Anthony D. Wright

University of Hawaiʻi at Hilo, Hilo, Hawaii, United States

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Publications (154)413.25 Total impact

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    ABSTRACT: Antioxidant activity of symbiotic organisms known as lichens is an intriguing field of research because of its strong contribution to their ability to withstand extremes of physical and biological stress (e.g., desiccation, temperature, UV radiation, and microbial infection). We present a comparative study on the antioxidant activities of 76 Icelandic and 41 Hawaiian lichen samples assessed employing the DPPH and FRAP based antioxidant assays. Utilizing this unprecedented sample size, we show that while highest individual sample activity is present in the Icelandic dataset, the overall antioxidant activity is higher for lichens found in Hawaii. Furthermore, we report that lichens from the genus Peltigera that have been described as strong antioxidant producers in studies on Chinese, Russian and Turkish lichens, also show high antioxidant activities in both Icelandic and Hawaiian lichen samples. Finally, we show that opportunistic sampling of lichens in both Iceland and Hawaii will yield high numbers of lichen species that exclusively include green algae as photobiont. This article is protected by copyright. All rights reserved.
    Environmental Microbiology 03/2015; 81(11). DOI:10.1111/1462-2920.12850 · 6.20 Impact Factor
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    ABSTRACT: From the organic extract of a deep-water Hawaiian sponge Dactylospongia sp., a new potent antioxidant and antimicrobial meroterpenoid, puupehenol (1), was isolated. The structure of 1 was determined using spectroscopic techniques ((1)H and (13)C NMR, MS, IR, UV, [α]D). The known compound puupehenone (2) was also isolated and suggested as a probable artifact of the isolation procedures. Complete unambiguous (1)H and (13)C NMR data are provided for compounds 1 and 2. Bioassays performed with 1 and 2 showed them both to be very effective antioxidants and to have antimicrobial properties.
    Journal of Natural Products 02/2015; 78(2). DOI:10.1021/np500793g · 3.80 Impact Factor
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    ABSTRACT: Over a decade ago Wright et al., proposed a putative antiplasmodial mechanism of action for marine isonitriles (1, and 3-6) and isothiocyanate (2) that involved interference in heme detoxification by Plasmodium falciparum thus inhibiting the growth of the parasite. In the current paper we describe the successful down scaling of Egan's β-hematin inhibition assay for analyses of small quantities of marine natural products as potential β-hematin inhibitors. The modified assay revealed for the first time that the most active antiplasmodial marine isonitrile 4 (IC50 13 nM) totally inhibited β-hematin crystallization while 5 (IC50 31 nM) and 6 (IC50 81 nM) showed inhibition at lower levels. A cursory ab initio molecular dynamics investigation into the relative stabilities of bonded complexes between isocyanate, isothiocyanate and isonitrile groups with the iron center of heme supported our findings that these marine metabolites do indeed interfere with biocrystallization of heme. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
    European Journal of Medicinal Chemistry 02/2015; 93C. DOI:10.1016/j.ejmech.2015.02.011 · 3.45 Impact Factor
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    ABSTRACT: Fish serum albumin (FSA) is an aquatic resource that has potential to be developed as nutraceutical. Therefore, research was undertaken to assess albumin levels in the aqueous extract of muscle tissue of several Perciformes commonly available at a local fish market in Indonesia. Three random replicates for each of 17 Perciformes species were collected and assessed for their FSA content by application of a reversed-phase (C4) HPLC analytical method. Results of these analyses showed that the albumin concentration of the extracts was in the range 3.49–12.61 g/L, and that they varied significantly (P < 0.05) between species and families. This finding may mean that FSA levels are species and family dependent, something that could be investigated in future studies. As fishes from the family Scrombidae showed the highest concentration (12.61 g/L) of FSA, they would likely have the most value as a source for production of albumin-based nutritional and/or clinical products
    Natural Product Research 01/2015; 29(23). DOI:10.1080/14786419.2014.1003298 · 0.92 Impact Factor
  • Kehau A. Hagiwara · Anthony D. Wright ·
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    ABSTRACT: In this review the reported effects of shade levels on the amounts of reputed biologically active potential key chemical markers l-theanine and caffeine, and the four catechin-polyphenols, (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), and (-)-epigallocatechin gallate (EGCG) found in the bud and first two leaves during development of tea (Camellia sinensis) grown on a Hawaiian plantation are discussed. Also discussed is the antioxidant activity of the overall extract of the tea leaf bud, and first and second leaves, together with the importance of employing 1H NMR spectroscopy as an analytical tool for the determination of the validity of reference materials.
