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ARS Home » Southeast Area » Oxford, Mississippi » Natural Products Utilization Research » Research » Research Project #429247

Research Project: Health-Promoting Bioactives and Biobased Pesticides from Medicinal and Herbal Crops

Location: Natural Products Utilization Research

2016 Annual Report

The main objective of this project is to isolate and identify compounds from natural sources with pesticidal activity or have properties that are beneficial for human health. The overall goal is to be able to provide compound(s) amenable for commercial development as a pesticide or identify a “high value” plant with unique bioactive compounds. Over the next 5 years, we will focus on the following objectives: Objective 1: Enable, from a technological standpoint, new commercial biopesticides; and identify optimum production practices for the plants from which these biopesticides are derived. Subobjective 1.1: Identify nematicidal compounds from tall fescue. Subobjective 1.2. Discover natural product based fungicides from plant extract collections or other useful sources for US agriculture. Subobjective 1.3: Investigation of cashew nut shell liquid for insecticide activity and synthetic modification of the isolated compounds to gain insights into structure-activity relationship. Sub-objective 1.4: Discover natural product based herbicidal and insecticidal compounds from crude plants and plant endophyte extract collections. Objective 2: Identify human bioactive compounds in select plants and herbs, and determine plant growth conditions to enhance or optimize bioactive compound concentrations. Subobjective 2.1: Identify anti-adipocyte compound(s) in Scutellaria ocmulgee and determine the effect of various growth conditions on the bioactive compound(s).

: An “activity-guided” isolation approach will be employed in efforts to discover novel bioactive compounds. Focus will be on isolating single compounds from active fractions. The che mical structure of bioactive compounds isolated will be elucidated using a combination of spectroscopic techniques such as ultraviolet, infrared, mass spectrometry and nuclear magnetic resonance spectroscopy. Simple structure modification of the bioactive constituent(s) and synthesis of analogs will be performed for activity optimization. In general, four projects are included in the plan, employing specific approaches. These include: 1) Identification of nematotoxic compound(s) from tall fescue cultivar Jesup (Max-Q). Isolation will be guided by an in vitro assay on inhibition of nematodes. The activity of the isolated nematotoxic compound will be tested in soil. 2) Identification of fungicidal compound(s) from select plants from China. Isolation will be guided using in vitro assays against Botrytis cinerea, Colletotrichum species, Fusarium species, and Phomopsis species. The activity of isolated compounds will be tested in detached leaf assays. 3) Identification of compound(s) from cashew nut shell liquid with insecticidal activity. Isolation will be performed using assays to determine activity against mosquito (Aedis egypti) larvae and adult. Analogs of the mosquito larvicidal/adulticdal compound(s) will be synthesized following standard synthetic procedures such as Friedel-Crafts acylation reaction. 4) Identification of anti-obesity compound from Scutellaria ocmulgee. Isolation of compounds will be performed using inhibition of adipocyte differentiation as acidity indicator. Anti-adipocyte compounds isolated will be used as chemical markers in associated study determining the appropriate agronomic practices to generate highest amount of anti-adipocyte compound(s) and biomass.

Progress Report
Towards achieving Objective 1, the following research were performed in FY 2015 and are continuing in FY 2016. 1. Tall fescue roots were extracted and extract fractionated by flash column chromatography, yielding 3 fractions (designated as fractions 1, 6, and 7) that inhibited nematode egg hatch and/or reduced the mobility of second-stage juveniles. Fractions 6 and 7 have been further fractionated, and the sub-fractions were sent to ARS collaborator at the ARS Nematology Laboratory in Beltsville for assay. Fractionation of subfraction 1 is underway. 2. Antifungal activity of bacteria (Actinomycete species) collected from banana fields heavily infested with Fusarium oxysporium f. sp. cubense was demonstrated. Collaborative research with an ARS scientist at the ARS Thad Cochran Southern Horticultural Laboratory, Poplarville, MS began in FY2016 to study the effects of this actinomycete on four isolates of Phytophthora cinammoni obtained from symptomatic blueberry roots. In challenge experiments, when P. cinammoni and the actinomycete were grown on V-8 juice agar in the same petri dish, growth of the P. cinammoni isolates were greatly inhibited by metabolites produced by the actinomycete. This is the first in a series of experiments to investigate the antifungal nature of this actinomycete and its potential to control important Phytophthora root rot diseases. 3. Following the isolation of constituents from cashew nutshell liquid, modification of the structures is being pursued in order to obtain analogs that retain activity against mosquito adults and larvae devoid of skin irritant effect. 4. Six antifungal constituents from a Texas native plant, Mountain torchwood (Amyris madrensis), were isolated and shown to have activity against Colletotrichum species. 5. A plant pathogenic fungus, Curvularia intermedia, was isolated from the pandan plant (Pandanus amaryllifolius) and cultured in the laboratory. From the culture broth two phytotoxic constituents (curvularin and a,ß-dehydrocurvularin) were isolated. a,ß-Dehydrocurvularin was the more phytotoxic according to laboratory bioassays. This compound also showed cell membrane disruption in cucumber cotyledons as indicated by conductivity measurements. Towards achieving Objective 2, extraction of the leaves of Scutllaria ocmulgee was performed. The extract fractionated by flash column chromatography, obtaining 8 fractions pooled according to TLC profile. The fractions were sent for anti-adipocyte testing to a collaborator at the Natural Products Center, University of Mississippi, Oxford, MS.

