scholarly journals New Unusual Alkaloids from the Ascidian Eudistoma vannamei

2014 ◽  
Vol 9 (12) ◽  
pp. 1934578X1400901 ◽  
Author(s):  
Antônia Torres Ávila Pimenta ◽  
Paula Christine Jimenez ◽  
Letícia Veras Costa-Lotufo ◽  
Raimundo Braz-Filho ◽  
Mary Anne Sousa Lima
Keyword(s):  
Mass Spectrometry ◽  
Meoh Extract ◽  
Peptide Derivative ◽  
New Compounds ◽  
Related Compounds

The MeOH extract of the ascidian Eudistoma vannamei was found to contain three novel compounds, the adenine alkaloid derivatives 9-[ N-(leucyl)-isoleucyl]-adenine (1) and 8-hydroxy-8-isopentyl-7,8-dihydroadenine (2), and the phenylalanine peptide derivative N-[ N-(leucyl)-isoleucyl]phenethylamine (3). Other previously related compounds isolated from this extract include thymidine, 2′-deoxyuridine and phenylalanine. The structures of the new compounds were elucidated through the use of NMR and mass spectrometry.

scholarly journals New Antiplasmodial Diterpenes from Gutierrezia Sarothrae

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Qingxi Su ◽  
Seema Dalal ◽  
Michael Goetz ◽  
Maria B. Cassera ◽  
David G. L Kingston
Keyword(s):  
Mass Spectrometry ◽  
Plasmodium Falciparum ◽  
Spectroscopic Data ◽  
2D Nmr ◽  
Antiplasmodial Activity ◽  
Drug Resistant ◽  
Meoh Extract ◽  
Bioassay Guided Fractionation ◽  
Gutierrezia Sarothrae ◽  
Related Compounds

Bioassay guided fractionation of the MeOH extract of the plant Gutierrezia sarothrae (Asteraceae) using an assay for antiplasmodial activity against the drug-resistant Dd2 strain of Plasmodium falciparum led to the isolation of the two new diterpenes 3α-angeloyloxy-15-hydroxylabda-7,13-dien-16,15-olid-18-oic acid (1) and 3α-angeloyloxy-15-methoxylabda-7,13-dien-16,15-olid-18-oic acid (2). The structures of 1 and 2 were elucidated by interpretation of ID and 2D NMR spectroscopic data, mass spectrometry, and comparison with the data of related compounds reported in the literature. Compound 1 exhibited moderate antiplasmodial activity with an IC50 values of 10.4 ± 4.3 μM.

scholarly journals 4-vinylpyridine derivatives: Protonation, methylation and silver(I) coordination chemistry

2021 ◽  
pp. 174751982198965
Author(s):  
Guoqi Zhang
Keyword(s):  
Mass Spectrometry ◽  
Schiff Base ◽  
Coordination Chemistry ◽  
Elemental Analysis ◽  
Silver Complex ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pyridine Moiety ◽  
New Compounds

( E)-4-[2-(Pyridin-4-yl)vinyl]benzaldehyde, containing both a 4-vinylpyridine and an aldehyde functionality, is utilized to develop new, highly conjugated chalcone compounds and a bis-Schiff base azine compound. The chalcone-containing compounds are further explored for their protonation, methylation and silver(I) coordination chemistry using the pyridine moiety. In parallel, a cyano-containing analogue, ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile is also synthesized and studied for its silver(I) coordination chemistry. These new compounds are fully characterized by mass spectrometry, elemental analysis and spectroscopic techniques. The methylated product of ( E)-1-(9-anthryl)-3-{4-[2-(pyridin-4-yl)vinyl]phenyl}prop-2-en-1-one and a silver complex of ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile are structurally determined by X-ray crystallography.

scholarly journals A Comprehensive Analysis Using Colorimetry, Liquid Chromatography-Tandem Mass Spectrometry and Bioassays for the Assessment of Indole Related Compounds Produced by Endophytes of Selected Wheat Cultivars

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1394
Author(s):  
Agnieszka Kuźniar ◽  
Kinga Włodarczyk ◽  
Ilona Sadok ◽  
Magdalena Staniszewska ◽  
Małgorzata Woźniak ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Endophytic Bacteria ◽  
Culture Medium ◽  
Tandem Mass ◽  
Wheat Cultivars ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Related Compounds

Liquid chromatography–tandem mass spectrometry (LC–MS/MS), colorimetry, and bioassays were employed for the evaluation of the ability of endophytic bacterial strains to synthesize indole-related compounds (IRCs) and in particular indole-3-acetic acid (IAA). A total of 54 endophytic strains belonging to seven bacterial genera isolated from tissues of common and spelt wheat cultivars were studied. The endophytic bacteria isolated from different tissues of the tested wheat types were capable of IRCs production, including IAA, which constituted from 1.75% to 52.68% of all IRCs, in in vitro conditions via the tryptophan dependent pathway. The selected post-culture medium was also examined using a plant bioassay. Substantial growth of wheat coleoptile segments treated with the bacterial post-culture medium was observed in several cases. Our data suggest that the studied endophytic bacteria produce auxin-type compounds to support plant development. Summarizing, our approach to use three complementary methods for estimation of IRCs in different endophytic strains provides a comprehensive picture of their effect on wheat growth.

