scholarly journals Two Peptides, Cycloaspeptide A and Nazumamide A from a Sponge Associated Marine Actinobacterium Salinispora sp

2014 ◽  
Vol 9 (4) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Utpal Bose ◽  
Mark P. Hodson ◽  
P. Nicholas Shaw ◽  
John A. Fuerst ◽  
Amitha K Hewavitharana
Keyword(s):  
Mass Spectra ◽  
Cyclic Peptide ◽  
Benthic Communities ◽  
Integrated Approach ◽  
Marine Sponges ◽  
Thrombin Inhibitor ◽  
Database Searching ◽  
Culturable Bacterium ◽  
Polarity Switching ◽  
Product Ions

Marine sponges are a major component of benthic communities and act as a reservoir for microbial species. In terms of biomass, they are the richest source of secondary metabolite production, with the potential to influence both benthic and pelagic systems. In most cases it is the sponge-associated microbes that account for many of the secondary metabolites assigned to the host. Here we report the occurrence of cycloaspeptide A, a fungus-derived cyclic peptide, in a culturable bacterium Salinispora arenicola. We have also identified nazumamide A, a sponge-derived linear tetrapeptide currently used as a thrombin inhibitor, in Salinispora pacifica. Their structures were determined using an integrated approach consisting of: (1) HPLC-UV-Vis-QToF-MS analysis with multimode ionization (ESI and APCI) and fast polarity switching; (2) database searching and matching of monoisotopic masses, retention times, mass spectra of the precursor and product ions of the compounds of interest and the authentic reference standards thereof.

scholarly journals 3-Alkylpyridinium salts from Haplosclerida marine sponges: Isolation, structure elucidations, and biosynthetic considerations

2009 ◽  
Vol 81 (6) ◽  
pp. 1033-1040 ◽  
Author(s):  
Rémi Laville ◽  
Philippe Amade ◽  
Olivier P. Thomas
Keyword(s):  
High Resolution ◽  
Mass Spectra ◽  
Biosynthetic Pathway ◽  
2D Nmr ◽  
Marine Sponges ◽  
Structure Characterization ◽  
Ionization Mass ◽  
Family Structures ◽  
Resolution Electron

A very little studied marine sponge Callyspongia sp. collected off the coast of Martinique was chemically investigated. The study led to the isolation and structure characterization of two new 3-alkylpyridinium salts which belonged to the recently isolated pachychaline family. Structures were elucidated by 1D, 2D NMR and detailed high-resolution electron spray ionization mass spectra (HRESIMS)-MS studies. The use of HRESIMS-MS studies proved to be highly efficient to identify two other close derivatives in a mixture. Finally, these studies allowed us to propose a general biosynthetic pathway leading to important 3-alkylpyridinium salts.

Mass Spectra and Ion Chemistry of Methylphosphine, Dimethylphosphine and Dimethyldeuterophosphine, Investigated by Ion Cyclotron Resonance Spectrometry

1975 ◽  
Vol 30 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Karl-Peter Wanczek
Keyword(s):  
Rate Constants ◽  
Cyclotron Resonance ◽  
Mass Spectra ◽  
Ion Cyclotron Resonance ◽  
Exchange Reactions ◽  
Ion Chemistry ◽  
Ion Molecule Reactions ◽  
Ion Cyclotron ◽  
Product Ions ◽  
Ion Cyclotron Resonance Spectrometry

The mass spectra and the ion molecule reactions of methylphosphine, dimethylphosphine and dimethyldeuterophosphine have been studied by ion cyclotron resonance spectrometry. About 50 ion molecule reaction are observed for each compound. The product ions can be classified as ions with two phosphorus atoms: P2R5+, P2R3+, P2R2+ and P2R+ (R = CH3 or H), as phosphonium and phosphinium ions and ions resulting from collision dissociations and charge exchange reactions. Tertiary ions with three phosphorus atoms like CH3P3H2+ (from CH3PH2) and (CH3)4P3H2 (from (CH3)2PH) have also been detected. The mechanisms of the ion molecule reactions, rearrangements, P -H- and C-H-reactivities and product ion structures are discussed, using in the case of dimethylphosphine the results obtained with the deuterated compound. Rate constants of formation of the more abundant product ions from the molecular ion and the CH3P+ ion, both odd electron particles, have been determined. The reactions with dimethylphosphine have much smaller rate constants than the reactions with methylphosphine.

