ORCID Profile
0000-0002-2509-5531
Current Organisation
University of South Australia
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Publisher: Wiley
Date: 12-02-2014
Abstract: Phosphorylation of eIF4E by human mitogen-activated protein kinase (MAPK)-interacting kinases (Mnks) is crucial for human tumourigenesis and development. Targeting Mnks may provide a novel anticancer therapeutic strategy. However, the lack of selective Mnk inhibitors has so far h ered pharmacological target validation and clinical drug development. Herein, we report, for the first time, the discovery of a series of 5-(2-(phenylamino)pyrimidin-4-yl)thiazole-2(3H)-one derivatives as Mnk inhibitors. Several derivatives demonstrate very potent Mnk2 inhibitory activity. The most active and selective compounds were tested against a panel of cancer cell lines, and the results confirm the cell-type-specific effect of these Mnk inhibitors. Detailed cellular mechanistic studies reveal that Mnk inhibitors are capable of reducing the expression level of anti-apoptotic protein Mcl-1, and of promoting apoptosis in MV4-11 acute myeloid leukaemia cells.
Publisher: American Chemical Society (ACS)
Date: 27-06-2013
DOI: 10.1021/ML400145X
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.EXER.2016.03.013
Abstract: Pseudoexfoliation (PEX) syndrome is a systemic disease involving the extracellular matrix. It increases the risk of glaucoma, an irreversible cause of blindness, and susceptibility to heart disease, stroke and hearing loss. Single nucleotide polymorphisms (SNPs) in the LOXL1 (Lysyl oxidase-like 1) gene are the major known genetic risk factor for PEX syndrome. Two coding SNPs, rs1048861 (G > T Arg141Leu) and rs3825942 (G > A Gly153Asp), in the LOXL1 gene are strongly associated with the disease risk in multiple populations worldwide. In the present study, we investigated functional effects of these SNPs on the LOXL1 protein. We show through molecular modelling that positions 141 and 153 are likely surface residues and hence possible recognition sites for protein-protein interactions the Arg141Leu and Gly153Asp substitutions cause charge changes that would lead to local differences in protein electrostatic potential and in turn the potential to modify protein-protein interactions. In RFL-6 rat fetal lung fibroblast cells ectopically expressing the LOXL1 protein variants related to PEX (Arg141_Gly153, Arg141_Asp153 or Leu141_Gly153), immunoprecipitation of the secreted variants showed differences in their processing by endogenous proteins, possibly Bone morphogenetic protein-1 (BMP-1) that cleaves and leads to enzymatic activation of LOXL1. Immunofluorescence labelling of the ectopically expressed protein variants in RFL-6 cells showed no significant difference in their extracellular accumulation tendency. In conclusion, this is the first report of a biological effect of the coding SNPs in the LOXL1 gene associated with PEX syndrome, on the LOXL1 protein. The findings indicate that the disease associated coding variants themselves may be involved in the manifestation of PEX syndrome.
Publisher: Bentham Science Publishers Ltd.
Date: 24-01-2018
DOI: 10.2174/1568026619666181220105726
Abstract: Poor profiles of potential drug candidates, including pharmacokinetic properties, have been acknowledged as a significant hindrance to the development of modern therapeutics. Contemporary drug discovery and development would be incomplete without the aid of molecular modeling (in-silico) techniques, allowing the prediction of pharmacokinetic properties such as clearance, unbound fraction, volume of distribution and bioavailability. As with all models, in-silico approaches are subject to their interpretability, a trait that must be balanced with accuracy when considering the development of new methods. The best models will always require reliable data to inform them, presenting significant challenges, particularly when appropriate in-vitro or in-vivo data may be difficult or time-consuming to obtain. This article seeks to review some of the key in-silico techniques used to predict key pharmacokinetic properties and give commentary on the current and future directions of the field.
Publisher: Public Library of Science (PLoS)
Date: 14-06-2012
Publisher: MDPI AG
Date: 25-03-2023
DOI: 10.3390/MOLECULES28072951
Abstract: Cyclin-dependent kinase 2 (CDK2) has been garnering considerable interest as a target to develop new cancer treatments and to ameliorate resistance to CDK4/6 inhibitors. However, a selective CDK2 inhibitor has yet to be clinically approved. With the desire to discover novel, potent, and selective CDK2 inhibitors, the phenylsulfonamide moiety of our previous lead compound 1 was bioisosterically replaced with pyrazole derivatives, affording a novel series of N,4-di(1H-pyrazol-4-yl)pyrimidin-2-amines that exhibited potent CDK2 inhibitory activity. Among them, 15 was the most potent CDK2 inhibitor (Ki = 0.005 µM) with a degree of selectivity over other CDKs tested. Meanwhile, this compound displayed sub-micromolar antiproliferative activity against a panel of 13 cancer cell lines (GI50 = 0.127–0.560 μM). Mechanistic studies in ovarian cancer cells revealed that 15 reduced the phosphorylation of retinoblastoma at Thr821, arrested cells at the S and G2/M phases, and induced apoptosis. These results accentuate the potential of the N,4-di(1H-pyrazol-4-yl)pyrimidin-2-amine scaffold to be developed into potent and selective CDK2 inhibitors for the treatment of cancer.
