Medicine and Health Sciences Commons^™

Preclinical Characterization And Target Validation Of The Antimalarial Pantothenamide Mmv693183., Laura E. De Vries, Patrick A. M. Jansen, Catalina Barcelo, Justin Munro, Julie M. J. Verhoef, Charisse Flerida A. Pasaje, Kelly Rubiano, Josefine Striepen, Nada Abla, Luuk Berning, Judith M. Bolscher, Claudia Demarta-Gatsi, Rob W. M. Henderson, Tonnie Huijs, Karin M J Koolen, Patrick K. Tumwebaze, Tomas Yeo, Anna C. C. Aguiar, Iñigo Angulo-Barturen, Alisje Churchyard, Jake Baum, Benigno Crespo Fernández, Aline Fuchs, Francisco-Javier Gamo, Rafael V. C. Guido, María Belén Jiménez-Diaz, Dhelio B. Pereira, Rosemary Rochford, Camille Roesch, Laura M. Sanz, Graham Trevitt, Benoit Witkowski, Sergio Wittlin, Roland A. Cooper, Philip J. Rosenthal, Robert W. Sauerwein, Joost Schalkwijk, Pedro H. H. Hermkens, Roger V. Bonnert, Brice Campo, David A. Fidock, Manuel Llinás, Jacquin C. Niles, Taco W. A. Kooij, Koen J. Dechering

Natural Sciences and Mathematics | Faculty Scholarship

Drug resistance and a dire lack of transmission-blocking antimalarials hamper malaria elimination. Here, we present the pantothenamide MMV693183 as a first-in-class acetyl-CoA synthetase (AcAS) inhibitor to enter preclinical development. Our studies demonstrate attractive drug-like properties and in vivo efficacy in a humanized mouse model of Plasmodium falciparum infection. The compound shows single digit nanomolar in vitro activity against P. falciparum and P. vivax clinical isolates, and potently blocks P. falciparum transmission to Anopheles mosquitoes. Genetic and biochemical studies identify AcAS as the target of the MMV693183-derived antimetabolite, CoA-MMV693183. Pharmacokinetic-pharmacodynamic modelling predict that a single 30 mg oral dose is sufficient …

Discovery And Preclinical Pharmacology Of Ine963, A Potent And Fast-Acting Blood-Stage Antimalarial With A High Barrier To Resistance And Potential For Single-Dose Cures In Uncomplicated Malaria., Benjamin R. Taft, Fumiaki Yokokawa, Tom Kirrane, Anne-Catherine Mata, Richard Huang, Nicole Blaquiere, Grace Waldron, Bin Zou, Oliver Simon, Subramanyam Vankadara, Wai Ling Chan, Mei Ding, Sandra Sim, Judith Straimer, Armand Guiguemde, Suresh B Lakshminarayana, Jay Prakash Jain, Christopher Bodenreider, Christopher Thompson, Christian Lanshoeft, Wei Shu, Eric Fang, Jafri Qumber, Katherine Chan, Luying Pei, Yen-Liang Chen, Hanna Schulz, Jessie Lim, Siti Nurdiana Abas, Xiaoman Ang, Yugang Liu, Iñigo Angulo-Barturen, María Belén Jiménez-Díaz, Glaxosmithkline Gamo, Benigno Crespo-Fernandez, Philip J. Rosenthal, Roland A. Cooper, Patrick Tumwebaze, Anna Caroline Campos Aguiar, Brice Campo, Simon Campbell, Jürgen Wagner, Thierry T Diagana, Christopher Sarko

Natural Sciences and Mathematics | Faculty Scholarship

A series of 5-aryl-2-amino-imidazothiadiazole (ITD) derivatives were identified by a phenotype-based high-throughput screening using a blood stage Plasmodium falciparum (Pf) growth inhibition assay. A lead optimization program focused on improving antiplasmodium potency, selectivity against human kinases, and absorption, distribution, metabolism, excretion, and toxicity properties and extended pharmacological profiles culminated in the identification of INE963 (1), which demonstrates potent cellular activity against Pf 3D7 (EC50 = 0.006 μM) and achieves "artemisinin-like" kill kinetics in vitro with a parasite clearance time of/kg is fully curative in the Pf-humanized severe combined immunodeficient mouse model. INE963 (1) also exhibits a high barrier to resistance …