Unexpected peaks in tandem mass spectra due to reaction of product ions with residual water in mass spectrometer collision cells

2014 ◽  
Vol 28 (23) ◽  
pp. 2645-2660 ◽  
Author(s):  
Pedatsur Neta ◽  
Mahnaz Farahani ◽  
Yamil Simón-Manso ◽  
Yuxue Liang ◽  
Xiaoyu Yang ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Mass Spectra ◽  
Residual Water ◽  
Tandem Mass ◽  
Tandem Mass Spectra ◽  
Product Ions

pClean: An Algorithm To Preprocess High-Resolution Tandem Mass Spectra for Database Searching

2019 ◽  
Vol 18 (9) ◽  
pp. 3235-3244
Author(s):  
Yamei Deng ◽  
Zhe Ren ◽  
Qingfei Pan ◽  
Da Qi ◽  
Bo Wen ◽  
...  
Keyword(s):  
High Resolution ◽  
Mass Spectra ◽  
Database Searching ◽  
Tandem Mass ◽  
Tandem Mass Spectra

scholarly journals Exploring the Antiangiogenic Potential of Solomonamide A Bioactive Precursors: In Vitro and in Vivo Evidences of the Inhibitory Activity of Solo F-OH During Angiogenesis

Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 228 ◽  
Author(s):  
Carrillo ◽  
Martínez-Poveda ◽  
Cheng-Sánchez ◽  
Guerra ◽  
Tobia ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Inhibitory Activity ◽  
Cyclic Peptide ◽  
Chorioallantoic Membrane ◽  
Tube Formation ◽  
Marine Sponges ◽  
Migration And Invasion ◽  
In Vivo Models

Marine sponges are a prolific source of bioactive compounds. In this work, the putative antiangiogenic potential of a series of synthetic precursors of Solomonamide A, a cyclic peptide isolated from a marine sponge, was evaluated. By means of an in vitro screening, based on the inhibitory activity of endothelial tube formation, the compound Solo F–OH was selected for a deeper characterization of its antiangiogenic potential. Our results indicate that Solo F–OH is able to inhibit some key steps of the angiogenic process, including the proliferation, migration, and invasion of endothelial cells, as well as diminish their capability to degrade the extracellular matrix proteins. The antiangiogenic potential of Solo F–OH was confirmed by means of two different in vivo models: the chorioallantoic membrane (CAM) and the zebrafish yolk membrane (ZFYM) assays. The reduction in ERK1/2 and Akt phosphorylation in endothelial cells treated with Solo F–OH denotes that this compound could target the upstream components that are common to both pathways. Taken together, our results show a new and interesting biological activity of Solo F–OH as an inhibitor of the persistent and deregulated angiogenesis that characterizes cancer and other pathologies.

scholarly journals Novel Long-Acting Somatostatin Analog with Endocrine Selectivity: Potent Suppression of Growth Hormone But Not of Insulin

Endocrinology ◽  
2001 ◽  
Vol 142 (1) ◽  
pp. 477-486 ◽  
Author(s):  
Michel Afargan ◽  
Eva Tiensuu Janson ◽  
Garry Gelerman ◽  
Rakefet Rosenfeld ◽  
Offer Ziv ◽  
...  
Keyword(s):  
Insulin Release ◽  
Cyclic Peptide ◽  
Hormone Secretion ◽  
Integrated Approach ◽  
Cell System ◽  
Binding Assays ◽  
Gh Secretion ◽  
Long Acting ◽  
Glucagon And Insulin

