Publications by authors named "Keabetswe Masike"

For over three decades, praziquantel (PZQ) has been the mainstay chemotherapy for prevention and treatment of schistosomiasis. The excessive use of PZQ, coupled with the lack of advanced drug candidates in the current anti-schistosomiasis drug development pipeline, emphasizes the genuine need for new drugs. In the current work, we investigated the antischistosomal potential of a new series of compounds derived from the privileged benzimidazole scaffold, which exhibited low micromolar IC potency in the range of 1.

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Applied sciences have increased focus on omics studies which merge data science with analytical tools. These studies often result in large amounts of data produced and the objective is to generate meaningful interpretations from them. This can sometimes mean combining and integrating different datasets through data fusion techniques.

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Drought is one of the major abiotic stresses causing severe damage and losses in economically important crops worldwide. Drought decreases the plant water status, leading to a disruptive metabolic reprogramming that negatively affects plant growth and yield. Seaweed extract-based biostimulants show potential as a sustainable strategy for improved crop health and stress resilience.

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Ion mobility spectrometry (IMS) is a rapid separation technique capable of extracting complementary structural information to chromatography and mass spectrometry (MS). IMS, especially in combination with MS, has experienced inordinate growth in recent years as an analytical technique, and elicited intense interest in many research fields. In natural product analysis, IMS shows promise as an additional tool to enhance the performance of analytical methods used to identify promising drug candidates.

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The postharvesting disorder leaf blackening is the main cause of product rejection in during export. In this study, we report an investigation into metabolites associated with leaf blackening in species. Methanol extracts of leaf and involucral bract tissue were analyzed by liquid chromatography hyphenated to photodiode array and high-resolution mass spectrometry (LC-PDA-HRMS), where 116 features were annotated.

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In this study we report a detailed investigation of the polyphenol composition of pure ( and ) and hybrid cultivars (Black beauty and Limelight). Aqueous methanol extracts of leaf and bract tissues were analyzed by ultrahigh pressure liquid chromatography hyphenated to photodiode array and ion mobility-high resolution mass spectrometric (UHPLC-PDA-IM-HR-MS) detection. A total of 67 metabolites were characterized based on their relative reversed phase (RP) retention, UV-vis spectra, low and high collision energy HR-MS data, and collisional cross section (CCS) values.

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As a contribution towards a better understanding of phenolic variation in the genus (honeybush tea), a collection of 82 samples from 15 of the 23 known species was analysed using liquid-chromatography-high resolution mass spectrometry (UPLC-HRMS) in electrospray ionization (ESI) negative mode. Mangiferin and isomangiferin were found to be the main compounds detected in most samples, with the exception of and where none of these compounds were detected. These xanthones were found to be absent from the seeds and also illustrated consistent differences between species and provenances.

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Liquid chromatography-mass spectrometry- (LC-MS-) based multiple reaction monitoring (MRM) methods have been used to detect and quantify metabolites for years. These approaches rely on the monitoring of various fragmentation pathways of multiple precursors and the subsequent corresponding product ions. However, MRM methods are incapable of confidently discriminating between isomeric and isobaric molecules and, as such, the development of methods capable of overcoming this challenge has become imperative.

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Dicaffeoylquinic acids (diCQAs) are plant metabolites and undergo --isomerization when exposed to UV irradiation. As such, diCQAs exist in both - and -configurations and amplify the already complex plant metabolome. However, analytical differentiation of these geometrical isomers using mass spectrometry (MS) approaches has proven to be extremely challenging.

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Background: Plants contain a myriad of metabolites which exhibit diverse biological activities. However, in-depth analyses of these natural products with current analytical platforms remains an undisputed challenge due to the multidimensional chemo-diversity of these molecules, amplified by both isomerization and conjugation. In this study, we looked at molecules such as hydroxyl-cinnamic acids (HCAs), which are known to exist as positional and geometrical isomers conjugated to different organic acids namely quinic- and isocitric acid.

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is a multi-purpose nutraceutical plant with interesting biological properties. However, very little is known about its phytochemical composition and, thus the need for its phytochemical characterization. In the current study, an environmentally friendly method, pressurized hot water extraction (PHWE), was used to extract metabolites from the leaves of at various temperatures (50 °C, 100 °C, 150 °C and 200 °C).

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Resolving the chemo-diversity of plant extract samples is an essential step for in-depth analyses of natural products which often exhibit promising biological activities. One of the challenges in this endeavor has been the confident differentiation of geometrical isomers. In this study, we investigated these aspects in chromatography (column chemistry and mobile phase composition) and mass spectrometry settings with regards to better differentiation of geometrical isomers.

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