David R McMullin

David R McMullin
Carleton University · Department of Chemistry

PhD Chemistry: Chemical and Environmental Toxicology

About

37
Publications
8,352
Reads
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741
Citations
Additional affiliations
July 2018 - present
Carleton University
Position
  • Professor (Assistant)
January 2017 - June 2018
Agriculture and Agri-Food Canada
Position
  • Researcher
September 2014 - December 2016
Carleton University
Position
  • Fellow

Publications

Publications (37)
Article
Ilyonectria mors-panacis, previously Cylindrocarpon destructans, is the main plant pathogen responsible for the fungal disease ginseng root rot. This economically important disease, also called disappearing root rot, reduces crop yields by an average of 30% at harvest. While the disease is well studied from ecological and genomic perspectives, the...
Article
Coffee silverskin is a byproduct of the coffee roasting process contributing to organic waste burdens in urban areas. Silverskin is a potential source of dietary fiber, protein, carbohydrates, caffeine as well as vitamins and minerals. However, phytosterols present in the plant are susceptible to thermal oxidation resulting in the formation of phyt...
Article
In an effort to describe bioactive antifungal compounds from antagonistic bacteria with potential for biocontrol of plant pathogens, a strain of Arthrobacter psychrophenolicus was collected from plant disease suppressive compost prepared from composted material of marine origin. Few natural products have been characterized from the non-filamentous...
Article
Antagonistic bacteria can act as biocontrol agents against various phytopathogens. Recently, Arthrobacter spp. demonstrated antifungal activity, but were not further characterized. In this study, the antimicrobial activity of Arthrobacter humicola strains M9-1A, M9-2, and M9-8, and Arthrobacter psychrophenolicus strain M9-17 were evaluated against...
Article
Cyanobacteria are ubiquitous photosynthetic prokaryotes that produce structurally diverse bioactive metabolites. While microcystins are extensively studied, other cyanopeptides produced by common bloom forming species have received little attention. Cyanopeptolins are a large cyanopeptide group that contain a diagnostic 3‐amino‐6‐hydroxy‐2‐piperido...
Article
As part of a survey of foliar endophytes of conifers in the Acadian forest, we isolated a strain of Lachnellula calyciformis from a healthy Picea rubens needle. From this fungus, the new natural products deoxylachnellulone (3) and lachnelluloic acid B (5), and the known metabolite lachnellulone (1), were isolated and structurally characterized. Iso...
Article
Fusarium graminearum and related species produce regulated mycotoxins that contaminate important food commodities resulting in serious agricultural and animal productivity losses. F. graminearum DAOMC 242077 was isolated from soft wheat in Eastern Canada and an investigation of this strains secondary metabolites confirmed it produced the recently d...
Article
As part of a broad survey of the metabolites produced by foliar endophytes of conifers, a strain was isolated from surface-sterilized needles collected from eastern white pine on the north shore of Lake Huron, Ontario. The isolate was sterile in culture. Species identity was not resolved by ITS sequence because of the absence of corresponding seque...
Article
Rationale Microbial natural products are often biosynthesized as classes of structurally related compounds that have similar MS/MS fragmentation patterns. Mining MS/MS datasets for precursor ions that share diagnostic or common features enables entire chemical classes to be identified, including novel derivatives that have previously been unreporte...
Article
Full-text available
Surveys of foliar endophytes from the Acadian forest region over the past three decades have identified numerous phylogenetically diverse fungi producing natural products toxic to forest pests and diseases. The life histories of some conifer endophytes can be restricted to plant foliage or may include saprotrophic phases on other plants tissues or...
Data
Supporting Information: Figure A. 1H (400 MHz, CD3OD) NMR spectrum for 1. Figure B. 13C (100 MHz, CD3OD) NMR spectrum for 1. Figure C. HMBC NMR spectrum for 1 in CD3OD. Figure D. 1H (400 MHz, CD3OD) NMR spectrum for 2. Figure E. 13C (100 MHz, CD3OD) NMR spectrum for 2. Figure F. HMBC NMR spectrum for 2 in CD3OD. Figure G. 1H (400 MHz, CD3OD) NMR sp...
Chapter
This chapter describes the ecology of foliar endophytes of the Acadian Forest that dominates Canada’s Maritime Provinces extending into Eastern Quebec and Maine. Recent evidence has illuminated the ‘foraging ascomycete’ life habit of fungi that can be endophytic in conifer needles. These fungi can occupy several eco-niches other than the needles in...
Article
The needles of Picea glauca (white spruce) and Pinus strobus (white pine) trees infected with toxigenic fungal endophytes contain varying concentrations of their secondary metabolites that are toxic to either insect pests or needle pathogens. In the present study, liquid chromatography-mass spectrometric methods to determine needle concentrations o...
Article
Several moderately pathogenic Fusarium species produce enniatins, a family of cyclohexadepsipeptides with insecticidal and phytotoxic activities. A semi-targeted LC-MS/MS approach utilizing reversed-phase C8 UHPLC column chromatography that combines both product ion and neutral loss filtering was developed to detect enniatins and structurally-relat...
Article
Most fungi that grow on damp building materials produce low molecular weight compounds, some of which are known to be toxic. In this study, we tested the hypothesis that exposure to some metabolites of fungi common on damp building materials would result in time-, dose-, and compound-specific responses in the production of various chemokines by RAW...
