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The iron chelating molecule, ethylenediaminetetraacetic acid (EDTA) is used in food applications for the preservation of oxidation prone ingredients. Research has suggested that EDTA is also capable of enhancing the antimicrobial effectiveness of various compounds including naturally-derived antimicrobials. With consumer demand for cleaner food labels, there remains an opportunity to introduce new chelating technology to replace synthetically-derived EDTA. Through photographting and chemical conversion, hydroxamic acid ligands were covalently bound to polypropylene films resulting in polypropylene-graft-poly(hydroxamic acid) (PP-g-PHA). The resulting films demonstrated an ability to chelate 64 nmol/cm2 from an iron saturated environment or 163 nmol/cm2 of magnesium and 139 nmol/cm2 of calcium from bacterial growth media. A surface pKa of 8.97 suggested that film ligands should remain protonated under acidic and neutral pH conditions. When combined with lysozyme, PP-g-PHA films were able to reduce inhibitory concentration of lysozyme for Listeria monocytogenes by half. When tested against Bacillus cereus, Pseudomonas fluorescens, and E. coli O157:H7; PP-g-PHA films were unable to inhibit growth and showed little enhancement of lysozyme. EDTA controls revealed that similar levels of soluble chelator were more effective than immobilized chelators. EDTA results also suggested that a chelating film with a higher affinity for iron (through coordination or ligand stability) may be able to control B. cereus growth. Both EDTA and PP-g-PHA caused P. fluorescens to produce siderophores (pyoerdines), suggesting that each treatment resulted in a low-iron growth environment. These findings suggest that surface bound chelating technology can affect the growth of L. monocytogenes and enhance the effectiveness of lysozyme. With improved surface chemistry (a higher binding constant with iron), this technology has the potential to influence the growth of other pathogens and spoilage microorganisms.

Foram preparados complexos de 2,2--sulfinildietanol (sde) com alguns percloratos e cloretos de metais bivalentes. Os percloratos apresentam a formula geral [M(sde) 2] (C10 4 ) 2 , em que M= Mn, Co, Ni, Cu e Zn, e [M(sde) 3] (C10 4 )2 , em que M= Co e Fe. São cristalinos e muito higroscópicos. Os diagramas de difração de raios-X sugerem que os dois complexos [M(sde) 3] (C10 4 ) 2 são isomorfos. Na série [M(sde)2 ] (C10 4 ) 2 , somente os compostos de cobalto e níquel deram diagramas semelhantes. Os espectros vibracionais são muito difíceis de interpretar. Conclusões inequívocas a respeito da posição da vibração de estiramento S = 0 não puderam ser obtidas. A análise dos espectros sugere que: a) os íons perclorato não se acham coordenados, b) ambos os grupos hidroxila do ligante estão coordenados ao metal nos complexos [M(sde) 2 ] (C10 4 ) 2 , e c) somente um grupo hidroxila está coordenado nos complexos [M(sde) 3 ] (C104)2. As condutâncias molares dos complexos em solução em nitrometano e acetonitrila indicam comportamento de eletrólitos 1:2. As massas moleculares aparentes dos complexos dissolvi dos em acetonitrila dependem da concentração. Isto pode ser explica do como resultante de uma ligeira dissociacão em soluções diluídas e da formação de pares iônicos em concentrações maiores. Os momentos magnéticos dos complexos estão dentro dos intervalos esperados para complexos octaédricos de spin alto. Os espectros eletrônicos dos complexos de ferro, cobalto e níquel são também característicos de espécies de spin alto com simetria Oh. A partir dos espectros de absorção eletrônica dos complexos de cobalto e níquel, foram calculados os parâmetros de campo ligante Dq e &#946;. 