Fractionation of sediment phosphate with chelating compounds: a simplification, and comparison with other methods

Hydrobiologia ◽  
1996 ◽  
Vol 335 (1) ◽  
pp. 87-95 ◽  
Author(s):  
H. L. Golterman
Keyword(s):  
Sediment Phosphate ◽  
Chelating Compounds

Change of quality indexes of premixes in the storage process

2020 ◽  
pp. 105-112
Author(s):  
Oksana Bitlian ◽  
Oksana Kravchenko ◽  
Tetiana Kodak ◽  
Andrii Onyshchenko ◽  
Tetiana Konks
Keyword(s):  
Raw Materials ◽  
Storage Process ◽  
Important Place ◽  
Inappropriate Use ◽  
Chemical Structures ◽  
Copper Zinc ◽  
Qualitative Responses ◽  
Chelating Compounds ◽  
Quality Indexes

The analysis of literature sources shows that the type and material from which the packaging is made has an important place in the system of factors which influence on the storage of feed products and also prevents reducing the quality of raw materials and finished products. Therefore, the purpose of our research is the technological justification of changing the quality indexes of premix samples with salts of trace elements of different chemical nature in the process of storage. For the solution of the tasks, common zootechnical and statistical methods of the research were used. The use of premixes in feeding pigs is based on the fact that they should be used taking into account the biogeochemical properties of the region for which they are calculated. Foods depending on regional properties have a special biochemical composition and excess or lack of individual substances should be offset by the composition of premix. Ignoring this provision necessarily leads to the inappropriate use of BAR, the misbalance of the diet in relation to the physiological needs and inefficiency of the industry. In turn, it requires the purchase and conservation of products for the period of use. Various chemical structures and structures of BAR during the storage process react differently and change qualitative indexes, which leads to a decrease in the productive activity of active substances. It was determined that the humidity of premixes varied within the limits of 12.0-13.0 %, which exceeded the normative, but was not critical, the highest acidity had premix with sulfuric acid salts (6.9 units), the least - premix with lysates (5.7 unit). According to the results of the study, positive qualitative responses were found for the presence of vitamins A, D and B2, macro- and micronutrients: potassium, magnesium, copper, zinc, cobalt, iodine. The above facts of changes in the properties of premixes in the process of storage must be taken into account when providing technological bases for feeding pigs in order to obtain high gains and the quality of manufactured products. Key words: premix, micro-and macro elements, combined fodders, fodder mixes, chelating compounds, feeding, using, pigs' livestock.

Production of Metal-Chelating Compounds by Species of Heterobasidion annosum sensu lato

2013 ◽  
Vol 161 (11-12) ◽  
pp. 791-799 ◽  
Author(s):  
Joanna Mucha ◽  
Marzenna Guzicka ◽  
Piotr Łakomy ◽  
Marcin Zadworny
Keyword(s):  
Heterobasidion Annosum ◽  
Metal Chelating ◽  
Chelating Compounds

Antistatic additives for petroleum products based on chelating compounds

1969 ◽  
Vol 5 (12) ◽  
pp. 873-876
Author(s):  
Ya. M. Paushkin ◽  
T. P. Vishnyakova ◽  
I. D. Vlasova ◽  
I. F. Krylov ◽  
F. F. Machus
Keyword(s):  
Petroleum Products ◽  
Antistatic Additives ◽  
Chelating Compounds

scholarly journals Peningkatan Mutu Minyak Nilam (Pogostemon cablin) dalam Proses Pemurnian Minyak Nilam Aceh Jaya dan Aceh Selatan dengan Metode Kompleksometri

2019 ◽  
Vol 4 (4) ◽  
pp. 310-318
Author(s):  
Rahmat Akbar Manalu ◽  
Anshar Patria ◽  
Syarifah Rohaya
Keyword(s):  
Refractive Index ◽  
Citric Acid ◽  
Block Design ◽  
Chemical Purification ◽  
Purification Method ◽  
Fe Content ◽  
Pogostemon Cablin ◽  
Two Factors ◽  
D Region ◽  
Chelating Compounds

