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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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From the Human Genome to the Human Proteome - 2014 - Angewandte Chemie International Edition

From the Human Genome to the Human Proteome - 2014 - Angewandte Chemie International Edition | Natural Products Chemistry Breaking News | Scoop.it
  1. Dr. Javier Muñoz2,* and
  2. Prof. Dr. Albert J. R. Heck1,*


DOI: 10.1002/anie.201406545

A herculean task: Determining the human proteome sets the ultimate challenge in cell biology as it is thought to consist of more than 1 000 000 proteoforms, in contrast to “only” 20 000 protein-coding genes. Two teams of researchers have now proved the translation of 18 000 proteins (and more than 27 000 isoforms) by mass spectrometry. They obtained important information on the extent of protein translation and alternative splicing.

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Microbial biosynthesis of medicinally important plant secondary metabolites - Natural Product Reports

Microbial biosynthesis of medicinally important plant secondary metabolites - Natural Product Reports | Natural Products Chemistry Breaking News | Scoop.it

Secondary metabolites derived from plants are a valuable source of pharmaceuticals, nutraceuticals, and cosmetics. To harness the potential of these natural products, reliable methods must be developed for their rapid and sustainable resupply. Microbial production of plant secondary metabolites through the heterologous expression of plant biosynthetic genes represents one such solution. This highlight focuses on recent advances in the microbial biosynthesis of plant secondary metabolites including terpenoids, flavonoids, and alkaloids as well as providing a brief insight into the current limitations and future prospects.


Show Affiliations
Nat. Prod. Rep., 2014, Advance Article


DOI: 10.1039/C4NP00057A





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8 Tips to Improve Your Pipetting Technique

8 Tips to Improve Your Pipetting Technique | Natural Products Chemistry Breaking News | Scoop.it

Learn new ways to improve the way you perform pipetting tasks in your lab. 

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Directly Decoupled Diffusion-Ordered NMR Spectroscopy for the Analysis of Compound Mixtures - Glanzer - 2014 - Chemistry - A European Journal -

Directly Decoupled Diffusion-Ordered NMR Spectroscopy for the Analysis of Compound Mixtures - Glanzer - 2014 - Chemistry - A European Journal - | Natural Products Chemistry Breaking News | Scoop.it
  1. Simon Glanzer and
  2. Prof. Dr. Klaus Zangger*

DOI: 10.1002/chem.201402920

For the analysis of compound mixtures by NMR spectroscopy, it is important to assign the different peaks to the individual constituents. Diffusion-ordered spectroscopy (DOSY) is often used for the separation of signals based on their self-diffusion coefficient. However, this method often fails in the case of signal overlap, which is a particular problem for 1H-detected DOSY spectra. Herein, an approach that allows the acquisition of homonuclear broadband-decoupled DOSY spectra without the introduction of an additional decoupling dimension, by instant decoupling during acquisition, is presented. It was demonstrated on a mixture of six alcohols, and the investigation of the binding of a dodecapeptide to membrane mimetics.

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Fungal polyketide biosynthesis – a personal perspective - Natural Product Reports

Fungal polyketide biosynthesis – a personal perspective - Natural Product Reports | Natural Products Chemistry Breaking News | Scoop.it

This Viewpoint article provides a personal viewpoint of research in the area of fungal polyketide biosynthesis. It spans the period from the first applications and subsequent development of modern stable-isotope labelling methods, the isolation, sequencing and expression of PKS genes, biochemical and structural characterisation of PKS domains, fungal genome sequencing, through to genetic engineering of whole pathways. This article forms part of a “trilogy” of related Viewpoints from three close contemporaries who have been privileged to share in these developments since their outset over forty years ago and to enjoy both professional and personal interactions throughout that time.


