DOI
https://doi.org/10.25772/R7BJ-2W40
Defense Date
2015
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Pharmaceutical Sciences
First Advisor
Dr. Umesh Desai
Abstract
Sulfated low molecular weight lignins (LMWLs) have shown good activity as anticoagulants by allosterically inhibiting thrombin, as well as promising agents for treating emphysema through inhibition of elastolysis, oxidation, and inflammation. Sulfated LMWLs are chemo-enzymatically synthesized from starting monomers caffeic, ferulic, and sinapic acid into sulfated dehydropolymers known as CDS, FDS, and SDS. To further the LMWLs’ development as drugs, their structural composition and physicochemical characteristics were defined in this work. The molecular weight distribution profile of the sulfated LMWLs from size exclusion chromatography performed on a high pressure liquid chromatography system (SEC-HPLC) changed from bimodal when no surfactant is used in the mobile phase of the HPLC to unimodal when surfactant is used in the mobile phase. This indicates that some large molecular weight species, likely an aggregate of smaller molecular weight chains, are disrupted when surfactant is present. The resulting estimates of molecular weight calculated when surfactant is used in the mobile phase resulted in peak average molecular weights of 5700 Da for CDS, 7400 Da for FDS, and 4300 Da for SDS. These molecular weights are 17-45% higher and can be considered more accurate than the previously reported molecular weights (CDS: 3320 Da, FDS: 4120 Da, SDS: 3550 Da) because they were measured directly whereas previous estimates were calculated from GPC-HPLC data of the unsulfated LMWL precursors. Elemental analysis and distribution coefficient measurements were also performed on the LMWL library, revealing information about the level of sulfation and hydrophobic character of the sulfated LMWLs.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
12-9-2015