - Virtual Issue | Natural Products Chemistry Breaking News | Scoop.it

Natural products are compounds made by living organisms―typically plants, microbes, and marine organisms but also insects and even mammals―that serve to propagate the species. Predating recorded history, the use of natural products for medicinal purposes has long benefited human societies. The poppy Papaver somniferum and its product opium (containing the key pharmacologically active natural product morphine) were cultivated and consumed by Neolithic tribes dating back more than 8000 years. Even today, about 40% of prescription drugs are natural products, or derive from them. "Natural products remain an important source of therapeutic drug leads and continue to inspire new approaches to problems in organic chemistry." Science has been elevated by the study of natural products. Organic chemists are innately fascinated with the intricacy of complex natural product structures, freighted with latent potential for synthetic design and expression of talent in the art of total synthesis. Pharmacologists, who measure biological properties of natural products, are often astounded by the potency and selectivity of the effects on cellular and organismal physiology. In the new millennium, there is a tendency among some to “retire” the field as a mature science, a presumption that is belied by the vigorous reprise of vitality in contemporary natural products chemistry. Here, in this ACS Virtual Issue, we can read of this steady ascendancy, augmented and propelled by new technologies in spectroscopy, synthesis, and genomics that link to allied fields in biology, computational chemistry―and yes―new classes of molecular structures. I invite you to peruse, read, and immerse your attention in 22 fine articles―highlighted and summarized from the ACS publications Organic Letters, The Journal of Organic Chemistry, and Journal of the American Chemical Society―that frame 22 stories of discovery, surprise, and scientific enlightenment.

- Tadeusz Molinski, Virtual Issue Guest Editor

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A must read for you NP chemists fellows!


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Natural Products Chemistry Breaking News
A recompilation of news and links about natural products, organic chemistry and science more generally ...
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Epicochalasines A and B: Two Bioactive Merocytochalasans Bearing Caged Epicoccine Dimer Units from Aspergillus flavipes

Epicochalasines A and B: Two Bioactive Merocytochalasans Bearing Caged Epicoccine Dimer Units from Aspergillus flavipes | Natural Products Chemistry Breaking News | Scoop.it

Two bioactive merocytochalasans, epicochalasines A (1) and B (2), a new class of cytochalasans bearing unexpected scaffolds consisting of fused aspochalasin and epicoccine dimer moieties, were isolated from the liquid culture broth of Aspergillus flavipes. Both 1 and 2 possess a hendecacyclic 5/6/11/5/6/5/6/5/6/6/5 ring system containing an adamantyl cage and as many as 19 stereogenic centers; however, the fusion patterns of 1 and 2 differ greatly, thus resulting in different carbon skeletons. The absolute configurations of 1 and 2 were determined by X-ray diffraction and calculated ECD, respectively. The biogenetic pathways of 1 and 2 are proposed to involve Diels–Alder and nucleophilic addition reactions. Both 1 and 2 induced significant G2/M-phase cell-cycle arrest. Furthermore, we found that merocytochalasans induce apoptosis in leukemia cells through the activation of caspase-3 and the degradation of PARP.

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Structural madness from Aspergillus !

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Antifungal Quinoline Alkaloids from Waltheria indica - Journal of Natural Products (ACS Publications)

Antifungal Quinoline Alkaloids from Waltheria indica - Journal of Natural Products (ACS Publications) | Natural Products Chemistry Breaking News | Scoop.it

Chemical investigation of a dichloromethane extract of the aerial parts of Waltheria indica led to the isolation and characterization of five polyhydroxymethoxyflavonoids, namely, oxyanin A (1), vitexicarpin (3), chrysosplenol E (4), flindulatin (5), 5-hydroxy-3,7,4′-trimethoxyflavone (6), and six quinolone alkaloids, waltheriones M–Q (2, 7, 8, 10, 11) and 5(R)-vanessine (9). Among these, compounds 2, 7, 8, 10, and 11 have not yet been described in the literature. Their chemical structures were established by means of spectroscopic data interpretation including 1H and 13C, HSQC, HMBC, COSY, and NOESY NMR experiments and UV, IR, and HRESIMS. The absolute configurations of the compounds were established by ECD. The isolated constituents and 10 additional quinoline alkaloids previously isolated from the roots of the plant were evaluated for their in vitro antifungal activity against the human fungal pathogen Candida albicans, and 10 compounds (7, 9, 1116, 18, 21) showed growth inhibitory activity on both planktonic cells and biofilms (MIC ≤ 32 μg/mL). Their spectrum of activity against other pathogenic Candida species and their cytotoxicity against human HeLa cells were also determined. In addition, the cytological effect of the antifungal isolated compounds on the ultrastructure of C. albicans was evaluated by transmission electron microscopy.