0 ligante 2,2- -sulfinildietanol fornece valores maiores de Dq do que os sulfóxidos e álcoois monodentados. Isto pode ser atribuído ao efeito quelato. Os valores de Dq dos complexos de cobalto indicam que o 2,2--sulfinildietanol atua como um ligante tridentado no complexo [Co(sde)<SUB2](C104 )2 e como bidentado no complexo [Co(sde)3] (C104)2. Foram também obtidos os complexos de cloretos apresentando as estequiometrias CoC12.2H20.sde, CoC12.sde e PdC12.sde. Os espectros de absorção no infravermelho indicam que o sde se liga pelo oxigênio nos complexos com CoC12 e pelo enxofre no complexo com PdC12. Uma estrutura binuclear com pontes de cloreto é sugerida para o complexo de paládio, com base em seu espectro infravermelho longínquo. A condutância molar deste composto em nitrometano e acetonitrila mostra que ele não é iônico. O comportamento dos complexos de cloreto de cobalto em solução em acetonitrila a tentativamente explicado com base na formação do ânion tetraédrico tetraclorocobaltato(II) e um cátion contendo cobalto(II) octaedricamente coordenado. / 2,2\' -sulfinyldiethanol (sde) complexes of some divalent metal perchlorates and chlorides were prepared. The perchlorates have the general formula [M(sde)2] (C104)2 , where M = Mn, Co, Ni, Cu and Zn, and [M(sde)3] (C104)2, where M = Co and Fe. They are crystalline and very hygroscopic. X- ray diffraction patterns suggest that the two complexes [M(sde)3] (C104)2 are isomorphous. In the [M(sde)2] (C104)2 series only cobalt and nickel compounds gave similar patterns.The vibrational spectra are very difficult to interpret. Unequivocal conclusions regarding the position of S = 0 stretching vibration could not be drawn. An analysis of the spectra does suggest that: a) the perchlorate ions are not coordinated, b) both ligand hydroxyl groups are coordinated to the metal in the [M(sde)2] (C104)2 complexes, and c) only one hydroxyl group is coordinated in the [M(sde)3] (C104)2 complexes.The molar conductance of the complexes in nitromethane and acetonitrile solutions indicate their behavior as 1:2 electrolytes. The apparent molecular weights of the complexes dissolved in acetonitrile depend upon the concentrations. This can be explained by a slight dissociation in dilute solutions and ion-pair formation in more concentrated ones. The magnetic moments of the complexes are within the range expected for high-spin octahedral complexes. The electronic spectra of the iron, cobalt and nickel complexes are also characteristic of high-spin species in Oh symmetry. From the electronic absorption spectra of cobalt and nickel complexes, the ligand field parameters, Dq and &#946; were calculated. The ligand 2,2- -sulfinyldiethanol gives larger Dq values than do monodentate sulfoxides or alcohols. This may be attributed to the chelate effect. The Dq values for the cobalt complexes indicate that 2,2--sulfinyldiethanol acts as a tridentate ligand in the [Co(sde)2] (C104)2 complex and as a bidentate one in the [Co(sde)3] (C104)2 complex. The chloro complexes having the stoichiometries CoC12 .2H20.sde, CoC12.sde, and PdC12 .sde were also obtained. Infrared spectra indicate that sde is oxygen-bonded in CoC12 complexes while it is sulphur-bonded in PdC12 complex. A chloro-bridged binuclear structure is suggested for the palladium complex, on the basis of its far infrared spectrum. The molar conductance of this compound in nitromethane and acetonitrile shows a non-ionic nature. The behavior of the cobalt chloride complexes in acetonitrile solution is tentatively explained on the basis of the formation of the tetrahedral tetrachlorocobaltate (II) ani , n and a cation containing octahedrally coordinated cobalt(II).

Foram preparados complexos de 2,2--sulfinildietanol (sde) com alguns percloratos e cloretos de metais bivalentes. Os percloratos apresentam a formula geral [M(sde) 2] (C10 4 ) 2 , em que M= Mn, Co, Ni, Cu e Zn, e [M(sde) 3] (C10 4 )2 , em que M= Co e Fe. São cristalinos e muito higroscópicos. Os diagramas de difração de raios-X sugerem que os dois complexos [M(sde) 3] (C10 4 ) 2 são isomorfos. Na série [M(sde)2 ] (C10 4 ) 2 , somente os compostos de cobalto e níquel deram diagramas semelhantes. Os espectros vibracionais são muito difíceis de interpretar. Conclusões inequívocas a respeito da posição da vibração de estiramento S = 0 não puderam ser obtidas. A análise dos espectros sugere que: a) os íons perclorato não se acham coordenados, b) ambos os grupos hidroxila do ligante estão coordenados ao metal nos complexos [M(sde) 2 ] (C10 4 ) 2 , e c) somente um grupo hidroxila está coordenado nos complexos [M(sde) 3 ] (C104)2. As condutâncias molares dos complexos em solução em nitrometano e acetonitrila indicam comportamento de eletrólitos 1:2. As massas moleculares aparentes dos complexos dissolvi dos em acetonitrila dependem da concentração. Isto pode ser explica do como resultante de uma ligeira dissociacão em soluções diluídas e da formação de pares iônicos em concentrações maiores. Os momentos magnéticos dos complexos estão dentro dos intervalos esperados para complexos octaédricos de spin alto. Os espectros eletrônicos dos complexos de ferro, cobalto e níquel são também característicos de espécies de spin alto com simetria Oh. A partir dos espectros de absorção eletrônica dos complexos de cobalto e níquel, foram calculados os parâmetros de campo ligante Dq e &#946;. 