scholarly journals Prebiotic synthesis of 2-deoxy-d-ribose from interstellar building blocks promoted by amino esters or amino nitriles

2017 ◽  
Vol 53 (75) ◽  
pp. 10362-10365 ◽  
Author(s):  
Andrew M. Steer ◽  
Nicolas Bia ◽  
David K. Smith ◽  
Paul A. Clarke
Keyword(s):  
Amino Acids ◽  
Prebiotic Synthesis ◽  
Building Blocks ◽  
Amino Esters ◽  
Interstellar Ices ◽  
Prebiotic Earth ◽  
Selective Formation

Amino esters and amino nitriles can promote the selective formation of 2-deoxy-d-ribose from materials present in interstellar ices. The use of amino nitriles suggests the possibility that carbohydrates may have existed before amino acids on the prebiotic Earth.

Prebiotic synthesis at impact craters: the role of Fe-clays and iron meteorites

2019 ◽  
Vol 55 (71) ◽  
pp. 10563-10566 ◽  
Author(s):  
Adam Pastorek ◽  
Jana Hrnčířová ◽  
Luboš Jankovič ◽  
Lukáš Nejdl ◽  
Svatopluk Civiš ◽  
...  
Keyword(s):  
Amino Acids ◽  
Prebiotic Synthesis ◽  
Building Blocks ◽  
Impact Craters ◽  
Iron Meteorites ◽  
Post Impact

Iron-rich smectites formed by reprocessing of basalts due to the residual post-impact heat could catalyze the synthesis and accumulation of important prebiotic building blocks such as nucleobases, amino acids and urea.

scholarly journals Stereoselective synthesis of perillaldehyde-based chiral β-amino acid derivatives through conjugate addition of lithium amides

2014 ◽  
Vol 10 ◽  
pp. 2738-2742 ◽  
Author(s):  
Zsolt Szakonyi ◽  
Reijo Sillanpää ◽  
Ferenc Fülöp
Keyword(s):  
Amino Acids ◽  
Stereoselective Synthesis ◽  
Minor Component ◽  
Conjugate Addition ◽  
Building Blocks ◽  
Major Product ◽  
Amino Ester ◽  
Chiral Amine ◽  
Amino Esters ◽  
Lithium Amides

The Michael addition of dibenzylamine to (+)-tert-butyl perillate (3) and to (+)-tert-butyl phellandrate (6), derived from (S)-(−)-perillaldehyde (1), resulted in diastereomeric β-amino esters 7A–D in a moderately stereospecific reaction in a ratio of 76:17:6:1. After separation of the diastereoisomers, the major product, cis isomer 7A, was quantitatively isomerized to the minor component, trans-amino ester 7D. All four isomers were transformed to the corresponding β-amino acids 10A–D, which are promising building blocks for the synthesis of β-peptides and 1,3-heterocycles in three steps. The steric effects of the isopropyl group at position 4 and of the α-methyl substituent of (R)-N-benzyl-N-α-methylbenzylamine on the reactivity were also studied and, upon application of a chiral amine, excellent stereoselectivity of the conjugate addition was observed. Amino ester 11 was obtained as a single product and transformed to the corresponding amino acids 10A and 10D in good yields on the gram scale.

Exogenous Directing Group Free, Ligand-Enabled gamma-C(sp3)–H Arylation of Free Primary Aliphatic Amines and α-Amino Esters

2019 ◽  
Author(s):  
Yongzheng Ding ◽  
Shuai Fan ◽  
Xiaoxi Chen ◽  
yuzhen gao ◽  
Gang Li
Keyword(s):  
Amino Acids ◽  
Large Scale ◽  
Free Ligand ◽  
Aliphatic Amines ◽  
Rapid Synthesis ◽  
Amino Esters ◽  
Directing Group ◽  
Large Scale Synthesis ◽  
Primary Aliphatic Amines

A Pdᴵᴵ-catalyzed, ligand-enabled gamma-C(sp3)–H arylation of free primary aliphatic amines and amino esters without using an exogenous directing group is reported. This reaction is compatible with unhindered free aliphatic amines, and it is also be applicable to the rapid synthesis of biologically and synthetically valuable unnatural α-amino acids. Large scale synthesis is also feasible using this method.<br>

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 Prebiotic synthesis of aminooxazoline-5′-phosphates in water by oxidative phosphorylation

2017 ◽  
Vol 53 (36) ◽  
pp. 4919-4921 ◽  
Author(s):  
C. Fernández-García ◽  
N. M. Grefenstette ◽  
M. W. Powner
Keyword(s):  
Amino Acids ◽  
Oxidative Phosphorylation ◽  
Prebiotic Synthesis ◽  
Strecker Synthesis ◽  
Novel Strategy