Show Affiliations
Nat. Prod. Rep., 2014, Advance Article


DOI: 10.1039/C4NP00065J



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Absolute Configuration of a Rare Sesquiterpene: (+)-3-Ishwarone

Absolute Configuration of a Rare Sesquiterpene: (+)-3-Ishwarone | Natural Products Chemistry Breaking News | Scoop.it

To determine the absolute configuration of 3-ishwarone, the experimental electronic circular dichroism (ECD), electronic dissymmetry factor (EDF), optical rotatory dispersion (ORD), vibrational circular dichroism (VCD), and vibrational dissymmetry factor (VDF) spectra of (+)-3-ishwarone are analyzed with the corresponding density functional theoretical predictions for different diastereomers. ECD and ORD spectra by themselves could not facilitate the determination of the absolute configuration of this molecule. However, the magnitude of the experimental EDF of (+)-3-ishwarone is found to match better with that predicted for the (1R,2S,4S,5R,9R,11R) diastereomer. The analyses of similarity measures between experimental and predicted spectra for VCD and VDF clearly suggested that the absolute configuration of (+)-3-ishwarone is (1R,2S,4S,5R,9R,11R).


J. Nat. Prod., Article ASAP
DOI: 10.1021/np500363e
Publication Date (Web): July 22, 2014
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Dereplication of depsides from the lichen Pseudevernia furfuracea by centrifugal partition chromatography combined to 13C nuclear magnetic resonance pattern recognition

Dereplication of depsides from the lichen Pseudevernia furfuracea by centrifugal partition chromatography combined to 13C nuclear magnetic resonance pattern recognition | Natural Products Chemistry Breaking News | Scoop.it


Highlights

The major depsides of a lichen extract were directly identified within mixtures.

The initial extract was rapidly fractionated by CPC in the pH-zone refining mode.

Hierarchical clustering of 13C NMR signals resulted in the identification of depside molecular skeletons.

13C chemical shift clusters were assigned to structures using a 13C NMR database.

Six depsides were unambiguously identified by this approach.


Abstract:

Lichens produce a diversity of secondary metabolites, among them depsides comprised of two or more hydroxybenzoic acid units linked by ester, ether, or CC-bonds. During classic solid support-based purification processes, depsides are often hydrolyzed and in many cases time, consuming procedures result only in the isolation of decomposition products. In an attempt to avoid extensive purification steps while maintaining metabolite structure integrity, we propose an alternative method to identify the major depsides of a lichen crude extract (Pseudevernia furfuracea var. ceratea (Ach.) D. Hawksw., Parmeliaceae) directly within mixtures.

Exploiting the acidic character of depsides and differences in polarity, the extract was fractionated by centrifugal partition chromatography in the pH-zone refining mode resulting in twelve simplified mixtures of depsides. After 13C nuclear magnetic resonance analysis of the produced fractions, the major molecular structures were directly identified within the fraction series by using a recently developed pattern recognition method, which combines spectral data alignment and hierarchical clustering analysis. The obtained clusters of 13C chemical shifts were assigned to their corresponding molecular structures with the help of an in-house 13C NMR chemical shift database, resulting in six unambiguously identified compounds, namely methyl β-orcinolcarboxylate (1), atranorin (2), 5-chloroatranorin (3), olivetol carboxylic acid (4), olivetoric acid (5), and olivetonide (6).



DOI: 10.1016/j.aca.2014.07.009

Available online 15 July 2014


NatProdChem's insight:

Countercurrent Separations are a method of choice for Lichens, as the material is usually not available in great amounts. Trying to reduce the losses due to separation steps is of crucial importance. We are pretty surprised by the compounds stability at these extreme pH ,but well if it works and they have made an extensive study of their sample stability before subjecting it to their pH zone solvent system.


Even if it doesn't say that overlap in 1H is not necessarily a problem  (see HiFSA articles we scooped recently), this article is also worth reading if you are interested by how to dereplicate your datasets by using NMR.

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Elucidation of Pseurotin Biosynthetic Pathway Points to Trans-Acting C-Methyltransferase: Generation of Chemical Diversity

Elucidation of Pseurotin Biosynthetic Pathway Points to Trans-Acting C-Methyltransferase: Generation of Chemical Diversity | Natural Products Chemistry Breaking News | Scoop.it

Pseurotins comprise a family of structurally related Aspergillal natural products having interesting bioactivity. However, little is known about the biosynthetic steps involved in the formation of their complex chemical features. Systematic deletion of the pseurotin biosynthetic genes in A. fumigatus and in vivo and in vitro characterization of the tailoring enzymes to determine the biosynthetic intermediates, and the gene products responsible for the formation of each intermediate, are described. Thus, the main biosynthetic steps leading to the formation of pseurotin A from the predominant precursor, azaspirene, were elucidated. The study revealed the combinatorial nature of the biosynthesis of the pseurotin family of compounds and the intermediates. Most interestingly, we report the first identification of an epoxidase C-methyltransferase bifunctional fusion protein PsoF which appears to methylate the nascent polyketide backbone carbon atom in trans.


