A new humic acid remedy with addition of silver nanoparticles

Alexandrova, G. P.; Dolmaa, G.; Enkhbadral, E; Grishenko, GL; Цэрэнпил, Ш; Сухов, Б. Г.; Regdel, D.; Trofimov, B. A.

doi:10.5564/mjc.v13i0.151

Cited by 5 publications

(4 citation statements)

References 7 publications

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“…In both lakes the sapropel sediments are organic sapropel with lower mineral content and with lover pH values. It is reported in [18], [19] that not only the color of sapropel sediments can vary, but also the color of extracted HS can be different, indicating the degree of humification and HA and FA concentration in the extracts. Color of extracts was from light yellow to dark brow.…”

Section: B Sapropel Extractmentioning

confidence: 99%

Extraction of Biologically Active Components From Freshwater Sapropel

Kļaviņa

Auce

Vanadziņš

et al. 2019

ETR

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Sapropel has been used for different purposes - in agriculture as fertilizer, in construction as building material, in cosmetic products, in balneology also in medicine and pharmaceuticals as bioactive component. Previously sapropel has been commonly used in raw form and there is no general accepted method or standard method for obtaining sapropel extract. However, most extraction methods follow the same path. Currently, there are few extraction methods using several extractants for obtaining bioactive components from raw sapropel. The most commonly used extractant is alkaline solution. When sapropel is subjected to alkaline environment, the humic and fulvic acids, together with some lipids, vitamins and sugar, present in the raw sapropel become soluble, however other organic and mineral content present in the sapropel remain solid. Alkaline extraction is followed by filtration and water present in the aqueous mixture is evaporated off. Latvian freshwater sapropel can be used as raw material for obtaining sapropel extract and use it as remedy. But the main question for sapropel usage in medicine, balneology and pharmacy is to develop quality criteria for raw sapropel and its extracts. The quality criteria should include minimum requirements for biologically active substance concentration, pH values, antioxidants as well as physical characteristics. In future studies the differences in extract characteristics of the various deposit sites, as well as the stability of the extracts under different storage conditions should be defined; also, there is need for a common approach to develop method of extraction process for active substances from sapropel and analysis procedures of its extract.

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Section: B Sapropel Extractmentioning

confidence: 99%

Extraction of Biologically Active Components From Freshwater Sapropel

Kļaviņa

Auce

Vanadziņš

et al. 2019

ETR

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“…They can also cause enzyme function disruption and DNA damage in bacteria, which ultimately leads to bacterial death [ 13 , 14 , 15 , 16 , 17 ]. There is a number of publications that show that HSs can be successfully used to reduce and stabilise silver NPs [ 18 , 19 , 20 , 21 , 22 , 23 ]. All reported studies used different sources and fractions of HSs.…”

Section: Introductionmentioning

confidence: 99%

“…All reported studies used different sources and fractions of HSs. Alexandrova et al [ 21 , 22 ] used coal HAs, mud Has, and shale HAs; Sal’nikov et al [ 20 ] used peat FAs; and Litvin et al [ 18 , 19 ] used artificial FAs. Our recent publication also presented screening results for a set of humic materials from different sources and fractional composition [ 23 ].…”

Section: Introductionmentioning

confidence: 99%

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Humic Polyelectrolytes Facilitate Rapid Microwave Synthesis of Silver Nanoparticles Suitable for Wound-Healing Applications

Zhang,

Larionov,

Zhang

et al. 2024

Polymers

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This article describes the one-pot microwave synthesis of silver nanoparticles (AgNPs) assisted with natural polyelectrolytes—humic substances (HS). The humic polyelectrolytes served both as chemical reductants for silver ions and as end-capping agents for AgNPs. Three commercially available sodium humates extracted from lignites and leonardite and one sodium fulvate isolated from natural brown water seeped through peat deposits were used in this study. The dynamics of the growth rate of AgNPs was characterised by UV–VIS spectroscopy by measuring the intensity of surface plasmon resonance at 420 nm. Transmission electron microscopy was used to characterise the size and morphology of AgNPs. Dynamic light scattering was used to determine size distributions of the synthesised AgNPs in the solutions. It was established that both conventional and microwave syntheses assisted with the coal humates produced small-size AgNPs in the range from 4 to 14 nm, with the maximum share of particles with sizes of (6 ± 2) nm by TEM estimates. The peat fulvate yielded much larger NPs with sizes from 10 to 50 nm by TEM estimates. DLS measurements revealed multimodal distributions of AgNPs stabilised with HS, which included both single NPs with the sizes from 5 to 15 nm, as well as their dominating aggregates with sizes from 20 to 200 nm and a smaller portion of extra-large aggregates up to 1000 nm. The given aggregates were loosely bound by humic polyelectrolyte, which prevented the coalescence of AgNPs into larger particles, as can be seen in the TEM images. The significant acceleration in the reaction time—a factor of 60 to 70—was achieved with the use of MW irradiation: from 240 min down to 210–240 s. The coal humate stabilised AgNPs showed antimicrobial properties in relation to S. aureus. A conclusion was made regarding the substantial advantages of microwave synthesis in the context of time and scaling up for the large-scale production of AgNP-HS preparations with antimicrobial properties suitable for external wound-healing applications.

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