Publisher: Wiley
Date: 18-04-2013
Abstract: Peptide-derived protease inhibitors are an important class of compounds with the potential to treat a wide range of diseases. Herein, we describe the synthesis of a series of triazole-containing macrocyclic protease inhibitors pre-organized into a β-strand conformation and an evaluation of their activity against a panel of proteases. Acyclic azido-alkyne-based aldehydes are also evaluated for comparison. The macrocyclic peptidomimetics showed considerable activity towards calpain II, cathepsin L and S, and the 20S proteasome chymotrypsin-like activity. Some of the first ex les of highly potent macrocyclic inhibitors of cathepsin S were identified. These adopt a well-defined β-strand geometry as shown by NMR spectroscopy, X-ray analysis, and molecular docking studies.
Publisher: American Chemical Society (ACS)
Date: 20-03-2019
Publisher: American Chemical Society (ACS)
Date: 24-10-2006
DOI: 10.1021/CI600221H
Abstract: Molecular modeling approaches for the prediction of the nonspecific binding of drugs to hepatic microsomes were examined using a published database of 56 compounds. Models generated were evaluated using an independent test set of 13 compounds. A pharmacophore approach identified structural features of drugs associated with nonspecific binding. A side-chain amino group and complementary hydrophobic domain were the principal features noted. The use of shape overlays, based on the pharmacophore, in conjunction with a chemical force field in the program ROCS, yielded discrimination between molecules classified as strong binders (experimental fraction unbound in microsomes 0.50). In the initial data set of 56 molecules, 18 were classified as strong binders (on the basis of the above criteria), and all of those were recovered in the top 22 molecular hits from ROCS. Additionally, computationally generated values of log P were shown to provide a reasonable estimate of the fraction unbound in microsomes, providing the compounds were in their basic form at physiological pH.
Publisher: Informa UK Limited
Date: 14-07-2016
DOI: 10.1080/00498254.2016.1203041
Abstract: 1. The metabolism of the anti-inflammatory diterpenoid polyandric acid A (PAA), a constituent of the Australian Aboriginal medicinal plant Dodonaea polyandra, and its de-esterified alcohol metabolite, hydrolysed polyandric acid A (PAAH) was studied in vitro using human liver microsomes (HLM) and recombinant UDP-glucuronosyltransferase (UGT) and cytochrome P450 (CYP) enzymes. 2. Hydrolysis of PAA to yield PAAH occurred upon incubation with HLM. Further incubations of PAAH with HLM in the presence of UGT and CYP cofactors resulted in significant depletion, with UGT-mediated depletion as the major pathway. 3. Reaction phenotyping utilising selective enzyme inhibitors and recombinant human UGT and CYP enzymes revealed UGT2B7 and UGT1A1, and CYP2C9 and CYP3A4 as the major enzymes involved in the metabolism of PAAH. 4. Analysis of incubations of PAAH with UDP-glucuronic acid-supplemented HLM and recombinant enzymes by UPLC/MS/MS identified three glucuronide metabolites. The metabolites were further characterised by β-glucuronidase and mild alkaline hydrolysis. The acyl glucuronide of PAAH was shown to be the major metabolite. 5. This study demonstrates the in vitro metabolism of PAA and PAAH and represents the first systematic study of the metabolism of an active constituent of an Australian Aboriginal medicinal plant.
Publisher: Elsevier BV
Date: 12-2020
Publisher: American Vacuum Society
Date: 12-2008
DOI: 10.1116/1.3040158
Abstract: The phase behavior and lateral organization of saturated phosphatidylethanolamine (PE) and phosphatidylcholine (PC) bilayers were investigated using atomic force microscopy (AFM) and force-volume (FV) imaging for both pure and two component mixed layers. The results demonstrated the existence of unexpected segregated domains in pure PE membranes at temperatures well below the transition temperature (Tm) of the component phospholipid. These domains were of low mechanical stability and lacked the capacity for hydrogen bonding between lipid headgroups. Temperature dependent studies for different PC/PE ratios using AFM also demonstrated the mixing of these phospholipid bilayers to exhibit only a single gel to liquid transition temperature. Further work performed using FV imaging and chemically modified probes established that no lipid segregation exists at the PC/PE ratios investigated.