J. Nat. Prod., Article ASAP
DOI: 10.1021/acs.jnatprod.5b00896
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Marine natural products - Natural Product Reports

Marine natural products - Natural Product Reports | Natural Products Chemistry Breaking News | Scoop.it
Covering: 2014. Previous review: Nat. Prod. Rep., 2015, 32, 116–211

This review covers the literature published in 2014 for marine natural products (MNPs), with 1116 citations (753 for the period January to December 2014) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1378 in 456 papers for 2014), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.


Nat. Prod. Rep., 2016, Advance Article


DOI: 10.1039/C5NP00156K

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Vacuum Desiccator as a Simple, Robust, and Inexpensive NMR Tube Cleaner

Vacuum Desiccator as a Simple, Robust, and Inexpensive NMR Tube Cleaner | Natural Products Chemistry Breaking News | Scoop.it

A simple, robust, and inexpensive apparatus for cleaning several NMR tubes is easily fit up and used from readily available glassware, including a beaker, a desiccator, and a rotary evaporator vacuum pump.


Organic Process Research & Development (ACS Publications)

Institut de Chimie des Substances Naturelles - CNRS-ICSN UPR 2301, Université Paris-Sud, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.6b00001
Publication Date (Web): January 6, 2016
Copyright © 2016 American Chemical Society
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Coming from a prolific chemist, no wonder he has to clean tubes in bulk.

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Cipacinoids A–D, Four Limonoids with Spirocyclic Skeletons from Cipadessa cinerascens

Cipacinoids A–D, Four Limonoids with Spirocyclic Skeletons from Cipadessa cinerascens | Natural Products Chemistry Breaking News | Scoop.it
Four limonoids, cipacinoids A–D (1–4), with spirocyclic skeletons were isolated from Cipadessa cinerascens. It is particularly notable that compounds 1–3 had a 17S-configuration for the first time in the limonoid family. Their structures with absolute configurations were assigned by spectroscopic data, X-ray crystallography, and CD analysis. Compound 1 showed moderate protein tyrosine phosphatase 1B (PTP1B) inhibition.
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Fragmentation reactions using electrospray ionization mass spectrometry: an important tool for the structural elucidation and characterization of synthetic and natural products

Fragmentation reactions using electrospray ionization mass spectrometry: an important tool for the structural elucidation and characterization of synthetic and natural products | Natural Products Chemistry Breaking News | Scoop.it

Over the last decade, the number of studies reporting the use of electrospray ionization mass spectrometry (ESI-MS) in combination with collision cells (or other activation methods) to promote fragmentation of synthetic and natural products for structural elucidation purposes has considerably increased. However, the lack of a systematic compilation of the gas-phase fragmentation reactions subjected to ESI-MS/MS conditions still represents a challenge and has led to many misunderstood results in the literature. This review article exploits the most common fragmentation reactions for ions generated by ESI in positive and negative modes using collision cells in an effort to stimulate the use of this technique by non-specialists, undergraduate students and researchers in related areas.


Nat. Prod. Rep., 2016, Advance Article


DOI: 10.1039/C5NP00073D

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Taichunamides: Prenylated Indole Alkaloids from Aspergillus taichungensis (IBT 19404) - Kagiyama

Taichunamides: Prenylated Indole Alkaloids from Aspergillus taichungensis (IBT 19404) - Kagiyama | Natural Products Chemistry Breaking News | Scoop.it

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.


