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Nicholas Oberlies

**Expertise: Medicinal Chemistry and Pharmacognosy **Education: B.S., Miami University, 1992--Ph.D., Purdue, 1997.

There are 43 included publications by Nicholas Oberlies :

TitleDateViewsBrief Description
Analysis of herbal teas made from the leaves of comfrey (Symphytum officinale): reduction of N-oxides results in order of magnitude increases in the measurable concentration of pyrrolizidine alkaloids. 2007 1052 Objectives: To determine the relative quantities of two hepatotoxic pyrrolizidine alkaloids, symphytine and echimidine, in teas prepared from comfrey leaves (Symphytum officinale), and to determine the potential contribution of the N- oxide forms of ...
Antioxidant activity and total phenolic content of aqueous and methanolic extracts of Jordanian plants: an ICBG project 2007 1799 As part of an International Cooperative Biodiversity Groups (ICBG) program to study Jordan's biodiversity, the relative levels of antioxidant activity and the total phenolic content of aqueous and methanolic extracts of a total of 95 plant species, a...
Clinical relevance of the small intestine as an organ of drug elimination: drug-fruit juice interactions. 2007 1134 Most drugs are taken orally. For those intended to act systemically, a significant fraction of the dose can be eliminated during its first passage through a sequence of organs before entry into the general circulation. For some drugs, the degree of f...
Dendrimer-encapsulated camptothecins: Increased solubility, cellular uptake, and cellular retention affords enhanced anticancer activity in vitro. 2006 956 A biocompatible polyester dendrimer composed of the natural metabolites, glycerol and succinic acid, is described for the encapsulation of the antitumor camptothecins, 10-hydroxycamptothecin and 7-butyl-10-aminocamptothecin. The cytotoxicity of the d...
Dereplication of Macrocyclic Trichothecenes from Extracts of Filamentous Fungi through UV and NMR Profiles 2010 385 Macrocyclic trichothecenes, which have potent cytotoxicity, have been isolated from many different fungal species. These compounds were evaluated clinically by the U.S. National Cancer Institute in the 1970's and 1980's. However, they have yet to be ...
Development of a fluorescence-based assay to screen antiviral drugs against Kaposi's sarcoma associated herpesvirus. 2007 293 Tumors associated with Kaposi's sarcoma–associated herpesvirus infection include Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. Virtually all of the tumor cells in these cancers are latently infected and dependent ...
Differential In Vitro effects of intravenous versus oral formulations of silibinin on the HCV life cycle and inflammation 2011 364 Silymarin prevents liver disease in many experimental rodent models, and is the most popular botanical medicine consumed by patients with hepatitis C. Silibinin is a major component of silymarin, consisting of the flavonolignans silybin A and sil...
Discovery of anticancer agents of diverse natural origin 2009 1516 A collaborative multidisciplinary research project is described in which new natural product anticancer drug leads are obtained from a diverse group of organisms, constituted by tropical plants, aquatic cyanobacteria, and filamentous fungi. Informati...
Diterpene glycosides from Egletes Viscosa 2005 562 A phytochemical investigation of the CHCl3-soluble extract of the entire plant of Egletes viscosa (Asteraceae), collected in Peru, afforded two new labdane glycosides, 13-hydroxy-7-oxolabda8,14-diene 13(R)-0-a-L-arabinopyranoside and 13–hydroxy-7-oxo...
Enhanced Bioactivity of silybin B methylation Products 2013 74 Flavonolignans from milk thistle (Silybum marianum) have been investigated for their cellular modulatory properties, including cancer chemoprevention and hepatoprotection, as an extract (silymarin), as partially purified mixtures (silibinin and isosi...
Evaluation of culture media for the production of secondary metabolites in a natural products screening program 2013 260 Variation in the growing environment can have significant impacts on the quantity and diversity of fungal secondary metabolites. In the industrial setting, optimization of growing conditions can lead to significantly increased production of a compoun...
Freshwater Ascomycetes: Minutisphaera (Dothideomycetes) revisited, including one new species from Japan 2013 209 During investigations of freshwater ascomycetes we found one interesting taxon from Aomori (Japan), as well as three additional taxa from North Carolina (USA), which were morphologically similar to Minutisphaera, a recently described freshwater fung...
Gram-scale purification of flavonolignan diastereoisomers from Silybum marianum (Milk Thistle) extract in support of preclinical in vivo studies for prostate cancer chemoprevention 2007 1759 Extracts of milk thistle (Silybum marianum, Asteraceae), termed "silymarin," are used worldwide, primarily for hepatoprotective applications and recently for prostate cancer chemoprevention. Silymarin is a mixture of at least eight compounds, and fou...
HiFSA Fingerprinting Applied to Isomers with Near-Identical NMR Spectra: The Silybin/Isosilybin Case 2013 147 This study demonstrates how regio- and diastereo-isomers with near-identical NMR spectra can be distinguished and unambiguously assigned using quantum mechanical driven 1H iterative Full Spin Analysis (HiFSA). The method is illustrated with four natu...
