Dissertation/Thesis Abstract

Ehtnobotanical- and chemometric-guided investigation of Phytolacca americana L.
by Chan, Michael Andrew Hok Duk, Ph.D., The University of Mississippi, 2015, 141; 10000699
Abstract (Summary)

The overall goal of this study was to determine the viability and effectiveness of a novel approach utilizing ethnobotanically guided chemometric comparisons to discover and identify biologically active compounds within the plant species Phytolacca americana L. A second goal of this study was to use the data and results obtained through this process to obtain a better understanding of the plant’s biological and chemical properties and their influence on preparations of the plant. These goals were accomplished through the completion of several specific aims.

First, a review of the available ethnobotanical and scientific knowledge on the species was compiled and used to guide further experiments. In the second aim 10 triterpenoid saponins from P. americana material were isolated and characterized to be used as standards. The third aim determined the chemical profiles and biological activities associated with P. americana samples harvested and prepared in accordance with traditional practices. Analysis and comparisons showed that the leaves harvested and prepared according to folk practices did not show activity in toxicity assays performed, whereas leaves harvested outside of the recommended season and leaves not properly cooked did show activity in the toxicity assays. For root materials, results supported the harvesting of material in the winter months as per traditional practice. Roots harvested in the winter were active in assays investigating intracellular oxidative stress and the targets related to inflammation and metabolic disorder, whereas roots harvested in the spring were not. The fourth aim of this study used statistical comparisons to identify compounds that differed significantly between the different samples and determined if these compounds could be correlated to the samples’ bioactivities. These statistical comparisons showed that the triterpenoid saponins were correlated with the activities of the samples. For the leaf samples two compounds with demonstrated bioactivity, namely phytolaccoside B and phytolaccoside D were putatively identified. Several biologically active compounds were also identified through the root comparisons, namely phytolaccoside D, phytolaccagenin and phytolaccoside A.

The overall results of these analyses provide significant evidence supporting the use of this ethnobotanical guided chemometric approach for the discovery of biologically active compounds in plant materials as well as provide further insights into the impact traditional harvesting and preparation practices have on the chemistry and biology of P. americana.

Indexing (document details)
Advisor: Khan, Ikhlas A.
Commitee: Croom, Edward M., Walker, Larry A., Zjawiony, Jordan K.
School: The University of Mississippi
Department: Pharmacognosy
School Location: United States -- Mississippi
Source: DAI-B 77/06(E), Dissertation Abstracts International
Source Type: DISSERTATION
Subjects: Analytical chemistry, Pharmacy sciences
Keywords: Chemometrics, Ethnobotany, Phytolacca
Publication Number: 10000699
ISBN: 9781339411255
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