Antimicrobial Activity and Chemical Constituents of the Extract from Jatropha curcas Fruit

Zaid

et al. 2014

J. Electrochem. Soc.

The electrochemical response of two biologically important phenazine derivatives was examined by using cyclic, differential pulse and square wave voltammetry in a wide pH range of 2.0 -12.0. Cyclic voltammetry was employed for the determination of heterogeneous electron transfer rate constant and diffusion coefficient of the analytes. The value of electron transfer rate constant was used for evaluation of Gibbs free energy, enthalpy and entropy changes of redox reactions of the compounds. Differential pulse voltammetry was used for the determination of number of protons and electrons involved in the redox processes. Limits of detection and quantification were assessed by square wave voltammetry. The detailed pH dependent redox mechanisms of the compounds were proposed on the basis of experimental results which were further supported by theoretical calculations. These redox mechanistic pathways are expected to play a key role in understanding the necessary aspects of structure-activity relationships and exploring the hidden routes by which this class of compounds exert its biochemical actions. Phenazines have broad range applications in biology and chemistry.1 This class constitutes a large group of nitrogen containing heterocyclic compounds, the members of which differ in their chemical and physical properties on the basis of type and position of functional groups present. Naturally, phenazines are produced by limited genera of bacteria including Pseudomonas, Burkholderia and Brevibacterium.2 Starting from different parent materials, phenazines can be synthesized by various reactions including oxidative condensation, electrochemical reduction, reductive cyclization and photochemical reactions.From the last 50 years, phenazines are the subject of extensive research investigations because of their broad range applications in pharmaceutical and clinical research.3 Such compounds have been reported for their wide variety of biological activities such as antitumor, anti-parasitic and antibiotic activities. Benzo [a] phenazine acts as efficient DNA intercalating ligand with antitumor activity in leukaemia and solid tumors. 4 1-Hydroxyphenazine has been reported to have promising antifungal activity against various microbes such as aspergillus fumigatus and candida albicans.5 Macrolactone synthesized from benzo [a] phenazine shows good activity against mycobacterium tuberculosis. 6 In general, natural and synthetic phenazines find useful applications against malaria 7 and hepatitis C viral replication. 8The biological activity of phenazines is due to their redox reactions leading to the formation of toxic radicals. 9 Different functional groups attached to phenazine determine their redox potential and solubility. The redox behavior and concomitant modulation of biological activities of phenazines by changing the nature and position of substituents attached to their aromatic rings have been reported by several research groups.10-12 Phenazines can alter cellular redox states and act as transporters of electrons to altern...

Section: Differential Pulse Voltammetry (Dpv)-mentioning

confidence: 99%

mentioning

confidence: 99%

pH Dependent Electrochemical Characterization, Computational Studies and Evaluation of Thermodynamic, Kinetic and Analytical Parameters of Two Phenazines

Zaid

et al. 2014

J. Electrochem. Soc.

“…Many studies extracted the compound from the cultural broth by using chloroform, but another solvent, such as dichloromethane, was also useful for pyocyanin extraction (Essar et al, 1990;Sudhakar et al, 2013;Salih and Mohammed, 2017). Other reports indicated further purification of pyocyanin by precipitating in aluminum sulfate or using gel membrane filtration, ion-exchange chromatography, silica gel column, Amberlite XDA-4 column and HPLC techniques (Hassanein et al, 2009;Saosoong et al, 2009;Ra'oof and Latif, 2010).…”

Section: Introductionmentioning

confidence: 99%

Effect of culture conditions on pyocyanin production by recombinant pyocyanin-producing strain Pseudomonas aeruginosa PS39-phzMS

Nguyen¹,

Nguyen²,

Nguyen³

et al. 2023

MJM

Aims: A suitable medium and cultivation parameters have an important role in the improvement of the production of pyocyanin pigment by Pseudomonas aeruginosa microorganism. The study aimed to optimize culture conditions and medium components for maximal pyocyanin production in a recombinant strain P. aeruginosa PS39-phzMS created in previous research. In addition, the process of extraction of pyocyanin was also investigated to select a proper applied solvent for recovering a high amount of pyocyanin as well as its quality. Methodology and results:The pyocyanin purification has based on solvent. Among six tested solvents for extracting pyocyanin out of bacterial broth, two out of six recovered a significant amount of pyocyanin, namely dichloromethane and chloroform, in which chloroform showed a higher pyocyanin yield (25.27 ± 1.02 µg/mL) than dichloromethane (20.26 ± 0.88 µg/mL). The thin-layer chromatography (TLC) of the extracted pyocyanin illustrated a similar to pure pyocyanin with Rf of 0.72 and no mark of other impurity metabolites. The UV-Vis spectra showed a similar peak at 520 nm with pure pyocyanin and the highest peak at 274 nm. Each single culture parameter was studied for the maximal production of pyocyanin. Next, a pyocyanin-producing GM medium was modified on the base of the KingA to find the relative capacity to biosynthesize high pyocyanin yield in P. aeruginosa PS39-phzMS. The results showed that pyocyanin production was the highest in optimal culture conditions, at 30 °C, pH 8, 120 h and agitation of 200 rpm. In the combination of culture condition with the GM, pyocyanin was created at the highest amount of 49.57 µg/mL. Conclusion, significance and impact of study: Based on the obtained results of the study, a pyocyanin-producing procedure was optimized, which suggests a promising application to scale-up pyocyanin production by the P. aeruginosa PS39-phzMS.

Caribbean Women’s Health and Transnational Ethnobotany

Vardeman

Vandebroek

2021

Econ Bot

Immigrants from the Dominican Republic (DR) and Haiti are among the top foreign-born communities in New York City (NYC). As people migrate to new countries, they bring their ethnomedical beliefs and practices, and adapt their plant pharmacopoeias. Haiti and the DR share a flora on the island of Hispaniola. In NYC, the flora is limited to what is available in the city. We selected plants for future laboratory research based on ethnobotanical data from two surveys among Dominicans in the DR and NYC, and a Haitian literature review. In both Dominican datasets, gynecological infections were the top women's health condition treated with plants. We identified 10 species for this purpose reported by Dominicans that are also known medicines in Haitian culture, although not yet documented for women's health. Plants for gynecological infections potentially cause dysbiosis of the vaginal microbiota, and may increase rather than prevent disease. There is a public health need to assess traditional medicines for their ability to inhibit pathogenic bacteria, while causing minimal disruption to the vaginal flora. Several species are known antibacterials, but remain to be tested for their efficacy. These results also provide a foundation for a planned ethnobotanical survey among NYC Haitian women.