0 ligante 2,2- -sulfinildietanol fornece valores maiores de Dq do que os sulfóxidos e álcoois monodentados. Isto pode ser atribuído ao efeito quelato. Os valores de Dq dos complexos de cobalto indicam que o 2,2--sulfinildietanol atua como um ligante tridentado no complexo [Co(sde)<SUB2](C104 )2 e como bidentado no complexo [Co(sde)3] (C104)2. Foram também obtidos os complexos de cloretos apresentando as estequiometrias CoC12.2H20.sde, CoC12.sde e PdC12.sde. Os espectros de absorção no infravermelho indicam que o sde se liga pelo oxigênio nos complexos com CoC12 e pelo enxofre no complexo com PdC12. Uma estrutura binuclear com pontes de cloreto é sugerida para o complexo de paládio, com base em seu espectro infravermelho longínquo. A condutância molar deste composto em nitrometano e acetonitrila mostra que ele não é iônico. O comportamento dos complexos de cloreto de cobalto em solução em acetonitrila a tentativamente explicado com base na formação do ânion tetraédrico tetraclorocobaltato(II) e um cátion contendo cobalto(II) octaedricamente coordenado. / 2,2\' -sulfinyldiethanol (sde) complexes of some divalent metal perchlorates and chlorides were prepared. The perchlorates have the general formula [M(sde)2] (C104)2 , where M = Mn, Co, Ni, Cu and Zn, and [M(sde)3] (C104)2, where M = Co and Fe. They are crystalline and very hygroscopic. X- ray diffraction patterns suggest that the two complexes [M(sde)3] (C104)2 are isomorphous. In the [M(sde)2] (C104)2 series only cobalt and nickel compounds gave similar patterns.The vibrational spectra are very difficult to interpret. Unequivocal conclusions regarding the position of S = 0 stretching vibration could not be drawn. An analysis of the spectra does suggest that: a) the perchlorate ions are not coordinated, b) both ligand hydroxyl groups are coordinated to the metal in the [M(sde)2] (C104)2 complexes, and c) only one hydroxyl group is coordinated in the [M(sde)3] (C104)2 complexes.The molar conductance of the complexes in nitromethane and acetonitrile solutions indicate their behavior as 1:2 electrolytes. The apparent molecular weights of the complexes dissolved in acetonitrile depend upon the concentrations. This can be explained by a slight dissociation in dilute solutions and ion-pair formation in more concentrated ones. The magnetic moments of the complexes are within the range expected for high-spin octahedral complexes. The electronic spectra of the iron, cobalt and nickel complexes are also characteristic of high-spin species in Oh symmetry. From the electronic absorption spectra of cobalt and nickel complexes, the ligand field parameters, Dq and &#946; were calculated. The ligand 2,2- -sulfinyldiethanol gives larger Dq values than do monodentate sulfoxides or alcohols. This may be attributed to the chelate effect. The Dq values for the cobalt complexes indicate that 2,2--sulfinyldiethanol acts as a tridentate ligand in the [Co(sde)2] (C104)2 complex and as a bidentate one in the [Co(sde)3] (C104)2 complex. The chloro complexes having the stoichiometries CoC12 .2H20.sde, CoC12.sde, and PdC12 .sde were also obtained. Infrared spectra indicate that sde is oxygen-bonded in CoC12 complexes while it is sulphur-bonded in PdC12 complex. A chloro-bridged binuclear structure is suggested for the palladium complex, on the basis of its far infrared spectrum. The molar conductance of this compound in nitromethane and acetonitrile shows a non-ionic nature. The behavior of the cobalt chloride complexes in acetonitrile solution is tentatively explained on the basis of the formation of the tetrahedral tetrachlorocobaltate (II) ani , n and a cation containing octahedrally coordinated cobalt(II).

