Purpose: Mebos, a traditional South Africa confection consisting of dried, pulped, and sugared apricots, is rich in fibre and vitamins, but also contains salicylic acid, flavonoids, and citric acid. We report a case of postoperative surgical site bleeding in a healthy patient who consumed approximately 2 kg of mebos per day prior to his elective spinal surgery.
Methods: The clinical course of a previously healthy 54-year-old male patient with cauda equina syndrome secondary to lumbar spinal stenosis who underwent surgical intervention with subsequent bleeding into the surgical site is discussed.
Secondary metabolic profiling, using UPLC-MS and molecular networking, revealed the secondary metabolites produced by Serratia marcescens NP10. The NP10 strain co-produced cyclic and open-ring stephensiolides (i.e.
View Article and Find Full Text PDFSouth Africa has a rich history of medicinal plant species and their documented uses as traditional medicines, and is also home to three well-known, blue-flowered sage species of ethnobotanical importance. The Namaqualand () has so far remained unstudied and apparently overlooked. Our study is the first to report on the essential oil chemistry of this medicinally relevant species and provide a comparison with the other two (well-studied) closely related Cape ( and ).
View Article and Find Full Text PDFThe genus has been of medicinal importance in southern Africa for millennia and (Aizoaceae), one of eight species in the genus has gained pharmaceutical importance as an anxiolytic and anti-depressant due to the presence of mesembrine alkaloids. is used for the manufacture of herbal teas, dietary supplements and other phytopharmaceutical products. This study aimed to provide a metabolomic characterization of and its sister species as these are not easy to distinguish using morphology alone.
View Article and Find Full Text PDFThe urease enzyme of Cryptococcus neoformans is linked to different metabolic pathways within the yeast cell, several of which are involved in polyamine metabolism. Cryptococcal biogenic amine production is, however, largely unexplored and is yet to be investigated in relation to urease. The aim of this study was therefore to explore and compare polyamine metabolism in wild-type, urease-negative and urease-reconstituted strains of C.
View Article and Find Full Text PDFSpecies from the genus endosymbiotic bacteria of nematodes, produce several antibacterial and antifungal compounds, some of which are anti-parasitic. In this study, we report on the effect growth conditions have on the production of antimicrobial compounds produced by J194. The strain was cultured in aerated and non-aerated broth, respectively, and on solid media.
View Article and Find Full Text PDFTryptocidine C (TpcC, cyclo[D-Phe-Pro-Trp-D-Trp-Asn-Gln-Trp-Val-Orn-Leu]) is a broad-spectrum antimicrobial peptide in the tyrothricin complex produced by a soil bacterium, Brevibacillus parabrevis. Electrospray mass spectrometric studies reveal the oligomerisation of TpcC into dimers and higher oligomers, analogous to tyrocidine C (TrcC, Trp replaced by Tyr). Ion mobility mass spectrometry (IMMS) further confirms the formation of stable peptide dimers and tetramers with diameters of 2.
View Article and Find Full Text PDFPara-aminosalicylic acid (PAS), often the last drug remaining for treatment of drug-resistant tuberculosis, is notorious for causing gastrointestinal intolerance; however, the cause of PAS intolerance is uncertain. The objective of this study was to assess relationships between peak concentrations of PAS administered as a granular slow-release enteric coated formulation, and its metabolites acetyl-PAS and glycine-PAS, and intolerance. PAS and its metabolites were measured in 29 adult patients with drug-resistant tuberculosis at Brooklyn Hospital, Cape Town, randomized to receive granular slow-release enteric-coated PAS 4 g twice daily or 8 g once daily for 1 week, followed by the alternative regimen.
View Article and Find Full Text PDFWildly grown in most regions of the world, is a highly underutilised fruit with significant antioxidant characteristics. The phyto and physicochemical properties of berries at different stages of ripening are evaluated in this work. Total flavonoids (TF), total phenolic content (TPC) and antioxidant activity were determined spectrophotometrically, while concentration of polyphenols was determined using liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry.
View Article and Find Full Text PDFBackground: Preterm preeclampsia has a high rate of fetal death or disability. There is no treatment to slow the disease, except delivery. Preclinical studies have identified proton pump inhibitors as a possible treatment.
View Article and Find Full Text PDFIt was previously observed that the lipopeptide surfactants in surfactin (Srf) have an antagonistic action towards the highly potent antimicrobial cyclodecapeptide, gramicidin S (GS). This study reports on some of the molecular aspects of the antagonism as investigated through complementary electrospray ionization mass spectrometry techniques. We were able to detect stable 1:1 and 2:1 hetero-oligomers in a mixture of surfactin and gramicidin S.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
September 2016
11-Oxygenated steroids such as 11-ketotestosterone and 11-ketodihydrotestosterone have recently been shown to play a putative role in the development and progression of castration resistant prostate cancer. In this study we report on the development of a high throughput ultra-performance convergence chromatography tandem mass spectrometry (UPC(2)-MS/MS) method for the analysis of thirteen 11-oxygenated and six canonical C19 steroids isolated from a cell culture matrix. Using an Acquity UPC(2) BEH 2-EP column we found that UPC(2) resulted in superior selectivity, increased chromatographic efficiency and a scattered elution order when compared to conventional reverse phase ultra-performance liquid chromatography (UPLC).