Influence of Dietary Substances on Intestinal Drug Metabolism and Transport 2010 1837 Successful delivery of promising new chemical entities via the oral route is rife with challenges, some of which cannot be explained or foreseen during drug development. Further complicating an already multifaceted problem is the obvious, yet often o...
Isolation and Identification of Intestinal CYP3A Inhibitors from Cranberry (Vaccinium macrocarpon) using Human Intestinal Microsomes 2010 446 Cranberry juice is used routinely, especially among women and the elderly, to prevent and treat urinary tract infections. These individuals are likely to be taking medications concomitantly with cranberry juice, leading to concern about potential dru...
Isosilybin B and isosilybin A inhibit growth, induce G1 arrest and cause apoptosis in human prostate cancer LNCaP and 22Rv1 cells. 2007 336 Silymarin and, one of its constituents, silibinin exert strong efficacy against prostate cancer (PCA); however, anticancer efficacy and associated mechanisms of other components of silymarin, which is a mixture of flavonolignans, are largely unknown....
Isosilybin B causes androgen receptor degradation in human prostate carcinoma cells via PI3K-Akt-Mdm2-mediated pathway 2008 739 The identification and development of novel nontoxic phytochemicals that target androgen and androgen receptor (AR) signaling remains a priority for prostate cancer (PCA) control. In the present study, we assessed the antiandrogenic efficacy of isosi...
Lindgomyces angustiascus, (Lindgomycetaceae, Pleosporales, Dothideomycetes), a new lignicolous species from freshwater habitats in the USA 2013 58 In this paper, we describe and illustrate a new species, Lindgomyces angustiascus, from submerged wood in lotic and lentic habitats from Florida, North Carolina and Wisconsin, USA. The new species is characterized by black, partially immersed, flatte...
Mapping of sample collection data: GIS tools for the natural product researcher 2009 453 Scientists engaged in the research of natural products often either conduct field collections themselves or collaborate with partners who do, such as botanists, mycologists, or SCUBA divers. The information gleaned from such collecting trips (e.g. lo...
Mechanistic Study of the Biomimetic Synthesis of Flavonolignan Diastereoisomers in Milk Thistle 2013 35 The mechanism for the biomimetic synthesis of flavonolignan diastereoisomers in milk thistle is proposed to proceed by single-electron oxidation of coniferyl alcohol, subsequent reaction with one of the oxygen atoms of taxifolin’s catechol moiety, an...
Microbial- mediated release of bisphenol A from polycarbonate vessels. 2008 404 Aim: To identify the source of bisphenol A (BPA) [2,2'-bis(4-hydroxyphenyl) propane] in cultures of an antibiotic-producing Bacillus sp. strain grown in polycarbonate flasks. Methods and Results: Although a culture of an antibiotic-producing Bacillu...
Milk thistle and prostate cancer: Differential effects of pure flavonolignans from Silybum marianum on antiproliferative end points in human prostate carcinoma cells. 2005 729 Extracts from the seeds of milk thistle, Silybum marianum, are known commonly as silibinin and silymarin and possess anticancer actions on human prostate carcinoma in vitro and in vivo. Seven distinct flavonolignan compounds and a flavonoid have been...
Milk thistle nomenclature: Why it matters in cancer research and pharmacokinetic studies. 2007 1672 Extracts of milk thistle have been recognized for centuries as "liver tonics" and are well-known to prevent or reverse hepatotoxicity of reactive drug metabolites or naturally occurring toxins. Milk thistle extracts are now under intense study in the...
Mode of action of bullatacin, a potent antitumor acetogenin: Inhibition of NADH oxidase activity of HeLa and HL-60, but not liver, plasma membranes. 1995 1699 Bullatacin, a potential antitumor substance isolated from plants of the Annonaceae, and analogs of bullatacin, known collectively as acetogenins, have been reported previously to show potent activity in the inhibition of growth of murine tumors and h...
A Modified Grapefruit Juice Eliminates Two Compound Classes as Major Mediators of the Grapefruit Juice–Fexofenadine Interaction: An In Vitro–In Vivo “Connect” 2013 36 The grapefruit juice (GFJ)–fexofenadine interaction involves inhibition of intestinal organic anion transporting polypeptide (OATP)-mediated uptake. Only naringin has been shown clinically to inhibit intestinal OATP; other constituents have not been ...
The most widely recognized mushroom: Chemistry of the genus Amanita. 2005 1189 Many review papers have been published on mushrooms of the genus Amanita, as these are well known to both scientific and lay audiences, probably due to the toxic and/or hallucinogenic properties of some species. This article aims to supplement the co...
Multiple Effects of Silymarin on the Hepatitis C Virus Lifecycle 2010 427 Silymarin, an extract from milk thistle (Silybum marianum), and its purified flavonolignans have been recently shown to inhibit hepatitis C virus (HCV) infection, both in vitro and in vivo. In the current study, we further characterized silymarin's a...