Article
Endophytes of healthy needles were collected from Picea rubens (red spruce) and P. mariana (black spruce) in a survey of southeastern New Brunswick, Canada. Four endophyte strains were selected for further investigation based on the production of biologically active extracts from culture filtrates during screening as well as phylogenetic relationsh...
Article
Buildings that have been flooded often have high concentrations of Trichoderma spores in the air while drying. Inhaled spores, spore and mycelial fragments contain large amounts of fungal glucan and natural products that contribute to the symptoms associated with indoor mold exposures. In this study, we considered both small molecules and peptaibol...
Article
Full-text available
The rapid identification of mycotoxins such as deoxynivalenol and aflatoxin B1 in agricultural commodities is an ongoing concern for food importers and processors. While sophisticated chromatography-based methods are well established for regulatory testing by food safety authorities, few techniques exist to provide a rapid assessment for traders. T...
Article
Full-text available
The genus . Diaporthe comprises close to 800 species, with around 2000 names attributed to it and its asexual morphs previously recognized in . Phomopsis. Diaporthe species are common plant associates, including saprotrophs, pathogens, and endophytes affiliated with a diverse range of hosts worldwide. In this study, an unknown . Diaporthe sp. was f...
Article
Ochratoxin A (OTA) is a mycotoxin produced by some Aspergillus and Penicillium species that grow on economically important agricultural crops and food products. OTA is classified as Group 2B carcinogen and is potently nephrotoxic, which is the basis for its regulation in some jurisdictions. Using high resolution mass spectroscopy, OTA and ochratoxi...
Article
A needle endophyte of Pinus strobus (eastern white pine) was isolated from a tree near Sussex, New Brunswick and screened for the production of antifungal compounds. This was identified as Lopherdermium nitens, a common endophyte of white pine known to produce potent antifungal compounds. Extracts of culture filtrates of L. nitens DAOM 250027 were...
Article
Full-text available
From the epidemiological studies conducted on the effect of mould and dampness on health a decade ago, the role of toxin-producing fungi in damp and mouldy buildings involved opinion more than evidence. Very little was known about the metabolites that were produced by the fungi that grew on damp building materials, and almost nothing had been repor...
Article
Full-text available
Infrared spectroscopy is a rapid, nondestructive analytical technique that can be applied to the authentication and characterization of food samples in high throughput. In particular, near infrared spectroscopy is commonly utilized in the food quality control industry to monitor the physical attributes of numerous cereal grains for protein, carbohy...
Article
Full-text available
Indoor exposure to the spores and mycelial fragments of fungi that grow on damp building materials can result in increased non-atopic asthma and upper respiratory disease. The mechanism appears to involve exposure to low doses of fungal metabolites. Penicillium corylophilum is surprisingly common in damp buildings in USA, Canada and western Europe....
Article
Wallemia sebi has been primarily known as a spoilage fungus of dried, salted fish and other foods that that are salty or sweet. However, this fungus is also very common in house dust. The health effects of chronic exposure to mold and dampness are known to be associated with both allergens and various inflammatory compounds, including the secondary...
Article
Seven new secondary metabolites, four isochromans (1-4) and three α-pyrones (5-7), were isolated from Penicillium corylophilum DAOM 242293 collected from a damp building in Halifax, Canada. Their structures were elucidated by HRESIMS, 1D and 2D NMR, chemical derivatization, ORD, UV, and comparison to the literature. Related isochromans have previou...
Article
Full-text available
Chaetomium globosum is one of the most common species of fungi found growing on damp building materials in North America and Europe. At doses that could be experienced in a building with some mould damage, exposure to metabolites from other fungi results in inflammatory changes in vivo and in vitro. This research requires knowledge of the dominant...
Article
Full-text available
In this study, intact flagellin proteins were purified from strains of Clostridium difficile and analyzed using quadrupole time of flight and linear ion trap mass spectrometers. Top-down studies showed the flagellin proteins to have a mass greater than that predicted from the corresponding gene sequence. These top-down studies revealed marker ions...
Article
Flagellins from Clostridium botulinum were shown to be post-translationally modified with novel glycan moieties by top-down MS analysis of purified flagellin protein from strains of various toxin serotypes. Detailed analyses of flagellin from two strains of C. botulinum demonstrated that the protein is modified by a novel glycan moiety of mass 417...
Article
Flagellins from Clostridium botulinum were shown to be post-translationally modified with novel glycan moieties by top-down MS analysis of purified flagellin protein from strains of various toxin serotypes. Detailed analyses of flagellin from two strains of C. botulinum demonstrated that the protein is modified by a novel glycan moiety of mass 417...

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