Application of Optimized and Validated Agar Overlay TLC–Bioautography Assay for Detecting the Antimicrobial Metabolites of Pharmaceutical Interest

2020 ◽  
Vol 58 (8) ◽  
pp. 737-746 ◽  
Author(s):  
Bettadapura Rameshgowda Nuthan ◽  
Devaraju Rakshith ◽  
Kuppuru Mallikarjunaiah Marulasiddaswamy ◽  
H C Yashavantha Rao ◽  
Kolathur Puttamadaiah Ramesha ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Tlc Bioautography ◽  
Relative Standard ◽  
Acceptable Method ◽  
Ft Ir ◽  
Antimicrobial Metabolite ◽  
In Situ Detection ◽  
Antimicrobial Metabolites

Abstract The agar overlay TLC–bioautography is one of the crucial methods for simultaneous in situ detection and separation of antimicrobial metabolites of pharmaceutical interest. The main focus of this research relies on the dereplication of an antimicrobial metabolite coriloxin derived from mycoendophytic Xylaria sp. NBRTSB-20 with a validation of agar overlay TLC–bioautography technique. This polyketide metabolite coriloxin was purified by column chromatography, and its purity was assessed by HPLC, UPLC-ESI-QTOF-MS, FT-IR and NMR spectral analysis. The antimicrobial capability of ethyl acetate extract and the purified compound coriloxin was determined by disc diffusion, minimal inhibitory concentration and agar overlay TLC–bioautography assay. The visible LOD of coriloxin antimicrobial activity was found at 10 μg for Escherichia coli and 20 μg for both Staphylococcus aureus and Fusarium oxysporum. Inter- and intra-day precision was determined as the relative standard deviation is less than 6.56%, which proved that this method was precise. The accuracy was expressed as recovery, and the values were found ranging from 91.18 to 108.73% with RSD values 0.94–2.30%, respectively. The overall findings of this investigation suggest that agar overlay TLC–bioautography assay is a suitable and acceptable method for the in situ determination of antimicrobial pharmaceuticals.

A Facile In-Situ Development of L-Valine Film onto the Surface of Carbon Paste Electrode Towards the Detection of Environmentally Hazardous 4-Amino Phenol

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
T. Venu Gopal ◽  
Tukiakula Madhusudana Reddy ◽  
P. Shaikshavali ◽  
G. Venkataprasad ◽  
P. Gopal
Keyword(s):  
Cyclic Voltammetry ◽  
Carbon Paste Electrode ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Small Scale ◽  
Carbon Paste ◽  
Relative Standard ◽  
Paste Electrode

Abstract A small scale of environmentally hazardous 4-aminophenol can show significant impact on human health. Hence, in the present work, we have designed L-Valine film (Vf) modified carbon paste electrode (Vf/CPE) for the determination of 4-aminophenol. Herein, a facile in-situ L-Valine film was developed by electrochemical polymerization method onto the surface of bare carbon paste electrode (BCPE) with the help of cyclic voltammetry (CV) technique. A two-folds of electrochemical peak current enhancement was achieved at Vf/CPE in comparison with BCPE towards the determination of 4-aminophenol in optimum pH 7.0 of phosphate buffer solution (PBS). This was achieved due to the large surface area and conductive nature of Vf/CPE, which was concluded through the techniques of cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The effect of pH of buffer and scan rate studies were successfully studied. Morphological changes of BCPE and Vf/CPE was studied with the help of scanning electron microscopy (SEM). The formation of Vf on CPE was also analyzed by Fourier transform infrared (FTIR) spectra. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) values of 4-aminophenol were estimated with the aid of chronoamperometry (CA) technique and was found to be 9.8 μM and 32 μM, respectively. Finally the proposed method was found to have satisfactory repeatability, reproducibility and stability results with low relative standard deviation (RSD) values.

A method of high sensitivity and in situ determination of trace cobalt(II) in water samples with salicyl fluorone

2014 ◽  
Vol 70 (7) ◽  
pp. 1182-1187 ◽  
Author(s):  
Zhe Chen ◽  
Hua Li
Keyword(s):  
Flow Injection ◽  
Water Samples ◽  
High Sensitivity ◽  
Basic Solution ◽  
Optimum Conditions ◽  
Cetylpyridinium Bromide ◽  
Test Conditions ◽  
Relative Standard

