scholarly journals Application and Construction of Microbial Biosensors in Chemical Forensics

2021 ◽  
Author(s):  
◽  
Justine Couper
Keyword(s):  
Illicit Drugs ◽  
Solid Phase ◽  
Preliminary Investigation ◽  
Inducible Promoter ◽  
Lower Sensitivity ◽  
Initial Water ◽  
Wide Range ◽  
Lux Biosensor ◽  
Analytical Time

<p>Forensic toxicologists are often required to rapidly determine if a suspicious substance, such as a white powder, contain toxins. Preliminary tests usually include screens for a wide range of 'Potentially Toxic Chemicals' (PTCs) such as cyanide, pesticides, herbicides, medicinal and illicit drugs. Subsequent analyses are generally very time-consuming and costly. Any protocol screening for a range of PTC's, prior to more robust chemical analysis, could therefore save significant analytical time. Microbial biosensors are ideal biological tools that can be utilised for these purposes. In vivo bioassays were developed for a range of PTCs using a suite of microbial biosensors, in a variety of complex matrices including water, white powders, soils and vomit to determine the effect of matrix complexities on the biosensors, as well as the toxins. The lux biosensor, Escherichia coli HB101 pUCD607, showed an EC50, (where EC50 is the effective concentration of toxin causing 50% reduction in bioluminescence), of cyanide in water of 20 mg/L. This biosensor still detected cyanide, in talc and flour, at EC50 values of 589 mg/L and 700 mg/L respectively. Vibrio harveyi showed good sensitivity to cyanide in initial water bioassays with an EC50 of 9.66 mg/L. The V. harveyi biosensor did not detect cyanide spiked in talc or flour when tested up to a maximum concentration of 10,000 mg/L. The Mycena citricolor ATCC 34884 fungal biosensor, showed lower sensitivity levels however it detected the presence of sodium monofluoroacetate (1080) at a concentration 1000 mg/L. Preliminary investigation of a novel, faster, solid-phase sample preparation method was also undertaken and its potential proven, particularly in PTC spiked white powders. Here the biosensor showed sensitivity to arsenate, arsenite, copper, cyanide and PCP at 1000 mg/L.This project highlighted the inability of current biosensors to reliably detect 1080 and the difficulty in constructing a specific biosensor. The utilisation of a reliable vector and inducible promoter are pivotal in biosensor construction.</p>

scholarly journals Application and Construction of Microbial Biosensors in Chemical Forensics

2021 ◽  
Author(s):  
◽  
Justine Couper
Keyword(s):  
Illicit Drugs ◽  
Solid Phase ◽  
Preliminary Investigation ◽  
Inducible Promoter ◽  
Lower Sensitivity ◽  
Initial Water ◽  
Wide Range ◽  
Lux Biosensor ◽  
Analytical Time

<p>Forensic toxicologists are often required to rapidly determine if a suspicious substance, such as a white powder, contain toxins. Preliminary tests usually include screens for a wide range of 'Potentially Toxic Chemicals' (PTCs) such as cyanide, pesticides, herbicides, medicinal and illicit drugs. Subsequent analyses are generally very time-consuming and costly. Any protocol screening for a range of PTC's, prior to more robust chemical analysis, could therefore save significant analytical time. Microbial biosensors are ideal biological tools that can be utilised for these purposes. In vivo bioassays were developed for a range of PTCs using a suite of microbial biosensors, in a variety of complex matrices including water, white powders, soils and vomit to determine the effect of matrix complexities on the biosensors, as well as the toxins. The lux biosensor, Escherichia coli HB101 pUCD607, showed an EC50, (where EC50 is the effective concentration of toxin causing 50% reduction in bioluminescence), of cyanide in water of 20 mg/L. This biosensor still detected cyanide, in talc and flour, at EC50 values of 589 mg/L and 700 mg/L respectively. Vibrio harveyi showed good sensitivity to cyanide in initial water bioassays with an EC50 of 9.66 mg/L. The V. harveyi biosensor did not detect cyanide spiked in talc or flour when tested up to a maximum concentration of 10,000 mg/L. The Mycena citricolor ATCC 34884 fungal biosensor, showed lower sensitivity levels however it detected the presence of sodium monofluoroacetate (1080) at a concentration 1000 mg/L. Preliminary investigation of a novel, faster, solid-phase sample preparation method was also undertaken and its potential proven, particularly in PTC spiked white powders. Here the biosensor showed sensitivity to arsenate, arsenite, copper, cyanide and PCP at 1000 mg/L.This project highlighted the inability of current biosensors to reliably detect 1080 and the difficulty in constructing a specific biosensor. The utilisation of a reliable vector and inducible promoter are pivotal in biosensor construction.</p>

scholarly journals In vivo and in vitro Volatile Constituents of the Flowers of Xylopia aromatica by HS‑SPME/GC-MS

