The role of low molecular weight ligands in nickel hyperaccumulation in Hybanthus floribundus subspecies floribundus

2010 ◽  
Vol 37 (12) ◽  
pp. 1143
Author(s):  
Anthony G. Kachenko ◽  
Balwant Singh ◽  
Naveen Bhatia
Keyword(s):  
Citric Acid ◽  
Organic Acids ◽  
Acid Concentration ◽  
Malic Acid ◽  
Dry Weight ◽  
Ultra Performance Liquid Chromatography ◽  
Citric Acid Concentration ◽  
Molar Ratios ◽  
Nickel Hyperaccumulation

The mechanisms responsible for nickel (Ni) hyperaccumulation in Hybanthus floribundus (Lindl.) F.Muell. subspecies floribundus are obscure. In this study, organic acids and free amino acids (AAs) were quantified in 0.025 M HCl H. floribundus subsp. floribundus shoot extracts using HPLC and ultra performance liquid chromatography (UPLC). In a 20 week pot experiment, plants exposed to five levels of Ni (0–3000 mg kg–1 Ni) accumulated up to 3200 mg Ni kg–1 dry weight in shoots, and the shoot : root Ni concentration ratios were >1.4. Concentration of organic acids followed the order malic acid > citric acid > oxalic acid. Citric acid concentration significantly increased upon Ni exposure, with concentrations between 2.3- and 5.9-fold higher in Ni treated plants that in control plants. Molar ratios of Ni to citric acid ranged from 1.3 : 1 to 1.7 : 1 equivalent to >60% of the accumulated Ni. Malic acid concentration also increased upon exposure to applied Ni. However, concentrations were statistically at par across 0–3000 mg kg–1 Ni treatments, suggesting that the production of malic acid is a constitutive property of the subspecies. Total AA concentrations were stimulated upon exposure to external Ni treatment, with glutamine, alanine and aspartic acids being the predominant acids. These AAs accounted for up to 64% of the total free AA concentration in control plants and up to 75% for the 2000 mg kg–1 Ni treatment plants. These results suggest that citric acid in addition to the aforementioned AAs are synthesised in H. floribundus subsp. floribundus plants following exposure to elevated concentrations of Ni and may act as potential ligands for detoxification and possibly storage of accumulated Ni.

scholarly journals Phytoextraction of Lead Using a Hedge Plant [Alternanthera bettzickiana (Regel) G. Nicholson]: Physiological and Biochemical Alterations through Bioresource Management

2021 ◽  
Vol 13 (9) ◽  
pp. 5074
Author(s):  
Urooj Kanwal ◽  
Muhammad Ibrahim ◽  
Farhat Abbas ◽  
Muhammad Yamin ◽  
Fariha Jabeen ◽  
...  
Keyword(s):  
Citric Acid ◽  
Growth Parameters ◽  
Cost Effective ◽  
Dry Weight ◽  
Citric Acid Concentration ◽  
Biochemical Alterations ◽  
Biomass Plant ◽  
Environmentally Friendly Approach ◽  
Pb Concentration

Phytoremediation is a cost-effective and environmentally friendly approach that can be used for the remediation of metals in polluted soil. This study used a hedge plant–calico (Alternanthera bettzickiana (Regel) G. Nicholson) to determine the role of citric acid in lead (Pb) phytoremediation by exposing it to different concentrations of Pb (0, 200, 500, and 1000 mg kg−1) as well as in a combination with citric acid concentration (0, 250, 500 µM). The analysis of variance was applied on results for significant effects of the independent variables on the dependent variables using SPSS (ver10). According to the results, maximum Pb concentration was measured in the upper parts of the plant. An increase in dry weight biomass, plant growth parameters, and photosynthetic contents was observed with the increase of Pb application (200 mg kg−1) in soil while a reduced growth was experienced at higher Pb concentration (1000 mg kg−1). The antioxidant enzymatic activities like superoxide dismutase (SOD) and peroxidase (POD) were enhanced under lower Pb concentration (200, 500 mg kg−1), whereas the reduction occurred at greater metal concentration Pb (1000 mg kg−1). There was a usual reduction in electrolyte leakage (EL) at lower Pb concentration (200, 500 mg kg−1), whereas EL increased at maximum Pb concentration (1000 mg kg−1). We concluded that this hedge plant, A. Bettzickiana, has the greater ability to remediate polluted soils aided with citric acid application.

