HUMIC AND FULVIC ACIDS IN SEDIMENTS AND SOILS OF AGRICULTURAL WATERSHEDS

1978 ◽  
Vol 58 (2) ◽  
pp. 167-178 ◽  
Author(s):  
L. M. WHITBY ◽  
M. SCHNITZER

Humic and fulvic acids were extracted from suspended and bottom sediments and soils of small agricultural watersheds of Southern Ontario and characterized by chemical and spectrophotometric methods and by chemical degradation. Soil humic and fulvic acids were found to be similar to sediment humic and fulvic acids, respectively, in elemental and functional group composition and in surface structural features. Metal-binding capacities of sediment and soil humic and fulvic acids were estimated from their CO2H and phenolic OH group contents. Because watershed soils contained per unit weight considerably more humic materials than did adjacent bottom sediments, the metal-binding capacity due to humic and fulvic acids in the watershed soils was considerably higher than that due to humic and fulvic acids in the sediments. Major products resulting from the alkaline KMnO4 oxidation of soil and sediment humic and fulvic acids were benzenecarboxylic and phenolic acids. The chemical, spectrophotometric and degradation data indicated that sediment and soil humic substances had similar chemical structures.

2021 ◽  
Vol 11 (18) ◽  
pp. 8466
Author(s):  
Christian Millo ◽  
Carlo Bravo ◽  
Stefano Covelli ◽  
Elena Pavoni ◽  
Elisa Petranich ◽  
...  

The Cananéia-Iguape estuarine–lagoon complex (São Paulo state, Brazil) is a natural laboratory to study metal binding by humic substances (HS) in subtropical settings. This transitional environment is evolving into a freshwater environment due to water input from the Ribeira River, funneled through the Valo Grande Canal (Iguape). Past mining activities in the Ribeira River basin and maritime traffic are suspected to be potential sources of trace metals in the system. In this study, the trace metal contents of Free Humic Acids (FHA), Bound Humic Acids (BHA), and Fulvic Acids (FA) extracted from sedimentary organic matter were investigated. Moreover, the sources of HS were traced using their stable carbon isotope compositions and C/N ratios. The results suggested a mixed marine–terrestrial source of FHA, BHA, and FA. Copper and Cr were the most abundant trace metals bound to HS. On average, Cu showed concentrations of 176, 115, and 37.9 μg g−1 in FHA, BHA, and FA, respectively, whereas Cr showed average concentrations of 47.4, 86.3, and 43.9 μg g−1 in FHA, BHA, and FA, respectively. Marine FHA showed the highest binding capacity for trace metals, whereas terrestrial FA derived from the decay of mangrove organic matter showed the lowest binding capacity.


1975 ◽  
Vol 55 (3) ◽  
pp. 251-267 ◽  
Author(s):  
S. M. GRIFFITH ◽  
M. SCHNITZER

To obtain a better understanding of the unusual accumulation of organic matter in tropical volcanic soils in the West Indies, humic and fulvic acids were extracted with 0.5 N NaOH under N2 from four surface and two subsurface horizons of four such soils from the island of Dominica and degraded by KMnO4 oxidation of unmethylated and methylated materials. The oxidation products were fractionated by solvent extraction and chromatographic methods and 52 compounds were identified on a gas chromatography–mass spectrometry–computer system. Major oxidation products (identified as esters and ethers) were benzenecarboxylic, phenolic and aliphatic mono- and dicarboxylic acids. Smaller amounts of n-alkanes, furan derivatives and dialkyl phthalates were also identified. The major chemical structures detected in the tropical volcanic humic and fulvic acids were aromatic rings substituted by: (a) three to six C atoms; (b) one OCH3 group and three, four and six C atoms; and (c) two OH groups and one, two, three and five C atoms. Judging from the qualitative and quantitative distribution of the major oxidation products, the chemical structure of tropical volcanic humic and fulvic acids did not appear to differ significantly from that of humic and fulvic acids extracted from soils from widely differing climatic zones. We were unable to detect any effect of depth of sampling or soil pH on the chemical structure of the humic materials extracted from the tropical volcanic soils.