1. Potent pytotoxins from toothpickweed identified. Plants constitute a rich source of novel and structurally diverse phytotoxic compounds to be explored in searching for effective and environmentally safe herbicides. ARS scientists at USDA-ARS-Natural Products Utilization Research Unit (NPURU) selected toothpickweed (Ammi visnaga) for further study from screening nearly 2400 plant extracts extract. Phytotoxicity-guided fractionation of the extract yielded two compounds: khellin and visnagin, whose herbicidal activity had not been described before. In laboratory assays, khellin and visnagin inhibited the growth of lettuce and duckweed. Also, both compounds reduced the growth and germination of weeds: ryegrass, morningglory, foxtail and millet. The inhibitory activities of these compounds were similar to those of the commercial herbicides acetochlor and glyphosate in the lab bioassays. During greenhouse studies visnagin was more active, with significant contact post-emergence herbicidal activity on velvetleaf and crabgrass 2 kg ai ha-1. Moreover, its effect on velvetleaf, crabgrass and barnyardgrass (Echinochloa crus-galli) at 4 kg ai ha-1 was comparable to the bioherbicide pelargonic acid at the same rate. These results support the potential of visnagin, and possibly khellin, as bioherbicides or lead molecules for the development of new herbicides.


Review Publications
Zheljazkov, V.D., Gawde, A., Cantrell, C.L., Astatkie, T., Schlegel, V. 2015. Distillation time as tool for improved antimalarial activity and differential oil composition of cumin seed oil. PLoS One. doi:10.1371/journal.pone.0144120.
Meepagala, K.M., Johnson, R.D., Duke, S.O. 2016. Curvularin and dehydrocurvularin as phytotoxic constituents from curvularia intermedia infecting pandanus amaryllifolius. Journal of Agricultural and Food Chemistry. 5:12-22.
Dhar, S., Kumar, A., Zhang, L., Rimando, A.M., Lage, J.M., Lewin, J.R., Atfi, A., Zhang, X., Levenson, A.S. 2016. Dietary Pterostilbene is a novel MTA1-targeted chemopreventive and therapeutic agent in prostate cancer. Oncotarget. doi: 10.18632/oncotarget.7841.
Trivella, A., Stawinoga, M., Dayan, F.E., Cantrell, C.L., Mazellier, P., Richard, C. 2015. Photolysis of natural B-triketonic herbicides in water. Water Research. 78:28-36.
Meepagala, K.M., Estep, A.S., Becnel, J.J. 2016. Larvicidal and adulticidal activity chroman and chromene analogues against susceptible and permethrin-resistant mosquito strains. Journal of Agricultural and Food Chemistry. 64(24):4914-4920.
Xie, Q., Li, S.-X., Liao, D.-F., Wang, W., Tekwani, B., Huang, H.-Y., Ali, A., ur Rehman, J., Schrader, K.K, Duke, S.O., Cantrell, C.L., Wedge, D.E. 2015. Bio-pesticidal and antimicrobial coumarins from Angelica dahurica (Fisch. Ex Hoffm). Natural Product Communications. 2016;10(3):294-306.
Meepagala, K.M., Johnson, R.D., Techen, N., Wedge, D.E., Duke, S.O. 2015. Phomalactone from a phytopathogenic fungus infecting Zinnia elegans (Asteraceae) leaves. Journal of Chemical Ecology. 41:602-612.
Kaymakcioglu, B.K., Beyhan, N., Tabanca, N., Ali, A., Wedge, D.E., Duke, S.O., Bernier, U.R., Khan, I.A. 2015. Discovery and structure activity relationships of 2-pyrazolines derived from chalcones from a pest management perspective. Medicinal Chemistry Research. 24:3632-3644.
Correa, E.A., Dayan, F.E., Owens, D.K., Rimando, A.M., Duke, S.O. 2016. Glyphosate-resistant and conventional canola (Brassica napus L.) responses to glyphosate and Aminomethylphosphonic Acid (AMPA) treatment. Journal of Agricultural and Food Chemistry. 64:3508-3513.
Carvalho, C.R., Wedge, D.E., Cantrell, C.L., Silva-Hughes, A.F., Pan, Z., Moraes, R.M., Madoxx, V.L., Rosa, L.H. 2016. Molecular phylogeny, diversity and bioprospecting of endophytic fungi associated with wild ethnomedicinal North American plant Echinacea purpurea (Asteraceae). Chemistry and Biodiversity. 13:918-930 DOI: 10.1002/cbdv.201500299.