  1. Dr. Yuta Tsunematsu1, 
  2. Manami Fukutomi1,
  3. Dr. Takayoshi Saruwatari1, 
  4. Prof. Dr. Hiroshi Noguchi1, 
  5. Prof. Dr. Kinya Hotta2, 
  6. Prof. Dr. Yi Tang3 and
  7. Prof. Dr. Kenji Watanabe1,*

Article first published online: 18 JUN 2014

DOI: 10.1002/anie.201404804


Angewandte Chemie International Edition


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Gene Transcription: Not Always Dictated by Histone Modifications! -

Gene Transcription: Not Always Dictated by Histone Modifications! - | Natural Products Chemistry Breaking News | Scoop.it

The proper regulation of gene expression is of fundamental importance in the maintenance of normal growth and development.  Misregulation of genes can lead to such outcomes as cancer, diabetes and neurodegenerative disease.  A key step in gene regulation occurs during the transcription of the chromosomal DNA into messenger RNA by the enzyme, RNA polymerase II. …


Zhang H, Gao L, Anandhakumar J, & Gross DS (2014). Uncoupling transcription from covalent histone modification. PLoS genetics, 10 (4) PMID: 24722509

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Linguistic statistics enable synthetic prophetics | Chemistry World

Linguistic statistics enable synthetic prophetics | Chemistry World | Natural Products Chemistry Breaking News | Scoop.it
A metric more commonly used by search engines to analyse language can now power organic chemistry retrosyntheses


NatProdChem's insight:

This is AWESOME !

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Eric Larson's curator insight, July 20, 5:18 AM

Interesting ideas.

juandoming's curator insight, July 20, 8:25 AM

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Simultaneous 1H and 13C NMR enantiodifferentiation from highly-resolved pure shift HSQC spectra - Chemical Communications

Simultaneous 1H and 13C NMR enantiodifferentiation from highly-resolved pure shift HSQC spectra - Chemical Communications | Natural Products Chemistry Breaking News | Scoop.it
NMR enantiodifferentiation studies are greatly improved by the simultaneous determination of 1H and 13C chemical shift differences through the analysis of highly resolved cross-peaks in Spectral Aliased Pure Shift (SAPS) HSQC spectra.
NatProdChem's insight:

Míriam Pérez-Trujillo,   Laura Castañar,   Eva Monteagudo,  Lars Kuhn,   Pau Nolis,   Albert Virgili,  Robert Thomas Williamson and   Teodor Parella  

DOI: 10.1039/C4CC04077E

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What the devil is in your phytomedicine? Exploring species substitution in Harpagophytum through chemometric modeling of 1H-NMR and UHPLC-MS datasets

What the devil is in your phytomedicine? Exploring species substitution in Harpagophytum through chemometric modeling of 1H-NMR and UHPLC-MS datasets | Natural Products Chemistry Breaking News | Scoop.it

• Harpagophytum procumbens and H. zeyheri are currently used interchangeably.

• UHPLC-MS analysis shows that harpagoside content is higher in H. procumbens (0.17–4.37%) than inH. zeyheri (0.00–3.07%).

• PCA and OPLS-DA analysis revealed cluster formation based on species.

• Biomarkers (retention time-mass/charge ratio pairs) were identified using OPLS-DA.

• Harpagophytum procumbens and H. zeyheri are not chemically equivalent.


