The purpose of this problem is to determine the presence and extent of antibiotic materials as found in the oleoresins of a selected group of garden vegetables. The problem has consisted of, first, the collection and preparation of specimens of twenty-five commonly used garden vegetables; second, the extraction of the oleoresins from these; third, the determination of the inhibitory and other effects of these oleoresins against several strains of selected gram-positive and gram-negative bacteria; and fourth, the evaluation of the potentialities of these oleoresins with regard to their future use as medicinal prophylactics and therapeutics.

This investigation deals with the study of the possible antibiotic effect of oleoresins of one hundred common Texas plants upon twenty-five gram-negative bacterial organisms.

Thesis (MSc. (Microbiology)) -- University of Limpopo, 2017 / This study was aimed at isolating and evaluating the antibacterial, antioxidant and cytotoxic effects of active compounds from selected medicinal plant species. The biological activities and cytotoxic effects of Commelina africana, Dombeya rotundifolia, Elephantorrhiza elephantina and Schkuhria pinnata were investigated based on their traditional uses. The plants were extracted with different solvents of varying polarities. Methanol was the best extractant with the highest yield. The presence of different phytoconstituents was screened using standard methods; this revealed the presence of terpenoids, flavonoids, tannins, and saponins. Meanwhile, the phytochemicals were screened on TLC, where different colours observed indicated the presence of different compounds. The total phenolic, tannin and flavonoid content were estimated using spectrophotometric methods. D. rotundifolia had the highest amounts of phenol, tannin and flavonoid content, while S. pinnata had the least. The antibacterial and antioxidant screening employed both qualitative and quantitative assays. Although not separated, this study demonstrated the antioxidant potential of D. rotundifolia extracts developed in BEA and CEF. D. rotundifolia also demonstrated the highest free radical scavenging and reducing power antioxidant potential. These activities could be attributed to the high phenolic, tannin and flavonoid content observed. All the selected plants had antibacterial potential against E. coli and P. aeruginosa. Only S. pinnata extracts were active against E. faecalis and S. aureus. The MIC values of the plants and ampicillin ranged from 0.02 to 2.50 mg/mL and 0.02 to 0.08 mg/mL, respectively. The plants were combined to determine any interaction effects in exhibiting antibacterial activity. Among all the possible combinations, combinations with S. pinnata had improved antibacterial activity. The effects of D. rotundifolia and S. pinnata extracts on the inhibition of the production of reactive oxygen species on LPS-induced RAW 264.7 macrophages was determined using the DCFHD-A assay. Both plants demonstrated anti-inflammatory potential by inhibiting the production of ROS in a dose-dependent manner. Cell viability assays revealed that S. pinnata had cytotoxic effects on African green monkey kidney (Vero) cells with the lowest LC50 (25 µg/mL). Bioassay guided fractionation and nuclear magnetic resonance spectroscopy of dichloromethane extracts of S. pinnata on column chromatography afforded isolation and characterisation of three sesquiterpene lactones. These were identified as 6-(2, 3- xxvi dihydroangeloylory)-6α-hydroxyinuviscolide, heliangolide and eucannabiolide. All three compounds had antibacterial, anti-inflammatory and cytotoxic effects. The compounds may serve as leads for synthesis of less toxic therapeutic antibacterial and anti-inflammatory drugs in the pharmaceutical industry. / National Research Foundation (NRF)

