Nadja B. Cech

**Expertise: Analytical Chemistry, Mass Spectrometry, Medicinal Plant Chemistry **Education: B.S., Southern Oregon University, 1997--Ph.D., The University of New Mexico, 2001

There are 51 included publications by Nadja B. Cech :

TitleDateViewsBrief Description
Alkaloid Variation Among Epichloid Endophytes of Sleepygrass (Achnatherum robustum) and Consequences for Resistance to Insect Herbivores 2014 1252 Epichloid endophytes are well known symbionts of many cool-season grasses that may alleviate environmental stresses for their hosts. For example, endophytes produce alkaloid compounds that may be toxic to invertebrate or vertebrate herbivores. Achnat...
Antimicrobial Fungal Endophytes from the Botanical Medicine Goldenseal (Hydrastis canadensis) 2016 253 The potential of fungal endophytes to alter or contribute to plant chemistry and biology has been the topic of a great deal of recent interest. For plants that are used medicinally, it has been proposed that endophytes might play an important role in...
Antimycobacterial Furofuran Lignans from the Roots of Anemopsis californica 2014 1029 Topical preparations of Anemopsis californica have been used by Native American tribes in the southwestern United States and northern Mexico to treat inflammation and infections. We report results of bioassay-guided isolation conducted on a sample of...
Apicidin Attenuates MRSA Virulence through Quorum-Sensing Inhibition and Enhanced Host Defense 2019 106 Recurrent epidemics of drug-resistant Staphylococcus aureus illustrate the rapid lapse of antibiotic efficacy following clinical implementation. Over the last decade, community-associated methicillin-resistant S. aureus (MRSA) has emerged as a domina...
Biochemometrics for Natural Products Research: Comparison of Data Analysis Approaches and Application to Identification of Bioactive Compounds 2016 215 [The original abstract for this article contains images that cannot be displayed here. Please click on the link below to read the full abstract and article.]
Biochemometrics to identify synergists and additives from botanical medicines: A case study with Hydrastis canadensis (Goldenseal) 2018 242 A critical challenge in the study of botanical natural products is the difficulty of identifying multiple compounds that may contribute additively, synergistically, or antagonistically to biological activity. Herein, it is demonstrated how combining ...
CodY-Mediated Regulation of the Staphylococcus aureus Agr System Integrates Nutritional and Population Density Signals 2014 1245 The Staphylococcus aureus Agr system regulates virulence gene expression by responding to cell population density (quorum sensing). When an extracellular peptide signal (AIP-III in strain UAMS-1, used for these experiments) reaches a concentration th...
Comparison of alkylamide yield in ethanolic extracts prepared from fresh versus dry Echinacea purpurea utilizing HPLC–ESI-MS 2009 1126 Echinacea purpurea (L.) Moench, a top selling botanical medicine, is currently of considerable interest due to immunomodulatory, anti-inflammatory, antiviral and cannabinoid receptor 2 (CB2) binding activities of its alkylamide constituents. The purp...
Comparison of the chemistry and diversity of endophytes isolated from wild-harvested and greenhouse-cultivated yerba mansa (Anemopsis californica) 2015 682 With this study, we explored the identity and chemistry of fungal endophytes from the roots of yerba mansa [Anemopsis californica (Nutt.) Hook. & Arn. (Saururaceae)], a botanical traditionally used to treat infection. We compared the diversity of fun...
Comparison of electrospray ionization and atmospheric pressure photoionization liquid chromatography mass spectrometry methods for analysis of ergot alkaloids from endophyte-infected sleepygrass (Achnatherum robustum) 2016 215 Ergot alkaloids are mycotoxins with an array of biological effects. With this study, we investigated for the first time the application of atmospheric pressure photoionization (APPI) as an ionization method for LC–MS analysis of ergot alkaloids, and ...
Comparison of Metabolomics Approaches for Evaluating the Variability of Complex Botanical Preparations: Green Tea (Camellia sinensis) as a Case Study 2017 271 A challenge that must be addressed when conducting studies with complex natural products is how to evaluate their complexity and variability. Traditional methods of quantifying a single or a small range of metabolites may not capture the full chemica...
Conventional and Accelerated-Solvent Extractions of Green Tea (Camellia sinensis) for Metabolomics-Based Chemometrics 2017 87 Metabolomics has emerged as an important analytical technique for multiple applications. The value of information obtained from metabolomics analysis depends on the degree to which the entire metabolome is present and the reliability of sample treatm...
