Sources of reducing power for nitrate reduction in spinach leaves

Planta ◽  
1978 ◽  
Vol 140 (3) ◽  
pp. 261-263 ◽  
Author(s):  
A. F. Mann ◽  
D. P. Hucklesby ◽  
E. J. Hewitt
Keyword(s):  
Nitrate Reduction ◽  
Reducing Power ◽  
Spinach Leaves

scholarly journals Effects of the Feeding Solution Composition on a Reductive/Oxidative Sequential Bioelectrochemical Process for Perchloroethylene Removal

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 405
Author(s):  
Edoardo Dell’Armi ◽  
Marco Zeppilli ◽  
Bruna Matturro ◽  
Simona Rossetti ◽  
Marco Petrangeli Papini ◽  
...  
Keyword(s):  
Reductive Dechlorination ◽  
Nitrate Reduction ◽  
Coulombic Efficiency ◽  
Reducing Power ◽  
Mineral Medium ◽  
Process Conditions ◽  
Microbial Electrolysis Cells ◽  
Dehalococcoides Mccartyi ◽  
In Series ◽  
Synthetic Groundwater

Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants due to their improper use in several industrial activities. Specialized microorganisms are able to perform the reductive dechlorination (RD) of high-chlorinated CAHs such as perchloroethylene (PCE), while the low-chlorinated ethenes such as vinyl chloride (VC) are more susceptible to oxidative mechanisms performed by aerobic dechlorinating microorganisms. Bioelectrochemical systems can be used as an effective strategy for the stimulation of both anaerobic and aerobic microbial dechlorination, i.e., a biocathode can be used as an electron donor to perform the RD, while a bioanode can provide the oxygen necessary for the aerobic dechlorination reaction. In this study, a sequential bioelectrochemical process constituted by two membrane-less microbial electrolysis cells connected in series has been, for the first time, operated with synthetic groundwater, also containing sulphate and nitrate, to simulate more realistic process conditions due to the possible establishment of competitive processes for the reducing power, with respect to previous research made with a PCE-contaminated mineral medium (with neither sulphate nor nitrate). The shift from mineral medium to synthetic groundwater showed the establishment of sulphate and nitrate reduction and caused the temporary decrease of the PCE removal efficiency from 100% to 85%. The analysis of the RD biomarkers (i.e., Dehalococcoides mccartyi 16S rRNA and tceA, bvcA, vcrA genes) confirmed the decrement of reductive dechlorination performances after the introduction of the synthetic groundwater, also characterized by a lower ionic strength and nutrients content. On the other hand, the system self-adapted the flowing current to the increased demand for the sulphate and nitrate reduction, so that reducing power was not in defect for the RD, although RD coulombic efficiency was less.

scholarly journals Analysis of Proximate Composition and Functional Properties of Selected Edible Leaves: Nutritional and Therapeutic Implication

2020 ◽  
Vol 12 (4) ◽  
pp. 621-632
Author(s):  
A. D. Pal ◽  
T. M. Zakir
Keyword(s):  
Functional Properties ◽  
Local Population ◽  
Antioxidant Properties ◽  
Reducing Power ◽  
Good Health ◽  
Proximate Analysis ◽  
Leaf Extracts ◽  
Therapeutic Benefits ◽  
Spinach Leaves

The present study was designed to document the nutritional and functional properties of Ceylon Spinach, Mustard as well as Pumpkin leaves. These samples were selected owing to their economic affordability and utilization within the local population. Proximate analysis revealed a significant percentage of minerals, proteins, carbohydrates and vitamin C in all the leaf extracts. Phytochemical screening displayed Ceylon Spinach, Pumpkin and Mustard leaves to be rich sources of polyphenols (106.6, 76.24 and 89.86 mg/100 g) and alkaloids (12.8 %, 13.2 % and 16.8 %) respectively. Furthermore, these edible leaves could effectively scavenge 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) and hydrogen peroxide (H2O2) free radicals with Mustard leaves showing the greatest efficiency, hence portraying antioxidant properties. Ceylon Spinach leaves depicted the highest reducing power compared to the other samples. Additionally, the edible leaf extracts were shown to possess anti-bacterial abilities with Mustard leaves displaying the strongest inhibition against growth of both Gram positive (ZOI 18.5mm) and negative bacteria (ZOI 25.5mm). Interestingly, the selected samples could also elevate the growth of probiotic Lactobacillus acidophilus in vitro thereby confirming their prebiotic potential. Therefore, inclusion of these edible leaves in the diet may promote good health owing to their nutritional and therapeutic benefits.