Can Repurposing Drugs Play A Role In Malaria Control?, Roland A. Cooper, Laura Kirkman

Natural Sciences and Mathematics | Faculty Scholarship

Innovative drug treatments for malaria, optimally with novel targets, are needed to combat the threat of parasite drug resistance. As drug development efforts continue, there may be a role for a host-targeting, repurposed cancer drug administered together with an artemisinin combination therapy that was shown to improve the speed of recovery from a malaria infection.

Associations Between Varied Susceptibilities To Pfatp4 Inhibitors And Genotypes In Ugandan Plasmodium Falciparum Isolates., Oriana Kreutzfeld, Stephanie A. Rasmussen, Aarti A. Ramanathan, Patrick K. Tumwebaze, Oswald Byaruhanga, Thomas Katairo, Victor Asua, Martin Okitwi, Stephen Orena, Jennifer Legac, Melissa D. Conrad, Samuel L. Nsobya, Ozkan Aydemir, Jeffrey Bailey, Maelle Duffey, Brett R. Bayles, Akhil B. Vaidya, Roland A. Cooper, Philip J. Rosenthal

Natural Sciences and Mathematics | Faculty Scholarship

Among novel compounds under recent investigation as potential new antimalarial drugs are three independently developed inhibitors of the Plasmodium falciparum P-type ATPase (PfATP4): KAE609 (cipargamin), PA92, and SJ733. We assessed ex vivo susceptibilities to these compounds of 374 fresh P. falciparum isolates collected in Tororo and Busia districts, Uganda, from 2016 to 2019. Median IC50s were 65 nM for SJ733, 9.1 nM for PA92, and 0.5 nM for KAE609. Sequencing of pfatp4 for 218 of these isolates demonstrated many nonsynonymous single nucleotide polymorphisms; the most frequent mutations were G1128R (69% of isolates mixed or mutant), Q1081K/R (68%), G223S (25%), N1045K …

Drug Susceptibility Of Plasmodium Falciparum In Eastern Uganda: A Longitudinal Phenotypic And Genotypic Study, Patrick K. Tumwebaze, Thomas Katairo, Martin Okitwi, Oswald Byaruhanga, Stephen Orena, Victor Asua, Marvin Duvalsaint, Jennifer Legac, Sevil Chelebieva, Frida G. Ceja, Stephanie A. Rasmussen, Melissa D. Conrad, Samuel L. Nsobya, Ozkan Aydemir, Jeffrey A. Bailey, Brett R. Bayles, Philip J. Rosenthal, Roland A. Cooper

Natural Sciences and Mathematics | Faculty Scholarship

Background: Treatment and control of malaria depends on artemisinin-based combination therapies (ACTs) and is challenged by drug resistance, but thus far resistance to artemisinins and partner drugs has primarily occurred in southeast Asia. The aim of this study was to characterise antimalarial drug susceptibility of Plasmodium falciparum isolates from Tororo and Busia districts in Uganda.

Methods: In this prospective longitudinal study, P falciparum isolates were collected from patients aged 6 months or older presenting at the Tororo District Hospital (Tororo district, a site with relatively low malaria incidence) or Masafu General Hospital (Busia district, a high-incidence site) in eastern Uganda …