scholarly journals Optimization of Betalain Pigments Extraction Using Beetroot by-Products as a Valuable Source

Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 50
Author(s):  
Silvia Lazăr (Mistrianu) ◽  
Oana Emilia Constantin ◽  
Nicoleta Stănciuc ◽  
Iuliana Aprodu ◽  
Constantin Croitoru ◽  
...  
Keyword(s):  
Citric Acid ◽  
Acid Concentration ◽  
Ethanol Concentration ◽  
Extraction Process ◽  
Extraction Time ◽  
Quadratic Model ◽  
Citric Acid Concentration ◽  
Operating Variables ◽  
Conventional Solvent Extraction ◽  
Optimized Conditions

(1) Background: This study is designed to extract the bioactive compounds from beetroot peel for future use in the food industry. (2) Methods: Spectrophotometry techniques analyzed the effect of conventional solvent extraction on betalains and polyphenolic compounds from beetroot peels. Several treatments by varying for factors (ethanol and citric acid concentration, temperature, and time) were applied to the beetroot peel samples. A Central Composite Design (CCD) has been used to investigate the effect of the extraction parameters on the extraction steps and optimize the betalains and total polyphenols extraction from beetroot. A quadratic model was suggested for all the parameters analyzed and used. (3) Results: The maximum and minimum variables investigated in the experimental plan in the coded form are citric acid concentration (0.10–1.5%), ethanol concentration (10–50%), operating temperature (20–60 °C), and extraction time (15–50 min). The experimental design revealed variation in betalain content ranging from 0.29 to 1.44 mg/g DW, and the yield of polyphenolic varied from 1.64 to 2.74 mg/g DW. The optimized conditions for the maximum recovery of betalains and phenols were citric acid concentration 1.5%, ethanol concentration 50%, temperature 52.52 °C, and extraction time 49.9 min. (4) Conclusions: Overall, it can be noted that the extraction process can be improved by adjusting operating variables in order to maximize the model responses.

scholarly journals Development of poly(vinyl alcohol)-based membranes by the response surface methodology for environmental applications

2020 ◽  
Vol 24 ◽  
pp. e5
Author(s):  
Juliana Zanol Merck ◽  
Camila Suliani Raota ◽  
Jocelei Duarte ◽  
Camila Baldasso ◽  
Janaina Da Silva Crespo ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Citric Acid ◽  
Response Surface ◽  
Acid Concentration ◽  
Vinyl Alcohol ◽  
Membrane Preparation ◽  
Poly Vinyl Alcohol ◽  
Esterification Reaction ◽  
Citric Acid Concentration ◽  
Ft Ir

The pollution of hydric sources by pharmaceuticals is an issue in many countries, particularly in Brazil. The presence of these substances causes deleterious effects on the environment and human health. One of the main sources of this contamination is domestic sewage, due to the expressive amount of medicines released in their unaltered form. Unfortunately, traditional wastewater treatment is not effective for the removal of pharmaceuticals and, for this reason, membrane technology is an attractive alternative to overcome this issue. In this regard, hydrophilic polymers, such as poly(vinyl alcohol) (PVA), are the most suitable. However, their high affinity with water causes intense swelling, leading to severe modifications in the membrane properties. In view of all these facts, the present work evaluated the swelling of PVA-based membranes, with the aim of finding the membrane preparation method that has the lowest swelling, thereby providing the most suitable characteristics for pharmaceutical removal from wastewater. The membranes were prepared by the casting of a polymeric solution, with PVA as a basis polymer, citric acid as a crosslink agent and glycerol and silver nanoparticles as performance additives. The process optimization was performed using a design of experiments with posterior analysis by the response surface methodology (RSM). The RSM assessed the effect on the membrane swelling of the factors, including citric acid concentration and the time and temperature of crosslinking. The membrane characterization was performed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy coupled with a field emission gun (SEM-FEG) and water contact angle (WCA) measurements. Overall, the condition that showed the lowest swelling was obtained with 10% of citric acid and crosslinking for 4 h at 130 °C. Under these conditions, the membrane had a mass swelling of 42% and a dimensional swelling of 24%. Additionally, our statistical analysis revealed that the factors with the dominant effects were the citric acid concentration and the temperature of crosslinking. The FT-IR analysis suggested that the crosslinking occurred by an esterification reaction, as showed by the stretching frequencies of C=O at 1710 cm-1 and ester C-O at 1230 cm-1. Moreover, the SEM-FEG images revealed a smooth and flat surface and a dense cross section with a thickness of ~113 μm. Concerning the WCA, the angle was at ~80°, which is characteristic of hydrophilic materials. Finally, the data suggested that it is possible to optimize the membrane preparation process with adequate properties so that it can be subsequently applied to the removal of pharmaceuticals from hospital wastewater.

