Semester

Fall

Date of Graduation

2023

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Chemistry

Committee Chair

Dr. Terry Gullion

Committee Member

Dr. Fabien Goulay

Committee Member

Dr. Justin Legleiter

Committee Member

Dr. Blake Mertz

Committee Member

Dr. Matt Kasson

Abstract

Solid State NMR is a powerful tool for analyzing the chemical composition of insects. Previous studies have used Solid State NMR to investigate the chemical composition and investigate the sclerotization (tanning) process of insect exoskeletons. Acquiring sufficient exoskeleton sample for analysis has been relatively simple. This is however not the case for other components of an insect’s physiology, particularly the wing membrane material. The wings of an insect only compose a small percentage of their overall body mass, and many hundreds to thousands of insects must be processed in order to achieve a few milligrams of wing membrane sample. The wing membranes which are in our interest are particularly challenging to collect as they are very small, surrounded by unwanted veins, extremely thin and nearly transparent. Compounding these difficulties is the factor of NMR signal strength due to low 13C isotopic natural abundance. The task of isotopically labelling living organisms such as insects ranges from challenging to impossible. Consequently NMR signal enhancement techniques are necessary to generate high quality useful spectra.

Solid State NMR has been used to investigate the chemical composition of the wing membranes of cicadas (Magicicada cassini), honeybees (Apis mellifera ligustica), ladybugs (Hippodamia convergens), and amber phantom butterflies (Haetera piera). DNP-MAS Solid State NMR has been used to investigate the chemical composition of cicada wing membranes of a small natural abundance sample, yielding high quality one-dimensional and two-dimensional spectra.

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