Quinolone-isoniazid hybrids: Synthesis and preliminary in vitro cytotoxicity and anti-tuberculosis evaluation
- Authors: Beteck, Richard M , Seldon, Ronnett , Khanye, Setshaba D , Legoabe, Lesetja J , Hoppe, Heinrich C , Laming, Dustin , Jordaan, Audrey , Warner, Digby F
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123151 , vital:35410 , https://doi.org/10.1039/C8MD00480C
- Description: Herein, we propose novel quinolones incorporating an INH moiety as potential drug templates against TB. The quinolone-based compounds bearing an INH moiety attached via a hydrazide–hydrazone bond were synthesised and evaluated against Mycobacterium tuberculosis H37Rv (MTB). The compounds were also evaluated for cytotoxicity against HeLa cell lines. These compounds showed significant activity (MIC90) against MTB in the range of 0.2–8 μM without any cytotoxic effects. Compounds 10 (MIC90; 0.9 μM), 11 (MIC90; 0.2 μM), 12 (MIC90; 0.8 μM) and compound 15 (MIC90; 0.8 μM), the most active compounds in this series, demonstrate activities on par with INH and superior to those reported for the fluoroquinolones. The SAR analysis suggests that the nature of substituents at positions −1 and −3 of the quinolone nucleus influences anti-MTB activity. Aqueous solubility evaluation and in vitro metabolic stability of compound 12 highlights favourable drug-like properties for this compound class.
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- Date Issued: 2019
Beneficial effects of medicinal plants in fish diseases
- Authors: Stratev, Deyan , Zhelyazkov, Georgi , Noundou, Xavier S , Krause, Rui W M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126177 , vital:35856 , https://doi.org/10.1007/s10499-017-0219-x
- Description: Fish are constantly in contact with pathogens inhabiting water. High populationdensity as well as poor hydrodynamic conditions and feeding lead to an increased sensitivitytowards infections. In order to prevent major economic losses due to diseases, variousmedications are used for treatment and prevention of infections. The use of antimicrobialdrugs in aquacultures could lead to emergence of resistance in pathogenic microorganisms.Alternatives are being sought over the last few years to replace antibiotics, and medicinalplants are one of available options for this purpose. These plants are rich in secondarymetabolites and phytochemical compounds, which have an effect against viral, bacterial, andparasitic diseases in fish. Their main advantage is their natural origin and most of these plantsdo not represent threat for human health, the fish, and the environment. The goal of this reviewis to present information on the treatment of viral, bacterial, and parasitic diseases in fishthrough medicinal plants, with focus on the mechanisms of action of the identified secondarymetabolites, fractions, or plant extracts.
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- Date Issued: 2018
The role of psychosocial factors in academic performance of first year psychology students at a historically white university
- Authors: Dlamini, Sipho Solomon
- Date: 2017
- Subjects: Rhodes University -- Students , Academic achievement , Undergraduates -- South Africa , Dropouts -- South Africa , College students -- South Africa , Psychology students -- South Africa , Minorities -- Education -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/5150 , vital:20781
- Description: The success rate of students in higher education has been a cause for concern in South Africa (Letseka & Maile, 2008; Department of Higher Education and Training, 2015). This has been particularly concerning for first-year students, where the rate of attrition is especially high (Letseka, Cosser, Breier, and Visser, 2010). A number of factors have been identified in past research as having an effect on academic performance, which influences attrition and graduation. These factors include age (Justice, & Dornan, 2001), gender (Buchmann, & DiPrete, 2006), socio-economic status which is confounded by race (Letseka & Breier, 2008), type of educational background (Spreen, & Vally, 2006), and whether a student is a domestic or international student (Li, Chen, Duanmu, 2009), social capital (Young & Strelitz, 2014), whether the student is a first language speaker of the language of instruction at the university (Snowball, and Boughey, 2012), student wellbeing (Quinn, & Duckworth, 2007), locus of control (Findley, & Cooper, 1983), and frequency of lecture attendance (van Wallbeek, 2004). The study was conducted at Rhodes University, a small historically white South African institution. For this study, academic performance was measured using the participant’s midyear exam results for an introductory psychology cause, a course that straddles faculties. Of the 690 students registered for the course, 361 (52%) completed an electronic survey that explored the various factors associated with academic performance. A hierarchical regression analysis indicates that pre-university factors (age, gender, race, nationality, language, type of school, and socio-economic status) were the only significant predictors of academic performance, contributing 11% of the effect. Race and nationality, when all the other factors were controlled for, were the only predictors of academic performance. The implications of these findings pose troubling questions of the institutional culture at the university.
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- Date Issued: 2017
Cyclodextrin grafted calcium carbonate vaterite particles: efficient system for tailored release of hydrophobic anticancer or hormone drugs
- Authors: Lakkakula, Jaya R , Kurapati, Rajendra , Tynga, Ivan , Krause, Rui W M , Abrahamse, Heidi , Raichur, Ashok M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125435 , vital:35783 , https://doi.org/10.1039/C6RA12951J
- Description: Porous CaCO3 microparticles have been used earlier for sustained drug release of hydrophilic drugs but have certain drawbacks for use with hydrophobic drugs. Hence, to overcome these drawbacks, a novel composite of CaCO3 along with cyclodextrin (CD–CaCO3) for the delivery of hydrophobic drugs was developed. Cyclodextrins (CDs), when incorporated within CaCO3, increased the porosity and surface area of microparticles thereby enhancing the encapsulation efficiency of hydrophobic drugs (5-Fluorouracil or Na-L-thyroxine) by forming inclusion complexes with cyclodextrin. Thermogravimetric and FTIR studies confirmed the interaction between the cyclodextrin and CaCO3 microparticles. Raman spectra confirmed the peak of vaterite crystals before and after loading of hydrophobic drugs within the composite. In vitro release studies when performed at pH 4.8 (5-Fu) and pH 1.2 (Na-L-thy) showed release at low pH as CaCO3 is soluble at acidic pH unlike slower release at basic pH. Release kinetics followed a Higuchi kinetic model at pH 4.8 (5-Fu) and pH 1.2 (Na-L-thy) respectively.
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- Date Issued: 2016
Facile deposition of gold nanoparticle thin films on semi-permeable cellulose substrate
- Authors: Sosibo, Ndabenhle , Mdluli, Phumlani , Mashazi, Philani N , Tshikhudo, Robert , Skepu, Amanda , Vilakazi, Sibulelo , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242638 , vital:51063 , xlink:href="https://doi.org/10.1016/j.matlet.2012.08.043"
- Description: This study reports the facile method for the deposition of gold nanoparticle thin film onto a monoporous semi-permeable cellulose membrane through the diffusion of borohydride ions leading to the reduction of AuCl4− ions. The synthesis of gold nanoparticle thin film was deposited on one side of the membrane that was exposed to AuCl4− ions while the other side containing a reducing agent remained clear. The gold nanoparticle thin film exhibited a broad surface plasmon resonance (SPR) peak at 529 nm. Various characterization techniques were employed and all demonstrated the presence of gold thin film. The reported method represents a simplistic method for the deposition of gold nanoparticle thin films and various other metal nanoparticles may be deposited following this method.
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- Date Issued: 2012