Core-modified porphyrins: novel building blocks in chemistry

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Aleksey E. Kuznetsov
Keyword(s):  
Periodic Table ◽  
Building Blocks ◽  
Effective Strategy ◽  
Research Groups ◽  
Structures And Properties ◽  
Porphyrin Core ◽  
Living Organisms ◽  
New Compounds ◽  
Related Compounds ◽  
Nitrogen Phosphorus

Abstract Various (metallo)porphyrins and related compounds have been intensively investigated by different research groups due to their extremely important role in living organisms along with their versatile applications in technology. The design of novel porphyrinoids by core-modification, or substitution of pyrrole nitrogens, with the elements of other groups of the Periodic Table has been considered as a highly promising methodology for tuning structures and properties of porphyrinoids and thus opening new possible applications for them. Much effort has been given to the modifications of the porphyrin core with elements of the main groups, namely O, S, Se (chalcogens), and the heavier congener of nitrogen, phosphorus. In general, the porphyrin core modification by replacing nitrogens with heteroatoms is a promising and effective strategy for obtaining new compounds with unusual structures and properties (optical, electrochemical, coordinating, etc.) as well as reactivity. These novel molecules can also be employed as promising building or construction blocks in various applications in the nanotechnology area.

A new furan carboxamide and two potential precursors from a terrestrial streptomycete

2017 ◽  
Vol 72 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Humaira Naureen ◽  
Michel Feussi Tala ◽  
Khaled A. Shaaban ◽  
Mohamed Shaaban ◽  
Anja Schüffler ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Density Functional ◽  
Acid Amide ◽  
Octadecenoic Acid ◽  
Gas Chromatography Mass Spectrometry ◽  
Bioactive Metabolites ◽  
Cytotoxic Activities ◽  
Tetradecanoic Acid ◽  
Vinyl Phenol ◽  
New Compounds

Abstract Three new bioactive metabolites, 1,6-dihydroxy- 2-methyl-heptan-4-one (1), 4-hydroxy-1-(2-methyl-oxiranyl)- pentan-2-one (2), and 2-(2-hydroxy-propyl)-4-methylfuran- 3-carboxylic acid amide (3) were isolated from the terrestrial Streptomyces sp. isolate ANK245, along with the new microbial constituent p-vinylanisol (4a) and the known metabolites p-vinyl-phenol (4b) and phenethyl alcohol. Analysis of the nonpolar part of the extract by gas chromatography/mass spectrometry (GC-MS) provided further evidence for tetradecanoic acid, 9-octadecenoic acid, hexadecanoic acid, 2-methoxy-4-vinylphenol (4c), 4-hydroxy-3-methoxy-benzaldehyde, o-hydroxybiphenyl, and 1,5,9-trimethyl-4,8,13-cyclotetradecatrien-1,3-diol (5). Structures 1–3 of the new compounds were elucidated by nuclear magnetic resonance (NMR) and NMR spectroscopy, but mass spectrometry (MS) techniques and their absolute configuration were determined by density functional theory (DFT) calculations and Mosher derivatisation. Their antimicrobial and cytotoxic activities were evaluated in comparison with the crude bacterial extract.

scholarly journals Natalenamides A–C, Cyclic Tripeptides from the Termite-Associated Actinomadura sp. RB99

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 3003 ◽  
Author(s):  
Seoung Rak Lee ◽  
Dahae Lee ◽  
Jae Sik Yu ◽  
René Benndorf ◽  
Sullim Lee ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cyclic Peptides ◽  
Culture Broth ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Inhibitory Effects ◽  
Associated Bacteria ◽  
Chemical Structures ◽  
New Compounds ◽  
Powerful Strategy

In recent years, investigations into the biochemistry of insect-associated bacteria have increased. When combined with analytical dereplication processes, these studies provide a powerful strategy to identify structurally and/or biologically novel compounds. Non-ribosomally synthesized cyclic peptides have a broad bioactivity spectrum with high medicinal potential. Here, we report the discovery of three new cyclic tripeptides: natalenamides A–C (compounds 1–3). These compounds were identified from the culture broth of the fungus-growing termite-associated Actinomadura sp. RB99 using a liquid chromatography (LC)/ultraviolet (UV)/mass spectrometry (MS)-based dereplication method. Chemical structures of the new compounds (1–3) were established by analysis of comprehensive spectroscopic methods, including one-dimensional (1H and 13C) and two-dimensional (1H-1H-COSY, HSQC, HMBC) nuclear magnetic resonance spectroscopy (NMR), together with high-resolution electrospray ionization mass spectrometry (HR-ESIMS) data. The absolute configurations of the new compounds were elucidated using Marfey’s analysis. Through several bioactivity tests for the tripeptides, we found that compound 3 exhibited significant inhibitory effects on 3-isobutyl-1-methylxanthine (IBMX)-induced melanin production. The effect of compound 3 was similar to that of kojic acid, a compound extensively used as a cosmetic material with a skin-whitening effect.

Sign in / Sign up

Export Citation Format

Share Document