Publisher: Hindawi Limited
Date: 25-08-2021
DOI: 10.1111/JCPT.13520
Abstract: Proton pump inhibitors (PPIs), used to treat and prevent gastro-oesophageal conditions, are well-tolerated but have been associated with risk including pneumonia. The extent to which initiation of PPIs can contribute to other respiratory conditions such as chronic obstructive pulmonary disease (COPD) is largely unknown. A sequence symmetry analysis (SSA) approach was applied to the Australian Department of Human Services, Pharmaceutical Benefits Scheme 10% extract. Participants were aged 45 years and older and were dispensed PPIs (ATC Codes A02BC01, A02BC02, A02BC03, A02BC04 and A02BC05) and long-acting bronchodilators (LABDs) for COPD (ATC Codes R03BB04 (PBS Item Code 10509D and 08626B), R03BB05, R03BB06, R03BB07 and R03AC18 (PBS Item Code 05137J and 05134F)) between 2013 and 2019. The analysis included patients initiated on an LABD within 12 months before or after their first prescription of a PPI. The crude sequence ratio (cSR) was calculated as the number of patients prescribed their first LABD after starting a PPI ided by the number of patients prescribed their first LABD before starting a PPI. Calculation of the adjusted sequence ratio (aSR) accounted for prescribing trends over time in initiation of each of the medicines. A signal was identified where the aSR lower 95% confidence interval (CI) was greater than one. Initiation of omeprazole was associated with a 29% increased risk of initiating a LABD (ASR = 1.29 95% CI 1.22-1.36). Initiation of esomeprazole, rabeprazole, pantoprazole or lansoprazole was associated with 25%, 15%, 8% and 8% increased risk, respectively. There is an established association between gastro-oesophageal reflux disease and COPD which has been confirmed by implementation of a sequence symmetry-based approach which demonstrated that PPI initiation is potentially associated with progression or exacerbation of COPD. The impact PPI use has directly on this association requires further investigation.
Publisher: Frontiers Media SA
Date: 29-08-2022
DOI: 10.3389/FMICB.2022.967949
Abstract: Acinetobacter baumannii is a pathogen with high intrinsic antimicrobial resistance while multidrug resistant (MDR) and extensively drug resistant (XDR) strains of this pathogen are emerging. Treatment options for infections by these strains are very limited, hence new therapies are urgently needed. The bacterial cell ision protein, FtsZ, is a promising drug target for the development of novel antimicrobial agents. We have previously reported limited activity of cinnamaldehyde analogs against Escherichia coli . In this study, we have determined the antimicrobial activity of six cinnamaldehyde analogs for antimicrobial activity against A. baumannii . Microscopic analysis was performed to determine if the compounds inhibit cell ision. The on-target effect of the compounds was assessed by analyzing their effect on polymerization and on the GTPase activity of purified FtsZ from A. baumannii . In silico docking was used to assess the binding of cinnamaldehyde analogs. Finally, in vivo and in vitro safety assays were performed. All six compounds displayed antibacterial activity against the critical priority pathogen A. baumannii , with 4-bromophenyl-substituted 4 displaying the most potent antimicrobial activity (MIC 32 μg/mL). Bioactivity was significantly increased in the presence of an efflux pump inhibitor for A. baumannii ATCC 19606 (up to 32-fold) and significantly, for extensively drug resistant UW 5075 (greater than 4-fold), suggesting that efflux contributes to the intrinsic resistance of A. baumannii against these agents. The compounds inhibited cell ision in A. baumannii as observed by the elongated phenotype and targeted the FtsZ protein as seen from the inhibition of polymerization and GTPase activity. In silico docking predicted that the compounds bind in the interdomain cleft adjacent to the H7 core helix. Di-chlorinated 6 was devoid of hemolytic activity and cytotoxicity against mammalian cells in vitro , as well as adverse activity in a Caenorhabditis elegans nematode model in vivo . Together, these findings present halogenated analogs 4 and 6 as promising candidates for further development as antimicrobial agents aimed at combating A. baumannii . This is also the first report of FtsZ-targeting compounds with activity against an XDR A. baumannii strain.