Abstract Somatostatin, also known as somatotropin release-inhibiting factor (SRIF), is a natural cyclic peptide inhibitor of pituitary, pancreatic, and gastrointestinal secretion. Its long-acting analogs are in clinical use for treatment of various endocrine syndromes and gastrointestinal anomalies. These analogs are more potent inhibitors of the endocrine release of GH, glucagon, and insulin than the native SRIF; hence, they do not display considerable physiological selectivity. Our goal was to design effective and physiologically selective SRIF analogs with potential therapeutic value. We employed an integrated approach consisting of screening of backbone cyclic peptide libraries constructed on the basis of molecular modeling of known SRIF agonists and of high throughput receptor binding assays with each of the five cloned human SRIF receptors (hsst1–5). By using this approach, we identified a novel, high affinity, enzymatically stable, and long-acting SRIF analog, PTR-3173, which binds with nanomolar affinity to human SRIF receptors hsst2, hsst4, and hsst5. The hsst5 and the rat sst5 (rsst5) forms have the same nanomolar affinity for this analog. In the human carcinoid-derived cell line BON-1, PTR-3173 inhibits forskolin-stimulated cAMP accumulation as efficiently as the drug octreotide, indicating its agonistic effect in this human cell system. In hormone secretion studies with rats, we found that PTR-3173 is 1000-fold and more than 10,000-fold more potent in inhibiting GH release than glucagon and insulin release, respectively. These results suggest that PTR-3173 is the first highly selective somatostatinergic analog for the in vivo inhibition of GH secretion, with minimal or no effect on glucagon and insulin release, respectively.

scholarly journals Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

2015 ◽  
Vol 11 ◽  
pp. 1667-1699 ◽  
Author(s):  
Louis P Sandjo ◽  
Victor Kuete ◽  
Maique W Biavatti
Keyword(s):  
Chemical Shift ◽  
Mass Spectra ◽  
Marine Sponges ◽  
Biomimetic Synthesis ◽  
Marine Alkaloids ◽  
Hydrogen Atoms ◽  
Data Synthesis ◽  
Synthesis Routes ◽  
Shift Assignment ◽  
C Nmr

This review focuses on pyridoacridine-related metabolites as one biologically interesting group of alkaloids identified from marine sources. They are produced by marine sponges, ascidians and tunicates, and they are structurally comprised of four to eight fused rings including heterocycles. Acridine, acridone, dihydroacridine, and quinolone cores are features regularly found in these alkaloid skeletons. The lack of hydrogen atoms next to quaternary carbon atoms for two or three rings makes the chemical shift assignment a difficult task. In this regard, one of the aims of this review is the compilation of previously reported, pyridoacridine 13C NMR data. Observations have been made on the delocalization of electrons and the presence of some functional groups that lead to changes in the chemical shift of some carbon resonances. The lack of mass spectra information for these alkaloids due to the compactness of their structures is further discussed. Moreover, the biosynthetic pathways of some of these metabolites have been shown since they could inspire biomimetic synthesis. The synthesis routes used to prepare members of these marine alkaloids (as well as their analogues), which are synthesized for biological purposes are also discussed. Pyridoacridines were found to have a large spectrum of bioactivity and this review highlights and compares the pharmacophores that are responsible for the observed bioactivity.

Analysis of Testosterone Esters by Tandem Mass Spectrometry

1993 ◽  
Vol 76 (2) ◽  
pp. 306-312 ◽  
Author(s):  
Thomas Cairns ◽  
Emil G Siegmund ◽  
Bobby Rader
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Relative Abundance ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Generic Product ◽  
Tandem Mass ◽  
Fragment Ions ◽  
Product Ions ◽  
The Individual

Abstract The electron ionization (El) and chemical ionization (CI) mass spectra of 12 representative testosterone esters were examined to explore the various analytical options available for identification and confirmation of the esters. Using El, a number of fragment ions indicated the identification of the testosterone moiety, but structural confirmation of the individual esters often required the observance of the molecular ion at very low relative abundance ratios. The acceptable analytical method involved CI/tandem mass spectrometry based on the production of the 2 generic product ions derived from the protonated molecule ion.

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