Abstrak : Pemurnian merupaakan proses penghilangan bahan-bahan yang tidak diinginkan dari minyak nilam hasil penyulingan. Metode pemurnian terbagi atas dua cara yaitu pemurnian secara kimia dan pemurnian secara fisik. Pengkelatan atau kompleksometri adaalah pengikatan logaam dengan cara menambbahkan senyawa pengkelat dan memmbentuk komplek logam senyawa pengkeelat. Proses pengkelat metode sama dengan adsorben, akan tetapi senyawa adsorben diganti dengan senyawa pengkelat. Senyawa pengkelat yang cukup dikenal dalam proses pemurnian minyak atsiri antara lain EDTA, asam sitratt, asam mallat, dan asam tartarrat. Peneliitian ini menggunakaan rancangan acaak kelomppok (RAK) faktorial yang terrdiri dari 2 fakktor. Faktor pertama yaitu asal daerah minyak nilam yang terdiri dari 2 taraf (D1=Aceh Selatan dan D2=Aceh Jaya). Faktor kedua yaitu konsentrasi senyawa EDTA yang terdiri dari 3 taraf (H1=1,5%, H2=2% dan H3=2,5%). Faktor asal daerah minyak nilam (D) berpengaruh ssangat nyataa terhadap nilai bobot jenis dan indeks bias juga berpengaruh nyata terhadap bilangan asam. Senyawa EDTA dapat menurunkan kadar Fe pada minyak nilam sebesar 34,8-38,0 %.Abstract : Purification is the process of removing undesirable materials from distilled patchouli oil. The purification method is divided into two ways, that is chemical purification and physical purification. Corrosion or complexometric is binding of metal by adding chelating compounds and making a metal complex of chelating compound. Chelating process is same as the adsorbent, but the adsorbent compound is replaced with chelating composition. Chelating compounds that are well known in the process of refining essential oils include EDTA, citric acid, malic acid, and tartaric acid. This sstudy used a Randoized Block Design (RDB) factorial consisting two factors. The first factor is the origin of patchouli oil which consists of 2 levels (D1 = South Aceh and D2 = Aceh Jaya). The second factor is the composition of EDTA which consists of 3 levels (H1 = 1.5%, H2 = 2% and H3 = 2.5%). Factors from patchouli oil (D) region have a very significant effect on the value of density and the refractive index also has a significant effect on acid numbers. EDTA compounds can reduce Fe content in patchouli oil by 34.8-38.0%.

scholarly journals Irreversible Inhibition of BoNT/A Protease: Unique Warhead Reactivity and Function Contingent upon a Bifunctional Approach

2021 ◽  
Author(s):  
Lewis Turner ◽  
Alexander Lund Nielsen ◽  
Lucy Lin ◽  
Sabine Pellett ◽  
Takashi Sugane ◽  
...  
Keyword(s):  
Enzyme Kinetics ◽  
Therapeutic Potential ◽  
Covalent Bond ◽  
Pharmacological Properties ◽  
Irreversible Inhibition ◽  
And Function ◽  
Chelating Compounds

We describe a comprehensive screening campaign of warheads, linked to a hydroxamate chelating anchor, for the modification of Cys165 within the BoNT/A protease. <div>Engaging thorough enzyme kinetics, we detail a remarkable proximity-driven covalent bond with an epoxide warhead, a weak electrophile; yet, one that possessed superior irreversible inhibition, and pharmacological properties, when compared to intrinsically higher reactive warheads. This directed, selective covalent bond was contingent upon the crucial hydroxamate-Zn<sup>2+ </sup>chelating interaction as exemplified by examining non-chelating compounds. </div><div>We discuss previous approaches using non-target selective cysteine-reactive warheads to modify the BoNT/A protease of which none present any therapeutic potential – our bifunctional strategy allows the use of intrinsically less reactive warheads to intercept the cysteine, which will allow for less off-target modifications of such inhibitors. Moreover, we also broach that this bifunctional approach is not a one-off strategy that we believe can be broadly translated to other metalloproteases that possess non-catalytic, yet, nucleophilic residues within the enzymes catalytic sphere. </div>

Sunlight exposure caused yellowing and increased mineral content in wool

2010 ◽  
Vol 50 (4) ◽  
pp. 300 ◽  
Author(s):  
M. R. Fleet ◽  
K. R. Millington ◽  
A. L. King
Keyword(s):  
Trace Metals ◽  
Ultraviolet Light ◽  
Mineral Content ◽  
Kojic Acid ◽  
Sunlight Exposure ◽  
Aqueous Alcohol ◽  
Mineral Contents ◽  
Base Level ◽  
Copper Chelator ◽  
Chelating Compounds

