ORCID Profile
0000-0001-6340-9354
Current Organisation
University of South Australia
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Publisher: American Chemical Society (ACS)
Date: 13-07-2021
DOI: 10.1021/ACS.BIOCONJCHEM.1C00287
Abstract: The applications of bioconjugation chemistry are rapidly expanding, and the addition of new strategies to the bioconjugation and ligation toolbox will further advance progress in this field. Herein, we present a detailed study of the Diels-Alder cycloaddition (DAC) reaction between pentafulvenes and maleimides in aqueous solutions and investigate the reaction as an emerging bioconjugation strategy. The DAC reactions were found to proceed efficiently, quantitatively yielding cycloadducts with reaction rates ranging up to ∼0.7 M
Publisher: Oxford University Press (OUP)
Date: 06-10-2021
Abstract: Advanced glycation end products (AGEs) are formed via non-enzymatic reactions between amino groups of proteins and the carbonyl groups of reducing sugars. Previous studies have shown that highly glycated albumin prepared using a glucose-bovine serum albumin (Glu-BSA) model system incubated at 60°C for 6 weeks induces genotoxicity in WIL2-NS cells at 9 days of exposure measured by the cytokinesis-block micronucleus cytome (CBMNcyt) assay. However, this AGE model system is not physiologically relevant as normal body temperature is 37°C and the degree of glycation may exceed the extent of albumin modification in vivo. We hypothesised that the incubation temperature and purification method used in these studies may cause changes to the chemical profile of the glycated albumin and may influence the extent of genotoxicity observed at 3, 6 and 9 days of exposure. We prepared AGEs generated using Glu-BSA model systems incubated at 60°C or 37°C purified using trichloroacetic acid (TCA) precipitation or ultrafiltration (UF) and compared their chemical profile (glycation, oxidation, and aggregation) and genotoxicity in WIL2-NS cells using the CBMNcyt assay after 3, 6 and 9 days of exposure. The number of micronuclei (MNi) was significantly higher for cells treated with Glu-BSA incubated at 60°C and purified via TCA (12 ± 1 MNi/1000 binucleated cells) compared to Glu-BSA incubated at 37°C and purified using UF (6 ± 1 MNi/1000 binucleated cells) after 9 days (P & 0.0001). The increase in genotoxicity observed could be explained by a higher level of protein glycation, oxidation, and aggregation of the Glu-BSA model system incubated at 60°C relative to 37°C. This study highlighted that the incubation temperature, purification method and cell exposure time are important variables to consider when generating AGEs in vitro and will enable future studies to better reflect in vivo situations of albumin glycation.
Publisher: Wiley
Date: 26-06-2020
DOI: 10.1002/DTA.2874
Publisher: American Chemical Society (ACS)
Date: 10-08-2021
Publisher: Elsevier BV
Date: 08-2021
Publisher: Wiley
Date: 29-11-2023
DOI: 10.1111/ADD.16083
Abstract: From 1 February 2018, codeine was rescheduled from an over‐the‐counter (OTC) to a prescription‐only medicine in Australia. We used wastewater‐based epidemiology to measure changes in population codeine consumption before and after rescheduling. We analysed 3703 wastewater s les from 48 wastewater treatment plants, taken between August 2016 and August 2019. Our s les represented 10.6 million people, 45% of the Australian population in state capitals and regional areas in each state or territory. Codeine concentrations were determined by liquid chromatography–tandem mass spectrometry and converted to per‐capita consumption estimates using the site daily wastewater volume, catchment populations and codeine excretion kinetics. Average per‐capita consumption of codeine decreased by 37% nationally immediately after the rescheduling in February 2018 [95% confidence interval (CI) = 35.3–39.4%] and substantially in all states between 24 and 51% (95% CI = 22.4–27.0% and 41.8–59.4%). The decrease was sustained at the lower level to August 2019. Locations with least pharmacy access decreased by 51% (95% CI = 41.7–61.7%), a greater decrease than 37% observed for those with greater pharmacy access (95% CI = 35.1–39.4%). Regional areas decreased by a smaller margin to cities (32 versus 38%, 95% CI = 30.2–34.1% versus 34.9–40.4%, respectively) from a base per‐capita usage approximately 40% higher than cities. Wastewater analysis shows that codeine consumption in Australia decreased by approximately 37% following its rescheduling as a prescription‐only medicine in 2018. Wastewater‐based epidemiology can be used to evaluate changes in population pharmaceutical consumption in responses to changes in drug scheduling.