Burkhardt, A., Gawde, A., Cantrell, C.L., Zheljazkov, V.D. 2015. Effect of varying ratios of produced water and municipal water on soil characteristics, plant biomass, and secondary metabolites of Artemisia annua and Panicum virgatum. Industrial Crops and Products. 76:987-994.
Burkhardt, A., Sintim, H., Gawde, A., Cantrell, C.L., Astatkie, T., Zheljazkov, V.D., Schlegel, V. 2015. Method for attaining fennel (Foeniculum vulgare Mill.) seed oil fractions with different composition and antioxidant capacity. Journal of Applied Research on Medicinal and Aromatic Plants. 2:87-91.
Chakraborty, S., Kumar, A., Butt, N.A., Zhang, L., Williams, R., Rimando, A.M., Biswas, P.K., Levenson, A.S. 2016. Molecular insight into the differential anti-androgenic activity of resveratrol and its natural analogs: In Silico approach to understand biological actions. Molecular Biosystems. 12:1702-1709. DOI: 10.1039/C6MB00186F
Dhar, S., Kumar, A., Rimando, A.M., Zhang, X., Levenson, A.S. 2015. Resveratrol and pterostilbene epigenetically restore PTEN expression by targeting OncomiRs of the miR-17 family in prostate cancer. Oncotarget. 6(29):27214-27226.
Gadetskaya, A.V., Tarawneh, A.H., Zhusupova, G.E., Gemejiyeva, N.G., Cantrell, C.L., Cutler, S.J., Ross, S.A. 2015. Sulfated phenolic compounds from Limonium caspium: Isolation, structural elucidation, and biological evaluation. Fitoterapia. 104:80-85.
Nicolau-Goncalves, V., Cantrell, C.L., Wedge, D.E., Ferreira, M.C., Soares, M.A., Jacob, M.R., Oliveira, F., Galante, D., Rodrigues, F., Alves, T., Zani, C., Junior, P., Murta, S., Romanho, A., Barbosa, E., Kroon, E., Oliveira, J., Gomez-Silva, B., Galetovic, A., Rosa, C.A., Rosa, L. 2015. Fungi associated with rocks of the Atacama Desert: taxonomy, distribution, diversity, ecology and bioprospection for bioactive compounds. Environmental Microbiology. 18:232-245.
Goncalves, V.N., Carvalho, C.R., Johann, S., Mendes, G., Alves, T.M., Zani, C.L., Policarpo, Jr, A., Murta, S.M., Romanha, A.J., Cantrell, C.L., Rosa, C.A., Rosa, L.H. 2015. Antibacterial, antifungal and antiprotozoal activities of fungal communities present in different substrates from Antarctica. Polar Biology. 38:1143-1152.
Joyce, B.L., Zheljazkov, V.D., Sykes, R., Cantrell, C.L., Hamilton, C., Mann, D.G., Rodriquez, M., Mielenz, J., Astatkie, T., Stewart, Jr., C. 2015. Ethanol and high-value terpene co-production from lignocellulosic biomass of Cymbopogon flexuosus and Cymbopogon martinii. PLoS One. 10(10):1-17. doi:10.1371/journal.pone.0139195
Kumar, A., Dhar, S., Rimando, A.M., Lage, J.M., Lewin, J.R., Zhang, X., Levenson, A.S. 2015. Epigenetic potential of resveratrol and analogs in preclinical models of prostate cancer. Annals of the New York Academy of Sciences. 1348:1-9.
Poudyal, S., Zheljazkov, V.D., Cantrell, C.L. 2016. Coal-bed methane water effects on dill and essential oils. Journal of Environmental Quality. 45:728-733.
Rimando, A.M., Khan, S.I., Mizuno, C., Ren, G., Mathews, S.T., Kim, H., Yokoyama, W.H. 2015. Evaluation of PPARa activation by known blueberry constituents. Journal of the Science of Food and Agriculture. 96(5):1666-1671. doi: 10.1002/jsfa.7269.
Burkhardt, A., Gawde, A., Cantrell, C.L., Baxter, H.L., Joyce, B.L., Stewart, Jr., C.N., Zheljazkov, V.D. 2015. Effects of produced water on soil characteristics, plant biomass, and secondary metabolites. Journal of Environmental Quality. 44:1938-1947.
Chen, S., Yu, J., Li, Q., Zhao, J., Wedge, D.E., Duke, S.O., Liao, D., Wang, Y., Fronczek, F.R., Khan, I.A., Wang, W. 2016. 7a-hydroxfriedelan-3one-26-OL-29-OIC acid and other constituents from Pileostegia Viburnoids VAR. Glabrescens. Natural Product Communications. 11(7):931-934.