Publisher: American Chemical Society (ACS)
Date: 27-10-2023
Publisher: Elsevier BV
Date: 06-2007
Publisher: Informa Healthcare
Date: 04-2007
Abstract: Despite being the first conjugation reaction demonstrated in humans, amino acid conjugation as a route of metabolism of xenobiotic carboxylic acids is not well characterised. This is principally due to the small number and limited structural ersity of xenobiotic substrates for amino acid conjugation. Unlike CYP and uridine 5'-diphosphate glucuronosyltransferase, which are localised in the endoplasmic reticulum, the enzymes of amino acid conjugation reside in mitochondria. Unique among drug metabolism pathways, amino acid conjugation involves initial formation of a xenobiotic acyl-CoA thioester that is then conjugated principally with glycine in humans. However, formation of the xenobiotic acyl-CoA thioester does not always infer subsequent amino acid conjugation. Evidence is presented that in the absence of glycine conjugation substrates that form acyl-CoA thioesters perturb mitochondrial function. This review discusses literature on the enzymes involved and the concept that xenobiotic substrate selectivity provides a barrier to protect the metabolic integrity of the mitochondria.
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.CANLET.2014.12.029
Abstract: The Ras/Raf/MAPK and PI3K/Akt/mTORC1 cascades are two most aberrantly regulated pathways in cancers. As MAPK-interacting kinases (Mnks) are part of the convergent node of these two pathways, and play a pivotal role in cellular transformation, targeting Mnks has emerged as a potential therapeutic strategy. Herein, a dual-specific Mnk1/2 inhibitor MNKI-57 and a potent Mnk2-specific inhibitor MNKI-4 were selected for a panel screen against 28 human cancer cell lines. The study reveals that MNKI-57 and MNKI-4 are most potent against leukemia cells KYO-1 (i.e. BC-CML) and KG-1 (i.e. AML). Interestingly, we found that sensitivity of selected leukemia cells to Mnk inhibitors is correlated with the level of phosphorylated 4E-BP1 at Thr70. The anti-proliferative effects of Mnk inhibitors are cytostatic in the sensitive KYO-1 cells, inducing significant G1 arrest via down-regulation of cyclin D1 expression. In KYO-1 cells where Akt is not constitutively active, Mnk inhibitors increase the sensitivity of cells to rapamycin, resulting in a more pronounced anti-proliferative activity. Remarkably, the synergistic anti-proliferative effects are associated with a marked de-phosphorylation of 4E-BP1 at Thr70. Collectively, these data highlight the importance of 4E-BP1 as a key integrator in the MAPK and mTORC1 cascades, and suggest that a combined pharmacologic inhibition of mTORC1 and Mnk kinases offers an innovative therapeutic opportunity in BC-CML.
Publisher: Wiley
Date: 03-2007
Abstract: The interactions of three cationic hiphilic drugs (CPZ, AMI, PROP) with phospholipid vesicles comprising DOPC, DMPC, or DSPC were investigated using surface plasmon resonance (SPR). Responses for CAD concentrations in the range 15.625 to 1500 microM were measured. The greatest uptake by each phospholipid bilayer occurred with CPZ. Inclusion of CAD concentrations between 750 and 1500 microM provided evidence for a second nonsaturable binding process, which may arise from intercalation of the drugs within the lipid bilayer. CAD binding was additionally shown to be dependent on membrane fluidity. Responses were initially fitted over a concentration range of 15.625 to 500 microM using a model which incorporated terms for a saturable binding site. This yielded very poor values of K(D) and nonsensible values of saturation responses. Subsequently, responses were fit to the expression for a model which incorporated terms for both a saturable binding site and second nonsaturable site. Measurable binding affinities (K(D) values ranged from 170 to 814 microM) were obtained for DOPC and DMPC bilayers which are similar to values reported previously. This work demonstrates that SPR studies with synthetic phospholipid bilayers provide a potentially useful approach for characterising drug-membrane binding interactions and for providing insight into the processes that contribute to drug-membrane binding.
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/CH15456
Abstract: Australian Aboriginal people have a long history of relying on plants for the treatment of various ailments and illnesses. Our ongoing collaborative research project initiated by Chuulangun Aboriginal Corporation (Cape York, Australia) has recently focussed on revealing whether Kuuku I’yu plant medicines possess anticancer-related activities and the chemistry responsible for this. Here, we present results from a study of the plant Litsea glutinosa, used traditionally for the treatment of gastrointestinal disorders. Four known aporphine alkaloids N-methylactinodaphnine (1), boldine (2), N-methyllaurotetanine (3), and isoboldine (4) were isolated by activity-guided fractionation and tested for cytotoxicity against HT29, SKMEL28, and primary human keratinocytes. Compound 1 was the most cytotoxic and this observation may be explained by the presence of a 1,2-methylenedioxy group. In silico docking revealed that a plausible mechanism for the observed cytotoxicity is the stabilization of a topoisomerase II (β) DNA–enzyme complex. The ethnopharmacological relevance of this study is discussed in the context of researching and using traditional knowledge in biomolecular discovery.
