Intramolecular functional group differentiation as a strategy for the synthesis of bridged bicyclic β-amino acids

RSC Advances ◽  
2016 ◽  
Vol 6 (27) ◽  
pp. 22737-22748 ◽  
Author(s):  
Andriy V. Tymtsunik ◽  
Serhii O. Kokhan ◽  
Yevhen M. Ivon ◽  
Igor V. Komarov ◽  
Oleksandr O. Grygorenko
Keyword(s):  
Amino Acids ◽  
Functional Groups ◽  
Functional Group ◽  
Amino Group ◽  
Group Differentiation

Differentiation of identical electrophilic functional groups (carboxylates) by a strategically placed internal nucleophile (an amino group) in cyclic precursors was used as a key general approach to functionalized azabicyclic scaffolds.

scholarly journals Natural Products Containing ‘Rare’ Organophosphorus Functional Groups

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 866 ◽  
Author(s):  
Janusz Petkowski ◽  
William Bains ◽  
Sara Seager
Keyword(s):  
Amino Acids ◽  
Natural Products ◽  
Functional Groups ◽  
Functional Group ◽  
Organophosphorus Compounds ◽  
Living Cells ◽  
Unusual Amino Acids ◽  
Biological Source ◽  
Technological Limitations

Phosphorous-containing molecules are essential constituents of all living cells. While the phosphate functional group is very common in small molecule natural products, nucleic acids, and as chemical modification in protein and peptides, phosphorous can form P–N (phosphoramidate), P–S (phosphorothioate), and P–C (e.g., phosphonate and phosphinate) linkages. While rare, these moieties play critical roles in many processes and in all forms of life. In this review we thoroughly categorize P–N, P–S, and P–C natural organophosphorus compounds. Information on biological source, biological activity, and biosynthesis is included, if known. This review also summarizes the role of phosphorylation on unusual amino acids in proteins (N- and S-phosphorylation) and reviews the natural phosphorothioate (P–S) and phosphoramidate (P–N) modifications of DNA and nucleotides with an emphasis on their role in the metabolism of the cell. We challenge the commonly held notion that nonphosphate organophosphorus functional groups are an oddity of biochemistry, with no central role in the metabolism of the cell. We postulate that the extent of utilization of some phosphorus groups by life, especially those containing P–N bonds, is likely severely underestimated and has been largely overlooked, mainly due to the technological limitations in their detection and analysis.

Effect of functional groups on sensitization of dye-sensitized solar cells (DSSCs) using free base porphyrins

2017 ◽  
Vol 21 (03) ◽  
pp. 222-230 ◽  
Author(s):  
Nivedita Chaudhri ◽  
Nipun Sawhney ◽  
Bijjam Madhusudhan ◽  
Anubhav Raghav ◽  
Muniappan Sankar ◽  
...  
Keyword(s):  
Solar Cells ◽  
Functional Groups ◽  
Functional Group ◽  
Power Conversion ◽  
Dye Sensitized Solar Cells ◽  
Amino Group ◽  
Free Base ◽  
Dye Sensitized ◽  
Conversion Efficiencies ◽  
Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) were fabricated with six meso-substituted A[Formula: see text]B and A[Formula: see text] free base porphyrin dyes having different functional groups, as sensitizers. The two step synthesis and the effect of different functional groups and their positions on the photosensitization properties of these porphyrin dyes are reported. The highest power conversion efficiencies ([Formula: see text] of 3.26%, 2.94% and 2.84% were achieved for the DSSC fabricated using 5,10,15-tris(4[Formula: see text]-pyridyl)-20-(4[Formula: see text]-carboxyphenyl)porphyrin (H[Formula: see text]TriPyMCPP), 5,10,15,20-tetrakis(4[Formula: see text]-aminophenyl)porphyrin (H[Formula: see text]TAPP) and 5-(4[Formula: see text]-pyridyl)-10,15,20-tris(4[Formula: see text]-carboxyphenyl)porphyrin (H[Formula: see text]MPyTriCPP) dyes, respectively. The electron donating amino group is shown to enhance the power conversion efficiency while pyridyl appended porphyrin sensitizers are shown to be superior sensitizers as compared to carboxyphenylporphyrins. The investigation of effect of functional group and position of functional group of porphyrin dye on DSSC can serve as an important tool to guide further selection and synthesis of potential candidates as sensitizers.

scholarly journals Versatile synthesis of amino acid functionalized nucleosides via a domino carboxamidation reaction

2014 ◽  
Vol 10 ◽  
pp. 2566-2572 ◽  
Author(s):  
Vicky Gheerardijn ◽  
Jos Van den Begin ◽  
Annemieke Madder
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nucleic Acid ◽  
Functional Groups ◽  
Functional Group ◽  
Binding Properties ◽  
Dna And Rna ◽  
Straightforward Method ◽  
Nucleic Acid Structures ◽  
Proof Of Principle

