Aliphatic chain-containing macrocycles as diazonamide A analogs

2020 ◽  
Vol 56 (5) ◽  
pp. 586-602
Author(s):  
Viktorija Vitkovska ◽  
Rimants Zogota ◽  
Toms Kalnins ◽  
Diana Zelencova ◽  
Edgars Suna
Keyword(s):  
Aliphatic Chain ◽  
Diazonamide A

scholarly journals Chiroptical activity of hydroxycarboxylic acids with implications for the origin of biological homochirality

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jana Bocková ◽  
Nykola C. Jones ◽  
Uwe J. Meierhenrich ◽  
Søren V. Hoffmann ◽  
Cornelia Meinert
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Organic Molecules ◽  
Building Blocks ◽  
Aliphatic Chain ◽  
Monocarboxylic Acids ◽  
Hydroxycarboxylic Acids ◽  
Polarised Light ◽  
Suitable Target ◽  
Anisotropy Spectra

AbstractCircularly polarised light (CPL) interacting with interstellar organic molecules might have imparted chiral bias and hence preluded prebiotic evolution of biomolecular homochirality. The l-enrichment of extra-terrestrial amino acids in meteorites, as opposed to no detectable excess in monocarboxylic acids and amines, has previously been attributed to their intrinsic interaction with stellar CPL revealed by substantial differences in their chiroptical signals. Recent analyses of meteoritic hydroxycarboxylic acids (HCAs) – potential co-building blocks of ancestral proto-peptides – indicated a chiral bias toward the l-enantiomer of lactic acid. Here we report on novel anisotropy spectra of several HCAs using a synchrotron radiation electronic circular dichroism spectrophotometer to support the re-evaluation of chiral biomarkers of extra-terrestrial origin in the context of absolute photochirogenesis. We found that irradiation by CPL which would yield l-excess in amino acids would also yield l-excess in aliphatic chain HCAs, including lactic acid and mandelic acid, in the examined conditions. Only tartaric acid would show “unnatural” d-enrichment, which makes it a suitable target compound for further assessing the relevance of the CPL scenario.

scholarly journals SERS Investigation on Oligopeptides Used as Biomimetic Coatings for Medical Devices

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 959
Author(s):  
Michele Di Foggia ◽  
Vitaliano Tugnoli ◽  
Stefano Ottani ◽  
Monica Dettin ◽  
Annj Zamuner ◽  
...  
Keyword(s):  
Medical Devices ◽  
Spatial Arrangement ◽  
Amide Bond ◽  
Substitution Effects ◽  
Aliphatic Chain ◽  
Molecular Systems ◽  
Self Assembling ◽  
Surface Enhanced Raman ◽  
Colloid Nanoparticles ◽  
Gamma Irradiated

The surface-enhanced Raman scattering (SERS) spectra of three amphiphilic oligopeptides derived from EAK16 (AEAEAKAK)2 were examined to study systematic amino acid substitution effects on the corresponding interaction with Ag colloidal nanoparticles. Such self-assembling molecular systems, known as “molecular Lego”, are of particular interest for their uses in tissue engineering and as biomimetic coatings for medical devices because they can form insoluble macroscopic membranes under physiological conditions. Spectra were collected for both native and gamma-irradiated samples. Quantum mechanical data on two of the examined oligopeptides were also obtained to clarify the assignment of the prominent significative bands observed in the spectra. In general, the peptide–nanoparticles interaction occurs through the COO− groups, with the amide bond and the aliphatic chain close to the colloid surface. After gamma irradiation, mimicking a free oxidative radical attack, the SERS spectra of the biomaterials show that COO− groups still provide the main peptide–nanoparticle interactions. However, the spatial arrangement of the peptides is different, exhibiting a systematic decrease in the distance between aliphatic chains and colloid nanoparticles.

scholarly journals Cytotoxic Acetogenins from the Roots of Annona purpurea

2019 ◽  
Vol 20 (8) ◽  
pp. 1870 ◽  
Author(s):  
Gustavo Alejandro Hernández-Fuentes ◽  
Aída Nelly García-Argáez ◽  
Ana Lilia Peraza Campos ◽  
Iván Delgado-Enciso ◽  
Roberto Muñiz-Valencia ◽  
...  
Keyword(s):  
Folk Medicine ◽  
Human Tumor ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Aliphatic Chain ◽  
Human Tumor Cell ◽  
Chemical Methods ◽  
Human Tumor Cell Lines ◽  
Interesting Compound ◽  
Complex I Activity