Nontobeko P. MncwangiAlvaro M. ViljoenJianping ZhaoIlze VermaakWei ChenIkhlas Khan


Available online 17 July 2014

DOI: 10.1016/j.phytochem.2014.06.012


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Synthetic microbial consortia: from systematic analysis to construction and applications

Synthetic microbial consortia: from systematic analysis to construction and applications | Natural Products Chemistry Breaking News | Scoop.it

Synthetic biology is an emerging research field that focuses on using rational engineering strategies to program biological systems, conferring on them new functions and behaviours. By developing genetic parts and devices based on transcriptional, translational, post-translational modules, many genetic circuits and metabolic pathways had been programmed in single cells. Extending engineering capabilities from single-cell behaviours to multicellular microbial consortia represents a new frontier of synthetic biology. Herein, we first reviewed binary interaction modes of microorganisms in microbial consortia and their underlying molecular mechanisms, which lay the foundation of programming cell–cell interactions in synthetic microbial consortia. Systems biology studies on cellular systems enable systematic understanding of diverse physiological processes of cells and their interactions, which in turn offer insights into the optimal design of synthetic consortia. Based on such fundamental understanding, a comprehensive array of synthetic microbial consortia constructed in the last decade were reviewed, including isogenic microbial communities programmed by quorum sensing-based cell–cell communications, sender–receiver microbial communities with one-way communications, and microbial ecosystems wired by two-way (bi-directional) communications. Furthermore, many applications including using synthetic microbial consortia for distributed bio-computations, chemicals and bioenergy production, medicine and human health, and environments were reviewed. Synergistic development of systems and synthetic biology will provide both a thorough understanding of naturally occurring microbial consortia and rational engineering of these complicated consortia for novel applications.


Synthetic microbial consortia: from systematic analysis to construction and applications
Hao Song,a   Ming-Zhu Ding,a   Xiao-Qiang Jia,a   Qian Maa and   Ying-Jin Yuan*a  
Show Affiliations
Chem. Soc. Rev., 2014, Advance Article


DOI: 10.1039/C4CS00114A



NatProdChem's insight:

Holistic integrative approaches ... the future !

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Marine Drugs | Free Full-Text | Activation of Dormant Secondary Metabolite Production by Introducing Neomycin Resistance into the Deep-Sea Fungus, Aspergillus versicolor ZBY-3

Marine Drugs | Free Full-Text | Activation of Dormant Secondary Metabolite Production by Introducing Neomycin Resistance into the Deep-Sea Fungus, Aspergillus versicolor ZBY-3 | Natural Products Chemistry Breaking News | Scoop.it
A new ultrasound-mediated approach has been developed to introduce neomycin-resistance to activate silent pathways for secondary metabolite production in a bio-inactive, deep-sea fungus, Aspergillus versicolor ZBY-3. Upon treatment of the ZBY-3 spores with a high concentration of neomycin by proper ultrasound irradiation, a total of 30 mutants were obtained by single colony isolation. The acquired resistance of the mutants to neomycin was confirmed by a resistance test. In contrast to the ZBY-3 strain, the EtOAc extracts of 22 of the 30 mutants inhibited the human cancer K562 cells, indicating that these mutants acquired a capability to produce antitumor metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses of the EtOAc extracts of seven bioactive mutants and the ZBY-3 strain indicated that diverse secondary metabolites have been newly produced in the mutant extracts in contrast to the ZBY-3 extract. The followed isolation and characterization demonstrated that six metabolites, cyclo(d-Pro-d-Phe) (1), cyclo(d-Tyr-d-Pro) (2), phenethyl 5-oxo-l-prolinate (3), cyclo(l-Ile-l-Pro) (4), cyclo(l-Leu-l-Pro) (5) and 3β,5α,9α-trihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (6), were newly produced by the mutant u2n2h3-3 compared to the parent ZBY-3 strain. Compound 3 was a new compound; 2 was isolated from a natural source for the first time, and all of these compounds were also not yet found in the metabolites of other A. versicolor strains. Compounds 1–6 inhibited the K562 cells, with inhibition rates of 54.6% (1), 72.9% (2), 23.5% (3), 29.6% (4), 30.9% (5) and 51.1% (6) at 100 μg/mL, and inhibited also other human cancer HL-60, BGC-823 and HeLa cells, to some extent. The present study demonstrated the effectiveness of the ultrasound-mediated approach to activate silent metabolite production in fungi by introducing acquired resistance to aminoglycosides and its potential for discovering new compounds from silent fungal metabolic pathways. This approach could be applied to elicit the metabolic potentials of other fungal isolates to discover new compounds from cryptic secondary metabolites.