Based on the sensitive reaction of Co(II) and salicyl fluorone with the presence of cetylpyridinium bromide in basic solution, a new method of flow injection micelle-solubilized spectrophotometry was developed for the determination of cobalt. The reaction was monitored for the absorbance of Co(II) at 540 nm. The reagents, flow injection variables and effects of foreign ions were investigated and the optimum conditions were established. At the optimum test conditions, the developed method provides a linearity range of 3–40 μg L−1 with a detection limit of 0.1 μg L−1 at about 60 h−1 sampling frequency. Relative standard deviation of 0.91, 0.95 and 0.89% were obtained for the determination of 3, 15 and 30 μg L−1 Co(II) solution. The proposed method has been successfully applied for analysis of trace amounts of cobalt in water samples.

scholarly journals Bacterial Concentration Detection using a PCB-based Contactless Conductivity Sensor

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 55 ◽  
Author(s):  
Xiao-Yan Zhang ◽  
Zhe-Yu Li ◽  
Yu Zhang ◽  
Xiao-Qian Zang ◽  
Kosei Ueno ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Printed Circuit Board ◽  
System Size ◽  
Circuit Board ◽  
Plate Count ◽  
Capacitively Coupled ◽  
Conductivity Sensor ◽  
Relative Standard ◽  
In Situ Detection

Capacitively coupled contactless conductivity detection (C4D) is an improved approach to avoid the problems of labor-intensive, time-consuming and insufficient accuracy of plate count as well as the high-cost apparatus of flow cytometry (FCM) in bacterial counting. This article describes a novel electrode-integrated printed-circuit-board (PCB)-based C4D device, which supports the simple and safe exchange of capillaries and improves the sensitivity and repeatability of the contactless detection. Furthermore, no syringe pump is needed in the detection, it reduces the system size, and, more importantly, avoids the effect on the bacteria due to high pressure. The recovered bacteria after C4D detection at excitation of 25 Vpp and 60–120 kHz were analyzed by flow cytometry, and a survival rate higher than 96% was given. It was verified that C4D detection did not influence the bacterial viability. Moreover, bacteria concentrations from 106 cells/mL to 108 cells/mL were measured in a linear range, and relative standard deviation (RSD) is below 0.2%. In addition, the effects on bacteria and C4D from background solutions were discussed. In contrast to common methods used in most laboratories, this method may provide a simple solution to in situ detection of bacterial cultures.

Determination of Matacil and Zectran by Fluorigenic Labeling, Thin Layer Chromatography, and In Situ Fluorimetry

1972 ◽  
Vol 55 (6) ◽  
pp. 1259-1264
Author(s):  
R W Frei ◽  
J F Lawrence
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Sulfonyl Chloride ◽  
Relative Standard ◽  
Dansyl Derivatives ◽  
Layer Chromatography ◽  
Derivatives Of ◽  
Fluorescent Derivatives

Abstract The fluorigenic labeling of Matacil (4-dimethylamino- m-tolyl N-methylcarbamate) and Zectran (4-dimethylamino-3,5-xylyl Wmethylcarbamate) with dansyl chloride (1-dimethylamino- naphthalene-5-sulfonyl chloride) results in 3 fluorescent derivatives, and labeling with NBD-Cl (4-chloro-7-nitrobenzo- 2,1,3-oxadiazole) produces 2 fluorescent derivatives for each carbamate, all of which can be separated by thin layer chromatography (TLC). These derivatives are identified by nuclear magnetic resonance, infrared, and fluorescence spectroscopy, aided by TLC data. The carbamates are hydrolyzed in dilute base and the resulting amine or phenol hydrolysis products react with the labeling reagents. The derivatives are analyzed by TLC and in situ fluorimetry with a spectrophotometer in the fluorescence mode and a spectrophotofluorometer with the thin layer scanning accessory. Reactions, fluorescence phenomena, and chromatographic properties of the derivatives are investigated for evaluation of the method as a quantitative technique. A reproducibility of 3–5% relative standard deviation can be expected in the concentration range from 15 to 300 ng/spot for derivatives of the 2 labeling procedures. The dansyl derivatives are instrumentally detectable as low as 1 ng/spot while the NBD derivatives may be detected at concentrations of less than 0.5 mg/spot.

scholarly journals Synthesis of a new organic probe 4-(4 acetamidophenylazo) pyrogallol for spectrophotometric determination of Bi(III) and Al(III) in pharmaceutical samples

