Publications by authors named "John B MacMillan"

Annotation is the process of assigning features in mass spectrometry metabolomics data sets to putative chemical structures or "analytes." The purpose of this study was to identify challenges in the annotation of untargeted mass spectrometry metabolomics datasets and suggest strategies to overcome them. Toward this goal, we analyzed an extract of the plant ashwagandha () using liquid chromatography-mass spectrometry on two different platforms (an Orbitrap and Q-ToF) with various acquisition modes.

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As drug and natural product libraries expand, assays for assessing mechanisms of action (MoA) are increasingly critical. Performing cytological profiling using the Cell Painting (CP) assay enables image-based profiling of cellular states upon treatment, yet many bioactive compounds remain uncharacterized due to undetectable cellular effects under standard conditions. To address this, we combined drug dosing with cell activation using the protein kinase C (PKC) agonist phorbol myristate acetate (PMA).

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As drug and natural product libraries expand, assays for assessing mechanisms of action (MoA) are increasingly critical. Performing cytological profiling using the Cell Painting (CP) assay enables image-based profiling of cellular states upon treatment, yet many bioactive compounds remain uncharacterized due to undetectable cellular effects under standard conditions. To address this, we combined drug dosing with cell activation using the protein kinase C (PKC) agonist phorbol myristate acetate (PMA).

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Botanical natural products have been widely consumed for their purported usefulness against COVID-19. Here, six botanical species from multiple sources and 173 isolated natural product compounds were screened for blockade of wild-type (WT) SARS-CoV-2 infection in human 293T epithelial cells overexpressing ACE-2 and TMPRSS2 protease (293TAT). Antiviral activity was demonstrated by an extract from .

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Determining mechanism of action (MOA) is one of the biggest challenges in natural products discovery. Here, we report a comprehensive platform that uses Similarity Network Fusion (SNF) to improve MOA predictions by integrating data from the cytological profiling high-content imaging platform and the gene expression platform Functional Signature Ontology, and pairs these data with untargeted metabolomics analysis for de novo bioactive compound discovery. The predictive value of the integrative approach was assessed using a library of target-annotated small molecules as benchmarks.

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Boron-containing compounds are commonly used in synthetic chemistry and are known to play important roles in biology. Despite the widespread relevance of boronated compounds, there have been limited methods to discover, characterize, and study them. Here, we describe the use of B NMR, including H-B HMBC, for the isolation and characterization of the boron-containing natural product diadenosine borate.

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Biosynthetic mechanisms of natural products primarily depend on systems of protein catalysts. However, within the field of biosynthesis, there are cases in which the inherent chemical reactivity of metabolic intermediates and substrates evades the involvement of enzymes. These reactions are difficult to characterize based on their reactivity and occlusion within the milieu of the cellular environment.

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We report the first total synthesis of an antimycobacterial natural product oxazinin A that takes advantage of a multi-component cascade reaction of anthranilic acid and a precursor polyketide containing an aldehyde. The route utilized for the synthesis of the pseudodimeric oxazinin A validates a previously proposed biosynthetic mechanism, invoking a non-enzymatic pathway to the complex molecule. We found a 76 : 10 : 9 : 5 ratio of oxazinin diastereomers from the synthetic cascade, which is an identical match to that found in the fermentation media from the fungus Eurotiomycetes 110162.

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Article Synopsis
  • Natural products are vital for biomedicine, but existing methods often rediscover known compounds instead of finding new ones.
  • Researchers used advanced NMR techniques to enhance the detection of boron-containing metabolites, successfully identifying compounds like aplasmomycin and autoinducer-2 as a proof of concept.
  • A screening of various plant and microbial extracts revealed a surprising abundance of boron-containing metabolites, indicating that the new NMR method could be effective for discovering novel natural compounds.
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  • - Research focused on creating new compounds based on the antibiotic natural product hunanamycin A, followed by testing their biological effectiveness.
  • - A promising compound, identified as compound 36, showed strong activity against Salmonella enterica and had favorable drug-like properties.
  • - Testing in Swiss albino mice indicated that compound 36 was not acutely toxic at doses up to 2 g/kg, suggesting its potential for treating foodborne infections caused by Salmonella.
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Article Synopsis
  • Systematic screening of asymptomatic individuals is crucial for controlling infectious diseases, particularly on college campuses during the COVID-19 pandemic.
  • UC Santa Cruz launched a Molecular Diagnostic Lab in April 2020, rapidly developing testing capabilities to address the lack of available testing.
  • The lab implemented a validated testing method and an efficient automated workflow, achieving the capacity to test thousands of samples daily and screen the entire campus population twice a week.
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Biofilms, the predominant growth mode of microorganisms, pose a significant risk to human health. The protective biofilm matrix, typically composed of exopolysaccharides, proteins, nucleic acids, and lipids, combined with biofilm-grown bacteria's heterogenous physiology, leads to enhanced fitness and tolerance to traditional methods for treatment. There is a need to identify biofilm inhibitors using diverse approaches and targeting different stages of biofilm formation.