The Antimalarial Mmv688533 Provides Potential For Single-Dose Cures With A High Barrier To, James M. Murithi, Cécile Pascal, Jade Bath, Xavier Boulenc, Nina F. Gnädig, Charisse Flerida A. Pasaje, Kelly Rubiano, Tomas Yeo, Sachel Mok, Sylvie Klieber, Paul Desert, María Belén Jiménez-Díaz, Jutta Marfurt, Mélanie Rouillier, Mohammed H. Cherkaoui-Rbati, Nathalie Gobeau, Sergio Wittlin, Anne-Catrin Uhlemann, Ric N. Price, Grennady Wirjanata, Rintis Noviyanti, Patrick K. Tumwebaze, Roland A. Cooper, Philip J. Rosenthal, Laura M. Sanz, Francisco-Javier Gamo, Jayan Joseph, Shivendra Singh, Sridevi Bashyam, Jean Michel Augereau, Elie Giraud, Tanguy Bozec, Thierry Vermat, Gilles Tuffal, Jean-Michel Guillon, Jérôme Menegotto, Laurent Sallé, Guillaume Louit, Marie-José Cabanis, Marie Françoise Nicolas, Michel Doubovetzky, Rita Merino, Nadir Bessila, Iñigo Angulo-Barturen, Delphine Baud, Lidiya Bebrevska, Fanny Escudié, Jacquin C. Niles, Benjamin Blasco, Simon Campbell, Gilles Courtemanche, Laurent Fraisse, Alain Pellet, David A. Fidock, Didier Leroy

Natural Sciences and Mathematics | Faculty Scholarship

The emergence and spread of Plasmodium falciparum resistance to first-line antimalarials creates an imperative to identify and develop potent preclinical candidates with distinct modes of action. Here, we report the identification of MMV688533, an acylguanidine that was developed following a whole-cell screen with compounds known to hit high-value targets in human cells. MMV688533 displays fast parasite clearance in vitro and is not cross-resistant with known antimalarials. In a P. falciparum NSG mouse model, MMV688533 displays a long-lasting pharmacokinetic profile and excellent safety. Selection studies reveal a low propensity for resistance, with modest loss of potency mediated by point mutations in …

The Antimalarial Mmv688533 Provides Potential For Single-Dose Cures With A High Barrier To, James M. Murithi, Cécile Pascal, Jade Bath, Xavier Boulenc, Nina F. Gnädig, Charisse Flerida A. Pasaje, Kelly Rubiano, Tomas Yeo, Sachel Mok, Sylvie Klieber, Paul Desert, María Belén Jiménez-Díaz, Jutta Marfurt, Mélanie Rouillier, Mohammed H. Cherkaoui-Rbati, Nathalie Gobeau, Sergio Wittlin, Anne-Catrin Uhlemann, Ric N. Price, Grennady Wirjanata, Rintis Noviyanti, Patrick Tumwebaze, Roland A. Cooper, Philip J. Rosenthal, Laura M. Sanz, Francisco-Javier Gamo, Jayan Joseph, Shivendra Singh, Sridevi Bashyam, Jean Michel Augereau, Elie Giraud, Tanguy Bozec, Thierry Vermat, Gilles Tuffal, Jean-Michel Guillon, Jérôme Menegotto, Laurent Sallé, Guillaume Louit, Marie-José Cabanis, Marie Françoise Nicolas, Michel Doubovetzky, Rita Merino, Nadir Bessila, Iñigo Angulo-Barturen, Delphine Baud, Lidiya Bebrevska, Fanny Escudié, Jacquin C. Niles, Benjamin Blasco, Simon Campbell, Gilles Courtemanche, Laurent Fraisse, Alain Pellet, David A. Fidock, Didier Leroy

Natural Sciences and Mathematics | Faculty Scholarship

The emergence and spread of Plasmodium falciparum resistance to first-line antimalarials creates an imperative to identify and develop potent preclinical candidates with distinct modes of action. Here, we report the identification of MMV688533, an acylguanidine that was developed following a whole-cell screen with compounds known to hit high-value targets in human cells. MMV688533 displays fast parasite clearance in vitro and is not cross-resistant with known antimalarials. In a P. falciparum NSG mouse model, MMV688533 displays a long-lasting pharmacokinetic profile and excellent safety. Selection studies reveal a low propensity for resistance, with modest loss of potency mediated by point mutations in …

Balanced Impacts Of Fitness And Drug Pressure On The Evolution Of Pfmdr1 Polymorphisms In Plasmodium Falciparum., Marvin Duvalsaint, Melissa D. Conrad, Stephen Tukwasibwe, Patrick K. Tumwebaze, Jennifer Legac, Roland A. Cooper, Philip J. Rosenthal

Natural Sciences and Mathematics | Faculty Scholarship

BACKGROUND: Anti-malarial drug resistance may be limited by decreased fitness in resistant parasites. Important contributors to resistance are mutations in the Plasmodium falciparum putative drug transporter PfMDR1.