A novel strategy for aminooxazoline-5′-phosphate synthesis in water from prebiotic feedstocks, which is generationally linked to Strecker synthesis of proteinogenic amino acids.

scholarly journals Synthesis, Characterization and Evaluation of Peptide Nanostructures for Biomedical Applications

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4587
Author(s):  
Fanny d’Orlyé ◽  
Laura Trapiella-Alfonso ◽  
Camille Lescot ◽  
Marie Pinvidic ◽  
Bich-Thuy Doan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biomedical Applications ◽  
Chemical Reactivity ◽  
Physical Stability ◽  
Chemical Properties ◽  
Building Blocks ◽  
Imaging Probes ◽  
Therapeutic Molecules

There is a challenging need for the development of new alternative nanostructures that can allow the coupling and/or encapsulation of therapeutic/diagnostic molecules while reducing their toxicity and improving their circulation and in-vivo targeting. Among the new materials using natural building blocks, peptides have attracted significant interest because of their simple structure, relative chemical and physical stability, diversity of sequences and forms, their easy functionalization with (bio)molecules and the possibility of synthesizing them in large quantities. A number of them have the ability to self-assemble into nanotubes, -spheres, -vesicles or -rods under mild conditions, which opens up new applications in biology and nanomedicine due to their intrinsic biocompatibility and biodegradability as well as their surface chemical reactivity via amino- and carboxyl groups. In order to obtain nanostructures suitable for biomedical applications, the structure, size, shape and surface chemistry of these nanoplatforms must be optimized. These properties depend directly on the nature and sequence of the amino acids that constitute them. It is therefore essential to control the order in which the amino acids are introduced during the synthesis of short peptide chains and to evaluate their in-vitro and in-vivo physico-chemical properties before testing them for biomedical applications. This review therefore focuses on the synthesis, functionalization and characterization of peptide sequences that can self-assemble to form nanostructures. The synthesis in batch or with new continuous flow and microflow techniques will be described and compared in terms of amino acids sequence, purification processes, functionalization or encapsulation of targeting ligands, imaging probes as well as therapeutic molecules. Their chemical and biological characterization will be presented to evaluate their purity, toxicity, biocompatibility and biodistribution, and some therapeutic properties in vitro and in vivo. Finally, their main applications in the biomedical field will be presented so as to highlight their importance and advantages over classical nanostructures.

Prebiotic synthesis of carboxylic acids, amino acids and nucleic acid bases from formamide under photochemical conditions⋆

2017 ◽  
Vol 132 (7) ◽  
Author(s):  
Lorenzo Botta ◽  
Bruno Mattia Bizzarri ◽  
Davide Piccinino ◽  
Teresa Fornaro ◽  
John Robert Brucato ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nucleic Acid ◽  
Carboxylic Acids ◽  
Prebiotic Synthesis ◽  
Nucleic Acid Bases

Coupling of Steroid O-(Carboxymethyl)oxime Derivatives with Amino Alcohols

1996 ◽  
Vol 61 (2) ◽  
pp. 288-297 ◽  
Author(s):  
Vladimír Pouzar ◽  
Ivan Černý
Keyword(s):  
Amino Acids ◽  
Hydroxy Group ◽  
Building Blocks ◽  
Amino Alcohols ◽  
New Approach ◽  
Alternative Synthesis ◽  
Oxime Derivatives ◽  
A Chain ◽  
Derivatives Of

New approach to the preparation of steroids with connecting bridge, based on an O-carboxymethyloxime (CMO) structure, and with terminal hydroxy group, is presented. 17-CMO derivatives of 3β-acetoxy- and 3β-methoxymethoxyandrost-5-en-17-one were condensed with α,ω-amino alcohols to give derivatives with a chain of seven to nine atoms. After THP-protection, these compounds were converted to 3-keto-4-ene derivatives. An alternative synthesis consisted in transformation of 17-CMO derivatives with bonded amino acids by reduction of the terminal carboxyl. The resulting compounds were designed as building blocks for the preparation of bis-haptens for sandwich immunoassays.

scholarly journals An aza-Diels–Alder route to quinoline-based unnatural amino acids and polypeptide surrogates

RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 14132-14139
Author(s):  
M. J. Umerani ◽  
H. Yang ◽  
P. Pratakshya ◽  
J. S. Nowick ◽  
A. A. Gorodetsky
Keyword(s):  
Amino Acids ◽  
Unnatural Amino Acids ◽  
Building Blocks ◽  
Solid Support ◽  
Diels Alder

The synthesis of quinoline-based unnatural amino acids and the subsequent preparation of polypeptide surrogates from these building blocks on solid support.

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