scholarly journals Current Status of and Future Perspectives in Bacterial Degradation of Benzo[a]pyrene

2020 ◽  
Vol 18 (1) ◽  
pp. 262
Author(s):  
Alexis Nzila ◽  
Musa M. Musa
Keyword(s):  
Molecular Weight ◽  
Current Knowledge ◽  
Bacterial Degradation ◽  
Current Status ◽  
Low Molecular Weight ◽  
Aromatic Rings ◽  
High Chemical ◽  
Compound A ◽  
Current Review ◽  
High Chemical Stability

Benzo[a]pyrene (BaP) is one the main pollutants belonging to the high-molecular-weight PAHs (HMW-PAHs) class and its degradation by microorganisms remains an important strategy for its removal from the environment. Extensive studies have been carried out on the isolation and characterisation of microorganisms that can actively degrade low-molecular-weight PAHs (LMW-PAHs), and to a certain extent, the HMW-PAH pyrene. However, so far, limited work has been carried out on BaP biodegradation. BaP consists of five fused aromatic rings, which confers this compound a high chemical stability, rendering it less amenable to biodegradation. The current review summarizes the emerging reports on BaP biodegradation. More specifically, work carried out on BaP bacterial degradation and current knowledge gaps that limit our understanding of BaP degradation are highlighted. Moreover, new avenues of research on BaP degradation are proposed, specifically in the context of the development of “omics” approaches.

scholarly journals Current Status of- and Future Perspectives in- Bacterial Degradation of Benzo[a]pyrene

2020 ◽  
Author(s):  
Alexis Nzila ◽  
Musa M. Musa
Keyword(s):  
Molecular Weight ◽  
Current Knowledge ◽  
Bacterial Degradation ◽  
Current Status ◽  
Low Molecular Weight ◽  
Future Perspectives ◽  
Aromatic Rings ◽  
Compound A ◽  
Current Review ◽  
Polycyclic Aromatic

Polycyclic aromatic hydrocarbons (PAHs), which consist of low-molecular-weight PAHs (LMW-PAHs) and high-molecular-weight PAHs (HMW-PAHs), form an important class of pollutants. Pyrene and benzo[a]pyrene (BaP) are the main pollutants belonging to HMW-PAHs, and their degradation by microorganisms remains an important strategy for their removal from the environments. Extensive studies have been carried out on the isolation and characterisation of microorganisms that actively degrade LMW-PAHs, and to a certain extent, the HMW-PAH pyrene. However, so far, limited work has been carried out on BaP biodegradation. BaP consists of five fused aromatic rings, which confers this compound a high stability, rendering it less amenable to biodegradation. The current review summarizes the emerging reports on BaP biodegradation. More specifically, work carried out on BaP bacterial degradation and current knowledge gaps that limit our understanding of BaP degradation are highlighted. Moreover, new avenues of research on BaP degradation are proposed, specifically in the context of the development of “omics” approaches

Low Molecular Weight Microfibers with Light Sensing Properties

2017 ◽  
Vol 54 (4) ◽  
pp. 655-658
Author(s):  
Andrei Bejan ◽  
Dragos Peptanariu ◽  
Bogdan Chiricuta ◽  
Elena Bicu ◽  
Dalila Belei
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Force Microscopy ◽  
Light Sensing ◽  
Sensing Applications ◽  
Atomic Force ◽  
Low Molecular Weight Compounds

Microfibers were obtained from organic low molecular weight compounds based on heteroaromatic and aromatic rings connected by aliphatic spacers. The obtaining of microfibers was proved by scanning electron microscopy. The deciphering of the mechanism of microfiber formation has been elucidated by X-ray diffraction, infrared spectroscopy, and atomic force microscopy measurements. By exciting with light of different wavelength, florescence microscopy revealed a specific optical response, recommending these materials for light sensing applications.

Synthesis and Liquid Crystalline Properties of Low Molecular Weight Bis-Chalcone Compounds

2021 ◽  
Vol 18 ◽  
Author(s):  
Anju K Sasidharan ◽  
Jomon Mathew ◽  
Ammathnadu S. Achalkumar ◽  
Manoj Mathews
Keyword(s):  
Molecular Weight ◽  
Liquid Crystalline ◽  
Low Molecular Weight ◽  
Aliphatic Chain ◽  
Aromatic Rings ◽  
Property Relationship ◽  
Crystalline Property ◽  
Liquid Crystalline Property ◽  
Mesomorphic Properties ◽  
Structure Liquid