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Actinobacteria represent a large source of diverse bioactive compounds of medical and economic importance. Here, we report the 8.8-Mb draft genome of the marine bacterium SNB-032.

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Herein we report the isolation of a novel actinomycete, strain MCCB 268, from the sediment sample collected from a high Arctic fjord Kongsfjorden. MCCB 268 showed greater than 97% 16S rRNA gene sequence similarity with those of Pseudonocardia konjuensis LM 157 (98.06%), Pseudonocardia soli NW8-21 (97.

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The gut-brain axis is crucial to microbial-host interactions. The neurotransmitter serotonin is primarily synthesized in the gastrointestinal (GI) tract, where it is secreted into the lumen and subsequently removed by the serotonin transporter, SERT. Here, we show that serotonin decreases virulence gene expression by enterohemorrhagic E.

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Pyonitrins A-D are recently isolated natural products from the insect-associated strain, which were isolated from complex fractions that exhibited antifungal activity via an murine candidiasis assay. Genomic studies of suggested that pyonitrins A-D are formed via a spontaneous nonenzymatic reaction between biosynthetic intermediates of two well-known natural products pyochelin and pyrrolnitrin. Herein we have accomplished the first biomimetic total synthesis of pyonitrins A-D in three steps and studied the nonenzymatic formation of the pyonitrins using N NMR spectroscopy.

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While great interest in health effects of natural product (NP) including dietary supplements and foods persists, promising preclinical NP research is not consistently translating into actionable clinical trial (CT) outcomes. Generally considered the gold standard for assessing safety and efficacy, CTs, especially phase III CTs, are costly and require rigorous planning to optimize the value of the information obtained. More effective bridging from NP research to CT was the goal of a September, 2018 transdisciplinary workshop.

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Gene expression signature-based inference of functional connectivity within and between genetic perturbations, chemical perturbations, and disease status can lead to the development of actionable hypotheses for gene function, chemical modes of action, and disease treatment strategies. Here, we report a FuSiOn-based genome-wide integration of hypomorphic cellular phenotypes that enables functional annotation of gene network topology, assignment of mechanistic hypotheses to genes of unknown function, and detection of cooperativity among cell regulatory systems. Dovetailing genetic perturbation data with chemical perturbation phenotypes allowed simultaneous generation of mechanism of action hypotheses for thousands of uncharacterized natural products fractions (NPFs).

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Correction for 'The value of universally available raw NMR data for transparency, reproducibility, and integrity in natural product research' by James B. McAlpine et al., Nat.

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Modulators of insulin secretion could be used to treat diabetes and as tools to investigate β cell regulatory pathways in order to increase our understanding of pancreatic islet function. Toward this goal, we previously used an insulin-linked luciferase that is cosecreted with insulin in MIN6 β cells to perform a high-throughput screen of natural products for chronic effects on glucose-stimulated insulin secretion. In this study, using multiple phenotypic analyses, we found that one of the top natural product hits, chromomycin A2 (CMA2), potently inhibited insulin secretion by at least three potential mechanisms: disruption of Wnt signaling, interference of β cell gene expression, and partial suppression of Ca influx.

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Article Synopsis
  • Cancer testis antigens (CTAs), specifically HORMAD1, are linked to resistance against the mitochondrial inhibitor piericidin A in non-small cell lung cancer (NSCLC) by creating a protective intracellular environment.
  • High levels of HORMAD1 in lung adenocarcinoma (LUAD) correlate with greater mutational burden and reduced survival rates, indicating a potential poor prognosis for patients.
  • The study suggests that targeting HORMAD1 could enhance tumor sensitivity to DNA-damaging treatments and might serve as a novel immunotherapeutic target in lung cancer.
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Covering: up to 2018With contributions from the global natural product (NP) research community, and continuing the Raw Data Initiative, this review collects a comprehensive demonstration of the immense scientific value of disseminating raw nuclear magnetic resonance (NMR) data, independently of, and in parallel with, classical publishing outlets. A comprehensive compilation of historic to present-day cases as well as contemporary and future applications show that addressing the urgent need for a repository of publicly accessible raw NMR data has the potential to transform natural products (NPs) and associated fields of chemical and biomedical research. The call for advancing open sharing mechanisms for raw data is intended to enhance the transparency of experimental protocols, augment the reproducibility of reported outcomes, including biological studies, become a regular component of responsible research, and thereby enrich the integrity of NP research and related fields.

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The originally published version of this Article contained an error in the spelling of the author Nathaniel W. Oswald, which was incorrectly given as Nathaniel W. Olswald.

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Diversity in the genetic lesions that cause cancer is extreme. In consequence, a pressing challenge is the development of drugs that target patient-specific disease mechanisms. To address this challenge, we employed a chemistry-first discovery paradigm for de novo identification of druggable targets linked to robust patient selection hypotheses.

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