METHODS: Impacts on in vitro fitness of two common PfMDR1 polymorphisms, N86Y, which is associated with sensitivity to multiple drugs, and Y184F, which has no clear impact on drug sensitivity, were evaluated to study associations between resistance mediators and parasite fitness, measured as relative growth in competitive culture experiments. NF10 P. falciparum lines engineered to represent all PfMDR1 N86Y and Y184F haplotypes were co-cultured for 40 days, and the genetic make-up of the …

Plasmodium Falciparum Resistance To A Lead Benzoxaborole Due To Blocked Compound Activation And Altered Ubiquitination Or Sumoylation., Kirthana M. V. Sindhe, Wesley Wu, Jenny Legac, Yong-Kang Zhang, Eric E. Easom, Roland A. Cooper, Jacob J. Plattner, Yvonne R. Freund, Joseph L. Derisi, Philip J. Rosenthal

Natural Sciences and Mathematics | Faculty Scholarship

New antimalarial drugs are needed. The benzoxaborole AN13762 showed excellent activity against cultured Plasmodium falciparum, against fresh Ugandan P. falciparum isolates, and in murine malaria models. To gain mechanistic insights, we selected in vitro for P. falciparum isolates resistant to AN13762. In all of 11 independent selections with 100 to 200 nM AN13762, the 50% inhibitory concentration (IC50) increased from 18-118 nM to 180-890 nM, and whole-genome sequencing of resistant parasites demonstrated mutations in prodrug activation and resistance esterase (PfPARE). The introduction of PfPARE mutations led to a similar level of resistance, and recombinant PfPARE hydrolyzed AN13762 to the benzoxaborole …

Sources And Toxicity Of Mercury In The San Francisco Bay Area, Spanning California And Beyond., Mietek Kolipinski, Mani Subramanian, Kristina Kristen, Steven Borish, Stacy Ditta

Natural Sciences and Mathematics | Faculty Scholarship

This report synthesizes and evaluates published scientific literature on the environmental occurrence and biomagnification of mercury with emphasis on the San Francisco Bay Area (SFBA), California. Mercury forms various compounds, well known for their toxicity in humans and environmental ecosystems. Elemental mercury is transported and distributed by air, water, and sediments. Through the metabolic processes of algae and bacteria, mercury is converted into organic compounds, such as methylmercury (MeHg), which then bioaccumulates up through trophic levels. In fish, it is found primarily in skeletal muscle, while in humans, the primary target organs are the brain and kidneys. Health concerns exist …

Novel Flexible Heteroarotinoid, Sl-1-39, Inhibits Her2-Positive Breast Cancer Cell Proliferation By Promoting Lysosomal Degradation Of Her2., Hongye Zou, Mary B. Sevigny, Shengquan Liu, David T. Madden, Maggie Louie

Natural Sciences and Mathematics | Faculty Scholarship

SL-1-39 [1-(4-chloro-3-methylphenyl)-3-(4-nitrophenyl)thiourea] is a new flexible heteroarotinoid (Flex-Het) analog derived from the parental compound, SHetA2, previously shown to inhibit cell growth across multiple cancer types. The current study aims to determine growth inhibitory effects of SL-1-39 across the different subtypes of breast cancer cells and delineate its molecular mechanism. Our results demonstrate that while SL-1-39 blocks cell proliferation of all breast cancer subtypes tested, it has the highest efficacy against HER2+ breast cancer cells. Molecular analyses suggest that SL-1-39 prevents S phase progression of HER2+ breast cancer cells (SKBR3 and MDA-MB-453), which is consistent with reduced expression of key cell-cycle …