Flavonoids and other phenolics are groups of natural bioactive compounds widely distributed in edible plants and are well documented to possess biological potential. Hyptis (Lamiaceae) is used in Brazilian folk medicine to treat various diseases. The aim of this study was to evaluate the antioxidant, anti-acetylcholinesterase, cytotoxic, antiviral and antibacterial potential of Hyptis radicans and Hyptis multibracteata by isolating and characterizing major constituents and their biological activities. H. radicans and H. multibracteata were dried, powdered and macerated in 70% ethanol which resulted in a crude ethanol extract (EE) for each species. EE were dissolved in 50% methanol and then was fractionated by partition with hexane and ethyl acetate; were obtained three phases: hexane phase (HP), ethyl acetate phase (EAP) and hydromethanol phase (HMP). EAP from H. radicans was the sample that presented the highest levels of total phenolic content, especially flavonoids, and was the sample with the high antioxidant activity with promising values of EC50: DPPH (32.12 µg mL-1), ABTS (5.04 µg mL-1), Metal chelator assay (42.36 µg mL-1), TBARS (40.46 µg mL-1) and nonsite-Specific Hydroxyl Radical-Mediated 2-Deoxy-D-ribose Degradation (NS-Spe) with EC50 of 75.08 µg mL-1. EE from H. radicans showed high antioxidant activity for FRAP and ORAC with EC50 of 6.01 and 2.68 µg mL-1, respectively and had the highest amount of rosmarinic acid (17.64 mg ?-CE g-1). HMP from H. radicans showed high antioxidant activity in Site-Specific Hydroxyl Radical-Mediated 2-Deoxy-D-ribose Degradation (S-Spe) assay with EC50 of 0.32 µg mL-1 and had the highest content of chlorogenic acid derivatives. Regarding the results of cytotoxicity, HP from H. multibracteata induced the death of more than 80% of RAW 264.7 Cell Lines at 100 µg mL-1. Nepetoidin B, isolated from H. multibracteata had the best EC50 (52.73 µg mL-1) for anti-acetylcholinesterase activity. Antibacterial activity was evaluated in vitro against two Gram-negative bacteria, Pseudomonas aeruginosa and Escherichia coli, and a Gram-positive Bacillus subtilis. Phases from H. multibracteata were more effective on inhibiting B. subtillis with MIC50 of 23.6 ?g mL-1 and 12.13 ?g mL-1 for HP and EAP, respectively. HP was also activity against P. aeruginosa with MIC50 of 37.55 µg mL-1. EE and HMP phase from H. radicans showed moderate anti-HIV-1 activity (MIC50 159 µg mL-1; MIC50 180 µg mL-1). Contents of total phenolic were not the main sample feature to define this activity, but there was correlation between Rosmarinic acid contents and anti-HIV1 activity of H. radicans. Cirsimaritin and litospermic acid A were isolated for the first time, being the first time that they are described for the genus Hyptis. This study provides the first evidence of chemical and biological potential for these two Brazilian native species of Hyptis / Flavonoides e outros compostos fenólicos são grupos de compostos bioativos naturais amplamente distribuídos em plantas e estão bem documentados por possuírem potencial biológico. Hyptis (Lamiaceae) é usado na medicina popular brasileira para tratar várias doenças. O objetivo deste estudo foi avaliar o potencial antioxidante, anti-acetilcolinesterase, citotóxico, antiviral e antibacteriano de Hyptis radicans, e Hyptis multibracteata, isolar e identificar substâncias e correlacionar as atividades biológicas com a quantidade de compostos fenólicos e substâncias isoladas. H. radicans e H. multibracteata foram secas, pulverizadas e maceradas em etanol 70%, resultando em extrato etanólico bruto (EE). EE foi dissolvido em metanol 50% e depois foi fracionado por partição com hexano e acetato de etila, o que resultou em três fases: fase hexânica (HP), fase acetato de etila (EAP) e fase hidrometanólica (HMP). EAP de H. radicans foi a amostra que apresentou os maiores teores de conteúdo fenólico, principalmente flavonoides, e foi a amostra com a maior atividade antioxidante, com valores promissores de EC50: DPPH (32,12 µg mL-1), ABTS (5,04 µg mL- 1), Quelante de metais (42,36 µg mL-1), TBARS (40,46 µg mL-1) e Degradação da 2-deoxy-D-ribose de sitio não especifico mediada pelo radical hidroxil (NS-Spe) com EC50 de 75,08 µg mL-1. EE de H. radicans apresentou a maior atividade antioxidante para FRAP e ORAC com EC50 de 6,01 e 2,68 µg mL-1, respectivamente, e apresentou a maior quantidade de ácido rosmarínico (17,64 mg ?-CE g-1). HMP de H. radicans apresentou a mais alta atividade antioxidante no ensaio de Degradação da 2-deoxy-D-ribose de sitio especifico mediada pelo radical hidroxil (S-Spe) com EC50 de 0,32 µg mL-1 e apresentou o maior teor de derivados de ácido clorogênico. Em relação aos resultados da citotoxicidade, HP de H. multibracteata induziu a morte de mais de 80% das células do tipo RAW 264.7 com uma concentração de 100 µg mL-1. A Nepetoidina B isolada de H. multibracteata apresentou a melhor EC50 (52,73 µg mL-1) para atividade anti-acetilcolinesterase. A atividade antibacteriana foi avaliada in vitro contra duas bactérias Gram-negativas, Pseudomonas aeruginosa e Escherichia coli, e uma bacteria Gram-positiva. Bacillus subtilis,. Fases de H. multibracteata foram mais eficazes na inibição de B. subtillis com MIC50 23,6 ?g mL-1 e 12,13 ?g mL-1 para HP e EAP, respectivamente. HP também apresentou atividade contra P. aeruginosa com MIC50 de 37,55 µg mL-1. EE e HMP de H. radicans mostraram moderada atividade anti-HIV-1 (MIC50 159 µg mL-1; MIC50 180 µg mL-1). Não há correlação entre o conteúdo total de fenólicos e esta atividade biológica, mas sim entre a quantidade de ácido rosmarínico das fases e a atividade anti-HIV1 de H. radicans. Foram isoladas pela primera vez a Cirsimaritina e o ácido litospermico A, sendo esta a primeira vez que se descrevem para o gênero Hyptis. Este estudo fornece a primeira evidência do potencial químico e biológico para estas duas espécies nativas de Hyptis

