Zur Frage der nicht-enzymatischen Bildung von kondensierten Phosphaten unter präbiotischen Bedingungen/ Non-Enzymatic Formation of Condensed Phosphates under Prebiotic Conditions

1986 ◽  
Vol 41 (7) ◽  
pp. 815-824 ◽  
Author(s):  
F. Seel ◽  
K.-P. Klos ◽  
D. Recktenwald ◽  
J. Schuh
Keyword(s):  
Phosphoric Acid ◽  
Chemical Evolution ◽  
Calcium Phosphates ◽  
Aqueous System ◽  
Hydrothermal Conditions ◽  
Primitive Earth ◽  
Spontaneous Condensation ◽  
Enzymatic Formation ◽  
Condensed Phosphates

AbstractOne of the problems of chemical evolution on the primitive Earth is the question of the possibility of a non-enzymatic spontaneous condensation o f phosphoric acid and hydrogen phosphates to yield polyphosphoric acids and polyphosphates in aqueous system s, by means of which phosphorus might have entered into early metabolisms. The extra- or intra-cellular formation of magnesium diphosphate under geologically plausible hydrothermal conditions from either magnesium hydrogen phosphates or calcium phosphates in media has been demonstrated.

scholarly journals Magnetite Synthesis in the Presence of Cyanide or Thiocyanate under Prebiotic Chemistry Conditions

Life ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 34
Author(s):  
Rafael Block Samulewski ◽  
Josué Martins Gonçalves ◽  
Alexandre Urbano ◽  
Antônio Carlos Saraiva da Costa ◽  
Flávio F. Ivashita ◽  
...  
Keyword(s):  
Prebiotic Chemistry ◽  
Protective Agent ◽  
Ion Composition ◽  
Mineral Formation ◽  
Mechanism Synthesis ◽  
Hydrothermal Conditions ◽  
Primitive Earth ◽  
Ion Interactions ◽  
The Earth ◽  
Prebiotic Earth

Magnetite is an iron oxide mineral component of primitive Earth. It is naturally synthesized in different ways, such as magma cooling as well as olivine decomposition under hydrothermal conditions. It is probable magnetite played a significant role in biogenesis. The seawater used in the current work contained high Mg2+, Ca2+ and SO42− concentrations, unlike the seawater of today that has high Na+ and Cl− concentrations. It is likely that this seawater better resembled the ion composition of the seas of the Earth from 4 billion years ago. Cyanide and thiocyanate were common molecules in prebiotic Earth, and especially in primitive oceans, where they could act on the magnetite mechanism synthesis via Fe2+ interaction. In this research, magnetite samples that were synthesized under prebiotic conditions in the presence of cyanide or thiocyanate, (both with and without artificial seawater), showed that, besides magnetite, goethite and ferrihydrite can be produced through different Fe2+-ion interactions. Cyanide apparently acts as a protective agent for magnetite production; however, thiocyanate and seawater 4.0 Gy ions produced goethite and ferrihydrite at different ratios. These results validate that Fe3+ oxides/hydroxides were possibly present in primitive Earth, even under anoxic conditions or in the absence of UV radiation. In addition, the results show that the composition of water in early oceans should not be neglected in prebiotic chemistry experiments, since this composition directly influences mineral formation.

Insights into structural characteristics and the mechanism of silicate-based calcium phosphates with phosphoric acid modulation

2020 ◽  
Vol 46 (3) ◽  
pp. 3456-3463 ◽  
Author(s):  
Zhengwen Ding ◽  
Qiyi Zhang ◽  
Yanan Wu ◽  
Mizhi Ji ◽  
Hong Chen ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Calcium Phosphates ◽  
Structural Characteristics

scholarly journals The solubility of calcium phosphates in citric acid

1917 ◽  
Vol 8 (3) ◽  
pp. 277-298 ◽  
Author(s):  
A. A. Ramsay
Keyword(s):  
Citric Acid ◽  
Hydrochloric Acid ◽  
Phosphoric Acid ◽  
Calcium Chloride ◽  
Tricalcium Phosphate ◽  
Sodium Phosphate ◽  
Calcium Phosphates ◽  
Bone Ash