Publisher: American Society for Pharmacology & Experimental Therapeutics (ASPET)
Date: 04-06-2015
Abstract: The Ras/Raf/MAPK and PI3K/Akt/mTOR pathways are key signaling cascades involved in the regulation of cell proliferation and survival, and have been implicated in the pathogenesis of several types of cancers, including acute myeloid leukemia (AML). The oncogenic activity of eIF4E driven by the Mnk kinases is a convergent determinant of the two cascades, suggesting that targeting the Mnk/eIF4E axis may provide therapeutic opportunity for the treatment of cancer. Herein, a potent and selective Mnk2 inhibitor (MNKI-85) and a dual-specific Mnk1 and Mnk2 inhibitor (MNKI-19), both derived from a thienopyrimidinyl chemotype, were selected to explore their antileukemic properties. MNKI-19 and MNKI-85 are effective in inhibiting the growth of AML cells that possess an M5 subtype with FLT3-internal tandem duplication mutation. Further mechanistic studies show that the downstream effects with respect to the selective Mnk1/2 kinase inhibition in AML cells causes G1 cell cycle arrest followed by induction of apoptosis. MNKI-19 and MNKI-85 demonstrate similar Mnk2 kinase activity and cellular antiproliferative activity but exhibit different time-dependent effects on cell cycle progression and apoptosis. Collectively, this study shows that pharmacologic inhibition of both Mnk1 and Mnk2 can result in a more pronounced cellular response than targeting Mnk2 alone. However, MNKI-85, a first-in-class inhibitor of Mnk2, can be used as a powerful pharmacologic tool in studying the Mnk2/eIF4E-mediated tumorigenic mechanism. In conclusion, this study provides a better understanding of the mechanism underlying the inhibition of AML cell growth by Mnk inhibitors and suggests their potential utility as a therapeutic agent for AML.
Publisher: Hindawi Limited
Date: 03-2013
DOI: 10.1002/HUMU.22260
Abstract: Congenital cataract is a heterogeneous disorder causing severe visual impairment in affected children. We screened four South Australian families with autosomal dominant congenital cataract for mutations in 10 crystallin genes known to cause congenital cataract. We identified a novel segregating heterozygous mutation, c.62G>A (p.R21Q), in the CRYΑA gene in one family. Western blotting of proteins freshly extracted from cataractous lens material of the proband demonstrated a marked reduction in the amount of the high-molecular-weight oligomers seen in the lens material of an unaffected in idual. We conclude that the p.R21Q mutation, which is located in the highly conserved and structurally significant N-terminal region of the protein, is responsible for the cataract phenotype observed in the family as this mutation likely reduces the formation of the functional oligomeric alpha-crystallin.
Publisher: American Chemical Society (ACS)
Date: 18-12-2008
DOI: 10.1021/LA803288S
Abstract: Drug-membrane interactions assume considerable importance in pharmacokinetics and drug metabolism. Here, we present the interaction of chlorpromazine hydrochloride (CPZ) with supported phospholipid bilayers. It was demonstrated that CPZ binds rapidly to phospholipid bilayers, disturbing the molecular ordering of the phospholipids. These interactions were observed to follow first order kinetics, with an activation energy of approximately 420 kJ mol(-1). Time-dependent membrane disruption was also observed for the interaction with CPZ, such that holes appeared in the phospholipid bilayer after the interaction of CPZ. For this process of membrane disruption, "lag-burst" kinetics was demonstrated.