    Processing and Impact on Active Components in Food, 01/2015: pages 591-596; , ISBN: 9780124046993
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    ABSTRACT: Two species of red algae belonging to the genus Plocamium, P. hamatum from Moreton Bay, Queensland, and P. costatum, from Pandalowie Bay, South Australia, were investigated to assess their chemical variation and as potential sources of new halogenated monoterpenes. The hyphenated technique HPLC-UV-MS-SPE-NMR was used to assess the algal extracts and to determine its potential for accelerated identification of halogenated monoterpenes generally. A combination of the hyphenated and traditional chromatographic techniques resulted in the isolation and characterization of a total of 10 halogenated monoterpene metabolites, eight of which are reported for the first time. Their structures, including configurations, were determined through interpretation of their 1D and 2D NMR, mass spectrometric, infrared, and X-ray data. The two species of Plocamium produced different secondary metabolites and contained a significant number of new polyhalogenated monoterpenes. The investigation also showed the hyphenated technique HPLC-UV-MS-SPE-NMR to be useful for preliminary investigation of the chemical content of algal extracts.
    Journal of Natural Products 05/2014; 77(5). DOI:10.1021/np500059h · 3.80 Impact Factor
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    Georgia M. Hart · Tamara Ticktin · Dovi Kelman · Anthony D. Wright · Nicole Tabandera ·
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    ABSTRACT: Contemporary Gathering Practice and Antioxidant Benefit of Wild Seaweeds in Hawai’i. Wild-gathered seaweeds (limu) are a prominent component of Native Hawaiian diet and culture, but are understudied for their nutritional benefits and contemporary cultural use. This study uses a combination of ethnographic, pharmacological, and ecological approaches to document contemporary levels of wild seaweed gathering and consumption, and it explores the impact of cultivation and eutrophication on the disease-preventive benefits wild seaweeds may provide. Levels of gathering and consumption of seaweed were assessed with surveys of high school students and interviews with adult limu gatherers on O’ahu island, Hawai’i. Antioxidant activity was assessed with laboratory-based assays. Almost all students surveyed reported consuming cultivated seaweeds, one-third reported having consumed wild seaweeds, and one-fifth had gathered them, confirming that gathering practice and traditional diet have persisted in Hawai’i despite major social and environmental change. Wild gathering was three times as high and consumption 60% more prevalent among Native Hawaiians compared to non-Hawaiian students. Further, students with a parent who gathered limu were six times more likely to have gathered limu themselves, asserting the importance of within-family transmission to cultural continuity. A larger proportion of male than female Hawaiian students reported gathering wild seaweeds, indicating a cultural shift from pre-Contact Hawai’i, when women were the predominant gatherers and consumers of limu. The wild seaweeds assessed demonstrated higher levels of antioxidant activity than did cultivated seaweeds. Eutrophication was correlated with a decline in antioxidant activity, indicating that changing ocean conditions may alter the nutritional quality of this traditional food. Today, nearly all students are receiving some antioxidant benefits from seaweed, with Native Hawaiian youth from families that gather seaweed most likely to receive this health benefit. Conservation and restoration of near-shore environments to promote native edible seaweeds in pollution-free areas would provide greater opportunities for Native Hawaiian gathering practice and would support Native Hawaiian health.