Mar. Drugs 2014, 12(8), 4326-4352; doi:10.3390/md12084326
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Detecting chirality | Chemistry World

Detecting chirality | Chemistry World | Natural Products Chemistry Breaking News | Scoop.it
Katia Moskvitch finds out about the latest techniques to determining a molecule’s chirality
NatProdChem's insight:

Most of you are already aware of these, but that's a good introduction for the others. While OR, CD are common in NPs labs, VCD and to a lower extent NMR are slowly but surely showing up.


The mass spectrometry approach is still science-fiction in the case of natural products, but who knows what will happen next…


J.

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Oxidative rearrangements during fungal biosynthesis - Natural Product Reports

Oxidative rearrangements during fungal biosynthesis - Natural Product Reports | Natural Products Chemistry Breaking News | Scoop.it

Oxidative rearrangements are key reactions during the biosyntheses of many secondary metabolites in fungi. This review highlights the most important examples of these reactions and aims to draw together key mechanistic themes to allow a better understanding and future exploitation of this key class of fungal catalysts.


Show Affiliations
Nat. Prod. Rep., 2014, Advance Article


DOI: 10.1039/C4NP00059E

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Explorations of fungal biosynthesis of reduced polyketides – a personal viewpoint

Explorations of fungal biosynthesis of reduced polyketides – a personal viewpoint | Natural Products Chemistry Breaking News | Scoop.it

This viewpoint on biosynthesis of reduced polyketides in fungi traces evolution of the research area over more than 4 decades. It is a companion to the related articles by two personal and scientific friends with whom there has been free exchange of ideas for over 30 years. Beginning with very rudimentary knowledge about assembly of such natural products, developments using stable isotope labelling and subsequently identification of biosynthetic genes, led to understanding of the processive nature of polyketide formation. Recent expression and isolation of fungal iterative polyketide synthase enzymes has enabled more detailed exploration of the mechanisms of these fascinating molecular machines.


Show Affiliations
Nat. Prod. Rep., 2014, Advance Article


DOI: 10.1039/C4NP00091A


NatProdChem's insight:

It's a whole NPR themed issue on fungal polyketide synthases ! Yayy !

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Alstolactines A–C, novel monoterpenoid indole alkaloids from Alstonia scholaris

Alstolactines A–C, novel monoterpenoid indole alkaloids from Alstonia scholaris | Natural Products Chemistry Breaking News | Scoop.it
NatProdChem's insight:
Three novel ring-fused monoterpenoid indole alkaloids, alstolactines A–C (13), were isolated from the long-term stored leaves of Alstonia scholaris. Their structures were identified on the basis of extensive spectroscopic data and X-ray diffractions. Moreover, the absolute configurations of these related structures were indicated by the crystal X-ray diffractions (Mo Kα) of 1a, a chlorinated derivative of 1.
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Chemo- and bioinformatics resources for in silico drug discovery from medicinal plants beyond their traditional use: a critical review

Chemo- and bioinformatics resources for in silico drug discovery from medicinal plants beyond their traditional use: a critical review | Natural Products Chemistry Breaking News | Scoop.it

Covering: up to 2014

In silico approaches have been widely recognised to be useful for drug discovery. Here, we consider the significance of available databases of medicinal plants and chemo- and bioinformatics tools for in silico drug discovery beyond the traditional use of folk medicines. This review contains a practical example of the application of combined chemo- and bioinformatics methods to study pleiotropic therapeutic effects (known and novel) of 50 medicinal plants from Traditional Indian Medicine.



Nat. Prod. Rep., 2014, Advance Article
DOI: 10.1039/C4NP00068D
Received 23 May 2014, First published online 22 Jul 2014
NatProdChem's insight:

An interesting review containing a list of databases and their characteristics, chemoinformatic tools along with their different uses in drug discovery. It is one of the most detailed review as far as we know. It is definitively something you have to read if you are into drug discovery, and if you are not, you'll probably be able to discover new tools.

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Chemist With Visual Flair Answers Burning Food Science Questions

Chemist With Visual Flair Answers Burning Food Science Questions | Natural Products Chemistry Breaking News | Scoop.it

High school chemistry teacher in the U.K. started honing his visual talents by making posters for students. Now his infographics about food science and chemistry basics are a hit on the Web.