Aim: In this paper, we report on the synthesis and liquid crystalline properties of some low molecular weight bis-chalcone compounds derived from acetone, cyclopentanone and cyclohexanone mesogenic cores. Background: Structurally bis-chalcones belong to a broader family of chalcone compounds. Chalcone is a compound that consists of two aromatic rings linked by an unsaturated objective. Liquid crystalline chalcones are prepared by aliphatic chain substituents on two aromatic rings. Chalcones are well studied for their mesomorphic properties. Compared to a large number of chalcone based LCs reported, only a few articles have been published on the mesomorphic properties of bis-chalcone compounds. The target compounds of the present study varied not only in their central core but also in number and position of terminal aliphatic chain substitutiona key structural unit in deciding the liquid crystalline properties of a compound. Method: All target compounds were synthesized in good yield by base catalyzed Claisen-Schmidt condensation reaction. Molecular structures were confirmed by FT-IR, 1H NMR, 13C NMR, and mass spectroscopic methods. Liquid crystalline property of these compounds was evaluated using polarizing optical microscopy and differential scanning calorimetry. Results: Although none of the acetone based compounds exhibited mesomorphism, cyclopentanone and cyclohexanone based compounds with octyloxy chain at para position on either side of the dibenzylidine ring stabilized liquid crystalline smectic (SmA and SmC) and nematic (N) phases. The observed structure-liquid crystalline property relationship was explained by structural analysis of molecules using DFT calculations. Considering the inherent photoluminescence nature of the chalcone moiety, a preliminary study was carried out on a selected compound to reveal its fluorescence property. Conclusion: Our study brings about an important structure-liquid crystalline property relationship in a relatively unexplored class of bis-chalcone liquid crystals.

scholarly journals Non-Extractable Polyphenols from Food By-Products: Current Knowledge on Recovery, Characterisation, and Potential Applications

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 925
Author(s):  
Yubin Ding ◽  
Ksenia Morozova ◽  
Matteo Scampicchio ◽  
Giovanna Ferrentino
Keyword(s):  
Molecular Weight ◽  
Current Knowledge ◽  
Biological Activities ◽  
Extraction Procedure ◽  
Economic Loss ◽  
Low Molecular Weight ◽  
Potential Applications ◽  
Valuable Compounds ◽  
Potential Food ◽  
By Products

Non-extractable polyphenols (NEPs), or bound polyphenols, are a significant fraction of polyphenols that are retained in the extraction residues after conventional aqueous organic solvent extraction. They include both high molecular weight polymeric polyphenols and low molecular weight phenolics attached to macromolecules. Current knowledge proved that these bioactive compounds possess high antioxidant, antidiabetic, and other biological activities. Plant-based food by-products, such as peels, pomace, and seeds, possess high amount of NEPs. The recovery of these valuable compounds is considered an effective way to recycle food by-products and mitigate pollution, bad manufacturing practice, and economic loss caused by the residues management. The current challenge to valorise NEPs from plant-based by-products is to increase the extraction efficiency with proper techniques, choose appropriate characterising methods, and explore potential functions to use in some products. Based on this scenario, the present review aims to summarise the extraction procedure and technologies applied to recover NEPs from plant-based by-products. Furthermore, it also describes the main techniques used for the characterisation of NEPs and outlines their potential food, pharmaceutical, nutraceutical, and cosmetic applications.

Parenteral anticoagulants in heart disease: Current status and perspectives (Section II)

2013 ◽  
Vol 109 (05) ◽  
pp. 769-786 ◽  
Author(s):  
Steen Husted ◽  
Lars Wallentin ◽  
Felicita Andreotti ◽  
Harald Arnesen ◽  
Fedor Bachmann ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Heart Disease ◽  
Unfractionated Heparin ◽  
Heart Diseases ◽  
Thrombin Inhibitors ◽  
Current Status ◽  
Direct Thrombin Inhibitors ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Ongoing Research

SummaryAnticoagulants are a mainstay of cardiovascular therapy, and parenteral anticoagulants have widespread use in cardiology, especially in acute situations. Parenteral anticoagulants include unfractionated heparin, low-molecular-weight heparins, the synthetic pentasaccharides fondaparinux, idraparinux and idrabiotaparinux, and parenteral direct thrombin inhibitors. The several shortcomings of unfractionated heparin and of low-molecular-weight heparins have prompted the development of the other newer agents. Here we review the mechanisms of action, pharmacological properties and side effects of parenteral anticoagulants used in the management of coronary heart disease treated with or without percutaneous coronary interventions, cardioversion for atrial fibrillation, and prosthetic heart valves and valve repair. Using an evidence-based approach, we describe the results of completed clinical trials, highlight ongoing research with currently available agents, and recommend therapeutic options for specific heart diseases.

scholarly journals The significance of pyrogenic polycyclic aromatic hydrocarbons in Borneo peat core for the reconstruction of fire history

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256853
Author(s):  
Sher-Rine Kong ◽  
Masanobu Yamamoto ◽  
Hasrizal Shaari ◽  
Ryoma Hayashi ◽  
Osamu Seki ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Fire History ◽  
Low Molecular Weight ◽  
Aromatic Rings ◽  
Peat Core ◽  
Polycyclic Aromatic ◽  
Core Depth ◽  
Similar Depth

The reconstruction of fire history is essential to understand the palaeoclimate and human history. Polycyclic aromatic hydrocarbons (PAHs) have been extensively used as a fire marker. In this work, the distribution of PAHs in Borneo peat archives was investigated to understand how PAHs reflect the palaeo-fire activity. In total, 52 peat samples were analysed from a Borneo peat core for the PAH analysis. Pyrogenic PAHs consist of 2–7 aromatic rings, some of which have methyl and ethyl groups. The results reveal that the concentration of pyrogenic PAHs fluctuated with the core depth. Compared to low-molecular-weight (LMW) PAHs, the high-molecular-weight (HMW) PAHs had a more similar depth variation to the charcoal abundance. This finding also suggests that the HMW PAHs were mainly formed at a local fire near the study area, while the LMW PAHs could be transported from remote locations.

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