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Please refer to full text for abstract

Peptídeos antimicrobianos (PAMs) fazem parte de um dos mecanismos da imunidade inata contra infecções. A microplusina é um PAM de 10.204 Da, isolado da hemolinfa livre de células e dos ovos do carrapato Rhipicephalus (Boophilus) microplus. É um PAM aniônico em pH fisiológico, possui seis resíduos de cisteína, com formação de três pontes dissulfeto, além de sete resíduos de histidina concentrados principalmente na sua porção C-terminal. O presente trabalho teve como objetivo investigar o mecanismo de ação antimicrobiana da microplusina. A microplusina recombinante é ativa contra várias bactérias Gram-positivas e fungos, porém não apresenta atividade contra bactérias Gram-negativas. Para avaliar o seu mecanismo de ação, foram utilizados dois modelos: a bactéria Micrococcus luteus e o fungo Cryptococcus neoformans. A microplusina é bacteriostática contra M. luteus e apresenta localização intracelular na bactéria. Além disso, observamos que a microplusina liga cobre e que a adição deste metal ao meio de cultivo reduz sua atividade antibacteriana. Bactérias M. luteus pré-incubadas com microplusina retomam o seu crescimento quando cobre é adicionado ao meio. Estes dados indicam que a atividade da microplusina está relacionada à sua habilidade de depletar cobre do meio extra ou intracelular, sugerindo um efeito nutricional para o peptídeo. A microplusina apresenta estrutura terciária com cinco a-hélices e sua ligação ao cobre não induz mudanças conformacionais. Observou-se que as histidinas 1, 2 e 74 da microplusina podem estar envolvidas na formação de um sítio de ligação ao cobre. Quanto à C. neoformans, verificou-se que a microplusina inibe a melanização do fungo, um fator de virulência catalisado pela lacase, uma enzima cobre-dependente. Entretanto, a microplusina não afeta a atividade da lacase, nem sua expressão gênica. O peptídeo também não inibe a auto-polimerização de substratos fenólicos que levam à melanização. Sendo assim, mais estudos são necessários a fim de avaliar o mecanismo pelo qual a microplusina inibe a melanização. Adicionalmente, a microplusina afeta a viabilidade do fungo e reduz o tamanho de sua cápsula, outro importante fator de virulência. As atividades da microplusina sobre C. neoformans sugerem o seu potencial terapêutico. Experimentos in vivo com modelo murino, mostraram que a microplusina reduz o processo inflamatório e a viabilidade de C. neoformans nos pulmões, indicando que em condições otimizadas, o peptídeo pode atuar no controle de infecções. / Antimicrobial peptides (AMPs) take part of innate immune mechanisms against infections. Microplusin is a 10,204 Da AMP, isolated from cell-free hemolymph and eggs of the tick Rhipicephalus (Boophilus) microplus. It is an anionic AMP at physiological pH, with six cysteine residues forming three disulfide bridges and seven histidine residues clustered mainly at the carboxy end portion. The goal of the present work was investigate the antimicrobial action mechanism of microplusin. Recombinant microplusin is active against Gram-positive bacteria and fungi, however, no activity is detected for Gram-negative bacteria. Two models were used to evaluate the action mechanism of microplusin: the bacteria Micrococcus luteus and the yeast Cryptococcus neoformans. Microplusin is bacteriostatic against M. luteus and its localization is intracellular for these bacteria. Moreover, microplusin binds copper and the addition of this metal into the medium reduces its antibacterial activity. M. luteus bacteria pre-treated with microplusin recover its growth when copper is added. These data indicate that microplusin activity is related to its ability to deplete copper present in the extracellular or intracellular environment, suggesting a nutritional effect. Microplusin presents a tertiary structure with five a-helix and the copper binding does not induce conformation changes. In addition, it was observed that histidines 1, 2 and 74 from microplusin may be involved in the formation of a copper binding site. About C. neoformans, it was verified microplusin inhibits its melanization, a virulence factor catalyzed by laccase, a copper dependent enzyme. However, microplusin does affect neither laccase activity nor its gene expression. The melanization caused by auto-polymerazation of phenolic substrates, is also not inhibited by microplusin. Hence, additional studies are required to evaluate the mechanism by which microplusin inhibits melanization. In addition, microplusin also affects the fungi viability and reduces the capsule size, another important virulence factor.The microplusin activities against C. neoformans suggest its therapeutic potential. In vivo experiments with murine model showed that microplusin reduces the inflammation and the viability of C. neoformans in the lungs, indicating that, in optimized conditions, the peptide may act in the infection control.