2021 ◽  
Author(s):  
João Junqueira ◽  
Michelle do Nascimento ◽  
Lucas da Costa ◽  
Lincoln Romualdo ◽  
Francisco de Aquino ◽  
...  
Keyword(s):  
Solid Phase ◽  
Floral Scent ◽  
Principal Component ◽  
Gas Chromatography Mass Spectrometry ◽  
Large White ◽  
Volatile Constituents ◽  
Wide Range ◽  
First Time

Xylopia aromatica (Lam.) Mart. (Annonaceae) is a typical species from the Brazilian cerrado that presents medicinal properties. The plant is distinguished by its large white flowers which produce a pleasant fragrance. X. aromatica is characterized by a wide range of medicinal application. These characteristics have motivated us to investigate the flowers volatile organic compounds (VOCs) via in vivo and in vitro protocols by a headspace solid-phase microextraction (HS‑SPME) technique combined with gas chromatography-mass spectrometry (HS-SPME/GC‑MS). Four different fibers, extraction times and temperatures were the parameters changed to lead to the maximum profiling of the volatile constituents. Data were analyzed using principal component analysis (PCA). A total of 77 VOCs were extracted from the floral scent, with 52 and 68 extracted from in vivo and in vitro sampling, respectively, of which 48 were reported for the first time in the literature as volatile constituents from X. aromatica flowers. The extraction and identification of VOCs were successfully performed through HS-SPME/GC-MS. The PCA data allowed the identification of parameters that led to the maximum number of VOCs, which were polyacrylate (PA) and carboxen/polydimethylsiloxane (CAR/PDMS) fibers, 60 min extraction time and temperature of 29.0 °C. Among the volatile constituents identified, sesquiterpenes predominated, comprising about 61.04%.

scholarly journals Development, Optimization and Applications of Thin Film Solid Phase Microextraction (TF-SPME) Devices for Thermal Desorption: A Comprehensive Review

Separations ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 39 ◽  
Author(s):  
Ronald V. Emmons ◽  
Ramin Tajali ◽  
Emanuela Gionfriddo
Keyword(s):  
Thin Film ◽  
Thermal Desorption ◽  
Solid Phase Microextraction ◽  
Method Development ◽  
Solid Phase ◽  
Volume Ratio ◽  
Sampling Device ◽  
Wide Range ◽  
Ultra Trace

Through the development of solid phase microextraction (SPME) technologies, thin film solid phase microextraction (TF-SPME) has been repeatedly validated as a novel sampling device well suited for various applications. These applications, encompassing a wide range of sampling methods such as onsite, in vivo and routine analysis, benefit greatly from the convenience and sensitivity TF-SPME offers. TF-SPME, having both an increased extraction phase volume and surface area to volume ratio compared to conventional microextraction techniques, allows high extraction rates and enhanced capacity, making it a convenient and ideal sampling tool for ultra-trace level analysis. This review provides a comprehensive discussion on the development of TF-SPME and the applications it has provided thus far. Emphasis is given on its application to thermal desorption, with method development and optimization for this desorption method discussed in detail. Moreover, a detailed outlook on the current progress of TF-SPME development and its future is also discussed with emphasis on its applications to environmental, food and fragrance analysis.

scholarly journals Bioactive form of resveratrol in glioblastoma cells and its safety for normal brain cells

2013 ◽  
Vol 3 (5) ◽  
pp. 146 ◽  
Author(s):  
Xiao-Hong Shu ◽  
Hong Li ◽  
Xiao-Xin Sun ◽  
Zheng Sun ◽  
Li-Li Wang ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase ◽  
Biological Activities ◽  
Brain Cells ◽  
Normal Brain ◽  
Glioblastoma Cells ◽  
Wide Range ◽  
U251 Cells