NatProdChem's insight:

Clean and nice graphics. The explanations are not too complex neither are they overly simplified. The blog http://www.compoundchem.com/ is something you may want to have in your RSS feeds if you are interested by food chemistry or just curious!

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Euphorbia Diterpenes: Isolation, Structure, Biological Activity, and Synthesis (2008–2012) - Chemical Reviews (ACS Publications)

Euphorbia Diterpenes: Isolation, Structure, Biological Activity, and Synthesis (2008–2012) - Chemical Reviews (ACS Publications) | Natural Products Chemistry Breaking News | Scoop.it
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Enhanced Detection and Identification in Metabolomics by Use of LC–MS/MS Untargeted Analysis in Combination with Gas-Phase Fractionation

Enhanced Detection and Identification in Metabolomics by Use of LC–MS/MS Untargeted Analysis in Combination with Gas-Phase Fractionation | Natural Products Chemistry Breaking News | Scoop.it

Liquid chromatography coupled to tandem mass spectrometry is one of the most widely used analytical platforms for profiling analysis in metabolomics. One weakness of untargeted metabolomic analysis, however, is the difficulty of identifying metabolites. In fact, the process typically involves mass-based searching of LC–MS and LC–MS/MS data and requires using MS/MS data for unequivocal identification. Current strategies use LC–MS analysis in the scan mode prior to acquiring MS/MS information about targeted metabolites or the “auto MS/MS” mode to fragment automatically the most intense precursor ions. Therefore, in both cases additional injections are required to obtain MS/MS data after data treatment to identify significant compounds whose signals are not so intense. Because an additional procedure is needed to enhance the fraction of metabolites with MS/MS data, in this work, the effectiveness of utilizing different MS/MS parameters across an analytical batch or repetitions of the same sample by using exclusion or inclusion criteria to select precursor ions is assessed. The procedure, known as “gas-phase fractionation (GPF)”, was used here for untargeted analysis of serum. The joint use of four methods with a different mass range for selection of precursor ions each provided useful MS/MS information for at least 80% of all molecular entities detected in the MS scan replicates. By contrast, the conventional “auto MS/MS” mode of data acquisition provided MS/MS data for only 48–57% of entities and was therefore less effective toward identifying metabolites. The additional use of GPF improved the detection and annotation of metabolite families such as phospholipids, amino acids, bile acids, carnitines, and fatty acids and their derivatives.


 Department of Analytical Chemistry, University of Córdoba, Annex Marie Curie Building, Campus of Rabanales, E-14071 Córdoba, Spain
§ Maimónides Institute of Biomedical Research (IMIBIC), Reina Sofía University Hospital, University of Córdoba, E-14071 Córdoba, Spain
Anal. Chem., Article ASAP
DOI: 10.1021/ac501353n




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Blue Blood Donors

Blue Blood Donors | Natural Products Chemistry Breaking News | Scoop.it
In the first half of the 20th century, scientists faced a vexing  problem. Too many people were being sickened and killed by bacterial endotoxin—a substance in a bacteria’s outer membrane toxic to animals and resistant to heat—contracted through vaccines and surgery tools. The only way to determine if something was contaminated was to test it on animals, a slow and expensive process.


In 1956 a scientist named Fred Bang was studying the blood circulation in horseshoe crabs. He observed that when a crab became infected with gram-negative bacteria (a type of bacteria difficult to detect with standard tests), its blood coagulated and turned into a thick jelly.  He continued analyzing this phenomenon and found that horseshoe crab blood contains a cell that releases a clotting agent that captures foreign contaminants before they infect the whole crab.


Horseshoe crabs need this clotting ability to keep the billions of microscopic organisms in the ocean at bay. If a crab gets a cut or a puncture in its shell, its blood will harden around the hole and freeze foreign contaminants in place. This trait may have helped the horseshoe become one of the oldest living animals; the species is more than 500 million years old.