    Economic Botany 03/2014; 68(1). DOI:10.1007/s12231-014-9258-7 · 1.20 Impact Factor
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    ABSTRACT: Oroidin (1), (E)-N-(3-(2-amino-1H-imidazol-4-yl)allyl)-4,5-dibromo-1H-pyrrole-2-carboxamide, is a pyrrole alkaloid isolated from the marine sponge Ageles oroides. Routine screening in a panel of twelve cancer cell lines revealed 1 to be poorly cytotoxic with the 50% growth inhibition concentration (GI50) of 42 μM in MCF-7 (breast) cells and 24 μM in A2780 (ovarian) cells and > 50 μM in all other cell lines tested. The development of eight focused libraries comprising thirty compounds total identified N-(biphenyl-4-ylmethyl)-1H-pyrrole-2-carboxamide (4l), N-benzyl-4,5-dibromo-1H-pyrrole-2-carboxamide (5a) and N-(biphenyl-4-ylmethyl)-4,5-dibromo-1H-pyrrole-2-carboxamide (5l) as potent inhibitors of cell growth in our panel of cell lines. Of these compounds GI50 values of < 5 μM were observed with 4l against HT29 (colon) and SW480 (colon); 5a against HT29; and 5l against HT29, SW480, MCF-7, A431 (skin), Du145 (prostate), BE2-C (neuroblastoma) and MIA (pancreas) cell lines. As a cancer class, colon cancer appears to be more sensitive to the oroidin class of compounds, with analogue 5l being the most active.
    Bioorganic & medicinal chemistry 03/2014; 22(5). DOI:10.1016/j.bmc.2014.01.021 · 2.79 Impact Factor
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    Dataset: Figure S2
    Dovi Kelman · Anthony D Wright ·

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    Dataset: Figure S1
    Dovi Kelman · Anthony D Wright ·

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    ABSTRACT: The methanol extract of an assemblage of Halimeda stuposa and a Dictyota sp., yielded three natural products characteristic of Dictyota sp., and one of Halimeda sp. These included the xenicane diterpene 4-hydroxydictyolactone (1), and the diterpenes dictyol E (2), 8a,11-dihydroxypachydictyol A (3) and indole-3-carboxaldehyde (4). A minor revision of 1 and new spectroscopic data for 1 and 2 are provided, along with associated anti-cancer activities of compounds.
    Molecules 12/2012; 17(3):2929-38. DOI:10.3390/molecules17032929 · 2.42 Impact Factor
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    ABSTRACT: The methanol extract of a Sinularia sp., collected from Bowden Reef, Queensland, Australia, yielded ten natural products. These included the new nitrogenous diterpene (4R*,5R*,9S*,10R*,11Z)-4-methoxy-9-((dimethylamino)-methyl)-12,15-epoxy-11(13)-en-decahydronaphthalen-16-ol (1), and the new lobane, (1R*,2R*,4S*,15E)-loba-8,10,13(14),15(16)-tetraen-17,18-diol-17-acetate (2). Also isolated were two known cembranes, sarcophytol-B and (1E,3E,7E)-11,12-epoxycembratrien-15-ol, and six known lobanes, loba-8,10,13(15)-triene-16,17,18-triol, 14,18-epoxyloba-8,10,13(15)-trien-17-ol, lobatrientriol, lobatrienolide, 14,17-epoxyloba-8,10,13(15)-trien-18-ol-18-acetate and (17R)-loba-8,10,13(15)-trien-17,18-diol. Structures of the new compounds were elucidated through interpretation of spectra obtained after extensive NMR and MS investigations and comparison with literature values. The tumour cell growth inhibition potential of 1 and 2 along with loba-8,10,13(15)-triene-16,17,18-triol, 14,17-epoxyloba-8,10,13(15)-trien-18-ol-18-acetate, lobatrienolide, (1E,3E,7E)-11,12-epoxycembratrien-15-ol and sarcophytol-B were assessed against three human tumour cell lines (SF-268, MCF-7 and H460). The lobanes and cembranes tested demonstrated 50% growth inhibition in the range 6.8-18.5 µM, with no selectivity, whilst 1 was less active (GI(50) 70-175 µM).
    Marine Drugs 08/2012; 10(8):1619-30. DOI:10.3390/md10081619 · 2.85 Impact Factor
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    Dovi Kelman · Anthony D Wright ·
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    ABSTRACT: This paper highlights the importance of recording at least a (1)H nuclear magnetic resonance (NMR) spectrum to verify identity of standards used in analyses of organic materials irrespective of source. We show the importance of this approach with an example of a quantitative high-performance liquid chromatography (HPLC) study undertaken with green tea extracts that required the use of several polyphenols as standards. In the course of the study one of these standards [(-)-epigallocatechin, EGC], although having the physical appearance and appropriate HPLC chromatographic behavior of EGC, proved by (1)H-NMR to be a completely different class of molecule. For us, this raised significant questions concerning validity of many published pieces of research that used quantitative HPLC methods without first performing rigorous validation of the employed standards prior to their use. This paper clearly illustrates the importance of validation of all standards used in analysis of organic materials by recording at least a (1)H-NMR spectrum of them prior to their use.