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B923719D
Publisher: Springer Science and Business Media LLC
Date: 22-12-2021
DOI: 10.1007/S40264-020-01027-X
Abstract: Antidepressant use during the first trimester is reported in 4-8% of pregnancies. The use of some selective serotonin reuptake inhibitors during the first trimester has been identified as increasing the odds for congenital heart defects however, little is known about the safety of non-selective serotonin reuptake inhibitor antidepressants. The objective of this study was to assess the odds of congenital heart defects associated with the use of antidepressants during the first trimester of pregnancy, and to update the literature as newer studies have been published since the latest systematic literature review and meta-analysis. PubMed and Embase were searched till 3 June, 2020. Study quality was assessed, and study details were extracted. Meta-analyses were performed using RevMan 5.4, which assessed: (1) any antidepressant usage (2) classes of antidepressants and (3) in idual antidepressants. Twenty studies were identified, encompassing 5,337,223 pregnancies. The odds ratio for maternal use of any antidepressant during the first trimester of pregnancy and the presence of congenital heart defects from the random effects meta-analysis was 1.28 (95% confidence interval [CI] 1.17-1.41). Significant odds ratios of 1.69 (95% CI 1.37-2.10) and 1.25 (95% CI 1.15-1.37) were reported for serotonin norepinephrine reuptake inhibitors and selective serotonin reuptake inhibitors, respectively. A non-statistically significant odds ratio of 1.02 (95% CI 0.82-1.25) was reported for the tricyclic antidepressants. Analyses of in idual SSRIs produced significant odds ratios of 1.57 (95% CI 1.25-1.97), 1.36 (95% CI 1.08-1.72), and 1.29 (95% CI 1.14-1.45) for paroxetine, fluoxetine, and sertraline, respectively. The norepinephrine-dopamine-reuptake inhibitor bupropion also produced a significant odds ratio of 1.23 (95% CI 1.01-1.49). The selective serotonin reuptake inhibitor and serotonin norepinephrine reuptake inhibitor classes of antidepressants pose a greater risk for causing congenital heart defects than the tricyclic antidepressants. However, this risk for in idual antidepressants within each class varies, and information regarding some antidepressants is still lacking.
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.BMC.2018.12.022
Abstract: The 26S proteasome and calpain are linked to a number of important human diseases. Here, we report a series of analogues of the prototypical tripeptide aldehyde inhibitor MG132 that show a unique combination of high activity and selectivity for calpains over proteasome. Tripeptide aldehydes (1-3) with an aromatic P3 substituent show enhanced activity and selectivity against ovine calpain 2 relative to chymotrypsin-like activity of proteasome. Docking studies reveal the key contacts between inhibitors and calpain to confirm the importance of the S3 pocket with respect to selectivity between calpains 1 and 2 and the proteasome.
Publisher: American Chemical Society (ACS)
Date: 23-07-190728635
DOI: 10.1021/JM7009793
Abstract: A validated database of 70 molecules known to undergo biotransformation by CYP2C9 was collated. The molecular alignment program ROCS was used with the query molecule flurbiprofen as a basis for predicting the correct active site orientation of the CYP2C9 database molecules. The quality of the results obtained was excellent, with 39 of the first 44 molecules (89%) sorted by ROCS combination score having alignments that accounted for the experimentally observed site of oxidation. Transposition of the first 39 correctly aligned molecules into the CYP2C9 active site yielded an average site of metabolism to iron heme distance of 5.21 A, in good agreement with previous experimental observations. Molecular docking studies were also undertaken, but the results were less successful than the ROCS-based alignment method, indicating that ligand-based approaches with chemical typing are important in the prediction of metabolism by CYP2C9.
Publisher: Elsevier BV
Date: 03-2020
Publisher: American Chemical Society (ACS)
Date: 16-02-2017
Abstract: Aberrant activity of cyclin-dependent kinase (CDK) 8 is implicated in various cancers. While CDK8-targeting anticancer drugs are highly sought-after, no CDK8 inhibitor has yet reached clinical trials. Herein a large library of drug-like molecules was computationally screened using two complementary cascades to identify potential CDK8 inhibitors. Thirty-three hits were identified to inhibit CDK8 and seven of them were active against colorectal cancer cell lines. Finally, the primary target was confirmed using three promising hits.
Publisher: Future Science Ltd
Date: 2015
DOI: 10.4155/FMC.14.145
Abstract: Pim oncogenes are highly expressed in many types of hematological and solid cancers. Pim kinases regulate the network of signaling pathways that are critical for tumorigenesis and development, making Pim kinases the attractive drug targets. Currently, two approaches have been employed in designing Pim kinase inhibitors: ATP-mimetics and non-ATP mimetics but all target the ATP-binding pocket and are ATP-competitive. In this review, we summarize the current progress in understanding the Pim-related structure and biology, and provide insights into the binding modes of some prototypical Pim-1 inhibitors. The challenges as well as opportunities are highlighted for development of Pim kinase inhibitors as potential anticancer agents.
Publisher: Elsevier BV
Date: 10-2015
DOI: 10.1016/J.EJMECH.2015.09.008
Abstract: Deregulation of protein synthesis is a common event in cancer. As MAPK-interacting kinases (Mnks) play critical roles in regulation of protein synthesis, they have emerged as novel anti-cancer targets. Mnks phosphorylate eukaryotic initiation factor 4E (eIF4E) and promote eIF4E-mediated oncogenic activity. Given that the kinase activity of Mnks is essential for oncogenesis but is dispensable for normal development, the discovery of potent and selective pharmacological Mnk inhibitors provides pharmacological target validation and offers a new strategy for cancer treatment. Herein, comprehensive in silico screening approaches were deployed, and three thieno[2,3-d]pyrimidine and pyrazolo[3,4-d]pyrimidine derivatives were identified as hit compounds. Further chemical modification of thieno[2,3-d]pyrimidine derivative 3 has given rise to a series of highly potent Mnk2 inhibitors that could be potential leads for the treatment of acute myeloid leukemia.