Background: Resveratrol, a plant polyphenol existing in grapes and many other natural foods, possesses a wide range of biological activities including cancer prevention. It has been recognized that resveratrol is intracellularly biotransformed to different metabolites, but no direct evidence has been available to ascertain its bioactive form because of the difficulty to maintain resveratrol unmetabolized in vivo or in vitro. It would be therefore worthwhile to elucidate the potential therapeutic implications of resveratrol metabolism using a reliable resveratrol-sensitive cancer cells.Objective: To identify the real biological form of trans-resveratrol and to evaluate the safety of the effective anticancer dose of resveratrol for the normal brain cells.Methods: The samples were prepared from the condition media and cell lysates of human glioblastoma U251 cells, and were purified by solid phase extraction (SPE). The samples were subjected to high performance liquid chromatography (HPLC) and liquid chromatography/tandem mass spectrometry (LC/MS) analysis. According to the metabolite(s), trans-resveratrol was biotransformed in vitro by the method described elsewhere, and the resulting solution was used to treat U251 cells. Meanwhile, the responses of U251 and primarily cultured rat normal brain cells (glial cells and neurons) to 100μM trans-resveratrol were evaluated by multiple experimental methods.Results: The results revealed that resveratrol monosulfate was the major metabolite in U251 cells. About half fraction of resveratrol monosulfate was prepared in vitro and this trans-resveratrol and resveratrol monosulfate mixture showed little inhibitory effect on U251 cells. It is also found that rat primary brain cells (PBCs) not only resist 100μM but also tolerate as high as 200μM resveratrol treatment. Conclusions: Our study thus demonstrated that trans-resveratrol was the bioactive form in glioblastoma cells and, therefore, the biotransforming activity of trans-resveratrol would be reversely correlated with the chemosensitivity of the treated cells. The findings from PBCs suggest that an effective anti-glioblastoma dose of resveratrol may not exert side-effect on normal brain cells, providing a strong evidence for practical use of resveratrol in the management of human brain malignancies.Key words: Resveratrol, glioblastoma, drug metabolism

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

Analysis of Aromatic Amines in Industrial Wastewater by Capillary Gas Chromatography-Mass Spectrometry

2000 ◽  
Vol 35 (2) ◽  
pp. 245-262 ◽  
Author(s):  
Francis I. Onuska ◽  
Ken A. Terry ◽  
R. James Maguire
Keyword(s):  
Gas Chromatography ◽  
Aromatic Amines ◽  
Methylene Chloride ◽  
Solid Phase ◽  
Stationary Phases ◽  
Gas Chromatography Mass Spectrometry ◽  
Substituted Anilines ◽  
Environmental Media ◽  
Solid Phase Extraction Cartridge ◽  
Wide Range

Abstract The analysis of aromatic amines, particularly benzidines, at trace levels in environmental media has been difficult because of the lack of suitable deactivated capillary column stationary phases for gas chromatography. This report describes the use of an improved type of column as well as a method for the analysis of anilines and benzidines in water, wastewater and sewage samples. Extraction procedures are applicable to a wide range of compounds that are effectively partitioned from an aqueous matrix into methylene chloride, or onto a solid-phase extraction cartridge. The extracted analytes are also amenable to separation on a capillary gas chromatographic column and transferable to the mass spectrometer. These contaminants are converted to their N-trifluoroacetyl derivatives. Aniline and some substituted anilines, and 3,3’-dichlorobenzidine and benzidine were determined in 24-h composite industrial water, wastewater, primary sludge and final effluent samples at concentrations from 0.03 up to 2760 µg/L.

Recent Application of Polystyrene-supported Triphenylphosphine in Solid-Phase Organic Synthesis

2019 ◽  
Vol 23 (6) ◽  
pp. 643-678
Author(s):  
Lalthazuala Rokhum ◽  
Ghanashyam Bez
Keyword(s):  
Organic Synthesis ◽  
Combinatorial Chemistry ◽  
Solid Phase ◽  
Recent Application ◽  
Organic Transformations ◽  
Solid Phase Organic Synthesis ◽  
Wide Range ◽  
Fast Development ◽  
Polymer Supported

Recent years have witnessed a fast development of solid phase synthetic pathways, a variety of solid-supported reagent and its applications in diverse synthetic strategies and pharmaceutical applicability’s. Polymer-supported triphenylphosphine is getting a lot of applications owing to the speed and simplicity in the process. Furthermore, ease of recyclability and reuse of polymer-supported triphenylphosphine added its advantages. This review covers a wide range of useful organic transformations which are accomplished using cross-linked polystyrene-supported triphenylphosphine with the aim of giving renewed interest in the field of organic and medicinal-combinatorial chemistry.