Annona purpurea, known in Mexico as “cabeza de negro” or “ilama”, belongs to the Annonaceae family. Its roots are employed in folk medicine in several regions of Mexico. Taking that information into account, a chemical and biological analysis of the components present in the roots of this species was proposed. Our results demonstrated that the dichloromethane (DCM) extract was exclusively constituted by a mixture of five new acetogenins named annopurpuricins A–E (1–5). These compounds have an aliphatic chain of 37 carbons with a terminal α,β unsaturated γ-lactone. Compounds 1 and 2 belong to the adjacent bis-THF (tetrahydrofuran) α-monohydroxylated type, while compounds 3 and 4 belong to the adjacent bis-THF α,α’-dihydroxylated type; only compound 5 possesses a bis-epoxide system. Complete structure analysis was carried out by spectroscopy and chemical methods. All compounds were evaluated for their antiproliferative activity on three human tumor cell lines (MSTO-211H, HeLa and HepG2). Compounds 1–4 inhibited significantly the growth of HeLa and HepG2 cells, showing GI50 values in the low/subnanomolar range, while 5 was completely ineffective under the tested conditions. The investigation of the mechanism of action responsible for cytotoxicity revealed for the most interesting compound 1 the ability to block the complex I activity on isolated rat liver mitochondria (RLM).

Modulation of PPAR receptor subtype selectivity of the ligands: Aliphatic chain vs aromatic ring as a spacer between pharmacophore and the lipophilic moiety

2008 ◽  
Vol 18 (24) ◽  
pp. 6471-6475 ◽  
Author(s):  
Harikishore Pingali ◽  
Mukul Jain ◽  
Shailesh Shah ◽  
Pravin Patil ◽  
Pankaj Makadia ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Receptor Subtype ◽  
Aliphatic Chain ◽  
Subtype Selectivity

Suppression of Radical-Induced Lipid Peroxidation in a Model System by Alkyl Esters of Cinnamate Quaternary Ammonium Salts

2001 ◽  
Vol 56 (9-10) ◽  
pp. 878-885 ◽  
Author(s):  
Anna Krasowska ◽  
Maria Stasiuk ◽  
Malgorzata Oswiecimska ◽  
Arkadiusz Kozubek ◽  
Malgorzata Bien ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Chain Length ◽  
Alkyl Chain ◽  
Quaternary Ammonium Salts ◽  
Alkyl Chain Length ◽  
Ammonium Salts ◽  
Yeast Cells ◽  
Phenolic Antioxidants ◽  
Lipid Phase ◽  
Aliphatic Chain

AbstractThree new groups of phenolic antioxidants, quaternary ammonium salts with a phenol ring and alkyl chains of different length (pyrrolidine ethyl esters of 3,5-di-t-butyl-4-hydroxydihydrocinnamic acid n-alkoxymethylchlorides (PYE-n) or n-alkylbromides (PYA-n) and 2-dimethylaminoethyl ester n-alkylbromides (PPA-n), were synthesized. Some of them were previously found to efficiently protect yeast cells against oxidants and to inhibit the production of thiobarbituric acid-reactive substances in whole yeast cells and in isolated membrane lipids. The new antioxidants (at 1-100 μm) abolished or diminished peroxidation of oliwe oil emulsions caused by the OH•-producing Fe2+ and RO• and ROO•-producing tertbutylhydroperoxide (TBHP) and the azo compounds 2,2′-azobis-(amidinopropane)dihydronitrile (AAPH) and 1,1′-azobis-(1-cyclohexanecarbonitrile) (ACHN): all present at 10 mᴍ . The efficiency of individual both antioxidants was examined in relation to the type of lipid peroxidation inducer, the site of antioxidant incorporation into the emulsion lipid phase, the length of the alkyl chain, and the maximum concentration of effective antioxidant monomers given by its critical micelle concentration. PYA-n class compounds were highly efficient against all peroxidation inducers and their efficiency did not depend on the position of their molecules in the lipid phase and/or on the aliphatic chain length. In contrast, the efficiency of PYE-n and PPA-n class compounds depended both on the type of oxidant and on the length of their aliphatic chain. Their potency against Fe2+ and ACHN increased with increasing alkyl chain length whereas with AAPH it dropped with increasing alkyl chain length. A similar pattern was found with the action of PYE-n against TBHP whereas in the PPA-n group an extending alkyl chain reduced the anti-TBHP efficiency. These relationships may not be entirely straightforward and other factors (chemical nature of each compound, its possible interaction with fluorescent probes used for diagnostics, etc.) may play a considerable and not yet quite clear role. PPA-n class antioxidants have the lowest critical micelle concentration, which may limit their efficiency. Nevertheless, these phenolic antioxidants can be conveniently employed as highly efficient inhibitors of lipid peroxidation.