1972 ◽  
Vol 52 (1) ◽  
pp. 43-51 ◽  
Author(s):  
S. U. KHAN ◽  
M. SCHNITZER

Humic acid, fulvic acid, and humin fractions extracted from a Black Chernozem, a Black Solod, and a Black Solonetz soil were methylated with diazomethane and oxidized with permanganate solution. The oxidation products were extracted into ethyl acetate, separated by preparative gas chromatography, and identified by comparing their mass and micro-IR spectra with those of authentic specimens. Total yields of oxidation products followed the order humic acids > humins > fulvic acids. The products resulting from the oxidation of humic and fulvic acids averaged 63% benzenecarboxylic, 32% phenolic, and 5% aliphatic carboxylic acids. The oxidation products from humins averaged 76% benzenecarboxylic but only 20% phenolic and 4% aliphatic carboxylic acids, indicating some differences in the chemical structure of humins from those of humic and fulvic acids. The most prominent compounds produced by the oxidation of the humic acids were hydroxy benzenepentacarboxylic and benzenetetracarboxylic acids. In general, differences in the distribution of the major oxidation products between the three major fractions were greater than those within individual humic fractions. Thus, the chemical structures of humic acids extracted from three different soils appeared to be more similar to each other than to those of fulvic acid and humin fractions from the same soil. The same was true for fulvic acids and humins extracted from the different soils. Between 79 and 95% of the oxidation products were identified. The oxidation products may have originated from (a) condensed lignin structures, (b) complex structures of microbiological origin, and/or (c) polymeric structures consisting of benzenecarboxylic and phenolic acids held together by hydrogen-bonding.


Author(s):  
Tara A Shrout

Titin is the largest known protein in the human body, and forms the backbone of all striated muscle sarcomeres. The elastic nature of titin is an important component of muscle compliance and functionality. A significant amount of energy is expended to synthesize titin, thus we postulate that titin gene expression is under strict regulatory control in order to conserve cellular resources. In general, gene expression is mediated in part by post-transcriptional control elements located within the 5’ and 3’ untranslated regions (UTRs) of mature mRNA. The 3’UTR in particular contains structural features that affect binding capacity to other RNA components, such as MicroRNA, which control mRNA localization, translation, and degradation. The degree and significance of the regulatory effects mediated by two determined variants of titin’s 3’ UTR were evaluated in Neonatal Rat Ventricular Myocyte and Human Embryonic Kidney cell lines. Recombinant plasmids to transfect these cells lines were engineered by insertion of the variant titin 3’UTR 431- and 1047-base pairs sequences into luciferase reporter vectors. Expression due to an unaltered reporter vector served as the control. Quantitative changes in luciferase activity due to the recombinants proportionally represented the effect titin’s respective 3’UTR conferred on downstream post-transcriptional expression relative to the control. The effect due to titin’s shorter 3’UTR sequence was inconclusive; however, results illustrated that titin’s longer 3’UTR sequence caused a 35 percent decrease in protein expression. Secondary structural analysis of the two sequences revealed differential folding patterns that affect the stability and degree of MicroRNA-binding within titin’s variant 3’UTR sequences.


Author(s):  
Ramiro Remigio Gaibor Fernández ◽  
Abraham Adalberto Bayas Zamora ◽  
Galo Israel Muñoz Sánchez ◽  
Cristhian Adrián Rivas Santacruz