The Value Of Universally Available Raw Nmr Data For Transparency, Reproducibility, And Integrity In Natural Product Research., James B. Mcalpine, Shao-Nong Chen, Andrei Kutateladze, John B. Macmillan, Giovanni Appendino, Andersson Barison, Mehdi A. Beniddir, Maique W. Biavatti, Stefan Bluml, Asmaa Boufridi, Mark S. Butler, Robert J. Capon, Young H. Choi, David Coppage, Phillip Crews, Michael T. Crimmins, Marie Csete, Pradeep Dewapriya, Joseph M. Egan, Mary J. Garson, Grégory Genta-Jouve, William H Gerwick, Harald Gross, Mary Kay Harper, Precilia Hermanto, James M. Hook, Luke Hunter, Damien Jeannerat, Nai-Yun Ji, Tyler A. Johnson, David G. I. Kingston, Hiroyuki Koshino, Hsiau-Wei Lee, Guy Lewin, Jie Li, Roger G Linington, Miaomiao Liu, Kerry L Mcphail, Tadeusz F Molinski, Bradley S Moore, Joo-Won Nam, Ram P Neupane, Matthias Niemitz, Jean-Marc Nuzillard, Nicholas H Oberlies, Fernanda M M Ocampos, Guohui Pan, Ronald J Quinn, D Sai Reddy, Jean-Hugues Renault, José Rivera-Chávez, Wolfgang Robien, Carla M Saunders, Thomas J Schmidt, Christoph Seger, Ben Shen, Christoph Steinbeck, Hermann Stuppner, Sonja Sturm, Orazio Taglialatela-Scafati, Dean J Tantillo, Robert Verpoorte, Bin-Gui Wang, Craig M Williams, Philip G Williams, Julien Wist, Jian-Min Yue, Chen Zhang, Zhengren Xu, Charlotte Simmler, David C Lankin, Jonathan Bisson, Guido F Pauli

Natural Sciences and Mathematics | Faculty Scholarship

With contributions from the global natural product (NP) research community, and continuing the Raw Data Initiative, this review collects a comprehensive demonstration of the immense scientific value of disseminating raw nuclear magnetic resonance (NMR) data, independently of, and in parallel with, classical publishing outlets. A comprehensive compilation of historic to present-day cases as well as contemporary and future applications show that addressing the urgent need for a repository of publicly accessible raw NMR data has the potential to transform natural products (NPs) and associated fields of chemical and biomedical research. The call for advancing open sharing mechanisms for raw data …

Antimalarial Proteasome Inhibitor Reveals Collateral Sensitivity From Intersubunit Interactions And Fitness Cost Of Resistance., Laura A. Kirkman, Wenhu Zhan, Joseph Visone, Alexis Dziedziech, Pradeep K. Singh, Hao Fan, Xinran Tong, Igor Bruzual, Ryoma Hara, Masanori Kawasaki, Toshihiro Imaeda, Rei Okamoto, Kenjiro Sato, Mayako Michino, Elena Fernandez Alvaro, Liselle F. Guiang, Laura M. Sanz, Daniel J. Mota, Kavitha Govindasamy, Rong Wang, Yan Ling, Patrick K. Tumwebaze, George Sukenick, Lei Shi, Jeremie Vendome, Purnima Bhanot, Philip J. Rosenthal, Kazuyoshi Aso, Michael A. Foley, Roland A. Cooper, Bjorn Kafsack, J Stone Doggett, Carl F. Nathan, Gang Lin

Natural Sciences and Mathematics | Faculty Scholarship

We describe noncovalent, reversible asparagine ethylenediamine (AsnEDA) inhibitors of the Plasmodium falciparum proteasome (Pf20S) β5 subunit that spare all active subunits of human constitutive and immuno-proteasomes. The compounds are active against erythrocytic, sexual, and liver-stage parasites, against parasites resistant to current antimalarials, and against P. falciparum strains from patients in Africa. The β5 inhibitors synergize with a β2 inhibitor in vitro and in mice and with artemisinin. P. falciparum selected for resistance to an AsnEDA β5 inhibitor surprisingly harbored a point mutation in the noncatalytic β6 subunit. The β6 mutant was resistant to the species-selective Pf20S β5 inhibitor but remained …