Publisher: American Chemical Society (ACS)
Date: 21-03-2022
DOI: 10.1021/ACS.JMEDCHEM.1C02139
Abstract: Tankyrases are multifunctional poly(adenosine diphosphate-ribose) polymerases that regulate erse biological processes including telomere maintenance and cellular signaling. These processes are often implicated in a number of human diseases, with cancer being the most prevalent ex le. Accordingly, tankyrase inhibitors have gained increasing attention as potential therapeutics. Since the discovery of XAV939 and IWR-1 as the first tankyrase inhibitors over two decades ago, tankyrase-targeted drug discovery has made significant progress. This review starts with an introduction of tankyrases, with emphasis placed on their cancer-related functions. Small-molecule inhibitors of tankyrases are subsequently delineated based on their distinct modes of binding to the enzymes. In addition to inhibitors that compete with oxidized nicotinamide adenine dinucleotide (NAD
Publisher: American Chemical Society (ACS)
Date: 09-10-2004
DOI: 10.1021/BI049146R
Abstract: An improved synthesis of a water-soluble derivative of dipyrido[3,2-a:2',3'-c]phenazine (dppz) is reported. The structures of both dppz and the cation ethylene-bipyridyldiylium-phenazine dinitrate [[1][(PF(6))(2)]] have been obtained via X-ray crystallography. Metal complex derivatives of dppz are very well studied. However, using the water soluble [1][(NO(3))(2)], the nature of the interaction of a simple dppz unit with duplex DNA has been investigated for the first time. In both organic solvents and water, 1 displays unstructured luminescence, assigned to an intramolecular charge transfer. The emission is quenched on binding to natural and synthetic duplex DNA, including poly(dA).poly(dT). A variety of techniques reveal that the cation binds to DNA with an affinity comparable to those of many metal dppz complexes, via an intercalative binding mode.
Publisher: Cold Spring Harbor Laboratory
Date: 27-02-2020
DOI: 10.1101/2020.02.24.20027532
Abstract: Antidepressant use during the first trimester is reported in 4% to 8% of pregnancies. The use of some selective serotonin reuptake inhibitors (SSRI) during this stage of gestation has been identified as increasing the odds for congenital heart defects, however little is known about the safety of non-SSRI antidepressants. To assess the odds of congenital heart defects associated with the use of any antidepressant during the first trimester of pregnancy. To investigate in idual classes of antidepressants: SSRIs, serotonin norepinephrine reuptake inhibitors (SNRI), tricyclic antidepressants (TCA) and in idual antidepressants. PubMed and Embase were searched without restrictions from inception till 2 January 2020. Prospective and retrospective cohort and case-control studies were included if they documented the maternal usage of antidepressants during the first trimester of pregnancy and assessed the presence of congenital heart defects. Data were extracted by two independent reviewers and the endpoint assessed was congenital heart defects. Where studies reported multiple results for different types of heart defects or in idual antidepressants, results were combined when possible. Analyses assessing in idual antidepressants and classes of antidepressants (SSRIs, SNRIs and TCAs) were undertaken. A total of 16 studies were identified, encompassing 4,564,798 pregnancy outcomes. The odds ratio for maternal use of any antidepressant and the presence of congenital heart defects from the mixed-methods meta-analysis was 1.22 (95% confidence interval (CI): 1.11 to 1.33). Analyses of antidepressants by class produced an odds ratio of 1.50 (95% CI: 1.19 to 1.89) for maternal SNRI use during the first trimester of pregnancy and the formation of congenital heart defects. A significant odds ratio of 1.22 (95% CI: 1.12 to 1.33) was reported for SSRIs. For the TCA class, no increased odds ratio was found. Analyses of in idual antidepressants produced significant odds ratios of 1.53 (95% CI: 1.25 to 1.88), 1.28 (95% CI: 1.01 to 1.62), 1.28 (95% CI: 1.14 to 1.45) and 1.23 (95% CI: 1.01 to 1.50) for paroxetine, fluoxetine, sertraline and bupropion respectively. While some insight has been gained into which classes of antidepressant and in idual antidepressants pose more risk than others for causing congenital heart defects, information regarding some antidepressants is still lacking.