The results of these investigations show1. The substances sold as “Phosphate of lime” and “Calcium Phosphas B.P.” are not pure tricalcic phosphate but are mixtures of di- and tricalcic phosphates.2. Sodium phosphate (Na2HPO4) added to ammoniacal calcium chloride and the resulting precipitate washed with water yields a mixture of di- and tricalcic phosphate and calcium hydrate.3. Bone ash dissolved in hydrochloric acid and precipitated with ammonia, the precipitate being well washed, yields also a mixture of di- and tricalcium phosphate and calcium hydrate.4. When three equivalents of lime (3CaO) are made to act on one equivalent of phosphoric acid (P2O5) and the resulting precipitate removed with little delay pure tricalcium phosphate is obtained.

scholarly journals Antibacterial Poly(ε-CL)/Hydroxyapatite Electrospun Fibers Reinforced by Poly(ε-CL)-b-Poly(Ethylene Phosphoric Acid)

2021 ◽  
Vol 22 (14) ◽  
pp. 7690
Author(s):  
Ilya Nifant’ev ◽  
Dmitry Gavrilov ◽  
Alexander Tavtorkin ◽  
Maria Chinova ◽  
Victoria Besprozvannykh ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Wound Dressing ◽  
Bone Repair ◽  
Mechanical Characteristics ◽  
High Efficiency ◽  
Calcium Phosphates ◽  
Close Attention ◽  
Bone Surgery ◽  
Biodegradable Polyesters ◽  
Poly Ethylene

In bone surgery and orthopedics, bioresorbable materials can be helpful in bone repair and countering post-op infections. Explicit antibacterial activity, osteoinductive and osteoconductive effects are essential to achieving this objective. Nonwoven electrospun (ES) fibers are receiving the close attention of physicians as promising materials for wound dressing and tissue engineering; potentially, in high contrast with dense materials, ES mats hamper regeneration of the bone extracellular matrix to a lesser extent. The use of the compositions of inherently biodegradable polyesters (poly(ε-caprolactone) PCL, poly(lactoglycolide), etc.), calcium phosphates and antibiotics is highly prospective, but the task of forming ES fibers from such compositions is complicated by the incompatibility of the main organic and inorganic ingredients, polyesters and calcium phosphates. In the present research we report the synthesis of hydroxyapatite (HAp) nanoparticles with uniform morphology, and demonstrate high efficiency of the block copolymer of PCL and poly(ethylene phosphoric acid) (PEPA) as an efficient compatibilizer for PCL/HAp mixtures that are able to form ES fibers with improved mechanical characteristics. The materials obtained in the presence of vancomycin exhibited incremental drug release against Staphylococcus aureus (St. aureus).

scholarly journals Formation of modified whitlockite-related calcium phosphates under conditions of coprecipitation from aqueous solutions

2021 ◽  
pp. 112-117
Author(s):  
N.Yu. Strutynska ◽  
◽  
M.S. Slobodyanik ◽  
Y.O. Titov ◽  
I.A. Kraievska ◽  
...  
Keyword(s):  
Room Temperature ◽  
Calcium Phosphates ◽  
Aqueous System ◽  
Molar Ratio ◽  
Mass Ratio ◽  
X Ray ◽  
Sodium Cations ◽  
Trigonal System ◽  
Optimized Conditions ◽  
Related Phase

The features of phase formation during wet coprecipitation from aqueous system Сa2+–NO3––Х (Х – NaH2PO4, Na2HPO4, Na3PO4) at the molar ratio Са2+/РО43–=1.6 and room temperature have been investigated. It was found formation of whitlockite-related calcium phosphates (trigonal system, space group R-3c). The results of elemental analysis indicated the chemical modification of calcium phosphates by sodium cations (samples contained 0.3–0.6 wt.% Na+). According to the resulta of thermogravimetry, the synthesized samples contained up to 6 wt.% of sorption water. Heating of samples to the temperature of 6000C is accompanied by water removal and an increase in particle size from 20–50 nm to 500 nm. It was shown that the use of sodium nitrate as a source of sodium cations in the formation of sodium-containing calcium phosphates allows obtaining compositions of whitlockite- and apatite-related phases. The mass ratio of phases can be adjusted by changing the content of sodium cations in the initial solution. The synthesized samples were characterized by X-ray powder diffraction, thermogravimetry, scanning electron microscopy and FTIR spectroscopy methods. Optimized conditions for preparation of whitlockite-related sodium-containing calcium phosphates as well as composites based on them with apatite-related phase can be further used in the development of materials with the required resorption rate for orthopedics.

Sign in / Sign up

Export Citation Format

Share Document