The role of malate in nitrate reduction in spinach leaves

1980 ◽  
Vol 58 (5) ◽  
pp. 517-521 ◽  
Author(s):  
K. C. Woo ◽  
D. T. Canvin
Keyword(s):  
Nitrate Reduction ◽  
Nitrite Accumulation ◽  
Antimycin A ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Leaf Discs ◽  
Spinach Leaf ◽  
Spinach Leaves

In spinach leaf discs the accumulation of nitrite from nitrate reduction under anaerobic conditions in the light in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) was inhibited by air. The inhibition of nitrate reduction by air was reversed by antimycin A but not by rotenone or amytal. The nitrate-reducing system of DCMU-inhibited leaf discs in the light appeared similar to noninhibited leaf discs in the dark. In aerobic conditions, the addition of malate stimulated nitrite accumulation. This stimulation was unaffected by malonate. Under anaerobic conditions, malate reversed the inhibition of nitrate reduction caused by either iodoacetate or arsenite to rates similar to those observed in the dark and in the light with DCMU. Malate can apparently provide a direct source of cytosolic NADH for nitrate reduction.

Nitrate Reduction by a Dicarboxylate Shuttle in a Reconstituted System from Spinach Leaves

1980 ◽  
Vol 7 (2) ◽  
pp. 123
Author(s):  
K.C Woo ◽  
Mark Jokinen ◽  
D.T Canvin
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reduction ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Reconstituted System ◽  
Spinach Leaves

A reconstituted system of supernatant and mitochondria from spinach leaves reduced NO3- in the presence of NAD+. A faster rate (2-6 times) of NO3- reduction was obtained when oxaloacetate (OAA) and glycine were present. The reduction of NO3- in the presence of OAA and glycine was sensitive to inhibition by n-butyl malonate, suggesting that the dicarboxylate exchange carrier was involved in the transport of malate out of the mitochondria. The capacity of the dicarboxylate shuttle to reduce NO,- was 63 % that of the in vitvo nitrate reductase activity in the supernatant

The regulation of nitrate reduction in spinach leaves

1979 ◽  
Vol 57 (10) ◽  
pp. 1155-1160 ◽  
Author(s):  
David T. Canvin ◽  
K. C. Woo
Keyword(s):  
Electron Transport ◽  
Nitrate Reduction ◽  
Electron Transport Chain ◽  
Antimycin A ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Transport Chain ◽  
Respiratory Electron Transport ◽  
Spinach Leaves

Nitrate reduction did not occur in leaves in the dark in aerobic conditions but did occur in anaerobic conditions. Nitrate reduction in leaves in the dark in aerobic conditions was observed, however, when the respiratory electron transport chain was inhibited with antimycin A but not when it was inhibited with amytal or rotenone. It would appear that NADH generated outside the mitochondria was used for nitrate reduction in the dark under anaerobic conditions. The relevance of this observation to nitrate reduction in the light is discussed.

COMPARISON OF VARIOUS METHODS FOR THE CHEMICAL ASSAY OF CORTICOIDS IN URINE

1955 ◽  
Vol 18 (4) ◽  
pp. 374-378
Author(s):  
Mogens Sprechler
Keyword(s):  
Calibration Curve ◽  
Periodic Acid ◽  
Reducing Power ◽  
Standard Technique ◽  
Phosphomolybdic Acid ◽  
Florisil Column ◽  
Chemical Assay ◽  
Chromatographic Procedure ◽  
Acid Reagent

SUMMARY Since 1949 about 10,000 urinary corticoid analyses have been performed routinely in our laboratory. The method used for this purpose was described in 1950 (Sprechler). We determine the corticoids which can be extracted from the urine with chloroform immediately after acidification to pH 1. The extract is washed with sodium hydroxide and water, a Girard separation is performed, and finally the reducing power of the ketonic fraction is measured by means of the phosphomolybdic acid reagent reaction. During the last few years two other chemical reactions have been used for comparison: The formaldehyde and the Porter-Silber method. After a thorough examination of the above methods a standard technique was followed. In the formaldehyde method a microdiffusion in a Conway unit was used instead of distillation of the formaldehyde following the oxidation with periodic acid. The calibration curve was corrected for loss of material by taking the standard doses of DOC through all the procedures of the method. A micromodification of the Porter-Silber method was chosen. Furthermore attempts were made to determine how specific the chromatographic procedure is in the determination of steroids in urinary extracts. For this purpose the Florisil column was used, and the technique described by Nelson & Samuels was followed. Finally we have investigated the glucuronide-bound corticoids in urine in a smaller series of objects.

