Search results

1

Non-racemic mixture model: a computational approach

100%

Polanco C., Buhse T.

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2017

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vol. 64

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issue 1

17-19

EN

The behavior of a slight chiral bias in favor of l-amino acids over d-amino acids was studied in an evolutionary mathematical model generating mixed chiral peptide hexamers. The simulations aimed to reproduce a very generalized prebiotic scenario involving a specified couple of amino acid enantiomers and a possible asymmetric amplification through autocatalytic peptide self-replication while forming small multimers of a defined length. Our simplified model allowed the observation of a small ascending but not conclusive tendency in the l-amino acid over the d-amino acid profile for the resulting mixed chiral hexamers in computer simulations of 100 peptide generations. This simulation was carried out by changing the chiral bias from 1% to 3%, in three stages of 15, 50 and 100 generations to observe any alteration that could mean a drastic change in behavior. So far, our simulations lead to the assumption that under the exposure of very slight non-racemic conditions, a significant bias between l- and d-amino acids, as present in our biosphere, was unlikely generated under prebiotic conditions if autocatalytic peptide self-replication was the main or the only driving force of chiral auto-amplification.

2

Structural factors influencing the reaction rates of 4-aryloxy-7-nitrobenzofurazans with amino acids

100%

Bem M., Vasilescu M., Caproiu M., Draghici C., Beteringhe A., Constantinescu T., Banciu M., Balaban A.

Open Chemistry

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2004

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vol. 2

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issue 4

672-685

EN

An interesting observation was made when studying the SNAr reaction between several 4-aryloxy-7-nitrobenzofurazans (2) and several amino acids leading to the apparition of detectable fluorescence from the substitution products3. Acidic amino acids reacted very slowly=while basic amino acids react fastest with2 having an unsubstituted phenyl or a 4-formyl-phenyl Ar group. Amongst neutral amino acids, proline reacts fastest at room temperature after 100 min. With2 having a methoxy-subtituted Ar group.

3

DEVELOPMENT OF HYDROGEL CAPSULES FOR USE IN DUAL-PHASE TOPICAL PREPARATIONS CONTAINING DIHYDROXYACETONE AND AMINO ACIDS – PRELIMINARY RESULTS

100%

Jacyna B., Mikolaszek B., Maciejewski B., Cal K.

Acta Poloniae Pharmaceutica - Drug Research

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2019

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vol. 76

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issue 4

715-724

EN

The aim of the following work was a preliminary assessment of the possibility of producing a topical preparation containing dihydroxyacetone (DHA) and amino acids, encapsulated separately in polysaccharide capsules. The colour reaction between the DHA and amino acids would be possible after mixing of the two components triggered with mechanical disruption of the capsules on application. Such preparation could be used in patients suffering from vitiligo, by masking the symptoms of the disease. Several capsule compositions were evaluated in terms of appearance, dimensions and mechanical parameters. In addition, the reactions of various amino acids with DHA were carried out and obtained colours were analysed. The results indicate that formation of the dual-phase formulation of encapsulated DHA and amino acids is possible. It was also found that certain amino acids vary in colour resulting from reaction with DHA. This feature can be potentially utilized to better design the colour resulting from application of the prepared composition.

4

Computational model of abiogenic amino acid condensation to obtain a polar amino acid profile

88%

Polanco C., Buhse T., Samaniego J., Castañón González J., Estrada M.

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2014

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vol. 61

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issue 2

253-258

EN

In accordance with the second law of thermodynamics, the Universe as a whole tends to higher entropy. However, the sequence of far-from-equilibrium events that led to the emergence of life on Earth could have imposed order and complexity during the course of chemical reactions in the so-called primordial soup of life. Hence, we may expect to find characteristic profiles or biases in the prebiotic product mixtures, as for instance among the first amino acids. Seeking to shed light on this hypothesis, we have designed a high performance computer program that simulates the spontaneous formation of the amino acid monomers in closed environments. The program was designed in reference to a prebiotic scenario proposed by Sydney W. Fox. The amino acid abundances and their polarities as the two principal biases were also taken into consideration. We regarded the computational model as exhaustive since 200 000 amino acid dimers were formed by simulation, subsequently expressed in a vector and compared with the corresponding amino acid dimers that were experimentally obtained by Fox. We found a very high similarity between the experimental results and our simulations.

5

Biomass of freshwater Cladophora as a raw material for agriculture and the cosmetic industry

88%

Messyasz B., Leska B., Fabrowska J., Pikosz M., Roj E., Cieslak A., Schroeder G.

Open Chemistry

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2015

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vol. 13

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issue 1

EN

This study was undertaken to determine mineral content, amino acid and fatty acid composition of the freshwater macroalga – Cladophora glomerata. The studies were based on the content comparison in algal biomass collected from a lake and cultured in a laboratory. To determine the ability of copper cumulating by macroalgae, Cladophora was cultured in the medium supplemented with Cu ions. This study indicated that the relative abundance of metals in filaments decreased in the following order: Ca > K > Mg > Na > Fe > Cu > Zn > Pb > As > Ni > Cd > Mn > Cr > Co. Total protein content ranged from 14.45% in Cladophora from a lake to 26.55% in Cladophora from a laboratory. The main amino acids analyzed were aspartic and glutamic acid. The fatty acid content in the dry matter of the extract varied depending on the extraction method used: ethylene alcohol (19.0%), acetone (34.5%) or supercritical fluid extraction (62.5%). Freshwater C. glomerata due to the macrominerals, trace elements, amino and fatty acids composition in the extracts can be a valuable resource for nutritional and cosmetic applications.

