Isolation and Structure Elucidation of Antibacterial Compound

A special issue of Separations (ISSN 2297-8739). This special issue belongs to the section "Analysis of Natural Products and Pharmaceuticals".

Deadline for manuscript submissions: closed (20 May 2023) | Viewed by 18695

Special Issue Editor

School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China
Interests: NMR spectroscopy; metabolomics; bioactive compounds; natural products; separation science; LC-MS/MS

Special Issue Information

Dear Colleagues,

Over the years, natural plants have been used to treat diseases. They are important sources in terms of their pharmacological effects and also contain many antibacterial agents.

The Special Issue aims to collect cutting-edge studies on the isolation and structure elucidation of antibacterial compounds, which could contribute to the improvement of human health and disease prevention. This Special Issue is expected to bring to light promising studies related to phytochemical extraction methodologies, chemical characterization and quantification, and bioavailability studies. We encourage research on the use of new NMR and mass spectrometry methods for structural analysis. Research on macromolecules with antibacterial activities will also be considered. Original articles and reviews in these areas are both of interest.

Dr. Shuqi Wang
Guest Editor

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Keywords

  • antibacterial compound
  • structure elucidation
  • extraction and separation
  • NMR
  • Mass

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Published Papers (5 papers)

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Research

11 pages, 1981 KiB  
Article
Synthesis, Characterization and Application of Novel Cationic Surfactants as Antibacterial Agents
by Shaban R. M. Sayed, Abdelrahman O. Ezzat, Mohamed Taha Yassin and Ashraf M. M. Abdelbacki
Separations 2023, 10(2), 97; https://doi.org/10.3390/separations10020097 - 1 Feb 2023
Cited by 5 | Viewed by 2355
Abstract
It is of great necessity to develop new antimicrobial agents to overcome the accelerated increment in drug-resistant bacteria. The main aim of this work is to manufacture two cationic surfactants, QHETA-9 and QHETA-14, based on quaternary hexamethylenetetramine with long alkyl chains (C-9 and [...] Read more.
It is of great necessity to develop new antimicrobial agents to overcome the accelerated increment in drug-resistant bacteria. The main aim of this work is to manufacture two cationic surfactants, QHETA-9 and QHETA-14, based on quaternary hexamethylenetetramine with long alkyl chains (C-9 and C-14) by simple one-step alkylation reaction. These surfactants were characterized by analytical and statistical data, including FTIR, 1H NMR, 13C NMR and DLS. The antibacterial activities of QHETA-9 and QHETA-14 against some pathogenic bacterial strains were tested using agar disk diffusion method. The results exhibited that QHETA-14 has higher antibacterial activity than that of QHETA-9. It displayed inhibitory zone values for Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis, as Gram-positive bacteria, of 22.7, 21.5 and 25.9 mm, respectively, at 200 μg/disk. Meanwhile, it recorded inhibition zone values of 17.5, 25.2 and 23.8 mm for Escherichia coli, Agrobacterium tumefaciens and Erwinia carotovora, respectively, at 200 μg/disk. As a result, the current investigation verified that the antibacterial properties of QHETA-14 were greater than those of QHETA-9 due to the increase in the length of the alkyl chain. It is clear that QHETA-14 has the potential to be used as an antibacterial agent against bacteria that cause nosocomial infections and food poisoning diseases. Full article
(This article belongs to the Special Issue Isolation and Structure Elucidation of Antibacterial Compound)
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15 pages, 2461 KiB  
Article
Biosynthesized Zinc Oxide Nanoparticles Using Ziziphus Jujube Plant Extract Assisted by Ultrasonic Irradiation and Their Biological Applications
by Maymounah N. Alharthi, Iqbal Ismail, Stefano Bellucci, Mariusz Jaremko, Salah E. M. Abo-Aba and Mohamed Abdel Salam
Separations 2023, 10(2), 78; https://doi.org/10.3390/separations10020078 - 22 Jan 2023
Cited by 14 | Viewed by 2690
Abstract
The green biosynthesis of zinc oxide nanoparticles (GBS ZnO NPs) using Ziziphus jujuba leaves extract assisted by ultrasonic irradiation was reported in this research work. The green biosynthesized ZnO NPs were characterized using different techniques and the results revealed the synthesis of hexagonal [...] Read more.
The green biosynthesis of zinc oxide nanoparticles (GBS ZnO NPs) using Ziziphus jujuba leaves extract assisted by ultrasonic irradiation was reported in this research work. The green biosynthesized ZnO NPs were characterized using different techniques and the results revealed the synthesis of hexagonal wurtzite crystal of GBS ZnO nanoparticles; per the XRD measurement, with average practice size of 90 ± 10 nm; based on both SEM and TEM images, and with specific surface area of 14.23 m2/g; per the nitrogen gas adsorption/desorption isotherms. The antibacterial activity of the prepared GBS ZnO NPs was explored against S. aureus and E. coli bacteria using different evaluation methods; disc diffusion, column (filter), and aqueous solution, and the results showed the effective antibacterial activities against S. aureus and E. coli bacteria, as the inhibition zones were 15 mm and 11 mm for the E. coli and S. aureus, respectively. Moreover, the anticancer activity of the green biosynthesized ZnO NPs was evaluated on two different cancer cells; human colon cancer cell lines (HCT-116) and the human liver cancer (HepG2) cells, and the experiments showed that GBS ZnO NPs had an outstanding cytotoxic effect on both cancer cell lines, as well as dose-dependent behavior, as the viability of the cancer cells decreased by using GBS ZnO NPs at concentrations of 10 and 20 µg/mL. Cell lines (HCT-116) and the human liver cancer (HepG2) cells, and the experiments showed that GBS ZnO NPs had an outstanding cytotoxic effect on both cancer cell lines, as the GBS ZnO NPs enhanced the cytotoxicity mechanism by generating ROS as the nanoparticles interact with cells, lower its cellular defense mechanism, and accordingly cause apoptosis to the cell. Full article