    PLoS ONE 07/2012; 7(7):e42061. DOI:10.1371/journal.pone.0042061 · 3.23 Impact Factor
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    ABSTRACT: Investigation of aqueous methanol extracts of the cyanobacterium Nodularia spumigena KAC 66 led to the isolation of the nodulopeptins 899, 901 and 917. The chemical structures were determined using high-resolution NMR and MS-data. The stereochemistry of the amino-acid residues was realized by LC–MS analysis using Marfey’s reagent. The bioactivity of the novel compounds was determined.
    Tetrahedron 02/2012; 68(5):1622-1628. DOI:10.1016/j.tet.2011.11.056 · 2.64 Impact Factor
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    ABSTRACT: Marine algae are known to contain a wide variety of bioactive compounds, many of which have commercial applications in pharmaceutical, medical, cosmetic, nutraceutical, food and agricultural industries. Natural antioxidants, found in many algae, are important bioactive compounds that play an important role against various diseases and ageing processes through protection of cells from oxidative damage. In this respect, relatively little is known about the bioactivity of Hawaiian algae that could be a potential natural source of such antioxidants. The total antioxidant activity of organic extracts of 37 algal samples, comprising of 30 species of Hawaiian algae from 27 different genera was determined. The activity was determined by employing the FRAP (Ferric Reducing Antioxidant Power) assays. Of the algae tested, the extract of Turbinaria ornata was found to be the most active. Bioassay-guided fractionation of this extract led to the isolation of a variety of different carotenoids as the active principles. The major bioactive antioxidant compound was identified as the carotenoid fucoxanthin. These results show, for the first time, that numerous Hawaiian algae exhibit significant antioxidant activity, a property that could lead to their application in one of many useful healthcare or related products as well as in chemoprevention of a variety of diseases including cancer.
    Marine Drugs 02/2012; 10(2):403-16. DOI:10.3390/md10020403 · 2.85 Impact Factor
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    ABSTRACT: From the organic extracts of two Guam sponges, Rhaphoxya sp. and Suberea sp., determined to have cytotoxic and chemopreventive activities, three new compounds, theonellin isocyanate (1) and psammaplysins I and J (5, 6), and six previously reported compounds (2-4, 7-9) were isolated and characterized spectroscopically ((1)H and (13)C NMR, MS, IR, UV, [α](D)). The two new metabolites (5 and 6) isolated from the Suberea sp. sponge are rare examples of compounds containing a bromotyramine moiety rather than the more usual dibromo analogue. For the compounds isolated from the Rhaphoxya sp., this is the first report of the known compounds 2-4 being found in a single sponge. For previously reported compounds 2-4 complete unambiguous (1)H and (13)C NMR data are provided.
    Journal of Natural Products 01/2012; 75(3):502-6. DOI:10.1021/np200939d · 3.80 Impact Factor
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    ABSTRACT: While investigating the cytotoxic activity of the methanol extract of an Australian marine sponge Stelletta sp. (Demospongiae), a new diketopiperazine, cyclo-(4-S-hydroxy-R-proline-R-isoleucine) (1), was isolated together with the known bengamides; A (2), F (3), N (4), Y (5), and bengazoles; Z (6), C(4) (7) and C(6) (8). The isolation and structure elucidation of the diketopiperazine (1), together with the activity of 1-8 against a panel of human and mammalian cell lines are discussed.