Angewandte Chemie International Edition

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

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Microbiology: Create a global microbiome effort

Microbiology: Create a global microbiome effort | Natural Products Chemistry Breaking News | Scoop.it
Understanding how microbes affect health and the biosphere requires an international initiative, argue Nicole Dubilier, Margaret McFall-Ngai and Liping Zhao.
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Get Your Atoms in Order—An Open-Source Implementation of a Novel and Robust Molecular Canonicalization Algorithm

Get Your Atoms in Order—An Open-Source Implementation of a Novel and Robust Molecular Canonicalization Algorithm | Natural Products Chemistry Breaking News | Scoop.it

Finding a canonical ordering of the atoms in a molecule is a prerequisite for generating a unique representation of the molecule. The canonicalization of a molecule is usually accomplished by applying some sort of graph relaxation algorithm, the most common of which is the Morgan algorithm. There are known issues with that algorithm that lead to noncanonical atom orderings as well as problems when it is applied to large molecules like proteins. Furthermore, each cheminformatics toolkit or software provides its own version of a canonical ordering, most based on unpublished algorithms, which also complicates the generation of a universal unique identifier for molecules. We present an alternative canonicalization approach that uses a standard stable-sorting algorithm instead of a Morgan-like index. Two new invariants that allow canonical ordering of molecules with dependent chirality as well as those with highly symmetrical cyclic graphs have been developed. The new approach proved to be robust and fast when tested on the 1.45 million compounds of the ChEMBL 20 data set in different scenarios like random renumbering of input atoms or SMILES round tripping. Our new algorithm is able to generate a canonical order of the atoms of protein molecules within a few milliseconds. The novel algorithm is implemented in the open-source cheminformatics toolkit RDKit. With this paper, we provide a reference Python implementation of the algorithm that could easily be integrated in any cheminformatics toolkit. This provides a first step toward a common standard for canonical atom ordering to generate a universal unique identifier for molecules other than InChI.


J. Chem. Inf. Model., 2015, 55 (10), pp 2111–2120
DOI: 10.1021/acs.jcim.5b00543



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Cytotoxic C20 Diterpenoid Alkaloids from the Australian Endemic Rainforest Plant Anopterus macleayanus

Cytotoxic C20 Diterpenoid Alkaloids from the Australian Endemic Rainforest Plant Anopterus macleayanus | Natural Products Chemistry Breaking News | Scoop.it

In order to identify new anticancer compounds from nature, a prefractionated library derived from Australian endemic plants was generated and screened against the prostate cancer cell line LNCaP using a metabolic assay. Fractions from the seeds, leaves, and wood of Anopterus macleayanus showed cytotoxic activity and were subsequently investigated using a combination of bioassay-guided fractionation and mass-directed isolation. This led to the identification of four new diterpenoid alkaloids, 6α-acetoxyanopterine (1), 4′-hydroxy-6α-acetoxyanopterine (2), 4′-hydroxyanopterine (3), and 11α-benzoylanopterine (4), along with four known compounds, anopterine (5), 7β-hydroxyanopterine (6), 7β,4′-dihydroxyanopterine (7), and 7β-hydroxy-11α-benzoylanopterine (8); all compounds were purified as their trifluoroacetate salt. The chemical structures of 18 were elucidated after analysis of 1D/2D NMR and MS data. Compounds 18 were evaluated for cytotoxic activity against a panel of human prostate cancer cells (LNCaP, C4-2B, and DuCaP) and nonmalignant cell lines (BPH-1 and WPMY-1), using a live-cell imaging system and a metabolic assay. All compounds showed potent cytotoxicity with IC50 values of <400 nM; compound 1 was the most active natural product from this series, with an IC50 value of 3.1 nM toward the LNCaP cell line. The live-cell imaging assay on 18 showed a concentration- and time-dependent effect on the cell morphology and proliferation of LNCaP cells.


J. Nat. Prod., Article ASAP
DOI: 10.1021/acs.jnatprod.5b00509
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Plant pathogenic anaerobic bacteria use aromatic polyketides to access aerobic territory

Plant pathogenic anaerobic bacteria use aromatic polyketides to access aerobic territory | Natural Products Chemistry Breaking News | Scoop.it

Around 25% of vegetable food is lost worldwide because of infectious plant diseases, including microbe-induced decay of harvested crops. In wet seasons and under humid storage conditions, potato tubers are readily infected and decomposed by anaerobic bacteria (Clostridium puniceum). We found that these anaerobic plant pathogens harbor a gene locus (type II polyketide synthase) to produce unusual polyketide metabolites (clostrubins) with dual functions. The clostrubins, which act as antibiotics against other microbial plant pathogens, enable the anaerobic bacteria to survive an oxygen-rich plant environment.