Ethnomedicinal uses, Phytochemistry and Pharmacological Aspects of the Genus Berberis Linn: A Comprehensive Review

2020 ◽  
Vol 23 ◽  
Author(s):  
Roohi Mohi-ud-din ◽  
Reyaz Hassan Mir ◽  
Prince Ahad Mir ◽  
Saeema Farooq ◽  
Syed Naiem Raza ◽  
...  
Keyword(s):  
Chemical Constituents ◽  
Pharmacological Activities ◽  
Traditional Use ◽  
Comprehensive Review ◽  
Wide Range ◽  
Anti Cancer ◽  
Comprehensive Survey ◽  
Ethnomedicinal Uses

Background: Genus Berberis (family Berberidaceae), which contains about 650 species and 17 genera worldwide, has been used in folklore and various traditional medicine systems. Berberis Linn. is the most established group among genera with around 450-500 species across the world. This comprehensive review will not only help researchers for further evaluation but also provide substantial information for future exploitation of species to develop novel herbal formulations. Objective: The present review is focussed to summarize and collect the updated review of information of Genus Berberis species reported to date regarding their ethnomedicinal information, chemical constituents, traditional/folklore use, and reported pharmacological activities on more than 40 species of Berberis. Conclusion: A comprehensive survey of the literature reveals that various species of the genus possess various phytoconstituents mainly alkaloids, flavonoid based compounds isolated from different parts of a plant with a wide range of pharmacological activities. So far, many pharmacological activities like anti-cancer, anti-hyperlipidemic, hepatoprotective, immunomodulatory, anti-inflammatory both in vitro & in vivo and clinical study of different extracts/isolated compounds of different species of Berberis have been reported, proving their importance as a medicinal plant and claiming their traditional use.

Current Status and Future Perspective for Research on Medicinal Plants with Anticancerous Activity and Minimum Cytotoxic Value

2019 ◽  
Vol 20 (12) ◽  
pp. 1227-1243
Author(s):  
Hina Qamar ◽  
Sumbul Rehman ◽  
D.K. Chauhan
Keyword(s):  
Side Effects ◽  
Medicinal Plants ◽  
Anticancer Agents ◽  
Drug Targets ◽  
Psidium Guajava ◽  
Current Status ◽  
Future Perspective ◽  
Wide Range

Cancer is the second leading cause of morbidity and mortality worldwide. Although chemotherapy and radiotherapy enhance the survival rate of cancerous patients but they have several acute toxic effects. Therefore, there is a need to search for new anticancer agents having better efficacy and lesser side effects. In this regard, herbal treatment is found to be a safe method for treating and preventing cancer. Here, an attempt has been made to screen some less explored medicinal plants like Ammania baccifera, Asclepias curassavica, Azadarichta indica, Butea monosperma, Croton tiglium, Hedera nepalensis, Jatropha curcas, Momordica charantia, Moringa oleifera, Psidium guajava, etc. having potent anticancer activity with minimum cytotoxic value (IC50 >3μM) and lesser or negligible toxicity. They are rich in active phytochemicals with a wide range of drug targets. In this study, these medicinal plants were evaluated for dose-dependent cytotoxicological studies via in vitro MTT assay and in vivo tumor models along with some more plants which are reported to have IC50 value in the range of 0.019-0.528 mg/ml. The findings indicate that these plants inhibit tumor growth by their antiproliferative, pro-apoptotic, anti-metastatic and anti-angiogenic molecular targets. They are widely used because of their easy availability, affordable price and having no or sometimes minimal side effects. This review provides a baseline for the discovery of anticancer drugs from medicinal plants having minimum cytotoxic value with minimal side effects and establishment of their analogues for the welfare of mankind.

Approach in improving potency and selectivity of kinase inhibitors: Allosteric kinase inhibitors

2020 ◽  
Vol 21 ◽  
Author(s):  
Shangfei Wei ◽  
Tianming Zhao ◽  
Jie Wang ◽  
Xin Zhai
Keyword(s):  
Protein Interactions ◽  
Kinase Inhibitors ◽  
Binding Modes ◽  
Allosteric Inhibitors ◽  
Wide Range ◽  
Allosteric Sites ◽  
Protein Functions ◽  
Regulate Protein

: Allostery is an efficient and particular regulatory mechanism to regulate protein functions. Different from conserved orthosteric sites, allosteric sites have distinctive functional mechanism to form the complex regulatory network. In drug discovery, kinase inhibitors targeting the allosteric pockets have received extensive attention for the advantages of high selectivity and low toxicity. The approval of trametinib as the first allosteric inhibitor validated that allosteric inhibitors could be used as effective therapeutic drugs for treatment of diseases. To date, a wide range of allosteric inhibitors have been identified. In this perspective, we outline different binding modes and potential advantages of allosteric inhibitors. In the meantime, the research processes of typical and novel allosteric inhibitors are described briefly in terms of structureactivity relationships, ligand-protein interactions and in vitro and in vivo activity. Additionally, challenges as well as opportunities are presented.

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