|CodY-Mediated Regulation of the Staphylococcus aureus Agr System Integrates Nutritional and Population Density Signals
||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
||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...
|Echinacea alkylamides inhibit interleukin-2 production by Jurkat T cells
||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
||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
||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...
|Goldenseal (Hydrastis canadensis L.) Extracts Synergistically Enhance the Antibacterial Activity of Berberine via Efflux Pump Inhibition
||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
||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)
||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...
|Liver Enzyme-Mediated Oxidation of Echinacea purpurea Alkylamides: Production of Novel Metabolites and Changes in Immunomodulatory Activity
||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
||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...
|Quantitative analysis of autoinducing peptide I (AIP-I) from Staphylococcus aureus cultures using ultrahigh performance liquid chromatography–high resolving power mass spectrometry
||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)
||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
||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
||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)
||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
||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...
|Small-molecule quorum quenchers to prevent Staphylococcus aureus infection
||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 ...
|Temperature-sensitive anthocyanin production in flowers of Plantago lanceolata
||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...