  1. Gulimila Shabuer1,*,
  2. Keishi Ishida1,*,
  3. Sacha J. Pidot1,2,*,
  4. Martin Roth3,
  5. Hans-Martin Dahse4,
  6. Christian Hertweck1,5,

Science 6 November 2015:
Vol. 350 no. 6261 pp. 670-674

DOI: 10.1126/science.aac9990

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Dereplication strategies in natural product research: How many tools and methodologies behind the same concept?

Dereplication strategies in natural product research: How many tools and methodologies behind the same concept? | Natural Products Chemistry Breaking News | Scoop.it
  • Jane Hubert 
  • Jean-Marc Nuzillard
  • Jean-Hugues Renault


« The development of new drugs will certainly benefit from an ever improving knowledge of the living beings chemistry. However, identification of drugable molecules within the immense biodiversity of forests, soils or oceans still requires considerable investments in technical equipments, time and human resources. An important part of this process is the quick identification of known substances in order to concentrate the efforts on the discovery of new ones. A range of “dereplication” procedures are currently emerging to meet this challenge as key strategies to improve the performance of natural product screening programs. Initially defined in 1990 as “a process of quickly identifying known chemotypes”, dereplication is today a not so univocal concept and has evolved over the last years in different ways. The present review covers all dereplication-related sudies in natural product research from 1990 to 2014. Its writing brought to light five distinct dereplication workflows that can be characterized by the nature of starting materials, by the selected analytical technique, and above all by the final objective. Dereplication can be used as an untargeted workflow for the rapid identification of the major compounds whatever their chemical class in a single sample or for the acceleration of bioactivity-guided fractionation procedures. In other cases dereplication is fully integrated in metabolomic studies for the untargeted chemical profiling of natural extract collections or for the targeted identification of a predetermined class of metabolites. Finally a quite distinct dereplication approach mainly based on gene-sequence analyses is frequently used for the taxonomic identification of microbial strains. »


Phytochemistry Reviews

pp 1-41

First online: 19 November 2015

© Springer International Publishing AG, Part of Springer Science+Business Media

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Dimeric Octaketide Spiroketals from the Jellyfish-Derived Fungus Paecilomyces variotii J08NF-1

Dimeric Octaketide Spiroketals from the Jellyfish-Derived Fungus Paecilomyces variotii J08NF-1 | Natural Products Chemistry Breaking News | Scoop.it

Paeciloketals (13), new benzannulated spiroketal derivatives, were isolated from the marine fungus Paecilomyces variotii derived from the giant jellyfish Nemopilema nomurai. Compound 1 was present as a racemate and was resolved into enantiopure 1a and 1b by chiral-phase separation on a cellulose column. Compounds 2 and 3, possessing a novel benzannulated spiroketal skeleton, were rapidly interconvertible and yielded an equilibrium mixture on standing at room temperature. The relative and absolute configurations of compounds 2 and 3 were determined by NOESY analysis and ECD calculations. Compound 1 showed modest antibacterial activity against the marine pathogen Vibrio ichthyoenteri.



J. Nat. Prod., Article ASAP
DOI: 10.1021/acs.jnatprod.5b00594
Publication Date (Web): November 12, 2015


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Natural Products as Sources of New Drugs from 1981 to 2014 - Journal of Natural Products

Natural Products as Sources of New Drugs from 1981 to 2014 - Journal of Natural Products | Natural Products Chemistry Breaking News | Scoop.it

This contribution is a completely updated and expanded version of the four prior analogous reviews that were published in this journal in 1997, 2003, 2007, and 2012. In the case of all approved therapeutic agents, the time frame has been extended to cover the 34 years from January 1, 1981, to December 31, 2014, for all diseases worldwide, and from 1950 (earliest so far identified) to December 2014 for all approved antitumor drugs worldwide. As mentioned in the 2012 review, we have continued to utilize our secondary subdivision of a “natural product mimic”, or “NM”, to join the original primary divisions and the designation “natural product botanical”, or “NB”, to cover those botanical “defined mixtures” now recognized as drug entities by the U.S. FDA (and similar organizations). From the data presented in this review, the utilization of natural products and/or their novel structures, in order to discover and develop the final drug entity, is still alive and well. For example, in the area of cancer, over the time frame from around the 1940s to the end of 2014, of the 175 small molecules approved, 131, or 75%, are other than “S” (synthetic), with 85, or 49%, actually being either natural products or directly derived therefrom. In other areas, the influence of natural product structures is quite marked, with, as expected from prior information, the anti-infective area being dependent on natural products and their structures. We wish to draw the attention of readers to the rapidly evolving recognition that a significant number of natural product drugs/leads are actually produced by microbes and/or microbial interactions with the “host from whence it was isolated”, and therefore it is considered that this area of natural product research should be expanded significantly.