Detection of Adulteration in Hydrastis canadensis (Goldenseal) Dietary Supplements via Untargeted Mass Spectrometry-Based Metabolomics 2018 354 Current estimates report that approximately 25% of U.S. adults use dietary supplements for medicinal purposes. Yet, regulation and transparency within the dietary supplement industry remains a challenge, and economic incentives encourage adulteration...
Diversity Reimagined: Creating a Culture of Possibilities by Relating to Others as Partners, Fellow Learners and Builders 2018 116 There’s no doubt. ‘Diversity’ has gotten a bad rap. It has become increasingly equated with a kind of moralism or political correctness that is not helpful. The word tends to get people all wound up, bent out of shape, and either clamped up or up on ...
Echinacea alkylamides inhibit interleukin-2 production by Jurkat T cells 2006 1501 Alkylamides present in Echinacea species have reported immunomodulatory actions, yet their direct effects on T lymphocytes, key mediators of antiviral immunity, are poorly understood. We hypothesized that constituents present in ethanolic extracts of...
Echinacea and its alkylamides: Effects on the influenza A-induced secretion of cytokines, chemokines, and PGE2 from RAW 264.7 macrophage-like cells 2010 2128 The goal of this study was to determine whether extracts and isolated alkylamides from Echinacea purpureawould be useful for prevention of the inflammatory response that accompanies infections with H1N1 influenza A. Seventeen extracts and 4 alkylamid...
Effects of herbal products and their constituents on human cytochrome P4502E1 activity 2007 1495 Ethanolic extracts from fresh Echinacea purpurea and Spilanthes acmella and dried Hydrastis canadensis were examined with regard to their ability to inhibit cytochrome P4502E1 mediated oxidation of p-nitrophenol in vitro. In addition, individual cons...
Epichloë endophytes of Poa alsodes employ alternative mechanisms for host defense: insecticidal versus deterrence 2019 103 Some cool-season pooid grasses partner with symbiotic fungal endophytes in the Epichloë genus for defense against insect herbivores via fungal alkaloids. Poa alsodes, North American woodland grass, independently hosts two species of Epichloë that var...
Ethanolic Echinacea purpurea Extracts Contain a Mixture of Cytokine-Suppressive and Cytokine-Inducing Compounds, Including Some That Originate from Endophytic Bacteria 2015 1684 Echinacea preparations, which are used for the prevention and treatment of upper respiratory infections, account for 10% of the dietary supplement market in the U.S., with sales totaling more than $100 million annually. In an attempt to shed light on...
Flavonolignans from Aspergillus iizukae, a Fungal Endophyte of Milk Thistle (Silybum marianum) 2014 1026 Silybin A (1), silybin B (2), and isosilybin A (3), three of the seven flavonolignans that constitute silymarin, an extract of the fruits of milk thistle (Silybum marianum), were detected for the first time from a fungal endophyte, Aspergillus iizuka...
Goldenseal (Hydrastis canadensis L.) Extracts Synergistically Enhance the Antibacterial Activity of Berberine via Efflux Pump Inhibition 2010 1546 Goldenseal (Hydrastis canadensis L.) is used to combat inflammation and infection. Its antibacterial activity in vitro has been attributed to its alkaloids, the most abundant of which is berberine. The goal of these studies was to compare the composi...
High performance liquid chromatography/electrospray ionization mass spectrometry for simultaneous analysis of alkamides and caffeic acid derivatives from Echinacea purpurea extracts 2006 1518 Extracts of the plant Echinacea purpurea are widely used for medicinal purposes. Effective quality control of these extracts requires rapid methods to determine their chemical composition. A new method for analysis of caffeic acid derivatives and alk...
High-Resolution MS, MS/MS, and UV Database of Fungal Secondary Metabolites as a Dereplication Protocol for Bioactive Natural Products 2013 123 A major problem in the discovery of new biologically active compounds from natural products is the reisolation of known compounds. Such reisolations waste time and resources, distracting chemists from more promising leads. To address this problem, de...
Inhibition of H1N1 influenza A virus growth and induction of inflammatory mediators by the isoquinoline alkaloid berberine and extracts of goldenseal (Hydrastis canadensis) 2011 2150 In this study we tested whether the isoquinoline alkaloid berberine can inhibit the growth of influenza A. Our experiments showed strong inhibition of the growth of H1N1 influenza A strains PR/8/34 or WS/33 in RAW 264.7 macrophage-like cells, A549 hu...
Integration of biochemometrics and molecular networking to identify antimicrobials in Angelica keiskei 2018 126 Botanical medicines have been utilized for centuries. but it remains challenging to identify bioactive constituents from complex botanical extracts. Bioassay-guided fractionation is often biased toward abundant or easily isolatable compounds. To comp...
