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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Tests for causes of rarity in goldenseal (Hydrastis canadensis L.)

Sanders, Suzanne M. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains ix, 247 p. : ill., map. Vita. Includes abstract. Includes bibliographical references.
2

A chemico-pharmaceutical study of Hydrastis canadensis L.

Hammond, Elmer Lionel, January 1941 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1941. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
3

Synthetic seed production for germplasm storage of Hydrastis canadensis L. (goldenseal)

Settipalli, Satyaprakash R. January 2007 (has links)
Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains vii, 48 p. : col. ill. Includes abstract. Includes bibliographical references (p. 40-42).
4

Genetic Variability in Hydrastis Canadensis L. Using Rapd Analysis

Kelley, Kerry 01 January 2009 (has links) (PDF)
ABSTRACT GENETIC VARIABILITY IN HYDRASTIS CANADENSIS L. USING RAPD ANALYSIS FEBRUARY 2009 KERRY J. KELLEY, B.A. MOUNT HOLYOKE COLLEGE M.A. UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Lyle Craker Hydrastis canadensis L. (goldenseal) is an endangered perennial wildflower species native to eastern North America. In this study, several populations of goldenseal, (both cultivated and wild type) were analyzed for genetic variability. The samples were collected from plant populations in North Carolina, Ohio, Pennsylvania and West Virginia and preserved using silica gel during collection. Random amplified polymorphic DNA (RAPD) analysis technique was used to generate DNA profiles from individual plants and to estimate genetic variability between groups (cultivated and wild type), among populations within groups and within populations using analysis of molecular variance (AMOVA) and a UPGMA clustering phenogram. Our results demonstrate that the bulk of genetic diversity may be within and among populations, but not between groups. This indicates the need for preservation and conservation efforts at the population level. The next step would be to study goldenseal populations more in depth for underlying causes of the genetic variability observed in this study. Further study of genetic variability with different molecular markers may be needed to clarify the level of diversity for the species at the group level. Increased knowledge of genetic variability and the identification of accessions of goldenseal would prove useful for reintroduction and cultivation strategies.
5

A study of electrospun nanofibers and diatomaceous earth materials for the extraction of alkaloids, flavonoids and aromatic amines in various matrices / Study of electrospun nanofibres and diatomaceous earth materials for the extraction of alkaloids, flavonoids and aromatic amines in various matrices

Mothibedi, Kediemetse (Kedimetse) 07 April 2013 (has links)
The thesis explored the use of different sorbent materials in solid phase extraction method development. The methods included the use of the polymeric Agilent Bond Elut Plexa solid phase extraction and electrospun polymer-silica composite sorbents for clean-up and preconcentration. Sample clean-up for alkaloids (hydrastine and berberine) in goldenseal, Hydrastis canadensis and flavonoids (quercetin, kaempferol and isorhamnetin) in Ginkgo biloba was achieved using Bond Elut Plexa SPE sorbent. Clean-up of flavonoids in Ginkgo biloba was also achieved using electrospun polymer-silica composite (polystyrene-silica, polyacrylonitrile-silica and nylon 6-silica) sorbents. All analysis of flavonoids and alkaloids was carried out using an Agilent 1200 Series HPLC coupled with a diode array detector. Good peak separation was achieved in less than 6 min employing an Agilent ZORBAX Eclipse Plus C18 column (4.6 x 75 mm, 3.5 μm) at 35⁰C. The mobile phases employed were 0.1% phosphoric acid/methanol gradient and 0.5% phosphoric acid/methanol (40:60) for alkaloids and flavonoids respectively. The calibration curves exhibited linearity up to 120 μg mL⁻¹ with correlation coefficients of more than 0.9980. The recoveries ranged from 73-109% with relative standard deviation of less than 5% for all analytes. Agilent Chem Elut supported liquid extraction was employed for the development of a sample preparation method for the determination of 24 banned aromatic amines from azo dyes in textile following the EU standard method EN 14362-1:2003 (E) and the Chinese standard method GB/T 17592-2006. The supported liquid extraction was effective in the extraction of the aromatic amines from textile (cotton, wool and polyester/cotton [80%:20%]). Most of the recoveries obtained were conforming to the minimum requirements set in the EN 14362-1:2003 (E) standard method and the relative standard deviations were less than 15%. Good peak separation was obtained within 70 min run time using the Agilent Zorbax SB-Phenyl column (4.6 mm x 250 mm, 5-micron) or the Agilent DB-35 MS (J & W) (30 m x 0.25 mm, 0.25 μm film thickness. It was demonstrated that the polymeric Agilent Bond Elut Plexa, electrospun nanofibers and diatomaceous earth were effective in extraction of alkaloids, flavonoids and aromatic amines in different matrices. The developed methods were simple, rapid and reproducible.
6

Pressurized hot water extraction of nutraceuticals and organic pollutants from medicinal plants

Mokgadi, Janes January 2011 (has links)
This thesis explores the robustness and the versatility of pressurized hot water extraction (PHWE) for a variety of analytes and matrices. Applications discussed include: selective extraction of alkaloids in goldenseal followed by their degradation studies; in-cell clean-up of pesticides in medicinal plants employing custom made molecularly imprinted polymers (MIPs) sorbents; in-cell pre-concentration followed by desorption of aflatoxins in plants with MIPs; desorption of pesticides from electrospun nanofiber sorbents; and removal of templates from MIPs sorbents. It was demonstrated that selective extractions could be achieved by just changing the temperature of water while adjusting the pressure. For instance, the alkaloids in goldenseal (hydrastine and berberine), were extracted at 140 °C, 50 bars, 1 mL min⁻¹ in 15 min; organochlorine pesticides from medicinal plants were extracted at 260 °C, 80 bars, 1 mL min-1 in 10 min; while aflatoxins AFG2, AFG1, AFB2 and AFB1 were extracted at 180 °C, 60 bars and a flow rate of 0.5 mL min⁻¹ in 10 min. The selectivity of PHWE was further enhanced by combining it with selective MIPs sorbents at higher temperatutes. In-cell clean-up of interfering chlorophyll was successfully removed from the medicinal plants during pesticides analysis while clean-up of aflatoxins AFG2, AFG1, AFB2 and AFB1 was achieved in two extraction cells connected in series. Ultrasound was also combined with PHWE for extraction of hydrastine and berberine at 80 °C and 40 bars in 30 min. PHWE was further evaluated for removal of templates from quercetin, phthalocynine and chlorophyll MIPs. The templates were thoroughly washed off their MIPs within 70 min with PHWE compared to over 8 h for Soxhlet and ultrasound assisted extraction. Pesticides were also desorbed from electrospun nanofibers at 260 °C, 80 bars in 10 min employing only water at 0.5 mL min⁻¹. In the light of green chemistry, the decrease in the usage of organic solvents was 100%, resulting in no organic solvent waste.
7

POPULATION LOSS OF GOLDENSEAL, HYDRASTIS CANADENSIS L., (RANUNCULACEAE), IN OHIO

Mulligan, Margaret R. 17 October 2003 (has links)
No description available.

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