(This article belongs to the Special Issue Isolation and Structure Elucidation of Antibacterial Compound)
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10 pages, 2853 KiB  
Article
Matrix-Assisted 1H DOSY Applied to Flavonoid Analysis in Scutellaria baicalensis
by Yulin You, Dongxiao Guo, Weiliang Cui, Zhifan Wang, Chunguo Yang, Yongqiang Lin and Shuqi Wang
Separations 2022, 9(12), 388; https://doi.org/10.3390/separations9120388 - 23 Nov 2022
Viewed by 1613
Abstract
Matrix-assisted diffusion-ordered spectroscopy (MA DOSY) technology enables efficient the virtual separation of components in a mixture according to their coefficients (D). In the current research, MA DOSY technology was applied for the analysis of a flavonoid mixture. To establish the method, five representative [...] Read more.
Matrix-assisted diffusion-ordered spectroscopy (MA DOSY) technology enables efficient the virtual separation of components in a mixture according to their coefficients (D). In the current research, MA DOSY technology was applied for the analysis of a flavonoid mixture. To establish the method, five representative active flavonoid ingredients, including baicalein, baicalin, quercetin, puerarin and rutinum, were selected for the mixture model. The effects of the type and concentration of the matrix, solvent polarity, and nuclear magnetic resonance (NMR) experimental conditions on the resolution of the DOSY spectrum were investigated. It turned out that sodium dodecyl sulfate (SDS) showed the best performance in increasing the resolution of different analytes, which initially increased to the peak below the added amount of 9 mg, and decreased upon the addition of more SDS. In addition, the five flavonoids showed higher resolution in DMSO–d6 than in MeOD. Experimental parameters of DOSY, including the number of scans (NS), dummy scans (DS), and value of the FID data points (TD), were also optimized. Finally, the above optimized method was used for the qualitative analysis of the total flavonoid mixture extracted from Scutellaria baicalensis Georgi. A total of nine compounds were identified and confirmed by comparing them with mass spectrometry data, which further verifies the practical value of this method upon analyzing flavonoid mixtures and provides some reference significance for the follow-up research. Full article
(This article belongs to the Special Issue Isolation and Structure Elucidation of Antibacterial Compound)
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15 pages, 2525 KiB  
Article
The Quality Control of Midecamycin and the Predictive Demarcation between Its Impurities and Components
by Mingyan Yu, Weijian Wang, Wenkun Liu, Huiru Yang, Tong Sun, Haiyun Zhao and Dejun Chen
Separations 2022, 9(8), 225; https://doi.org/10.3390/separations9080225 - 17 Aug 2022
Viewed by 1591
Abstract
Midecamycin is a 16-membered macrolide antibiotic. It can inhibit the synthesis of bacterial proteins by blocking up the activity of peptidyl transferase in the 50S ribosome. We used high-resolution mass spectrometry to analyze midecamycin, and quantitatively analyzed of each component of midecamycin produced [...] Read more.
Midecamycin is a 16-membered macrolide antibiotic. It can inhibit the synthesis of bacterial proteins by blocking up the activity of peptidyl transferase in the 50S ribosome. We used high-resolution mass spectrometry to analyze midecamycin, and quantitatively analyzed of each component of midecamycin produced by 18 different companies. The developed methods were validated by assessing linearity, limit of quantitation (LOQ), accuracy, precision, and robustness. Good separations were achieved for all components. Ten components of midecamycin were identified, and the contents of these components were determined in midecamycin produced by different companies. The demarcation between impurities and components of midecamycin was not clear. A ligand-docking model was used for predicting the impurities and components of midecamycin. Components and impurities were docked with the target. The results reported in this article may be important for quality control and the predictive demarcation between impurities and components of midecamycin. Full article
(This article belongs to the Special Issue Isolation and Structure Elucidation of Antibacterial Compound)
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10 pages, 1367 KiB  
Article
Extraction and Evaluation of the Antimicrobial Activity of Polyphenols from Banana Peels Employing Different Extraction Techniques
by Faiqa Chaudhry, Muhammad Laiq Ahmad, Zafar Hayat, Muhammad Modassar Ali Nawaz Ranjha, Komal Chaudhry, Noureddine Elboughdiri, Mufarreh Asmari and Jalal Uddin
Separations 2022, 9(7), 165; https://doi.org/10.3390/separations9070165 - 29 Jun 2022
Cited by 29 | Viewed by 9638
Abstract
Polyphenols are natural antioxidants and play a vital role in inhibiting oxidative stress induced by the body’s free radicals. Banana peels are a significant agro-industrial waste. This waste could be utilized to extract polyphenols to process various functional foods and nutraceuticals. An investigation [...] Read more.
Polyphenols are natural antioxidants and play a vital role in inhibiting oxidative stress induced by the body’s free radicals. Banana peels are a significant agro-industrial waste. This waste could be utilized to extract polyphenols to process various functional foods and nutraceuticals. An investigation was executed to extract polyphenols from banana peel using the sonication and maceration techniques. Three different polar solvents, methanol, ethanol and acetone, were used at four different concentrations: 25%, 50%, 75% and 100%. Yield (%), Total Polyphenolic Content (TPC), Total Flavonoid Content (TFC) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) Radical Scavenging assays were performed. The results from the current study articulate that extraction by sonication yields a higher quantity of polyphenols than the maceration technique. The study also concludes that ethanol leads to better extraction than other solvents used in this study. Full article
(This article belongs to the Special Issue Isolation and Structure Elucidation of Antibacterial Compound)
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