The objective of the present investigation was to evaluate the physical characteristics of the vermicompost and the quality of the purine of the red Californian (Eisenia foetida) using different substrates of feed for these worms. For this purpose, nine treatments were studied: 75% African palm rachis + 25% cattle manure, 50% African palm rachis + 50% cattle manure, 25% African palm rachis + 75% livestock manure, 50% manure of cattle, 50% of manure of cattle, 25% of manure of cattle, 50% of manure of cattle, 50% of manure of cattle, 50% of rach of coconut + 50% of manure of Livestock, 25% coccus rachis + 75% livestock manure. The substrate made up of 50% of rachis of coconut and 50% of livestock manure can be used in nurseries or nurseries for being the one that registered a value of pH 7.3 plus the closest to the neutral compared to the others, besides this (75% of oil palm rachis and 25% of cattle manure) showed a higher content of humic and fulvic acids (0.87 and 0.45 p / p, respectively), compounds that are important for agriculture by stimulating plant growth, in addition to this reflection 0.06% sulfur content, 4.0 ppm boron, 7.0 ppm copper, 47.5 ppm iron, 6.0 ppm manganese, with a presence of microorganisms of the species Trichoderma, Penicillium, Cladosporium sp. in amounts of 1.91x105 UFC / ml, however in this substrate was obtained between 13.3 and 43.5% less liquid slurry in Comparison with other treatments.


2018 ◽  
Vol 18 (5) ◽  
pp. 321-368 ◽  
Author(s):  
Juan A. Bisceglia ◽  
Maria C. Mollo ◽  
Nadia Gruber ◽  
Liliana R. Orelli

Neglected diseases due to the parasitic protozoa Leishmania and Trypanosoma (kinetoplastids) affect millions of people worldwide, and the lack of suitable treatments has promoted an ongoing drug discovery effort to identify novel nontoxic and cost-effective chemotherapies. Polyamines are ubiquitous small organic molecules that play key roles in kinetoplastid parasites metabolism, redox homeostasis and in the normal progression of cell cycles, which differ from those found in the mammalian host. These features make polyamines attractive in terms of antiparasitic drug development. The present work provides a comprehensive insight on the use of polyamine derivatives and related nitrogen compounds in the chemotherapy of kinetoplastid diseases. The amount of literature on this subject is considerable, and a classification considering drug targets and chemical structures were made. Polyamines, aminoalcohols and basic heterocycles designed to target the relevant parasitic enzyme trypanothione reductase are discussed in the first section, followed by compounds directed to less common targets, like parasite SOD and the aminopurine P2 transporter. Finally, the third section comprises nitrogen compounds structurally derived from antimalaric agents. References on the chemical synthesis of the selected compounds are reported together with their in vivo and/or in vitro IC50 values, and structureactivity relationships within each group are analyzed. Some favourable structural features were identified from the SAR analyses comprising protonable sites, hydrophobic groups and optimum distances between them. The importance of certain pharmacophoric groups or amino acid residues in the bioactivity of polyamine derived compounds is also discussed.


2013 ◽  
Vol 24 (2) ◽  
pp. 106-112 ◽  
Author(s):  
Dariusz Man ◽  
Izabella Pisarek ◽  
Michał Braczkowski ◽  
Barbara Pytel ◽  
Ryszard Olchawa

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 330
Author(s):  
Timofey V. Malyarenko ◽  
Alla A. Kicha ◽  
Valentin A. Stonik ◽  
Natalia V. Ivanchina

Sphingolipids are complex lipids widespread in nature as structural components of biomembranes. Commonly, the sphingolipids of marine organisms differ from those of terrestrial animals and plants. The gangliosides are the most complex sphingolipids characteristic of vertebrates that have been found in only the Echinodermata (echinoderms) phylum of invertebrates. Sphingolipids of the representatives of the Asteroidea and Holothuroidea classes are the most studied among all echinoderms. In this review, we have summarized the data on sphingolipids of these two classes of marine invertebrates over the past two decades. Recently established structures, properties, and peculiarities of biogenesis of ceramides, cerebrosides, and gangliosides from starfishes and holothurians are discussed. The purpose of this review is to provide the most complete information on the chemical structures, structural features, and biological activities of sphingolipids of the Asteroidea and Holothuroidea classes.


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