Metal oxide-facilitated transformation is likely an important degradation pathway of antibacterial agents at soil-water interfaces. Phenolic disinfectants (triclosan and chlorophene), fluoroquinolones (FQs), and aromatic N-oxides are of particular concern due to their widespread usage, potential toxicity and frequent detection in the environment. Results of the present study show that the above antibacterial agents are highly susceptible to metal oxide-facilitated oxidation. The interfacial reactions exhibit complex reaction kinetics, which are affected by solution pH, the presence of co-solutes, surface properties of metal oxides, and structural characteristics of antibacterial agents. Adsorption of the antibacterial agents to Mn and Fe oxide surfaces generally proceeds faster than oxidation reactions of these compounds by Mn and Fe oxides, especially in the case of Fe oxides. Reaction intermediates and end products are identified by GC/MS, LC/MS and/or FTIR. Structurally-related model compounds are examined to facilitate reaction site and mechanism elucidation. On the basis of experimental results and literature, reaction schemes are proposed. In general, the antibacterial agent is adsorbed to the oxide surface, forming a precursor complex. Electrons are transferred within the precursor complex from the antibacterial agent to the oxide, followed by releasing of the radical intermediates which undergo further reactions to generate oxidation products. The precursor complex formation and electron transfer are likely rate-limiting. For triclosan, phenoxy radicals are critical intermediates to form oxidation products through three pathways (i.e., radical coupling, further oxidation of the radical, and breakdown of an ether bond within the radical). The first two pathways are also operative in the oxidation of chlorophene. For FQs, oxidation generates radical intermediates that are most likely centered on the inner N in the piperazine ring. The radical intermediates then undergo three major pathways (i.e., radical coupling, N-dealkylation, and hydroxylation) to yield a variety of products. For aromatic N-oxides, a N-oxide radical intermediate is generated upon oxidation by MnO2, followed by the loss of oxygen from the N-oxide moiety and the formation of a hydroxyl group at the C-atom adjacent to the N-oxide moiety. Overall, a fundamental understanding of the reaction mechanisms between three classes of antibacterial agents and metal oxides has been obtained.

Debido a los sucesos que contrajo la pandemia del Covid-19 en nuestro país, se incrementó la demanda de productos de limpieza de higiene como jabones y gel antibacteriales para generar protección ante un posible contagio de este virus. Según datos reportados el sector que tuvo un mayor incremento en ventas fue el de limpieza. Dentro de este sector se encuentra Paper Clean, el cual, es un proyecto de negocio que tiene como propósito brindar un producto de limpieza de manos, tal como son las láminas de jabón que tiene como características ser antibacterial, con insumos naturales, variedad de aromas, innovador, con calidad e higiénico. Asimismo, nuestros jabones en láminas estarán enfocados a Mujeres del sector A y B dentro de Lima moderna.  Este proyecto surge con la finalidad de poder brindar a nuestro público un producto de calidad, diferente y que tenga un valor agregado para poder diferenciarnos del resto del mercado y que a la vez le genere bienestar y seguridad a nuestro público al usar nuestro producto. Este proyecto expone un análisis de los retos que conlleva participar en un mercado altamente competitivo y que nos obliga a diferenciarnos de la competencia, como también cómo emplearemos nuestras estrategias de operación, publicidad y se mostrará que el proyecto es viable lo que debe ser avalado por nuestros análisis financieros. / Due to the events of the Covid-19 pandemic in our country, the demand for hygiene cleaning products such as antibacterial soaps and gel was increased to generate protection against possible contagion of this virus. According to reported data the sector that had the greatest increase in sales was the cleaning. Within this sector is Paper Clean, which is a business project that aims to provide a hand cleaning product, such as soap sheets, which has the characteristics of being antibacterial, with natural inputs, a variety of aromas, innovative, with quality and hygienic. In addition, our foil soaps will be focused on Women from sector B within modern Lima. This project arises in order to be able to provide our audience with a quality product, different and that has added value to be able to differentiate us from the rest of the market and that at the same time generates well-being and safety to our public when using our product. This project sets out an analysis of the challenges of participating in a highly competitive market that forces us to differentiate ourselves from competition, as well as how we will use our trading strategies, advertising and show that the project is viable which should be endorsed by our financial analyses. / Trabajo de investigación