† NIH Special Volunteer, Wayne, Pennsylvania 19087, United States
‡ NIH Special Volunteer, Bethesda, Maryland 20814, United States
J. Nat. Prod., Article ASAP
DOI: 10.1021/acs.jnatprod.5b01055
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SageRave of Get Custom Content's curator insight, February 8, 10:50 AM

Labels don't tell the whole story. Sometimes, that chemical word you shun is actually a fancy name for a natural ingredient,

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Capturing in Vivo Plant Metabolism by Real-Time Analysis of Low to High Molecular Weight Volatiles

Capturing in Vivo Plant Metabolism by Real-Time Analysis of Low to High Molecular Weight Volatiles | Natural Products Chemistry Breaking News | Scoop.it

We have deployed an efficient secondary electrospray ionization source coupled to an Orbitrap mass analyzer (SESI-MS) to investigate the emissions of a Begonia semperflorens. We document how hundreds of species can be tracked with an unparalleled time resolution of 2 min during day–night cycles. To further illustrate the capabilities of this system for volatile organic compounds (VOCs) analysis, we subjected the plant to mechanical damage and monitored its response. As a result, ∼1200 VOCs were monitored displaying different kinetics. To validate the soundness of our in vivo measurements, we fully characterized some key compounds via tandem mass spectrometry (MS/MS) and confirmed their expected behavior based on prior gas chromatography/mass spectrometry (GC/MS) studies. For example, β-caryophyllene, which is directly related to photosynthesis, was found to show a periodic day–night pattern with highest concentrations during the day. We conclude that the capability of SESI-MS to capture highly dynamic VOC emissions and wide analyte coverage makes it an attractive tool to complement GC/MS in plant studies.


Anal. Chem., Article ASAP
DOI: 10.1021/acs.analchem.5b04452
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Biochemometrics for Natural Products Research: Comparison of Data Analysis Approaches and Application to Identification of Bioactive Compounds

Biochemometrics for Natural Products Research: Comparison of Data Analysis Approaches and Application to Identification of Bioactive Compounds | Natural Products Chemistry Breaking News | Scoop.it

A central challenge of natural products research is assigning bioactive compounds from complex mixtures. The gold standard approach to address this challenge, bioassay-guided fractionation, is often biased toward abundant, rather than bioactive, mixture components. This study evaluated the combination of bioassay-guided fractionation with untargeted metabolite profiling to improve active component identification early in the fractionation process. Key to this methodology was statistical modeling of the integrated biological and chemical data sets (biochemometric analysis). Three data analysis approaches for biochemometric analysis were compared, namely, partial least-squares loading vectors, S-plots, and the selectivity ratio. Extracts from the endophytic fungi Alternaria sp. and Pyrenochaeta sp. with antimicrobial activity against Staphylococcus aureus served as test cases. Biochemometric analysis incorporating the selectivity ratio performed best in identifying bioactive ions from these extracts early in the fractionation process, yielding altersetin (3, MIC 0.23 μg/mL) and macrosphelide A (4, MIC 75 μg/mL) as antibacterial constituents from Alternaria sp. and Pyrenochaeta sp., respectively. This study demonstrates the potential of biochemometrics coupled with bioassay-guided fractionation to identify bioactive mixture components. A benefit of this approach is the ability to integrate multiple stages of fractionation and bioassay data into a single analysis


† Department of Chemistry & Biochemistry, University of North Carolina Greensboro, Greensboro, North Carolina 27402, United States
‡ Department of Chemistry, University of Bergen, Bergen 5020,Norway
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Dengvaxia®, World’s First Dengue Vaccine, Approved in Mexico

- First marketing authorization of Dengvaxia® is a historic milestone paving the way
to significantly impact dengue burden in endemic countries -
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Illuminating the dark matter in metabolomics

Illuminating the dark matter in metabolomics | Natural Products Chemistry Breaking News | Scoop.it

