scholarly journals Low Molecular Weight Fluorescent Probes (LMFPs) to Detect the Group 12 Metal Triad

Chemosensors ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 22 ◽  
Author(s):  
Ashley D. Johnson ◽  
Rose M. Curtis ◽  
Karl J. Wallace
Keyword(s):  
Molecular Weight ◽  
Metal Ions ◽  
21St Century ◽  
Fluorescent Probes ◽  
Environmental Applications ◽  
Chemical Characteristics ◽  
Low Molecular Weight ◽  
Fluorescence Sensing ◽  
Similar Chemical ◽  
Group 12

Fluorescence sensing, of d-block elements such as Cu2+, Fe3+, Fe2+, Cd2+, Hg2+, and Zn2+ has significantly increased since the beginning of the 21st century. These particular metal ions play essential roles in biological, industrial, and environmental applications, therefore, there has been a drive to measure, detect, and remediate these metal ions. We have chosen to highlight the low molecular weight fluorescent probes (LMFPs) that undergo an optical response upon coordination with the group 12 triad (Zn2+, Cd2+, and Hg2+), as these metals have similar chemical characteristics but behave differently in the environment.

Isocyanonaphthalenes as extremely low molecular weight, selective, ratiometric fluorescent probes for Mercury(II)

Talanta ◽  
2019 ◽  
Vol 201 ◽  
pp. 165-173 ◽  
Author(s):  
Miklós Nagy ◽  
Sándor Lajos Kovács ◽  
Tibor Nagy ◽  
Dávid Rácz ◽  
Miklós Zsuga ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Fluorescent Probes ◽  
Low Molecular Weight

Low-molecular-weight heparin from Cu2+ and Fe2+ Fenton type depolymerisation processes

2010 ◽  
Vol 103 (03) ◽  
pp. 613-622 ◽  
Author(s):  
Monica Pierini ◽  
Lino Liverani ◽  
Marcelo Lima ◽  
Marco Guerrini ◽  
Giangiacomo Torri ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Transition Metal ◽  
Metal Ions ◽  
Low Molecular Weight Heparin ◽  
Transition Metal Ions ◽  
Low Molecular Weight ◽  
Oh Radicals ◽  
Hydrogen Atoms ◽  
Radical Chain ◽  
Radical Processes

SummaryHydrogen peroxide (H2O2) and Cu(OAc)2 or FeSO4 (Fenton type reagents) perform heparin (Hep) depolymerisation to low-molecular-weight heparin (LMWH) following a radical chain mechanism. Hydroxyl (OH) radicals which are initially generated from H2O2 reduction by transition metal ions abstract hydrogen atoms on the heparin chain providing carbon centred radicals whose decay leads to the depolymerisation process. The main depolymerisation mechanism involves Hep radical intermediates that cleave the glycosidic linkage at unsulphated uronic acids followed by a 6-O-nonsulphated glucosamine, thus largely preserving the pentasaccharide sequence responsible for the binding to antithrombin III (AT). Both the transition metal ions influence the overall efficiency of the radical chain processes: Fe2+ acting as a catalyst, while Cu2+ acts as a reagent. LMWHs, especially those afforded by Cu2+, are somewhat unstable to the usual basic workup. However, this lack of stability can be eliminated by a previous NaBH4 reduction. Furthermore, with Cu2+, the process is much more reproducible than with Fe2+. Therefore, for the process of Fenton type depolymerisation of heparin, the use of Cu(OAc)2 is clearly preferable to the more “classical” FeSO4. The resulting activities and characteristics of these LMWHs are peculiar to these oxidative radical processes. In addition, LMWH provided by H2O2/Cu(OAc)2 in optimised conditions was found to posses anti-Xa and anti-IIa activities comparable to those of LMWHs currently in clinical use.Footnote: Dedicated to Prof. Pietro Bianchini.

scholarly journals Dynamic utilization of low-molecular-weight organic substrates across a microbial growth rate gradient

2021 ◽  
Author(s):  
K. Taylor Cyle ◽  
Annaleise R. Klein ◽  
Ludmilla Aristilde ◽  
Carmen Enid Martínez
Keyword(s):  
Molecular Weight ◽  
Growth Rate ◽  
Soil Solution ◽  
Oxidation State ◽  
Fungal Isolate ◽  
Chemical Characteristics ◽  
Low Molecular Weight ◽  
Bacterial Isolates ◽  
Ralstonia Pickettii ◽  
Use Efficiency

AbstractConstantly in flux, low-molecular-weight organic substances (LMWOSs) are at the nexus between microorganisms, plant roots, detritus, and the soil mineral matrix. Nominal oxidation state of carbon (NOSC) has been put forward as one way to parameterize microbial uptake rates of LMWOSs and efficiency of carbon incorporation into new biomass. In this study, we employed an ecophysiological approach to test these proposed relationships using targeted exometabolomics (1H-NMR, HR-LCMS) coupled with stable isotope (13C) probing. We assessed the role of compound class and oxidation state on uptake kinetics and substrate-specific carbon use efficiency (SUE) during the growth of three model soil microorganisms (Penicillium spinulosum, Paraburkholderia solitsugae, and Ralstonia pickettii) in media containing 34 common LMWOSs. Microbial isolates were chosen to span a gradient in growth rate (0.046-0.316 hr−1) and differ phylogenetically (a fungal isolate and two bacterial isolates). Clustered, co-utilization of LMWOSs occured for all three organisms, but temporal cluster separation was most apparent for P. solitsugae. Potential trends (p <0.05) for early utilization of more oxidized substrates were present for the two bacterial isolates (P. solitsugae and R. pickettii), but high variability (R2 > 0.15) and a small effect of NOSC indicate these are not useful relationships for prediction. The SUEs ranged from 0.16-0.99 and the hypothesized inverse relationship between NOSC and SUE was not observed. Thus, our results do not provide compelling support for NOSC as a predictive tool, implying that metabolic strategies of organisms may be more important than chemical identity in determining LMWOS cycling in soils.ImportanceCommunity-level observations from soils indicate that low-molecular-weight compounds of higher oxidation state tend to be depleted from soil solution faster and incorporated less efficiently into microbial biomass under oxic conditions. Here, we tested hypothetical relationships between substrate chemical characteristics and the order of substrate utilization by aerobic heterotrophs at the population-level in culture, using two bacterial isolates (Ralstonia pickettii and Paraburkholderia solitsugae) and one fungal isolate from soil (Penicillium spinulosum). We found weak relationships indicating earlier uptake of more oxidized substrates by the two bacterial isolates but no relationship for the fungal isolate. We found no relationship between substrate identity and substrate use efficiency. Our findings indicate that substrate chemical characteristics have limited utility for modeling the depletion of low-molecular-weight organics from soil solution and incorporation into biomass over broader phylogenetic gradients.

Taste and chemical characteristics of low molecular weight fractions from tofuyo – Japanese fermented soybean curd

2018 ◽  
Vol 252 ◽  
pp. 265-270 ◽  
Author(s):  
Hanifah Nuryani Lioe ◽  
Ayano Kinjo ◽  
Shin Yasuda ◽  
Megumi Kuba-Miyara ◽  
Shinjiro Tachibana ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chemical Characteristics ◽  
Low Molecular Weight ◽  
Fermented Soybean ◽  
Soybean Curd ◽  
Molecular Weight Fractions
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