Experimental and theoretical studies of interaction of aliphatic chain α-aminobisphosphonates with DNA

2017 ◽  
Vol 338 ◽  
pp. 183-191 ◽  
Author(s):  
M.B. Gholivand ◽  
H. Peyman ◽  
Kh. Gholivand ◽  
H. Roshanfekr ◽  
A.A. Taherpour ◽  
...  
Keyword(s):  
Aliphatic Chain ◽  
Theoretical Studies ◽  
Experimental And Theoretical Studies

Quantum mechanically calculated NIR spectra of fatty acids

NIR news ◽  
2017 ◽  
Vol 28 (8) ◽  
pp. 11-16 ◽  
Author(s):  
Justyna Grabska
Keyword(s):  
Fatty Acids ◽  
Near Infrared ◽  
Unsaturated Fatty Acids ◽  
Theoretical Study ◽  
Calculated Data ◽  
Nir Spectroscopy ◽  
Theoretical Modelling ◽  
Aliphatic Chain ◽  
Computing Power ◽  
Technical Article

The advances in theory as well as steady development of the computing power have made quantum mechanical simulation of NIR spectra feasible. Recently, we have demonstrated the ability to accurately reproduce in theory the NIR spectra of several complex biomolecules, including fatty acids. In the present technical article, some of these achievements are overviewed. Examples of theoretical modelling of NIR spectra of short- (aliphatic chain up to four carbon atoms) and medium-chain (aliphatic chain counting six carbon atoms) fatty acids are presented and discussed. The calculated data are used directly for explaining the experimental NIR spectra of these systems. Spectral features distinctive to saturated vs. unsaturated fatty acids are essential in various types of samples typically treated by NIR spectroscopy; i.e. food, tissue, biomaterial, etc. Therefore, the theoretical study offers considerable support for basic and applied NIRS. An example of possible practical application of the results of theoretical study for biochemical studies is provided. The topic discussed here has been presented during the 18th International Conference on Near Infrared Spectroscopy (ICNIRS-2017) in Copenhagen, June 2017.

The effect of aliphatic chain length on thermal properties of poly(alkylene dicarboxylate)s

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Corrado Berti ◽  
Annamaria Celli ◽  
Paola Marchese ◽  
Elisabetta Marianucci ◽  
Giancarlo Barbiroli ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Three Dimensional ◽  
The Other ◽  
Aliphatic Chain ◽  
Melting Temperatures ◽  
Avrami Analysis ◽  
Isothermal Analysis ◽  
Dimensional Growth ◽  
Crystallizing Polymers ◽  
Crystalline Forms

AbstractSome poly(alkylene dicarboxylate)s, derived from ethanediol or 1,4- butanediol and different diacids, have been synthesized and analyzed by DSC to determine the correlations existing between the thermal properties and the length of the aliphatic chain. The polymers show crystallization and melting temperatures and enthalpies which increase as the polymethylene segments lengthen, due to the formation of more stable crystals. The samples derived from ethanediol are peculiar; they show reorganization processes during the melting and the melting temperatures are notably higher with respect to those of the other polyesters. This behavior is discussed. Isothermal analysis highlights that poly(alkylene dicarboxylate)s are fast crystallizing polymers. The Avrami analysis suggests a crystallization mechanism characterized by heterogeneous nucleation and three dimensional growth; secondary crystallizations is present only in the samples characterized by short -(CH2)- sequences, due to the reorganization of less perfect crystalline forms. A comparative study between the crystallization rates as a function of the undercooling is reported.

Formal Total Synthesis of Diazonamide A by Indole Oxidative Rearrangement

2016 ◽  
Vol 22 (31) ◽  
pp. 10867-10876 ◽  
Author(s):  
Nadège David ◽  
Raffaele Pasceri ◽  
Russell R. A. Kitson ◽  
Alexandre Pradal ◽  
Christopher J. Moody
Keyword(s):  
Total Synthesis ◽  
Diazonamide A ◽  
Oxidative Rearrangement
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