Functionalized oligonucleotides have recently gained increased attention for incorporation in modified nucleic acid structures both for the design of aptamers with enhanced binding properties as well as the construction of catalytic DNA and RNA. As a shortcut alternative to the incorporation of multiple modified residues, each bearing one extra functional group, we present here a straightforward method for direct linking of functionalized amino acids to the nucleoside base, thus equipping the nucleoside with two extra functionalities at once. As a proof of principle, we have introduced three amino acids with functional groups frequently used as key-intermediates in DNA- and RNAzymes via an efficient and straightforward domino carboxamidation reaction.

scholarly journals Resilience of Epiphytic Lichens to Combined Effects of Increasing Nitrogen and Solar Radiation

2021 ◽  
Vol 7 (5) ◽  
pp. 333
Author(s):  
Lourdes Morillas ◽  
Javier Roales ◽  
Cristina Cruz ◽  
Silvana Munzi
Keyword(s):  
Global Change ◽  
Solar Radiation ◽  
Functional Groups ◽  
Physiological Response ◽  
Functional Group ◽  
Environmental Drivers ◽  
Combined Effects ◽  
Environmental Stressor ◽  
Comprehensive Understanding ◽  
Direct Sunlight

Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution’s effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems.

The potential mechanism of atmospheric new particle formation involving amino acids with multiple functional groups

2021 ◽  
Author(s):  
Jiarong Liu ◽  
Ling Liu ◽  
Hui Rong ◽  
Xiuhui Zhang
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Functional Groups ◽  
Atmospheric Aerosols ◽  
Potential Role ◽  
Particle Formation ◽  
Potential Mechanism ◽  
New Particle Formation

Amino acids are recognized as significant components of atmospheric aerosols. However, its potential role in the atmospheric new particle formation (NPF) is poorly understood, especially aspartic acid (ASP), one of...

Vanadocene complexes of amino acids bearing functional group in the side chain

2013 ◽  
Vol 405 ◽  
pp. 121-127 ◽  
Author(s):  
Jaromír Vinklárek ◽  
Jan Honzíček ◽  
Milan Erben ◽  
Iva Klepalová ◽  
Aleš Eisner ◽  
...  
Keyword(s):  
Amino Acids ◽  
Functional Group ◽  
Side Chain

Special transport and neurological significance of two amino acids in a configuration conventionally designated as D.

1994 ◽  
Vol 196 (1) ◽  
pp. 297-305 ◽  
Author(s):  
H N Christensen ◽  
A A Greene ◽  
D K Kakuda ◽  
C L MacLeod
Keyword(s):  
Amino Acids ◽  
Receptor Site ◽  
Amino Group ◽  
Carboxylate Group ◽  
Gamma Aminobutyric Acid ◽  
Imino Group ◽  
Group A ◽  
The Central Nervous System ◽  
Lower Homolog ◽  
Alpha Amino Acid

We point out an ability of certain amino acids to be recognized at a biological receptor site as though their amino group bore, instead of an alpha relationship to a carboxylate group, a beta, gamma or delta relationship to the same or a second carboxylate group. For aspartate, the unbalanced position of its amino group between a pair of carboxylates allows its occasional biorecognition as a beta-rather than as an alpha-amino acid, whereas for proline and its homologs, their cyclic arrangement may allow the imino group, without its being replicated, to be sensed analogously as falling at either of two distances from the single carboxylate group. The greater separation might allow proline to be seen as biologically analogous to gamma-aminobutyric acid. This more remote positioning of the imino group would allow the D-form of both amino acids to present its amino group in the orientation characteristic of the natural L-form. The dual modes of recognition should accordingly be signalled by what appears to be low stereospecificity, actually due to a distinction in the enantiorecognition of the two isomers. Competing recognition for transport between their respective D- and L-forms, although it does not prove that phenomenon, has been shown for proline and, significantly, even more strongly for its lower homolog, 2-azetidine carboxylate. Such indications have so far revealed themselves rather inconspicuously for the central nervous system binding of proline, reviewed here as a possible feature of a role suspected for proline in neurotransmission.

scholarly journals Food Additives Frequency in processed baby products in Cochabamba, Bolivia

2021 ◽  
Vol 17 (Especial) ◽  
pp. 19-27
Author(s):  
Nelcy Aguilar Sasari ◽  
Milenka Alessandra Fernández Ledezma ◽  
Tania Araujo-Burgos
Keyword(s):  
Shelf Life ◽  
Functional Groups ◽  
Frequency Analysis ◽  
Metropolitan Area ◽  
Sodium Nitrate ◽  
Functional Group ◽  
Food Additives ◽  
Processed Food ◽  
Food Labels ◽  
Organoleptic Properties

Additives are necessary substances to improve the nutritional and organoleptic properties and the shelf life of processed food. In addition, their use is regulated, and it must be declared on the food labels. Thus, the objective of this research was to determine the frequency of food additives in processed baby products in Cochabamba metropolitan area (Bolivia). Data were collected by label reading and a frequency analysis was performed by additives and by functional group. 26 baby products were found where 41 food additives were identified with an occurrence of 256 times, and a mean of 9,8 additives per product. Moreover, the functional groups most widely used are antioxidants and colorants. Finally, the most frequent additives are mostly harmless, except for sodium nitrate and copper sulfate.

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