A novel small molecule that selectively inhibits glioblastoma cells expressing EGFRvIII. 2007 329 Background: Mutations of the epidermal growth factor receptor (EGFR) are a possible molecular target for cancer therapy. EGFR is frequently amplified in glioblastomas and 30 to 40% of glioblastomas also express the deletion mutation EGFRvIII. This fr...
Novel Strategies for the Discovery of Plant-Derived Anticancer Agents. 2003 3897 Work has continued on the investigation of plants, collected mainly from tropical rainforests, as potential sources of new cancer chemotherapeutic agents. About 400 primary samples are obtained each year, with the chloroform-soluble extract of each b...
Physiologically Based Pharmacokinetic Modeling Framework for Quantitative Prediction of an Herb–Drug Interaction 2014 337 Herb–drug interaction predictions remain challenging. Physiologically based pharmacokinetic (PBPK) modeling was used to improve prediction accuracy of potential herb–drug interactions using the semipurified milk thistle preparation, silibinin, as an ...
Phytochemical studies and cytotoxicity evaluations of Colchicum tunicatum Feinbr and Colchicum hierosolymitanum Feinbr (Colchicaceae): Two native Jordanian meadow saffrons. 2006 911 As a part of our continuing investigation of Jordanian Colchicum species, the biologically active components of Colchicum hierosolymitanum Feinbr and Colchicum tunicatum Feinbr (Colchicaceae) were pursued. The brine shrimp lethality test (BSLT) was u...
Proliferation of antibiotic-producing bacteria and concomitant antibiotic production as the basis for the antibiotic activity of Jordan’s Red Soils. 2009 611 Anecdotes, both historical and recent, recount the curing of skin infections, including diaper rash, by using red soils from the Hashemite Kingdom of Jordan. Following inoculation of red soils isolated from geographically separate areas of Jordan, Mi...
Pyrrolizidine alkaloids from Echium glomeratum (Boraginaceae). 2008 676 The methanolic extract of the whole plant of Echium glomeratum Poir. (Boraginaceae) has afforded five pyrrolizidine alkaloids, three that were (7S, 8R)-petranine (1), (7S, 8S)-petranine (2), and (7R, 8R)-petranine (3a) or (7R, 8S)-petranine (3b), com...
Recent advances in Annonaceous acetogenins. 1996 5523 Annonaceous acetogenins are waxy substances consisting of C32 or C34 long chain fatty acids which have been combined with a propan-2-ol unit at C-2 to form a gama-lactone. They are only found in several genera of the plant family, Annonaceae. Their d...
Sarothrin from Alkanna orientalis Is an Antimicrobial Agent and Efflux Pump Inhibitor 2013 144 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...
Semisynthesis, Cytotoxicity, Antiviral Activity, and Drug Interaction Liability of 7-O-methylated Analogues of Flavonolignans from Milk Thistle 2013 334 Silymarin, an extract of the seeds of milk thistle (Silybum marianum), is used as an herbal remedy, particularly for hepatoprotection. The main chemical constituents in silymarin are seven flavonolignans. Recent studies explored the non-selective met...
Silibinin inhibits hepatitis C virus entry into hepatocytes by hindering clathrin-dependent trafficking 2013 33 Hepatitis C virus (HCV) is a global health concern infecting 170 million people worldwide. Previous studies indicate that the extract from milk thistle known as silymarin and its main component silibinin inhibit HCV infection. Here we investigated th...
Silymarin for HCV infection 2013 181 Silymarin, an extract of milk thistle seeds, and silymarin-derived compounds have been considered hepatoprotective since the plant was first described in ancient times. Hepatoprotection is defined as several non-mutually exclusive biological activiti...
Simple and inexpensive methods to prevent botanical misfortune. 2006 466 Botanical dietary supplements are often targeted by the mainstream media and scientific/medical communities as being unscientific and unsafe relative to prescription pharmaceuticals and over-the counter drugs. However, the relative risk of botanical ...
Synergistic antimicrobial activity of metabolites produced by a nonobligate bacterial predator 2003 441 A naturally occurring, gram-negative, nonobligate predator bacterial strain 679-2, exhibits broad-spectrum antimicrobial activity that is due, in part, to the production of three extracellular compounds. Antimicrobial-activity-directed fractionation ...
Waol A, trans-dihydrowaol A, and cis-dihydrowaol A: polyketide-derived (gamma)-lactones from a Volutella species 2013 105 An organic extract of a filamentous fungus (MSX 58801), identified as a Volutella sp. (Hypocreales, Ascomycota), displayed moderate cytotoxic activity against NCI-H460 human large cell lung carcinoma. Bioactivity-directed fractionation led to the iso...
The warfarin–cranberry juice interaction revisited: A systematic in vitro–in vivo evaluation 2010 264 Background: Cranberry products have been implicated in several case reports to enhance the anticoagulant effect of warfarin. The mechanism could involve inhibition of the hepatic CYP2C9-mediated metabolic clearance of warfarin by components in cranbe...