2021 ◽  
Vol 40 (1) ◽  
pp. 108-126
Author(s):  
Jumana W. Ammar ◽  
Zainab A. Khan ◽  
Marwa N. Ghazi ◽  
Naser A. Naser
Keyword(s):  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Scanning Calorimetry ◽  
Spectrophotometric Methods ◽  
Modern Development ◽  
Relative Standard ◽  
Visible Spectra ◽  
Ft Ir ◽  
Linear Solvation Energy

Abstract A modern development discusses the synthesis and validity of simple, sensitive, and versatile spectrophotometric methods for Bi(III) and Al(III) determination in pharmaceutical formulations have been conducted. In the present paper, 4-(4 acetamidophenylazo) pyrogallol has been synthesized as a new organic compound, 4-APAP, by coupling pyrogallol in a regulated pH medium with diazotized p-aminoacetanilide. 4-APAP was identified by methods of FT-IR, 1H-NMR, 13C-NMR, and thermal analysis (thermogravimetry and differential scanning calorimetry). Solvatochromic activity was also studied in solvents with different polarities. The Kamlet and Taft linear solvation energy relationship was used to correlate shifts in UV-Visible spectra of 4-APAP with Kamlet-Taft parameters (α, β, and π*). The optimum assay conditions showed linearity from 0.3–13 to 0.5–11 μg·mL−1 for Bi(III) and Al(III), respectively. Molar absorptivity values were 3.365 × 104 and 0.356 × 104 L·mol−1·cm−1 for Bi(III) and Al(III), with similar Sandell's sensitivity measures of 0.006 and 0.008 μg·cm−2. Detection limits and quantification limits were 0.013 and 0.043 μg·mL−1 for Bi(III), respectively, and 0.018 and 0.059 μg·mL−1 for Al(III) with the relative standard deviation for determination of both metal ions using 4-APAP probe being <2.0%. The validity, accuracy, and efficiency of the approaches were demonstrated by the determination of Bi(III) and Al(III) in different formulations.

In situ determination of the grafting sites on nanosized ceramic powders by FT-IR spectrometry

1997 ◽  
Vol 9 (1-8) ◽  
pp. 319-322 ◽  
Author(s):  
M.-I. Baraton ◽  
F. Chancel ◽  
L. Merhari
Keyword(s):  
Ceramic Powders ◽  
Ir Spectrometry ◽  
Ft Ir

scholarly journals Determination of in situ detection efficiency for IM-NAA of non-standard geometrical samples

2021 ◽  
Vol 9 (4) ◽  
pp. 27-33
Author(s):  
Duy Quang Nguyen ◽  
Van Cuong Trinh ◽  
Tuan Anh Tran ◽  
Van Doanh Ho ◽  
Thi Tho Nguyen ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Standard Geometry ◽  
Activation Products ◽  
Geometrical Effects ◽  
In Situ Detection ◽  
Relative Detection

The k0-based internal mono-standard (IM) method was first proposed for the concentration analysis of samples of non-standard geometry in the 2000s. The method has demonstrated several advantages such as the elimination of gamma-ray self-attenuation and geometrical effects. On the other hand, the accuracy of the method principally depends on the in situ relative detection efficiency, which requires to be obtained in each measurement. Therefore, the relative detection efficiency is always under consideration for the improvement of the analysis results. The present paper describes a simple and automatic procedure for the determination of the relative efficiency using one or more activation products emitting gamma rays over a considered range of the spectrum. The procedure can be applied for INAA and PGNAA analysis.

scholarly journals In situ detection of live-to-dead bacteria ratio after inactivation by means of synchronous fluorescence and PCA

2018 ◽  
Vol 115 (4) ◽  
pp. 668-673 ◽  
Author(s):  
Runze Li ◽  
Umang Goswami ◽  
Maria King ◽  
Jie Chen ◽  
Thomas C. Cesario ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Rapid Detection ◽  
Fluorescence Spectra ◽  
Uv Light ◽  
Principal Component ◽  
Synchronous Fluorescence ◽  
Health Care Associated Infection ◽  
In Situ Detection

The determination of live and dead bacteria is of considerable significance for preventing health care-associated infection in hospitals, field clinics, and other areas. In this study, the viable (live) and nonviable (dead) bacteria in a sample were determined by means of their fluorescence spectra and principal component analysis (PCA). Data obtained in this study show that it is possible to identify bacteria strains and determine the live/dead ratio after UV light inactivation and antibiotic treatment, in situ, within minutes. In addition, synchronous fluorescence scans enable the identification of bacterial components such as tryptophan, tyrosine, and DNA. Compared with the time-consuming plating and culturing methods, this study renders a means for rapid detection and determination of live and dead bacteria.

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