Scientists were quick to isolate the clotting agent (named Limulus amebocyte lysate, or LAL) and use it to test the presence of bacteria in medicine and pharmaceutical equipment. If the LAL turns into gel after coming into contact with a vaccine, the vaccine is contaminated. If nothing happens, it is safe to use on humans. This simple test has saved thousands of lives since its invention.


The only issue is that scientists now need horseshoe crab blood, and lots of it. Hundreds of thousands of crabs are bled each year to keep up with the demand for LAL, and each time a crab is harvested about 30% of its blood is taken before it is released back into the ocean. The blood is drained by strapping down the crab and inserting a large needle into the tissue near its heart. The medical industry claims that mortality rates are low, but some studies suggest that as many as 15% of all crabs harvested end up dying.  Additionally, other studies have shown that even though the crabs can replenish most of their blood in a few weeks, the harvesting process has a detrimental effect on their movement speed and breeding ability. With horseshoe crab populations already threatened by fishermen who use them as bait, pharmaceutical companies need to switch to an alternative to LAL sooner rather than later.


Luckily there are some promising substitutes already available. A laboratory at Princeton University is testing microchip coated with antimicrobial peptides found on the back of the African clawed frog. When the peptides react with bacteria, the microchip sends out an alert. Other labs have developed recombinant Factor C, essentially a synthetic version of the clotting agent in horseshoe crab blood.


By Jacob Roberts


Image: Horseshoe crab blood is harvested and used to test for vaccines for potentially deadly contaminations. The bright blue color of the animal’s blood comes from the copper molecules used to carry oxygen (human blood uses iron). Wikimedia Commons.
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The antibiofilm activity of lingonberry flavonoids against oral pathogens is a case connected to residual complexity

The antibiofilm activity of lingonberry flavonoids against oral pathogens is a case connected to residual complexity | Natural Products Chemistry Breaking News | Scoop.it

4


The antimicrobial activity of lingonberry (Vaccinium vitis-idaea L.) was evaluated against two oral pathogens, Streptococcus mutans and Fusobacterium nucleatum. Long-bed gel permeation chromatography (GPC; Sephadex LH-20) yielded purified flavonoids, with the most efficient minimum inhibitory concentrations (MICs) against planktonic cells in the anthocyanin and procyanidin primary fractions against F. nucleatum (63–125 μg/ml) and in the procyanidin rich fraction against S. mutans (16–31 μg/ml). The purified flavonol glycosides and procyanidins inhibited biofilm formation of S. mutans (MICs 16–31 μg/ml), while the corresponding reference compounds showed no activity. Secondary GPC purification yielded flavonol glycosides devoid of antibiofilm activity in the 50% MeOH fraction, while elution with 70% acetone recovered a brownish material with activity against S. mutans biofilm (MIC 8 μg/ml). Even after HPLC-PDA, NMR, and MALDI-TOF analyses, the structural identity of this material remained unknown, while its color and analytical characteristics appear to be consistent with flavonoid oxidation products.



Volume 97621, September 2014, Pages 78–86

DOI: 10.1016/j.fitote.2014.05.012

NatProdChem's insight:

3

This publication shows an example of "residual complexity". A phenomenon that "refers to the inherent deviation of nature-derived agents from single chemical entities, caused by their metabolomic origin. This leads to non-simplistic and often unexpectedly complex behavior in biological systems, such as hormesis612." (http://tigger.uic.edu/~gfp/rt/residualcomplexity.html613)


More exactly it is shown that the bioactivity initially believed to be beared by a specific compound was actually due to minor components of the compound's fraction.

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A Minor Diterpenoid with a New 6/5/7/3 Fused-Ring Skeleton from Euphorbia micractina

A Minor Diterpenoid with a New 6/5/7/3 Fused-Ring Skeleton from Euphorbia micractina | Natural Products Chemistry Breaking News | Scoop.it

A novel diterpenoid with an unprecedented 6/5/7/3 fused-ring skeleton, euphorbactin (1), was isolated from an ethanol extract of the roots of Euphorbia micractina. The structure was determined by extensive spectroscopic studies, especially by 2D NMR and CD data analysis. A proposed biosynthetic pathway and preliminary investigations of the biological activity of compound 1 are also discussed.


Org. Lett., Article ASAP
DOI: 10.1021/ol501760h
Publication Date (Web): July 17, 2014




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