Debido al contexto del Covid 19, decidimos desarrollar un modelo de negocio basado en las necesidades que se presentan a partir de la “nueva normalidad”. Luego de una investigación realizada en Lima, la cual incluyó distintos niveles socioeconómicos, analizamos la información recopilada para determinar cómo los hábitos de higiene de las personas han cambiado y cómo se pueden satisfacer esas nuevas necesidades. La propuesta de negocio es atractiva y viable debido a que encontramos que las personas no cuentan con los insumos necesarios para una correcta rutina de higiene fuera de casa. Es por ello por lo que esta propuesta se basa en la venta, a través de canales digitales, de un producto innovador en el mercado peruano. El producto es un papel jabón antibacterial que permite un correcto lavado de manos fuera de casa que se almacena en un estuche antiviral y antibacterial. Además, el empaquetado del producto es eco amigable y el estuche que hace transportable el Papel jabón es reutilizable, por lo que tiene un impacto positivo en el medio ambiente. El proyecto ha sido evaluado y analizado en distintos niveles para garantizar su viabilidad. Los puntos evaluados fueron: el análisis del entorno, análisis financiero, planeamiento operativo y preoperativo, Recursos Humanos, Marketing, Responsabilidad Social Empresarial y La validación del modelo de negocio y del producto a partir de encuestas y entrevistas tanto a usuarios como expertos en la materia. / Due to the actual context of the Covid 19 we decided to develop a business focused on the needs that this “new reality” demands. After a research carried in Lima, involving different socioeconomic levels and demographic profiles and Based on interviews and online information we analyzed that the habits of the consumer have changed a lot this year, especially the cleaning routine. The business proposition is attractive and viable because we realized that people don’t have the necessary resources to complete a properly cleaning routine when they are not at home. So that’s why this business model is based on selling an innovative product in the Peruvian market throughout the social media. The product is an antibacterial paper soap that allows you to wash your hands properly when you are not at home; it also comes with an antibacterial and antiviral case that makes it portable and reliable. The packaging is eco friendly and the case itself too because it can be reused so it has a positive impact in the environment. The project has been evaluated and analyzed from different perspectives to guarantee its viability. The items evaluated were the context analysis, financial analysis, operative and pre-operative planning, HR planning, Marketing planning, social responsibility and a validation of the product with customers and specialists. / Trabajo de investigación

Indiana University-Purdue University Indianapolis (IUPUI) / Both quaternary ammonium bromide (QAB) and furanone derivatives were synthesized, characterized and formulated into dental resin composites for improved antibacterial properties. Compressive strength (CS) and S. mutans viability were used to evaluate the mechanical strength and antibacterial activity of the restoratives. The effects of chain length, loading, saliva and aging on CS and S. mutans viability were investigated. Chapter 2 describes how we studied and evaluated the formulated antibacterial resin composites by incorporating the synthesized QAB-containing oligomers into the formulation. The results show that all the QAB-modified resin composites showed significant antibacterial activity and mechanical strength reduction. Increasing chain length and loading significantly enhanced the antibacterial activity but dramatically reduced the CS as well. The 30-day aging study showed that the incorporation of the QAB accelerated the degradation of the composite, suggesting that the QAB may not be well suitable for development of antibacterial dental resin composites or at least the QAB loading should be well controlled. Chapter 3 describes how we studied and evaluated the formulated antibacterial resin composite by incorporating the synthesized furanone derivative into the formulation. The results show that the modified resin composites showed a significant antibacterial activity without substantially decreasing the mechanical strengths. With 5 to 30% addition of the furanone derivative, the composite kept its original CS unchanged but showed a significant antibacterial activity with a 16-68% reduction in the S. mutans viability. Further, the antibacterial function of the new composite was found not to be affected by human saliva. The aging study indicates that the composite may have a long-lasting antibacterial function. In summary, we have developed a novel QAB- and furanone-containing antibacterial system for dental restoratives. Both QAB- and furanone-modified resin composites have demonstrated significant antibacterial activities. The QAS-modified experimental resin composite may not be well suitable for development of antibacterial dental resin composites due to its accelerated degradation in water unless the QAB loading is well controlled. The furanone-modified resin composite shows nearly no reduction in mechanical strength after incorporation of the antibacterial furanone derivative. It appears that the furanone-modified resin composite is a clinically attractive dental restorative that can be potentially used for long-lasting restorations due to its high mechanical strength and permanent antibacterial function.