Despite the over 100-y history of mass spectrometry, it remains challenging to link the large volume of known chemical structures to the data obtained with mass spectrometers. Presently, only 1.8% of spectra in an untargeted metabolomics experiment can be annotated. This means that the vast majority of information collected by metabolomics is “dark matter,” chemical signatures that remain uncharacterized (Fig. 1). For a genomic comparison, 80% of predicted genes in the Escherichia coli genome are known. In a bacteriophage metagenome, a well-known frontier of biological dark matter, the amount of known genes is 1–30%, depending on the sample (1). Thus, one could argue that we know more about the genetics of uncultured phage than we do about the chemistry within our own bodies. Much of the chemical dark matter may include known structures, but they remain undiscovered because the reference spectra are not available in mass spectrometry databases. The only way to overcome this challenge is through the development of computational solutions. In PNAS, Dührkop et al. describe the development of such a computational tool, called CSI (compound structure identification):FingerID (2). The tool is designed to aid in the annotation of chemistries that can be observed by mass spectrometry. CSI:FingerID uses fragmentation trees to connect tandem MS (MS/MS) data to chemical structures found in public chemistry databases. Tools such as this can allow metabolomics with mass spectrometry to become as commonly used and scientifically productive as sequencing technologies have in the field of genomics.

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A powerfull insight on MS-based metabolomic challenges !

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Anti-Candida Cassane-Type Diterpenoids from the Root Bark of Swartzia simplex

Anti-Candida Cassane-Type Diterpenoids from the Root Bark of Swartzia simplex | Natural Products Chemistry Breaking News | Scoop.it

A dichloromethane extract of the roots from the Panamanian plant Swartzia simplex exhibited a strong antifungal activity in a bioautography assay against a genetically modified hypersusceptible strain of Candida albicans. At-line HPLC activity based profiling of the crude extract enabled a precise localization of the antifungal compounds, and dereplication by UHPLC-HRESIMS indicated the presence of potentially new metabolites. Transposition of the HPLC reversed-phase analytical conditions to medium-pressure liquid chromatography (MPLC) allowed an efficient isolation of the major constituents. Minor compounds of interest were isolated from the MPLC fractions using semipreparative HPLC. Using this strategy, 14 diterpenes (114) were isolated, with seven (510, 14) being new antifungal natural products. The new structures were elucidated using NMR spectroscopy and HRESIMS analysis. The absolute configurations of some of the compounds were elucidated by electronic circular dichroism spectroscopy. The antifungal properties of these compounds were evaluated as their minimum inhibitory concentrations in a dilution assay against both hypersusceptible and wild-type strains of C. albicans and by assessment of their antibiofilm activities. The potential cytological effects on the ultrastructure of C. albicans of the antifungal compounds isolated were evaluated on thin sections by transmission electron microscopy.


J. Nat. Prod., Article ASAP
DOI: 10.1021/acs.jnatprod.5b00744
Publication Date (Web): December 11, 2015



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Biosynthetic Studies of 13-Desmethylspirolide C Produced by Alexandrium ostenfeldii (= A. peruvianum): Rationalization of the Biosynthetic Pathway Following Incorporation of 13C-Labeled Methionine ...

Biosynthetic Studies of 13-Desmethylspirolide C Produced by Alexandrium ostenfeldii (= A. peruvianum): Rationalization of the Biosynthetic Pathway Following Incorporation of 13C-Labeled Methionine ... | Natural Products Chemistry Breaking News | Scoop.it

Understanding the biosynthesis of dinoflagellate polyketides presents many unique challenges. Because of the remaining hurdles to dinoflagellate genome sequencing, precursor labeling studies remain the only viable way to investigate dinoflagellate biosynthesis. However, prior studies have shown that polyketide chain assembly does not follow any of the established processes. Additionally, acetate, the common precursor for polyketides, is frequently scrambled, thus compromising interpretation. These factors are further compounded by low production yields of the compounds of interest. A recent report on the biosynthesis of spirolides, a group belonging to the growing class of toxic spiroimines, provided some insight into the polyketide assembly process based on acetate labeling studies, but many details were left uncertain. By feeding 13C methyl-labeled methionine to cultures of Alexandrium ostenfeldii, the producing organism of 13-desmethylspirolide C, and application of the odd–even methylation rule, the complete biosynthetic pathway has been established.