Characterization of non polar-polar solvent extracts from some tea plantation shade tree leaves with special reference to antioxidant and antibacterial activities

2020 ◽  
pp. 15-21
Author(s):  
Arindam Ghosh ◽  
Soumya Majumder ◽  
Sumedha Saha ◽  
Malay Bhattacharya
Keyword(s):  
Cardiac Glycosides ◽  
Polar Solvent ◽  
Reducing Power ◽  
Scavenging Activity ◽  
Shade Trees ◽  
Crude Fibre ◽  
Shade Tree ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging

Beneficial properties of shade trees of tea plantations other than their medicinal properties have been extensively studied. This research was initiated to explore the properties of some shade trees with special emphasis on their antioxidant and antibacterial properties. Leaves from shade tree like Dalbergia sissoo (DS), Cassia siamea (CS), Derris robusta (DR), Leucaena leucocephala (LL), Acacia lenticularis (AL) and Melia azedarach (MA) were used for the study. Characterization of shade tree leaves by determination of moisture, crude fibre and ash content and tests of non polar – polar solvent extracts for steroid, tannins, cardiac glycosides and coumarin, free radical scavenging, ferric reducing power, NO scavenging activities, quantification of Flavonoids and antibacterial activity were conducted. The average moisture, crude fibre and ash percentage of shade tree plants were found to be 62.95, 11.28 and 1.86 respectively. Methanol, ethanol, acetone and ethyl acetate respectively proved to be the most potent solvent for various phytochemical extractions as it gave positive results for tests like tannin, steroid, cardiac glycosides and coumarin. AL (91.46%), DR (92.69%), LL (94.32%) and MA (93.34%) leaf extracts showed a high level of DPPH scavenging activity in their water extracts. In DS (88.11%) and CS (83.23%) maximum DPPH scavenging activity was observed in Diethyl ether and Methanol extracts respectively.  Acetone extracts were more active than the water extracts in exhibiting ferric reducing power and NO scavenging activity. Summation of the quantity revealed that DS showed maximum presence of flavonoids and acetone as most potential for isolation of flavonoids. The decreasing order of summative antibacterial activity was recorded in DS, followed by CS, DR, AL, MA and LL. Chloroform showed the highest summative inhibition zone followed by ethanol, ethyl acetate, diethyl ether, acetone, water,  hexane, benzene and methanol. The antioxidant and antibacterial potential of shade trees were established.

Turmeric and cinnamon dominate in antioxidant potential among four major spices

2017 ◽  
Vol 26 (1) ◽  
pp. 27 ◽  
Author(s):  
B Saranya ◽  
T Sulfikarali ◽  
S Chindhu ◽  
A M Muneeb ◽  
N K Leela ◽  
...  
Keyword(s):  
Methanol Extract ◽  
Reducing Power ◽  
Black Pepper ◽  
Chloroform Extract ◽  
Antioxidant Potential ◽  
Total Phenol Content ◽  
Power Method ◽  
Phenol Content ◽  
Dpph Assay ◽  
Synthetic Antioxidant

Antioxidant activity of sequential extracts of black pepper, ginger, turmeric and cinnamon was determined by DPPH assay, phosphomolybdate method and ferric reducing power method and compared with that of the synthetic antioxidant BHA. The results revealed that methanol extract of cinnamon has highest antioxidant potential followed by chloroform extract of turmeric. The antioxidant potential was also correlated with total phenol content.  

Physiochemical properties and antioxidant potential of Persea Americana seed oil

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Seed Oil ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Acid Value ◽  
Persea Americana ◽  
Antioxidant Potential ◽  
Physiochemical Properties ◽  
Physiochemical Parameters ◽  
Ic50 Value

Oil extracted from Persea Americana seed was assayed for its physiochemical properties and antioxidant potential using various standard methods. The oil content of the seed was found to be < 10%. Brownish-red color oil was liquid at room temperature, with specific gravity of 0.91±0.02 g/mL. Other physiochemical parameters determined were; acid value (4.51±0.08 mgKOH/g), %FFA (2.26±0.08), peroxide value (2.40±0.57 mgO2/Kg), ester value (31.26±0.03 mgKOH/g), saponification value (35.76±0.07 mgKOH/g) and iodine value (23.5±0.07). The results of the antioxidant activities of the seed oil showed that the flavonoid content (80.00±1.41 mgQE/g) was ~10 folds higher than the phenolic content (8.27±0.06 mgGAE/g). The DPPH radical scavenging value was found to be 51.54±0.25% with an IC50 value of 4.68±0.02 mg/mL and reducing power with an average absorbance of 0.85±0.01 and an IC50 value of 0.001±0.02 mg/mL. Gallic acid showed better antioxidant activities than the oil studied. The results obtained in this study showed that Persea Americana seed oil has nutritional, industrial as well as medicinal potentials.

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