scholarly journals The Cardioprotective Effects of Citric Acid and L-Malic Acid on Myocardial Ischemia/Reperfusion Injury

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Xilan Tang ◽  
Jianxun Liu ◽  
Wei Dong ◽  
Peng Li ◽  
Lei Li ◽  
...  
Keyword(s):  
Citric Acid ◽  
Myocardial Ischemia ◽  
Organic Acids ◽  
Reperfusion Injury ◽  
Malic Acid ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Protective Effects ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

Organic acids in Chinese herbs, the long-neglected components, have been reported to possess antioxidant, anti-inflammatory, and antiplatelet aggregation activities; thus they may have potentially protective effect on ischemic heart disease. Therefore, this study aims to investigate the protective effects of two organic acids, that is, citric acid and L-malic acid, which are the main components ofFructus Choerospondiatis, on myocardial ischemia/reperfusion injury and the underlying mechanisms. Inin vivorat model of myocardial ischemia/reperfusion injury, we found that treatments with citric acid and L-malic acid significantly reduced myocardial infarct size, serum levels of TNF-α, and platelet aggregation.In vitroexperiments revealed that both citric acid and L-malic acid significantly reduced LDH release, decreased apoptotic rate, downregulated the expression of cleaved caspase-3, and upregulated the expression of phosphorylated Akt in primary neonatal rat cardiomyocytes subjected to hypoxia/reoxygenation injury. These results suggest that both citric acid and L-malic acid have protective effects on myocardial ischemia/reperfusion injury; the underlying mechanism may be related to their anti-inflammatory, antiplatelet aggregation and direct cardiomyocyte protective effects. These results also demonstrate that organic acids, besides flavonoids, may also be the major active ingredient ofFructus Choerospondiatisresponsible for its cardioprotective effects and should be attached great importance in the therapy of ischemic heart disease.

scholarly journals Extending Metabolomic Studies of Apis mellifera Venom: LC-MS-Based Targeted Analysis of Organic Acids

Toxins ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 14
Author(s):  
Magdalena Pawlak ◽  
Agnieszka Klupczynska ◽  
Zenon J Kokot ◽  
Jan Matysiak
Keyword(s):  
Citric Acid ◽  
Organic Acids ◽  
Kynurenic Acid ◽  
Glutaric Acid ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Dry Weight ◽  
Triple Quadrupole Mass Spectrometer ◽  
Targeted Analysis

Organic acids are important active small molecules present in venoms and toxins, which have not been fully explored yet. The aim of the study was the determination of organic acids in honeybee venom (HBV) samples by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two protocols for sample preparation were employed. A solid-phase extraction was used for the determination of malonic acid, fumaric acid, glutaric acid, and kynurenic acid. A dilute-and-shoot method was optimal for: citric acid, malic acid, and succinic acid. Chromatographic separation was performed using a Synergi Hydro-RP column. Detection was performed on a triple-quadrupole mass spectrometer operating in multiple reaction monitoring mode. Among the analytes, glutaric acid and kynurenic acid were present in HBV samples in the lowest concentrations, whereas citric acid was the most abundant acid in each sample, and accounted for an average of 86 mg/g (8.6%) of the venom dry weight. Organic acids were discussed in terms of function. This is the first study in the available literature that provides specific data on the content of organic acids in HBV using a validated quantitative method.

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