A doença de Wilson (DW) é distúrbio da excreção biliar de cobre, de herança autossômica recessiva, devido a mutações no gene ATP7B. O cobre que não se liga à apoceruloplasmina circula no organismo ligado a aminoácidos, deposita-se principalmente no fígado e no cérebro e é excretado pelos rins. A cuprúria maior que 100ug/24h pode auxiliar no diagnóstico, embora cerca 20% dos pacientes com DW apresentem níveis anormais de cuprúria basal. A administração da d-penicilamina (DPA) pode promover, em crianças, valores maiores que 1.600ug/24h. A fim de se conhecer os níveis de cuprúria de possíveis indivíduos heterozigotos adultos, foram avaliados 25 pais e 25 mães de pacientes (média 61 anos em homens; 57 anos em mulheres) com diagnóstico de DW. Foram obtidos os níveis séricos de enzimas hepáticas, cobre e ceruloplasmina, e quantificada a cuprúria de 24h. A seguir, os indivíduos receberam DPA 1,0g por via oral dividido em duas tomadas, durante nova coleta de urina para dosagem de cuprúria de 24h. Esta análise foi realizada pelo método de espectrometria de absorção atômica eletrotérmica. Os níveis de enzimas hepáticas foram semelhantes nos dois grupos, exceto o nível médio de fosfatase alcalina que foi maior nas mulheres (H= 68,72 UI/L; M=81,68 UI/L). Os níveis de ceruloplasmina (H=21,72mg/dL; M=27,78mg/dL) e de cobre sérico (H=71,38 ?g/dl; M=88,0 ug/dl) foram maiores em mulheres do que em homens (p<0,001). Os níveis de cuprúria basal foram 22,43ug/24h (média) e 21,40ug/24h (mediana); e, após a DPA, de 523,54 ug/24h (média) e 511,5 ug/24h (mediana). A cuprúria média basal masculina foi de 26,19. ug/24h, enquanto a feminina foi de 18,28. ug/24h (p=0,005). Com o presente estudo, ficou definida possível faixa de variação da cuprúria antes e depois da administração de dpenicilamina em pais de portadores com doença de Wilson; que os pais apresentaram cupremia e níveis de ceruloplasmina menores e cuprúria basal maior do que as mães; que as faixas de variação de normalidade para os parâmetros ceruloplasmina, cobre sérico e urinário deveriam ser diferenciadas de acordo com o sexo. / Wilson disease is a biliary copper excretion disturbance, of recessive autossomic heritage, due to ATP7B gene mutations. The copper not bound to apoceruloplasmin circulates in the organism bound to amino acids and accumulates mainly in the liver and brain being excreted by the kidneys. Urinary copper higher than 100ug/24h can be useful in the diagnosis, but only about 20% of Wilson disease patients have abnormal basal levels. In this case, d-penicillamine (DPA) administration can lead, in children, to levels higher than 1.600ug/24h. Twenty five fathers and twenty five mothers of wilson disease patients (mean 61 years for male, and 57 years for female) were assessed in order to obtain urinary copper levels of probable heterozygote adults. Fasting liver enzymes, copper and ceruloplasmin serum levels were obtained along with 24h urinary copper excretion. After, patients got DPA 1.0g by oral route, twice a day, while collecting urine for 24h urinary copper excretion dosage. These analyses were performed by elethrotermic atomic absortion spectrometry method. Liver enzyme levels were similar in men and women but those of alkaline phosphatase were higher in women (M= 68.72 UI/L; F=81.68 UI/L). Serum ceruloplasmin (F=21.72mg/dl; F=27.78mg/dl) and copper (M=71.38 ug/dl; F=88.0 ug/dl) levels were higher in women than in men (p<0.001). Urinary copper levels before DPA were, 43ug/24h (mean) and 21.40 ug/24h (median); and, after DPA, 523.54 ug/24h (mean) and 511.5 ug/24h (median). Basal urinary copper levels in men were 26.9 ug/24h, and in women were 18.67 ug/24h (p=0.005). With the results of this study, we defined a possible range for urinary copper before and after oral intake of DPA in parents of Wilson disease patients. Furthermore, fathers had lower levels of serum copper and of ceruloplasmin, and greater levels of baseline cupriuresis than mothers; and finally the normal range for serum copper and ceruloplasmin, and urinary copper should be differentiated according to the gender.