The Potential Of Achiral Sponge-Derived And Synthetic Bromoindoles As Selective Cytotoxins Against Panc-1 Tumor Cells., Nicholas Lorig-Roach, Frances Hamkins-Indik, Tyler A. Johnson, Karen Tenney, Frederick A. Valeriote, Phillip Crews

Natural Sciences and Mathematics | Faculty Scholarship

Our quest to isolate and characterize natural products with in vitro solid tumor selectivity is driven by access to repositories of Indo-Pacific sponge extracts. In this project an extract of a species of Haplosclerida sponge obtained from the US NCI Natural Products Repository displayed, by in vitro disk diffusion assay (DDA) and IC

Another Look At Pyrroloiminoquinone Alkaloids-Perspectives On Their Therapeutic Potential From Known Structures And Semisynthetic Analogues., Sheng Lin, Erin P. Mccauley, Nicholas Lorig-Roach, Karen Tenney, Cassandra N. Naphen, Ai-Mei Yang, Tyler A. Johnson, Thalia Hernadez, Ramandeep Rattan, Frederick A. Valeriote, Phillip Crews

Natural Sciences and Mathematics | Faculty Scholarship

This study began with the goal of identifying constituents from Zyzzya fuliginosa extracts that showed selectivity in our primary cytotoxicity screen against the PANC-1 tumor cell line. During the course of this project, which focused on six Z. fuliginosa samples collected from various regions of the Indo-Pacific, known compounds were obtained consisting of nine makaluvamine and three damirone analogues. Four new acetylated derivatives were also prepared. High-accuracy electrospray ionization mass spectrometry (HAESI-MS) m/z ions produced through MS² runs were obtained and interpreted to provide a rapid way for dereplicating isomers containing a pyrrolo[4,3,2-de]quinoline core. In vitro human pancreas/duct epithelioid …

Chemically Diverse Microtubule Stabilizing Agents Initiate Distinct Mitotic Defects And Dysregulated Expression Of Key Mitotic Kinases., Cristina C. Rohena, Jiangnan Peng, Tyler A. Johnson, Phillip Crews, Susan L. Mooberry

Natural Sciences and Mathematics | Faculty Scholarship

Microtubule stabilizers are some of the most successful drugs used in the treatment of adult solid tumors and yet the molecular events responsible for their antimitotic actions are not well defined. The mitotic events initiated by three structurally and biologically diverse microtubule stabilizers; taccalonolide AJ, laulimalide/fijianolide B and paclitaxel were studied. These microtubule stabilizers cause the formation of aberrant, but structurally distinct mitotic spindles leading to the hypothesis that they differentially affect mitotic signaling. Each microtubule stabilizer initiated different patterns of expression of key mitotic signaling proteins. Taccalonolide AJ causes centrosome separation and disjunction failure to a much greater extent …

Lipophilic Stinging Nettle Extracts Possess Potent Anti-Inflammatory Activity, Are Not Cytotoxic And May Be Superior To Traditional Tinctures For Treating Inflammatory Disorders., Tyler A. Johnson, Johann Sohn, Wayne D Inman, Leonard F. Bjeldanes, Keith Rayburn

Natural Sciences and Mathematics | Faculty Scholarship

Extracts of four plant portions (roots, stems, leaves and flowers) of Urtica dioica (the stinging nettle) were prepared using accelerated solvent extraction (ASE) involving water, hexanes, methanol and dichloromethane. The extracts were evaluated for their anti-inflammatory and cytotoxic activities in an NF-κB luciferase and MTT assay using macrophage immune (RAW264.7) cells. A standardized commercial ethanol extract of nettle leaves was also evaluated. The methanolic extract of the flowering portions displayed significant anti-inflammatory activity on par with a standard compound celastrol (1) but were moderately cytotoxic. Alternatively, the polar extracts (water, methanol, ethanol) of the roots, stems and leaves displayed moderate …

Development And Validation Of A Simple Method For The Detection Of Fascaplysin In Plasma, Kenneth H. Swartz, Frederick A. Valeriote, Joseph Media, Tyler A. Johnson, Karen Tenney, Phillip Crews, Jiajiu Shaw