Publisher: Springer Science and Business Media LLC
Date: 12-05-2023
DOI: 10.1007/S11095-023-03516-X
Abstract: Chronic Obstructive Pulmonary Disease is characterised by declining lung function and a greater oxidative stress burden due to reduced activity of antioxidant enzymes such as Glutathione Peroxidase 1. The extent to which drugs may contribute to this compromised activity is largely unknown. An integrative drug safety model explores inhibition of Glutathione Peroxidase 1 by drugs and their association with chronic obstructive pulmonary disease adverse drug events. In silico molecular modelling approaches were utilised to predict the interactions that drugs have within the active site of Glutathione Peroxidase 1 in both human and bovine models. Similarities of chemical features between approved drugs and the known inhibitor tiopronin were also investigated. Subsequently the Food and Drug Administration Adverse Event System was searched to uncover adverse drug event signals associated with chronic obstructive pulmonary disease. Statistical and molecular modelling analyses confirmed that the use of several registered drugs, including acetylsalicylic acid and atenolol may be associated with inhibition of Glutathione Peroxidase 1 and chronic obstructive pulmonary disease. The integration of molecular modelling and pharmacoepidemological data has the potential to advance drug safety science. Ongoing review of medication use and further pharmacoepidemiological and biological analyses are warranted to ensure appropriate use is recommended.
Publisher: American Chemical Society (ACS)
Date: 10-01-2003
DOI: 10.1021/CI025597B
Abstract: It is shown that quantum-mechanical descriptors obtained as parameters from the one-dimensional radial distribution function of electron momentum can be used to predict molecular activities or properties to a precision that compares favorably with the more traditional QSAR/QSPR methods. The distribution function is derived from momentum space ab initio wave functions. The predictive value of the descriptors is illustrated by their application to the estimation of McGowan's volume, gas-chromatographic retention time, gas-hexadecane partition coefficient, second hyperpolarizability, and tadpole narcotic activity.
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.PHRS.2022.106249
Abstract: Cyclin-dependent kinase 3 (CDK3) is a major player driving retinoblastoma (Rb) phosphorylation during the G
Publisher: Elsevier BV
Date: 02-2023
Publisher: MDPI AG
Date: 08-07-2022
DOI: 10.3390/BIOM12070960
Abstract: The regulation of vitamin D3 actions in humans occurs mainly through the Cytochrome P450 24-hydroxylase (CYP24A1) enzyme activity. CYP24A1 hydroxylates both 25-hydroxycholecalciferol (25(OH)D3) and 1,25-dihydroxycholecalciferol (1,25(OH)2D3), which is the first step of vitamin D catabolism. An abnormal status of the upregulation of CYP24A1 occurs in many diseases, including chronic kidney disease (CKD). CYP24A1 upregulation in CKD and diminished activation of vitamin D3 contribute to secondary hyperparathyroidism (SHPT), progressive bone deterioration, and soft tissue and cardiovascular calcification. Previous studies have indicated that CYP24A1 inhibition may be an effective strategy to increase endogenous vitamin D activity and decrease SHPT. This study has designed and synthesized a novel C-24 O-methyloxime analogue of vitamin D3 (VD1-6) to have specific CYP24A1 inhibitory properties. VD1-6 did not bind to the vitamin D receptor (VDR) in concentrations up to 10−7 M, assessed by a VDR binding assay. The absence of VDR binding by VD1-6 was confirmed in human embryonic kidney HEK293T cultures through the lack of CYP24A1 induction. However, in silico docking experiments demonstrated that VD1-6 was predicted to have superior binding to CYP24A1, when compared to that of 1,25(OH)2D3. The inhibition of CYP24A1 by VD1-6 was also evident by the synergistic potentiation of 1,25(OH)2D3-mediated transcription and reduced 1,25(OH)2D3 catabolism over 24 h. A further indication of CYP24A1 inhibition by VD1-6 was the reduced accumulation of the 24,25(OH)D3, the first metabolite of 25(OH)D catabolism by CYP24A1. Our findings suggest the potent CYP24A1 inhibitory properties of VD1-6 and its potential for testing as an alternative therapeutic candidate for treating SHPT.
Publisher: Royal Society of Chemistry (RSC)
Date: 2007
DOI: 10.1039/B707574J
Abstract: This work presents a Generalized Born model for the computation of the electrostatic component of solvation energies which is based on volume integration. An analytic masking function is introduced to remove Coulombic singularities. This approach leads to analytic formulae for the computation of Born radii, which are differentiable to arbitrary order, and computationally straightforward to implement.
No related grants have been discovered for Matthew Sykes.