Interspecific and intraspecific hybrid Epichloë species symbiotic with the North American native grass Poa alsodes 2017 136 The endophyte presence and diversity in natural populations of Poa alsodes were evaluated along a latitudinal transect from the southern distribution range in North Carolina to New York. Two distinct Epichloë hybrid taxa were identified from 23 popul...
Liver Enzyme-Mediated Oxidation of Echinacea purpurea Alkylamides: Production of Novel Metabolites and Changes in Immunomodulatory Activity 2006 2140 The medicinal plant Echinacea is widely used to treat upper respiratory infections and is reported to stimulate the human immune system. A major constituent class of Echinacea, the alkyl-amides, has immunomodulatory effects. Recent studies show that ...
Maplexins, new a-glucosidase inhibitors from red maple (Acer rubrum) stems 2012 991 Thirteen gallic acid derivatives including five new gallotannins, named maplexins A–E, were isolated from red maple (Acer rubrum) stems. The compounds were identified by spectral analyses. The maplexins varied in number and location of galloyl groups...
A Mass Spectrometry-Based Assay for Improved Quantitative Measurements of Efflux Pump Inhibition 2015 1386 Bacterial efflux pumps are active transport proteins responsible for resistance to selectedbiocides and antibiotics. It has been shown that production of efflux pumps is up-regulatedin a number of highly pathogenic bacteria, including methicillin res...
Mast cell degranulation and calcium influx are inhibited by an Echinacea purpurea extract and the alkylamide dodeca-2E,4E-dienoic acid isobutylamide 2018 9 Ethnopharmacological relevance: Native Americans used plants from the genus Echinacea to treat a variety of different inflammatory conditions including swollen gums, sore throats, skin inflammation, and gastrointestinal disorders. Today, various Echi...
MroQ is a novel Abi-domain protein that influences virulence gene expression in Staphylococcus aureus via modulation of agr activity 2019 11 Numerous factors have, to date, been identified as playing a role in the regulation of Agr activity in Staphylococcus aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigated the product of SAUSA300_1984 (ter...
Phylogenetic and chemical diversity of fungal endophytes isolated from Silybum marianum (L) Gaertn. (milk thistle) 2015 869 Use of the herb milk thistle (Silybum marianum) is widespread, and its chemistry has been studied for over 50 years. However, milk thistle endophytes have not been studied previously for their fungal and chemical diversity. We examined the fungal end...
Polyhydroxyanthraquinones as Quorum Sensing Inhibitors from the Guttates of Penicillium restrictum and Their Analysis by Desorption Electrospray Ionization Mass Spectrometry 2014 1103 The endophytic fungus Penicillium restrictum was isolated from the stems of a milk thistle (Silybum marianum) plant. In culture, the fungus produced distinct red guttates, which have been virtually uninvestigated, particularly from the standpoint of ...
Prenylated Diresorcinols Inhibit Bacterial Quorum Sensing 2019 60 [The original abstract for this article contains images that cannot be displayed here. Please click on the link below to read the full abstract and article.]
qNMR for Profiling the Production of Fungal Secondary Metabolites 2017 243 Analysis of complex mixtures is a common challenge in natural products research. Quantitative nuclear magnetic resonance spectroscopy offers analysis of complex mixtures at early stages and with benefits that are orthogonal to more common methods of ...
Quantitative analysis of autoinducing peptide I (AIP-I) from Staphylococcus aureus cultures using ultrahigh performance liquid chromatography–high resolving power mass spectrometry 2013 1094 Staphylococcus aureus infections acquired in hospitals now cause more deaths per annum in the US than does HIV/AIDS. Perhaps even more alarming is the rise in community associated methicillin-resistant S. aureus (CA-MRSA) infections, which have sprea...
Quorum Quenching and Antimicrobial Activity of Goldenseal (Hydrastis canadensis) against Methicillin-Resistant Staphylococcus aureus (MRSA) 2012 2139 The popular herbal remedy goldenseal (Hydrastis canadensis L.) is traditionally used to treat skin infections. With this study, we show activity of H. canadensis extracts in vitro against methicillin-resistant Staphylococcus aureus (MRSA). An extract...
Quorum sensing between bacterial species on the skin protects against epidermal injury in atopic dermatitis 2019 17 Colonization of the skin by Staphylococcus aureus is associated with exacerbation of atopic dermatitis (AD), but any direct mechanism through which dysbiosis of the skin microbiome may influence the development of AD is unknown. Here, we show that pr...