Publisher: American Chemical Society (ACS)
Date: 08-12-2021
Publisher: American Chemical Society (ACS)
Date: 16-09-2021
Publisher: Wiley
Date: 10-2020
DOI: 10.1111/ADD.15256
Abstract: To assess the effects of social distancing and social isolation policies triggered by COVID‐19 on alcohol consumption using wastewater analysis in Adelaide, South Australia. Longitudinal quantitative analysis of influent wastewater data for alcohol concentration. Adelaide, South Australia. Wastewater catchment area representative of 1.1 million inhabitants. Twenty‐four hour composite influent wastewater s les were collected from four wastewater treatment plants in Adelaide, South Australia for 7 consecutive days (Wednesday–Tuesday) every 2 months from April 2016–April 2020. The alcohol metabolite ethyl sulfate was measured in s les using chromatography–tandem mass spectrometry. Data were population‐weighted adjusted with consumption expressed as standard drinks/day/1000 people. Weekly consumption and weekend to mid‐week consumption ratios were analysed to identify changes in weekday alcohol use pattern. Estimated weekend alcohol consumption was significantly lower (698 standard drinks/day/1000 people) after self‐isolation measures were enforced in April 2020 compared with the preceding s ling period in February 2020 (1047 standard drinks/day/1000 people), P 0.05. Weekend to midweek consumption ratio was 12% lower than the average ratio compared with all previous s ling periods. April 2020 recorded the lowest alcohol consumption relative to April in previous years, dating back to 2016. Wastewater analysis suggests that introduction of social distancing and isolation policies triggered by COVID‐19 in Adelaide, South Australia, was associated with a decrease in population‐level weekend alcohol consumption.
Publisher: Springer Science and Business Media LLC
Date: 21-08-2022
DOI: 10.1007/S00726-021-03069-6
Abstract: Glycation is a non-enzymatic reaction that occurs between the free amino group of proteins and reducing sugars and/or lipids, leading to the formation of advanced glycation end products (AGEs). The reaction also produces reactive oxygen species that have detrimental effects on cellular and extracellular proteins. Aminoguanidine is a known inhibitor of AGEs, and some fatty acids are known to have a beneficial role in vivo by reducing inflammation and oxidative stress. However, the role of fatty acids on AGE formation has not been thoroughly reported. We investigated the role of a range of fatty acids in the formation of AGEs and their reactive intermediates using an in vitro BSA-dicarbonyl model. The model assessed a time-dependent (0-72 h) and dicarbonyl concentration (0-2 mM) -dependent studies for the optimal formation of AGEs. A 72 h time point was found to be optimal for the reaction of BSA with either methylglyoxal (MGO) or glyoxal (GO) to generate AGE-BSA complexes. When arachidonic, eicosapentaenoic or docosahexaenoic acids were included in the reaction, a significant decrease in protein-bound fluorescent AGEs was seen compared to the respective controls. In contrast, saturated and 18 carbon polyunsaturated fatty acids showed no significant activity. Liquid chromatography-mass spectrometry (LC-MS/MS) analysis showed saturated fatty acids significantly decreased the production of N
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.SCITOTENV.2022.155696
Abstract: Methcathinone is a prevalent Novel Psychoactive Substance (NPS) used illicitly in some countries. Routine analysis of wastewater s led from catchments in South Australia has shown a consistent low-level presence of the compound, inconsistent with NPS use. This raised the question was the occurrence due to regular use as a drug of choice or was it an artefact being produced from other sources in the sewer system? NPS consumption is generally sporadic and would therefore point to the origin of methcathinone in wastewater being due to in-sewer oxidation of its legal precursor, pseudoephedrine. The present study tested this hypothesis by comparing the levels of pseudoephedrine and methcathinone in wastewater s les collected bimonthly from 8 catchment sites in South Australia. Laboratory experiments exposing pseudoephedrine to common household oxidizing agents (hypochlorite and percarbonate) were also performed and the production of methcathinone was demonstrated and monitored. The results of this study showed that the level of pseudoephedrine and methcathinone measured in wastewater followed a similar pattern. However, there were periods when the levels of each compound erged. Laboratory experiments showed that when exposed to various oxidizing agents, pseudoephedrine is oxidised to non-stoichiometric quantities of methcathinone. Although the use of methcathinone as a drug of choice remains possible, the results of this study indicate that the low and persistent level of methcathinone found in wastewater may arise in part from the oxidation of pseudoephedrine in the sewer system.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0AY00560F
Abstract: With illicit and designer benzodiazepines becoming more prevalent in the community, this work presents the validation and application of an analytical method for prescribed benzodiazepines and metabolites in wastewater.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for MAULIK GHETIA.