View Article and Find Full Text PDFSotolon has been reported to play an important role in the atypical ageing and aroma character of many wines. A number of analytical techniques for sotolon analysis in wine have been reported, but these often require extensive sample preparation. In this work we report a HPLC-UV method and a novel UPLC-MS method to determine sotolon concentrations in white wines with little sample preparation applied for the first time for the evaluation of sotolon levels in South African wines.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
March 2014
Rationale: The speciation of the purely inorganic [PtCl6-n Brn](2-) (n = 0-6) anions and their corresponding mono-aquated [PtCl5-n Brn (H2O)](-) (n = 0-5) anions is of considerable importance to the precious metal refining and recycling industry, to ensure optimum recovery and separation efficiencies. Speciation of platinum complexes present in precursor solutions used for the preparation of precious metal nano-crystals of defined size and morphology appears also to be important. The various possible Pt(IV) complex anions in dilute aqueous can be characterized using ion-pairing reversed-phase high-performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOFMS).
View Article and Find Full Text PDFA group of non-ribosomally produced antimicrobial peptides, the tyrocidines from the tyrothricin complex, have potential as antimicrobial agents in both medicine and industry. Previous work by our group illustrated that the more polar tyrocidines rich in Trp residues in their structure were more active toward Gram-positive bacteria, while the more non-polar tyrocidines rich in Phe residues had greater activity toward Plasmodium falciparum, one of the major causative pathogens of malaria in humans. Our group also found that the tyrocidines have pronounced antifungal activity, dictated by the primary sequence of the tyrocidine.
View Article and Find Full Text PDFFood Addit Contam Part A Chem Anal Control Expo Risk Assess
April 2014
Adulteration of fruit juices--by the addition of sugar or other less expensive fruit juices as well as preservatives, artificial sweeteners and colours--was tested for by using a developed screening method. The method employs hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) using electrospray ionisation in the negative mode and ultraviolet light detection. Different fruit juices can be differentiated by the content of marker compounds like sorbitol, certain phenolic molecules and their saccharide profile.
View Article and Find Full Text PDFAntibiotic production as a defence mechanism is a characteristic of a wide variety of organisms. In natural evolutionary adaptation, cellular events such as sporulation, biofilm formation and resistance to antibiotics enable some micro-organisms to survive environmental and antibiotic stress conditions. The two antimicrobial cyclic peptides in this study, gramicidin S (GS) from Aneurinibacillus migulanus and the lipopeptide surfactin (Srf) from Bacillus subtilis, have been shown to affect both membrane and intercellular components of target organisms.
View Article and Find Full Text PDFEnvironmental stresses can significantly alter the synthesis of both primary and secondary metabolites, resulting in medicinal plants with unpredictable biological activity. Here, in vitro shoot cultures of the medicinal plant Sutherlandia frutescens were used to study the impact of three abiotic stresses (nitrogen availability, drought and salinity), primarily on l-canavanine synthesis. This compound, a non-protein amino acid, is amongst those metabolites linked to the health benefits of Sutherlandia extracts.
View Article and Find Full Text PDFThe interaction between a common soil yeast, Cryptococcus laurentii, and a slow-growing medicinal plant adapted to low-nutrient soils, Agathosma betulina (Berg.) Pillans, was studied. C.
View Article and Find Full Text PDFAn ultra performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (UPLC-APCI-MS) method was developed for the separation and quantification of adrenal steroid metabolites from heterologous expression media. Steroids were extracted by liquid-liquid extraction, separated on a Waters UPLC BEH C18 column, ionized by APCI, and detected using a triple quadrupole mass spectrometer in APCI positive mode with single ion monitoring. The incorporation of UPLC enabled the detection of seven structurally closely related steroids at between 5 and 40 ng/ml using run times of 11 min.
View Article and Find Full Text PDFTyrothricin, a complex mixture of antibiotic peptides from Bacillus brevis, was reported in 1944 to have antimalarial activity rivalling that of quinine in chickens infected with Plasmodium gallinaceum. We have isolated the major components of tyrothricin, cyclic decapeptides collectively known as the tyrocidines, and tested them against the human malaria parasite Plasmodium falciparum using standard in vitro assays. Although the tyrocidines differ from each other by conservative amino acid substitutions in only three positions, their observed 50% parasite inhibitory concentrations (IC(50)) spanned three orders of magnitude (0.
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