This study determines how levels of various trace metals in wool and the colour of the fibre change as a result of sunlight exposure and treatment with chelating compounds during wool growth. Twenty-four yearling Merino sheep were clipped on the shoulders and rumps and fitted with sheep coats modified with transparent patches. Patches over the shoulder wool (one per sheep) were either polyethylene (PE) that transmits ultraviolet light or polyvinyl chloride (PVC) that excludes ultraviolet light. The rump wool on each sheep was treated either with a copper chelator treatment (kojic acid or methyl gentisate in aqueous alcohol) or aqueous alcohol only. For 12 of the sheep the rumps were exposed to sunlight through PE patches while rump wool on the other sheep was covered by the sheep coat. Wool was harvested after 11 weeks’ growth with yellowness (Y-Z) and individual mineral contents measured using the same clean wool sample. Sunlight exposure through PE patches caused a mean increase in Y-Z to 9.1 (shoulder) or 9.5–10.1 (rump) from a base level of 7.1–7.2 (shoulder) or 7.0–7.6 (rump) in wool protected by the sheep coat. In contrast, there was no significant change in Y-Z for the PVC patch (shoulder). Therefore, it appears that ultraviolet light damage caused the increased Y-Z. Most of the trace metals analysed increased in the shoulder wool exposed to sunlight but the paired differences for PVC were lower than PE. It appears that changes in fibre caused by sunlight exposure (especially ultraviolet light) facilitate adsorption of minerals from the environment, including the animal’s own suint. Application of the chelating compounds to the rump wool caused pronounced yellowing of the wool with Y-Z increase being most pronounced for kojic acid. Copper levels in the wool were reduced by kojic acid and methyl gentisate while calcium levels were increased by kojic acid and reduced by methyl gentisate. It is not clear from these findings whether minerals and copper in particular contribute to yellowing of wool. However, the different effects of sunlight and chelation on mineral contents in wool shown may well relate to alternative mechanisms of discoloration (i.e. photoyellowing versus bacterial).

scholarly journals The effect of N-alkyl modification on the antimalarial activity of 3- hydroxypyridin-4-one oral iron chelators

Blood ◽  
1991 ◽  
Vol 77 (3) ◽  
pp. 637-643 ◽  
Author(s):  
C Hershko ◽  
EN Theanacho ◽  
DT Spira ◽  
HH Peter ◽  
P Dobbin ◽  
...  
Keyword(s):  
Antimalarial Activity ◽  
Iron Chelators ◽  
Lipid Solubility ◽  
Lipophilic Compounds ◽  
Labile Iron Pool ◽  
Ring Nitrogen ◽  
Iron Pool ◽  
Chelating Compounds

Abstract The antimalaria effect of iron chelators is attributed to their interaction with a labile iron pool within parasitised erythrocytes, and it was postulated that increased affinity to iron as well as increased lipophilicity may improve antimalarial activity. In the present study we have examined the antimalarial effect of 3- hydroxypyridin-4-ones, a family of bidentate orally effective iron chelators whose lipophilicity may be modified by altering the length of the R2 substituent on the ring nitrogen. A significant dose-related suppression of Plasmodium falciparum cultures was observed with all drugs tested in vitro at concentrations of 5 mumol/L or higher. In contrast, there was a clear segregation of the in vivo effect on P berghei in rats (300 mg/kg/d subcutaneous) into two categories: compounds CP20, 38, and 40 failed to suppress malaria, whereas CP51, 94, and 96 had a strong antimalarial effect, similar or better than deferoxamine. There was a close linear correlation between the suppression of peak parasite counts and the reduction in hepatic nonheme iron induced by the various drugs tested (r = .9837). The most lipophilic compounds were also the most effective in suppressing malaria and in depleting hepatic iron stores. These data indicate that 3-hydroxypyrydin-4-ones are able to suppress malaria in vivo and in vitro. Because lipid solubility is an important determinant of antimalarial action, our study provides useful information regarding the selection of orally effective iron-chelating compounds that may be suitable for clinical application as antimalarial agents.

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