Rapid Quantitation of Furanocoumarins and Flavonoids in Grapefruit Juice using Ultra-Performance Liquid Chromatography 2013 1768 Introduction:Grapefruit juice can increase or decrease the systemic exposure of myriad oral medications, leading to untoward effects or reduced efficacy. Furanocoumarins in grapefruit juice have been established as inhibitors of cytochrome P450 3A (C...
Relative Importance of Basicity in the Gas Phase and in Solution for Determining Selectivity in Electrospray Ionization Mass Spectrometry 2008 1180 Electrospray ionization mass spectrometry is a critically important technique for the determination of small molecules, but its application for this purpose is complicated by its selectivity. For positive ion ESI-MS analysis of basic analytes, severa...
The relative influences of acidity and polarity on responsiveness of small organic molecules to analysis with negative ion electrospray ionization mass spectrometry (ESI-MS) 2005 1165 The purpose of the work presented here was to evaluate the influence of solution composition and analyte characteristics on responsiveness to analysis with negative ion electrospray ionization mass spectrometry. The responses of a series of structura...
Role for PPAR-gamma in IL-2 inhibition in T cells by Echinacea-derived undeca-2E-ene-8,10-diynoic acid isobutylamide 2009 1 Certain fatty acid amides from Echinacea spp. have demonstrated moderate to high cannabinoid activity. As a result, CB2 activation is currently hypothesized to be the basis of activity for immunomodulation by Echinacea spp. PPAR-gamma, an orphan nucl...
Sarothrin from Alkanna orientalis Is an Antimicrobial Agent and Efflux Pump Inhibitor 2013 1283 An Alkanna orientalis leaf and flower extract inhibited the growth of Staphylococcus aureus, a pathogen that causes an estimated 478000 hospitalizations in the US annually. Bioassay-guided fractionation of A. orientalis resulted in isolation of the f...
Secondary Metabolites from Fungal Endophytes of Echinacea purpurea Suppress Cytokine Secretion by Macrophage-Type Cells 2016 169 Botanical extracts of Echinacea purpurea have been widely used for the treatment of upper respiratory infections. We sought to chemically examine fungal endophytes inhabiting E. purpurea, and to identify compounds produced by these endophytes with in...
Secondary Metabolites from the Leaves of the Medicinal Plant Goldenseal (Hydrastis Canadensis) 2017 131 The study presented herein constitutes an extensive investigation of constituents in Hydrastis canadensis L. (Ranunculaceae) leaves. It describes the isolation and identification of two previously unknown compounds, 3,4-dimethoxy-2-(methoxycarbonyl)b...
Small-molecule quorum quenchers to prevent Staphylococcus aureus infection 2013 1749 Antibiotic-resistant bacteria are one of the most significant current threats to human health. The diminishing antibiotic development pipeline coupled with the propensity for bacterial pathogens to evolve resistance represents an ongoing crisis that ...
Synergy-Directed Fractionation of Botanical Medicines: A Case Study with Goldenseal (Hydrastis canadensis) 2011 1020 It is often argued that the efficacy of herbal medicines is a result of the combined action of multiple constituents that work synergistically or additively. Determining the bioactive constituents in these mixtures poses a significant challenge. We h...
Temperature-sensitive anthocyanin production in flowers of Plantago lanceolata 2007 3536 Flower color in the weedy perennial Plantago lanceolata is phenotypically plastic. Darker flowers are produced at cooler ambient temperatures, and circumstantial evidence suggests that this is adaptive. The goal of this project was to investigate the...
A Validated UHPLC-Tandem Mass Spectrometry Method for Quantitative Analysis of Flavonolignans in Milk Thistle (Silybum marianum) Extracts 2016 315 Validated methods are needed for the analysis of natural product secondary metabolites. These methods are particularly important to translate in vitro observations to in vivo studies. Herein, a method is reported for the analysis of the key secondary...
w-Hydroxyemodin Limits Staphylococcus aureus Quorum Sensing-Mediated Pathogenesis and Inflammation 2015 1046 Antibiotic-resistant pathogens are a global health threat. Small molecules that inhibit bacterial virulence have been suggested as alternatives or adjuncts to conventional antibiotics, as they may limit pathogenesis and increase bacterial susceptibil...
‘Yes, and’ as Teaching-Learning Methodology 2017 375 Here we present ‘Yes, and,’ a concept derived from improvisational theatre, as a teaching-learning methodology that supports engaged experiential learning. In this approach, the leader of the group and co-participants affirm each other and creatively...