J. Nat. Prod., Article ASAP
DOI: 10.1021/acs.jnatprod.5b00869
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Niizalactams A–C, Multicyclic Macrolactams Isolated from Combined Culture of Streptomyces with Mycolic Acid-Containing Bacterium

Niizalactams A–C, Multicyclic Macrolactams Isolated from Combined Culture of Streptomyces with Mycolic Acid-Containing Bacterium | Natural Products Chemistry Breaking News | Scoop.it

A terrestrial bacterium, Streptomyces sp. NZ-6, produced niizalactams A–C (13), unprecedented di- and tricyclic macrolactams, by coculturing with the mycolic acid-containing bacterium Tsukamurella pulmonis TP-B0596. Their complete structures, including absolute configurations, were elucidated on the basis of spectroscopic data and chemical derivatization. Their unique skeletons are proposed to be biosynthesized from a common 26-membered macrolactam intermediate by SN2 cyclization or an intramolecular Diels–Alder reaction.


J. Nat. Prod., Article ASAP
DOI: 10.1021/acs.jnatprod.5b00804
Publication Date (Web): December 1, 2015
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Epigenetic stimulation of polyketide production in Chaetomium cancroideum by an NAD+-dependent HDAC inhibitor

Epigenetic stimulation of polyketide production in Chaetomium cancroideum by an NAD+-dependent HDAC inhibitor | Natural Products Chemistry Breaking News | Scoop.it
Exposure of the fungus Chaetomium cancroideum to an NAD+-dependent HDAC inhibitor, nicotinamide, enhanced the production of aromatic and branched aliphatic polyketides, which allowed us to isolate new secondary metabolites, chaetophenol G and cancrolides A and B. Their structures were determined using spectroscopic


Org. Biomol. Chem., 2016, Advance Article


DOI: 10.1039/C5OB01595B

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Integration of high-content screening and untargeted metabolomics for comprehensive functional annotation of natural product libraries

Integration of high-content screening and untargeted metabolomics for comprehensive functional annotation of natural product libraries | Natural Products Chemistry Breaking News | Scoop.it

Compound Activity Mapping provides an alternative approach to natural products drug discovery by integrating high-content biological screening and untargeted metabolomics to directly reveal the identities and biological functions of individual bioactive compounds in complex natural product libraries. This accelerated discovery pipeline addresses many of the issues that have contributed to the decline of natural products research in some areas by improving dereplication and lead prioritization strategies. The detailed structural and functional annotation offered by this tool may help to improve the integration of natural products with modern high-content, high-throughput screening and provide an additional strategy for the discovery of the next generation of natural product-inspired drug leads and chemical probes.

NatProdChem's insight:

Amazing breakthrough in mapping biological activity on metabolomics data !

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Babara Lopez's curator insight, December 22, 2015 3:18 AM

Compound Activity Mapping

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Artemisinin, a miracle of traditional Chinese medicine

Artemisinin, a miracle of traditional Chinese medicine | Natural Products Chemistry Breaking News | Scoop.it
The 2015 Nobel Prize in Physiology or Medicine, shared by Professor Youyou Tu, focused worldwide attention on artemisinin, a natural product antimalarial drug inspired by traditional Chinese medicine (TCM). This is the first Nobel Prize in natural sciences presented to a Chinese scientist for her impactful research work in China in collaboration with other Chinese scientists. We are delighted to provide the background and implications of the discovery of artemisinin, along with our personal viewpoints toward the affordability of modern medicines from natural products.


Nat. Prod. Rep., 2015,32, 1617-1621


DOI: 10.1039/C5NP00133A

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Dried whole-plant Artemisia annua slows evolution of malaria drug resistance and overcomes resistance to artemisinin

Dried whole-plant Artemisia annua slows evolution of malaria drug resistance and overcomes resistance to artemisinin | Natural Products Chemistry Breaking News | Scoop.it

Evolution of malaria parasite drug resistance has thwarted efforts to control this deadly disease. Use of drug combinations has been proposed to slow that evolution. Artemisinin is a favorite drug in the global war on malaria and is frequently used in combination therapies. Here we show that using the whole plant (Artemisia annua) from which artemisinin is derived can overcome parasite resistance and is actually more resilient to evolution of parasite resistance; i.e., parasites take longer to evolve resistance, thus increasing the effective life span of the therapy.



  1. Mostafa A. Elfawala,
  2. Melissa J. Towlerb,
  3. Nicholas G. Reichc,
  4. Pamela J. Weathersb, and
  5. Stephen M. Richa,1

PNAS


doi: 10.1073/pnas.1413127112

NatProdChem's insight:

The type of papers big pharma loves :)

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