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / The world is continuously losing the battle against superbugs (resistant bacteria towards commonly used antibiotics), hence there is an urgent need to develop novel antibacterial agents. In this study, green synthesized silver nanoparticles (AgNPs) and eucalyptus oil, were incorporated into the polymer blend fibres of polyvinyl alcohol (PVA) and cellulose nanocrystals (CNC’s). Various techniques were used to characterize the AgNPs, PVA/CNC polymer fibres, and PVA/CNC incorporated with AgNPs/eucalyptus oil. The morphology of AgNPs synthesized using an increasing concentration of the Citrus sinensis peels (CSP) extract was obtained from transmission electron microscopy (TEM). AgNPs synthesized using 1 and 2 % m/v (CSP) were agglomerated and whereas those synthesized using 3 % m/v of the extract were spherical with an average particle size 10 ± 1.2 nm. UV/Visible absorption spectra for all the synthesized AgNPs exhibited a surface plasmon resonance (SPR) peak at around 400 nm which is a characteristic peak of silver. Significant shifts in the absorption peaks or maxima were observed to signify changes in the shape and size of the nanoparticles. Scanning electron microscopy (SEM) was used to study the morphology of the fabricated polymer fibres. The Addition of CNC’s to PVA resulted in an increase in fibre diameter due to an increase in viscosity of the solution. An increase in the concentration of silver nanoparticles and the eucalyptus oil in the PVA/CNC resulted in a decrease in fibre diameter due to an increase in conductivity of the material. The fibres with AgNPs were smooth while the ones with the eucalyptus oil were beaded. X-ray diffraction (XRD) showed the presence of the AgNPs in the polymer fibres and Fourier transform infrared (FTIR) showed the presence of the functional groups that are available in the eucalyptus oil. The antibacterial efficiency of the PVA/CNC incorporated with AgNPs, eucalyptus oil, and the mixture of AgNPs and the eucalyptus oil was investigated using S. aureus and K. pneumoniae. All the materials showed significant inhibition of the growth of the selected bacterial strains. PVA/CNC polymer fibres incorporated with AgNPs showed higher antibacterial activity compared to PVA/CNC polymer fibres incorporated with eucalyptus oil.

Healthcare-associated infections (HAIs), especially those caused by different antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and multidrug resistant Pseudomonas aeruginosa are of growing concern in healthcare facilities. Since 1995, overall incidence rates of MRSA in Canadian hospitals have increased 19-fold, leading to unnecessary suffering by patients and increasing costs to hospitals. There have been many reports that link pathogen-carrying hospital textiles and cases of infections. The development of effective, durable and rechargeable antibacterial healthcare textiles is expected to impede the transmission of infectious microorganisms, and act as an additional prevention measure to infection control. N-chloramines have been proven to be one of the most suitable antimicrobial agents to be immobilized onto healthcare textiles to impart them with potent and rechargeable antimicrobial functions. However, the majority of the hospital used medical textiles are synthetic fibers which are chemically inert and hard to be chemically modified with N-chloramine functions. This study focuses on developing an industry scalable process to durably immobilize N-chloramine onto poly (ethylene terephthalate) (PET), a common synthetic fiber used in healthcare textiles. Many techniques have been reported till now to activate the chemically inert PET surface with reactive functional groups. Among all the techniques, aminolysis and plasma treatments have attracted great attention due to their easy process to introduce functional group onto PET and can be set up for large production. However, aminolysis suffers from polymer degradation and plasma treatments suffer from less deposition which hinders these two processes to produce commercial antibacterial textiles. In this study, a new combined process was introduced by combining aminolysis and plasma treatments in a specific way that not only minimize the problems associated with these two processes but also can create more N-chloramine precursor functional groups onto the surface of PET. The covalently bonded N-chloramine precursor groups can be easily converted to N-chloramine by dilute sodium hypochlorite solution. The presence of nitrogen on the PET substrates after the modification was confirmed by CHNS/O elemental analyzer and ATR/FTIR analysis showing a successful incorporation of N-chloramine precursor. The morphology of the treated fibers was kept relatively similar with a slight decrease in their diameter. Moreover, the tensile strength of the treated fabric was also acceptably maintained. The N-chloramine modified PET presented highly effective antimicrobial properties, even after 50 home launderings the rechargeable treated fabric demonstrated 100% reduction of both MRSA and P. aeruginosa within a contact time of 5 min. / May 2016