Date of Award
1-1-2012
Document Type
Thesis
Degree Name
M.S. in Pharmaceutical Science
Department
Pharmaceutics and Drug Delivery
First Advisor
Mark T. Hamann
Second Advisor
Jordan K. Zjawiony
Third Advisor
Daneel Ferreira
Relational Format
dissertation/thesis
Abstract
This thesis is composed of studies that regard the advancement to the Arctic region and the importance of host-microbe interactions in natural product discovery. Bioactive metabolites have been reported from a myriad of marine and terrestrial organisms around the world including plants, insects, sponges, tunicates, bacteria, and fungi among others. Many macroorganisms, of which the metabolites are found, depend on the symbiotic relationship of microorganisms for metabolite production. The scope of this work is to investigate secondary metabolism of both marine and terrestrial organisms from different areas of the world as well as search for the importance of host-microbe symbiosis on a chemical level. Chapter 1 comprises a review of bioactive sponge secondary metabolites reported from Arctic sponge species. Although more tropical and easily accessible waters have been investigated, other regions including the more dark, cold polar regions, specifically the Arctic, represent a less explored frontier for secondary metabolite discovery. Additionally, a survey of a 2010 sponge collection in the Aleutian Islands, AK, is displayed and assesses the chemical potential of sponge species in the area. The description of two small molecule aldehydes with reported broad spectrum bioactivity from a new species of Guitarra obtained through this collection is also given. Chapter 2 discusses the chemical investigation of a new sponge species of the genus Monanchora from the Aleutian Islands. Different species of Monanchora, including M. pulchra, have been classified within the region. Through de-replication, members of the class of potent cytotoxic, antimicrobial compounds known as the monanchocidins were identified from the sponge. Further investigation of the metabolome and development of bioactivity will continue to be investigated in the future. Studies have suggested that the chemical complexity of sponges is dependent upon not only the sponge itself, but rather an intricate associated microbial community. Chapter 3 presents the results of fermentations of sponge-associated Micromonospora sp. M42, yielding seven small molecule secondary metabolites, with four belonging to a class of broad spectrum bioactive molecules known as diketopiperazines. Previous research suggests that these compounds possess bioactivities that can benefit the sponge in a symbiotic relationship, including growth promoter and antifouling properties. Screening of the crude extracts revealed the presence of the diketopiperazines in the sponge. Additionally, a genomic evaluation of the biosynthetic machinery of M42 was performed. This data was generated in supplement of previously done work regarding the entire sponge-associated microbiome and previous confirmation of manzamine production by M42 as well as a series of biotranformation studies that add insight to the generation of the array of manzamine derivatives found in the sponge. Chapter 4 discusses the metabolite nicotianamine, a compound found in all higher plant species that possesses antioxidant and metal-binding properties that can be helpful in use as a food preservative in replacement of EDTA. Preliminary data into the optimization of the isolation and quantification of nicotianamine on an analytical scale is presented.
Recommended Citation
Abbas, Samuel Hamed, "Geographic and Host-Microbe Symbiotic Influence on Secondary Metabolism" (2012). Electronic Theses and Dissertations. 1342.
https://egrove.olemiss.edu/etd/1342
Concentration/Emphasis
Emphasis: Pharmacognosy