Electronic Theses and Dissertations

Date of Award

1-1-2017

Document Type

Dissertation

Degree Name

Ph.D. in Pharmaceutical Sciences

Department

Biomolecular Sciences

First Advisor

John M. Rimoldi

Second Advisor

Samir A. Ross

Third Advisor

David A. Colby

Relational Format

dissertation/thesis

Abstract

Neurological disorders include disorders such as migraine, tension-type headaches, Parkinson’s disease (PD), epilepsy, dementia, and Alzheimer’s disease (AD). Globally, PD is the second most common neurodegenerative disorder following AD. In developed countries, PD affects 1% of all population over 60 years of age. The prevalence of PD is increasing over the years and is expected to double by 2030. It is proposed that combination of dopaminergic drugs with monoamine oxidase B (MAO-B) inhibitors, anticholinergics, catechol-O-methyl transferase inhibitors, and other non-dopaminergic drugs can better alleviate levodopa-induced motor complications along with better control of motor symptoms. MAO-B inhibitors play a significant role in dopamine (DA) metabolism and can be used as monotherapy in the early stages of PD, or in combination with levodopa. Currently, there are only three MAO-B inhibitors that are approved by Food and Drug Administration (FDA): selegiline, rasagiline, and safinamide. Hence, there is the need to discover potent and selective MAO-B inhibitors for effective treatment of PD. About 60% of the marketed drugs today are either natural products or derivatives that are inspired from natural products. We studied plants with extensive traditional use in CNS-related disorders, in which the chloroform extract of C. urticifolia exhibited potent inhibition of MAO-A and -B. Calea urticifolia (Asteraceae) commonly known as “Juanislama” is native to the Central America. Bioassay-guided fractionation has been implemented for the isolation of the secondary metabolites from C. urticifolia. From the bioactive fraction, acacetin and a series of sesquiterpenes were isolated; acacetin was found to be the bioactive compound. A series of acacetin analogs were designed with the aid of computational docking studies, to improve their selectivity towards MAO-B. The structures of the isolated compounds were determined on the basis of HR-MS and 1D- and 2D-NMR studies; configurations were partly established by ECD calculations. Monoamine oxidase assays were performed on the extracts, fractions, and purified compounds. Molecular modeling and molecular dynamic studies were used to predict the binding modes on the active sites of the MAO isoenzymes.

Concentration/Emphasis

Emphasis: Medicinal Chemistry

Available for download on Thursday, July 23, 2020

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