Well stimulation is the treatment remedy when oil/gas productivity decreases to unacceptable economical limits. Well stimulation can be carried out through either "Matrix Acidizing" or fracturing with both "Hydraulic Fracturing" and "Acid Fracturing" techniques. "Matrix Acidizing" and "Acid Fracturing" applications involve injecting an acid to react with the formation and dissolve some of the minerals present and recover or increase the permeability. The permeability enhancement is achieved by creating conductive channels "wormholes" in case of "Matrix Acidizing" or creating uneven etching pattern in case of "Acid Fracturing" treatments. In both cases, and to design a treatment successfully, it is necessary to determine the distance that the live acid will be able to penetrate inside the formation, which in turn, determines the volume of the acid needed to carry out the treatment. This distance can be obtained through lab experiments, if formation cores are available, or estimated by modeling the treatment. The successful model will depend on several chemical and physical processes that take place including: the acid transport to the surface of the rock, the speed of the reaction of the acid with the rock, which is often referred to as "Reaction Rate", and the acid leak-off. The parameters describing these processes such as acid diffusion coefficient and reaction kinetics have to be determined experimentally to ensure accurate and reliable modeling. Hydrochloric acid and simple organic acids such as acetic and citric acids have been used extensively for stimulation treatments. The diffusion and reaction kinetics of these acids, in a straight form, were investigated thoroughly in literature. However, solely these acids are used in a simple form in the field. Acid systems such as gelled, crosslinked gelled, surfactant-based, foam-based, or emulsified acids are used to either retard the reaction rate or to enhance acid diversion. Literature review shows that additional work is needed to understand the reaction and report the diffusion and kinetics of these systems with carbonate. In addition, a new chelating agent (GLDA) was recently introduced as a stand-alone stimulating fluid. The kinetics and the mass transfer properties of this acid were not studied before. Therefore, the objective of this work is to study the reaction of different acid systems with calcite and dolomite and report the mass transport and kinetic data experimentally. Lactic acid, a chelating agent (GLDA), and in-situ gelled HCl-formic acids were investigated in this study. In some cases, rheology measurements and core flood experiments were conducted. The data were combined with the reaction study to understand the behavior of these acids and examine their efficiency if injected in the formation.

Three effective solutions to dissolve the filter cake created by water-based drilling fluids weighted with Mn3O4 particles were developed. Hydrochloric acid at concentration lower than 5 wt% can dissolve most of Mn3O4-based filter cake. Dissolving the filter cake in two-stage treatment of enzyme and organic acid was effective and eliminated the associated drawbacks of using HCl. Finally, combining low and safe concentration of HCl with an organic acid in one-stage treatment was very effective. Hydrochloric acid (10-wt%) dissolved 78 wt% of Mn3O4-based filter cake at 250°F after 28 hours soaking time. However, Chlorine gas was detected during the reaction of 5 to 15-wt% HCl with Mn3O4 particles. At 190°F, 1- and 4-wt% HCl dissolved most Mn3O4 particles (up to 70-wt% solubility). Their reactions with Mn3O4 particles followed Eq. 8 at 190°F, which further confirmed the absence of chlorine gas production at HCl concentrations lower than 5-wt%. EDTA and DTPA at high pH (12) and acetic, propionic, butyric, and gluconic acids at low pH (3-5) showed very low solubilities of Mn3O4 particles. GLDA, citric, oxalic, and tartaric acids produced large amount of white precipitation upon the reactions with Mn3O4 particles. Similarly, DTPA will produce damaging material if used to dissolve Mn3O4-based filter cake in sandstone formation. At 4-wt% acid concentration, lactic, glycolic, and formic acids dissolved Mn3O4 particles up to 76 wt% solubility at 190°F. Malonic acid at lower concentration (2-wt%) dissolved 54 wt% of Mn3O4 particles at 190°F. Manganese tetraoxide particles were covered with polymeric material (starch), which significantly reduced the solubility of filter cake in organic acids. Therefore, there was a need to remove Mn3O4-based filter cake in two-stage treatment. Enzyme-A (10-wt%) and Precursor of lactic acid (12.5-wt%) dissolved 84 wt% of the filter cake. An innovative approach led to complete solubility of Mn3O4 particles when low and safe concentration of HCl (1-wt%) combined with 4-wt% lactic acid at 190°F. HCl (1-wt%) combined with lactic acid (4-wt%), dissolved 85 wt% of the Mn3O4-based filter cake after 18-22 hours soaking time at 250°F in one stage treatment.