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 43 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 1051 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 114 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 905 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...
Biochemometrics for Natural Products Research: Comparison of Data Analysis Approaches and Application to Identification of Bioactive Compounds 2016 98 [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 78 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 1116 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 975 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 516 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 49 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 125 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...
Detection of Adulteration in Hydrastis canadensis (Goldenseal) Dietary Supplements via Untargeted Mass Spectrometry-Based Metabolomics 2018 131 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 73 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 1364 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 1644 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 1337 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 16 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 1457 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 864 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 1329 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 1229 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...
Inhibition of H1N1 influenza A virus growth and induction of inflammatory mediators by the isoquinoline alkaloid berberine and extracts of goldenseal (Hydrastis canadensis) 2011 1851 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 22 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 24 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 2015 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 894 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 1245 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...
Phylogenetic and chemical diversity of fungal endophytes isolated from Silybum marianum (L) Gaertn. (milk thistle) 2015 756 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 950 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 ...
qNMR for Profiling the Production of Fungal Secondary Metabolites 2017 131 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 973 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 1989 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...
Rapid Quantitation of Furanocoumarins and Flavonoids in Grapefruit Juice using Ultra-Performance Liquid Chromatography 2013 1597 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 1035 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 1015 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...
Sarothrin from Alkanna orientalis Is an Antimicrobial Agent and Efflux Pump Inhibitor 2013 1121 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 90 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 29 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 1580 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 850 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 3282 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 113 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 894 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 136 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...