    Marine Drugs 12/2011; 9(11):2469-78. DOI:10.3390/md9112469 · 2.85 Impact Factor
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    ABSTRACT: Callophycin A was originally isolated from the red algae Callophycus oppositifolius and shown to mediate anticancer and cytotoxic effects. In our collaborative effort to identify potential chemopreventive and anticancer agents with enhanced potency and selectivity, we employed a tetrahydro-β-carboline-based template inspired by callophycin A for production of a chemical library. Utilizing a parallel synthetic approach, 50 various functionalized tetrahydro-β-carboline derivatives were prepared and assessed for activities related to cancer chemoprevention and cancer treatment: induction of quinone reductase 1 (QR1) and inhibition of aromatase, nitric oxide (NO) production, tumor necrosis factor (TNF)-α-induced NFκB activity, and MCF7 breast cancer cell proliferation. Biological results showed that the n-pentyl urea S-isomer 6a was the strongest inducer of QR1 with an induction ratio (IR) value of 4.9 at 50 μM [the concentration to double the activity (CD)=3.8 μM] and its corresponding R-isomer 6f had an IR value of 4.3 (CD=0.2 μM). The isobutyl carbamate derivative 3d with R stereochemistry demonstrated the most potent inhibitory activity of NFκB, with the half maximal inhibitory concentration (IC(50)) value of 4.8 μM, and also showed over 60% inhibition at 50 μM of NO production (IC(50)=2.8 μM). The R-isomer urea derivative 6j, having an appended adamantyl group, exhibited the most potent MCF7 cell proliferation inhibitory activity (IC(50)=14.7 μM). The S-isomer 12a of callophycin A showed the most potent activity in aromatase inhibition (IC(50)=10.5 μM).
    Bioorganic & medicinal chemistry 11/2011; 19(21):6182-95. DOI:10.1016/j.bmc.2011.09.020 · 2.79 Impact Factor
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    ABSTRACT: The tetrahydro-β-carboline, callophycin A (1), was isolated from the methanol extract of the red alga Callophycus oppositifolius collected from Pugh Shoal, north east of Truant Island, Northern Territory, Australia. The structure and relative stereochemistry of 1 was determined through extensive NMR analysis. Callophycin A (1) was tested against a panel of mammalian cell lines and found to be generally cytotoxic. © 2010 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.
    Phytochemistry Letters 06/2011; 4(2):69-71. DOI:10.1016/j.phytol.2010.07.010 · 1.45 Impact Factor
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    ABSTRACT: Three new merosesquiterpenoids, metachromins U, V, and W (1-3), were isolated from a specimen of the marine sponge Thorecta reticulata collected off Hunter Island, Tasmania, Australia. Structures of the new compounds were elucidated through extensive NMR investigations and comparison with literature values. The cytotoxicities of 1-3 were assessed against a panel of human tumor cell lines (SF-268, H460, MCF-7, and HT-29) and a mammalian cell line (CHO-K1). All compounds were found to have 50% growth inhibition activities in the range 2.1-130 μM, with 2 being the most active (GI50 2.1-10 μM).
    Journal of Natural Products 05/2011; 74(5):1335-8. DOI:10.1021/np200041v · 3.80 Impact Factor

Publication Stats

3k Citations
413.25 Total Impact Points


  • 2007-2015
    • University of Hawaiʻi at Hilo
      • • Department of Pharmaceutical Sciences
      • • College of Pharmacy
      Hilo, Hawaii, United States
  • 2006-2011
    • Australian Institute of Marine Science
      Townsville, Queensland, Australia
  • 2010
    • Hochschule für Technik Zürich
      Zürich, Zurich, Switzerland
  • 2009
    • University of Guam
      Mangilao Village, Mangilao Municipality, Guam
  • 2004-2009
    • James Cook University
      Townsville, Queensland, Australia
  • 1999-2009
    • University of Bonn
      • Institut für Pharmazeutische Biologie
      Bonn, North Rhine-Westphalia, Germany
  • 2005
    • University of Alabama at Birmingham
      Birmingham, Alabama, United States
  • 1996-2002
    • Technische Universität Braunschweig
      • Institute of Pharmaceutical Biology
      Braunschweig, Lower Saxony, Germany
    • University of Illinois at Chicago
      Chicago, Illinois, United States
  • 1993-1995
    • Hacettepe University
      • • Department of Pharmacognosy
      • • Faculty of Pharmacy
      Engüri, Ankara, Turkey
    • University of Papua New Guinea
      • Department of Chemistry
      Port Moresby, National Capital, Papua New Guinea
  • 1992-1994
    • ETH Zurich
      • Institute of Pharmaceutical Sciences
      Zürich, Zurich, Switzerland