Natural Sciences and Mathematics | Faculty Scholarship

Fascaplysin is a cytotoxic natural product isolated from a variety of Indo-Pacific marine organisms, primarily Fascaplysinopsis sponges and Didemnum tunicates. Positive xenograft studies involving this alkaloid structural class have indicated that fascaplysin may serve as an important lead compound for preclinical development. This study was undertaken as a prelude to a full pharmacokinetics and therapeutic assessment of fascaplysin. We describe here a simple plasma preparation and a rapid HPLC method for the detection of fascaplysin in mice. The method was validated by parameters including good linear correlation, a limit of quantification of 107.1 μg/ mL, and a good precision with …

Myxobacteria Versus Sponge-Derived Alkaloids: The Bengamide Family Identified As Potent Immune Modulating Agents By Scrutiny Of Lc-Ms/Elsd Libraries., Tyler A. Johnson, Johann Sohn, Yvette M. Vaske, Kimberly N. White, Tanya L. Cohen, Helene C. Vervoort, Karen Tenney, Frederick A. Valeriote, Leonard F. Bjeldanes, Phillip Crews

Natural Sciences and Mathematics | Faculty Scholarship

A nuclear factor-κB (NF-κB) luciferase assay has been employed to identify the bengamides, previously known for their anti-tumor activity, as a new class of immune modulators. A unique element of this study was that the bengamide analogs were isolated from two disparate sources, Myxococcus virescens (bacterium) and Jaspis coriacea (sponge). Comparative LC-MS/ELSD and NMR analysis facilitated the isolation of M. viriscens derived samples of bengamide E (8) and two congeners, bengamide E' (13) and F' (14) each isolated as an insperable mixture of diastereomers. Additional compounds drawn from the UC, Santa Cruz repository allowed expansion of the structure activity relationship …

The Marine Sponge Metabolite Mycothiazole: A Novel Prototype Mitochondrial Complex I Inhibitor., J Brian Morgan, Fakhri Mahdi, Yang Liu, Veena Coothankandaswamy, Mika B. Jekabsons, Tyler A. Johnson, Koneni V. Sashidhara, Phillip Crews, Dale G. Nagle, Yu-Dong Zhou

Natural Sciences and Mathematics | Faculty Scholarship

A natural product chemistry-based approach was applied to discover small-molecule inhibitors of hypoxia-inducible factor-1 (HIF-1). A Petrosaspongia mycofijiensis marine sponge extract yielded mycothiazole (1), a solid tumor selective compound with no known mechanism for its cell line-dependent cytotoxic activity. Compound 1 inhibited hypoxic HIF-1 signaling in tumor cells (IC(50) 1nM) that correlated with the suppression of hypoxia-stimulated tumor angiogenesis in vitro. However, 1 exhibited pronounced neurotoxicity in vitro. Mechanistic studies revealed that 1 selectively suppresses mitochondrial respiration at complex I (NADH-ubiquinone oxidoreductase). Unlike rotenone, MPP(+), annonaceous acetogenins, piericidin A, and other complex I inhibitors, mycothiazole is a mixed polyketide/peptide-derived compound …

Development And Validation Of A Rapid Method For The Detection Of Latrunculol A In Plasma., Jiajiu Shaw, Frederick A. Valeriote, Joseph Media, Tyler A. Johnson, Taro Amagata, Karen Tenney, Phillip Crews

Natural Sciences and Mathematics | Faculty Scholarship

Latrunculol A is a recently discovered 6,7-dihydroxy analog of the potent actin inhibitor latrunculin A. Latrunculol A has exhibited greater cytotoxicity than latrunculin A against both murine and human colon tumor cell lines in vitro. Currently, there are no reports regarding the bioavailability of latrunculol A in vivo. This study was undertaken as a prelude to pharmacokinetic assessments and it is the first work where bioavailability of latrunculol A was studied. In the present work, a simple plasma preparation and a rapid HPLC method have been developed. Mouse plasma containing latrunculol A was first treated by acetonitrile and then centrifuged …