6

Studies on carotenoproteins in animals. X. Euphausia superba Dana 1852 (Crustacea, Euphausiacea)

88%

Czeczuga B., Czeczuga B.

Polish Polar Research

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1984

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vol. 5

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issue 1-2

7

Structure and function relationships of proteins based on polar profile: a review

75%

Polanco C., Buhse T., Uversky V.

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2016

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vol. 63

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issue 2

229-233

EN

Proteins in the post-genome era impose diverse research challenges, the main are the understanding of their structure-function mechanism, and the growing need for new pharmaceutical drugs, particularly antibiotics that help clinicians treat the ever- increasing number of Multidrug-Resistant Organisms (MDROs). Although, there is a wide range of mathematical-computational algorithms to satisfy the demand, among them the Quantitative Structure-Activity Relationship algorithms that have shown better performance using a characteristic training data of the property searched; their performance has stagnated regardless of the number of metrics they evaluate and their complexity. This article reviews the characteristics of these metrics, and the need to reconsider the mathematical structure that expresses them, directing their design to a more comprehensive algebraic structure. It also shows how the main function of a protein can be determined by measuring the polarity of its linear sequence, with a high level of accuracy, and how such exhaustive metric stands as a "fingerprint" that can be applied to scan the protein regions to obtain new pharmaceutical drugs, and thus to establish how the singularities led to the specialization of the protein groups known today.

8

Distribution of bacteria, organic carbon and amino acids in the southern part of Drake Passage and in Bransfield Strait during the BIOMASS - SIBEX (December1983 —January 1984)

75%

Zdanowski M. K., Zdanowski M. K.

Polish Polar Research

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1985

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vol. 6

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issue 1-2

9

A toy model of prebiotic peptide evolution: the possible role of relative amino acid abundances

75%

Polanco C., Buhse T., Samaniego J. L., González J. A. C.

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2013

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vol. 60

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issue 2

175-182

EN

This paper presents a mathematical-computational toy model based on the assumed dynamic principles of prebiotic peptide evolution. Starting from a pool of amino acid monomers, the model describes in a generalized manner the generation of peptides and their sequential information. The model integrates the intrinsic and dynamic key elements of the initiation of biopolymerization, such as the relative amino acid abundances and polarities, as well as the oligomer reversibility, i.e. fragmentation and recombination, and peptide self-replication. Our modeling results suggest that the relative amino acid abundances, as indicated by Miller-Urey type electric discharge experiments, played a principal role in the early sequential information of peptide profiles. Moreover, the computed profiles display an astonishing similarity to peptide profiles observed in so-called biological common ancestors found in the following three microorganisms; E. coli, M. jannaschii, and S. cereviasiae. The prebiotic peptide fingerprint was obtained by the so-called polarity index method that was earlier reported as a tool for the identification of cationic amphipathic antibacterial short peptides.

10

Promotory wchłaniania wapnia

45%

Dolińska B., Mikulska A., Ryszka F.

Annales Academiae Medicae Silesiensis

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2009

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vol. 63

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issue 1

76-83

EN

The inappropriate supply of calcium influences bone loss and the risk of the osteoporosis. Health benefits expected from calcium depend on the amount of consumed calcium and also are strongly dependent on the possibility of organism to absorb calcium. Many studies devoted to this topic do not consider the absorbed calcium amount indeed which on average gives 10-75% of total calcium consumed. In order to make calcium absorption higher and more effective, researchers still conduct an investigation concerned with the factors enhancing calcium absorption and not having any negative influence on excretion of this element. The following can be rated among such substances: vitamin D, magnesium, inulin and other indigestible oligosaccharides, some amino acids, short-chain fatty acids, lactose, casein, phosvitin.

PL

Nieodpowiednia podaż wapnia wpływa na utratę masy kostnej oraz ryzyko wystąpienia osteoporozy. Zdrowotne korzyści oczekiwane od wapnia zależą nie tylko od ilości spożywanego wapnia, ale również są bardzo silnie zależne od możliwości organizmu do wchłaniania przyjętego wapnia. Wiele badań poświęconych temu tematowi nie rozważa ilości wapnia rzeczywiście wchłanianego, która nigdy nie wynosi 100%, a waha się w granicach 10-75% w zależności od wieku i stanu zdrowia. Aby wchłanianie wapnia było jak najefektywniejsze poszukuje się substancji zwiększających absorpcję wapnia w przewodzie pokarmowym, a ponadto nie wpływających negatywnie na jego wydalanie. Do takich substancji można obecnie zaliczyć: witaminę D, magnez, inulinę i inneniestrawne sacharydy, niektóre aminokwasy, krótkołańcuchowe kwasy tłuszczowe, laktozę, fosfopeptydy kazeiny i foswityny.

Refine search results

Non-racemic mixture model: a computational approach

Structural factors influencing the reaction rates of 4-aryloxy-7-nitrobenzofurazans with amino acids

DEVELOPMENT OF HYDROGEL CAPSULES FOR USE IN DUAL-PHASE TOPICAL PREPARATIONS CONTAINING DIHYDROXYACETONE AND AMINO ACIDS – PRELIMINARY RESULTS

Computational model of abiogenic amino acid condensation to obtain a polar amino acid profile

Biomass of freshwater Cladophora as a raw material for agriculture and the cosmetic industry

Studies on carotenoproteins in animals. X. Euphausia superba Dana 1852 (Crustacea, Euphausiacea)

Structure and function relationships of proteins based on polar profile: a review

Distribution of bacteria, organic carbon and amino acids in the southern part of Drake Passage and in Bransfield Strait during the BIOMASS - SIBEX (December1983 —January 1984)

A toy model of prebiotic peptide evolution: the possible role of relative amino acid abundances

Promotory wchłaniania wapnia