Mass Stranding Of Marine Birds Caused By A Surfactant-Producing Red Tide., David A. Jessup, Melissa A. Miller, John P. Ryan, Hannah M. Nevins, Heather A. Kerkering, Abdou Mekebri, David B. Crane, Tyler A. Johnson, Raphael M. Kudela

Natural Sciences and Mathematics | Faculty Scholarship

In November-December 2007 a widespread seabird mortality event occurred in Monterey Bay, California, USA, coincident with a massive red tide caused by the dinoflagellate Akashiwo sanguinea. Affected birds had a slimy yellow-green material on their feathers, which were saturated with water, and they were severely hypothermic. We determined that foam containing surfactant-like proteins, derived from organic matter of the red tide, coated their feathers and neutralized natural water repellency and insulation. No evidence of exposure to petroleum or other oils or biotoxins were found. This is the first documented case of its kind, but previous similar events may have gone …

Rapid Enzyme-Linked Immunosorbent Assay For Detection Of The Algal Toxin Domoic Acid, R Wayne Litaker, Thomas N. Stewart, Bich-Thuy L. Eberhart, John C. Wekell, Vera L. Trainer, Raphael M. Kudela, Peter E. Miller, Alice Roberts, Cassandra Hertz, Tyler A. Johnson, Greg Frankfurter, G. Jason Smith, Astrid Schnetzer, Joe Schumacker, Jonnette L. Bastian, Anthony Odell, Patrick Gentien, Dominique Le Gal, D Ransom Hardison, Patricia A. Tester

Natural Sciences and Mathematics | Faculty Scholarship

Domoic acid (DA) is a potent toxin produced by bloom-forming phytoplankton in the genus Pseudo-nitzschia, which is responsible for causing amnesic shellfish poisoning (ASP) in humans. ASP symptoms include vomiting, diarrhea, and in more severe cases confusion, loss of memory, disorientation, and even coma or death. This paper describes the development and validation of a rapid, sensitive, enzyme linked immunosorbent assay test kit for detecting DA using a monoclonal antibody. The assay gives equivalent results to those obtained using standard high performance liquid chromatography, fluorenylmethoxycarbonyl high performance liquid chromatography, or liquid chromatography—mass spectrometry methods. It has a linear range …

Discovery Of Platelet-Type 12-Human Lipoxygenase Selective Inhibitors By High-Throughput Screening Of Structurally Diverse Libraries., Joshua D. Deschamps, Jeffrey T. Gautschi, Stephanie Whitman, Tyler A. Johnson, Nadine C. Gassner, Phillip Crews, Theodore R. Holman

Natural Sciences and Mathematics | Faculty Scholarship

Human lipoxygenases (hLO) have been implicated in a variety of diseases and cancers and each hLO isozyme appears to have distinct roles in cellular biology. This fact emphasizes the need for discovering selective hLO inhibitors for both understanding the role of specific lipoxygenases in the cell and developing pharmaceutical therapeutics. To this end, we have modified a known lipoxygenase assay for high-throughput (HTP) screening of both the National Cancer Institute (NCI) and the UC Santa Cruz marine extract library (UCSC-MEL) in search of platelet-type 12-hLO (12-hLO) selective inhibitors. The HTP screen led to the characterization of five novel 12-hLO inhibitors …

Glycosylation Regulates Turnover Of Cyclooxygenase-2., Mary B. Sevigny, Chai-Fei Li, Monika Alas, Millie Hughes-Fulford

Natural Sciences and Mathematics | Faculty Scholarship

Cyclooxygenase-2 (COX-2) catalyzes the rate-limiting step in the prostanoid biosynthesis pathway, converting arachidonic acid into prostaglandin H(2). COX-2 exists as 72 and 74kDa glycoforms, the latter resulting from an additional oligosaccharide chain at residue Asn(580). In this study, Asn(580) was mutated to determine the biological significance of this variable glycosylation. COS-1 cells transfected with the mutant gene were unable to express the 74kDa glycoform and were found to accumulate more COX-2 protein and have five times greater COX-2 activity than cells expressing both glycoforms. Thus, COX-2 turnover appears to depend upon glycosylation of the 72kDa glycoform.