Publication Date

12-2019

Date of Final Oral Examination (Defense)

10-1-2019

Type of Culminating Activity

Dissertation

Degree Title

Doctor of Philosophy in Biomolecular Sciences

Department

Biology

Major Advisor

Owen M. McDougal, Ph.D.

Advisor

Julia T. Oxford, Ph.D.

Advisor

Daniel Fologea, Ph.D.

Advisor

Xinzhu Pu, Ph.D.

Abstract

Veratrum californicum, commonly referred to as corn lily or Californian false hellebore, grows in high mountain meadows and produces bioactive steroidal alkaloids, including cyclopamine. Cyclopamine is a potent inhibitor of the Hedgehog (Hh) signaling pathway. Our lab has optimized methods to extract cyclopamine and related steroidal alkaloids from V. californicum, and implemented in-house Hh signaling bioactivity evaluation of these steroidal alkaloids using a Shh-Light II cell assay. A survey of extraction methods and solvents resulted in the identification of conditions most favorable for alkaloid extraction yield and antagonist activity in the Shh-Light II cell assay. The highest amount of bioactive cyclopamine was obtained by soaking V. californicum biomass in ethanol for 24 hr. with vigorous stirring. The extraction protocol was effective for isolating additional alkaloids beyond cyclopamine, some of which have been reported in the literature prior and some that have not. In all cases, bioactivity screening was performed and new insights provided. Expansion of the extraction protocol for the investigation of detailed differences in alkaloid composition of V. californicum based on plant part, harvest location, and growth stage, provides a detailed assessment of alkaloids that have been characterized previously (cyclopamine, veratramine, muldamine and isorubijervine), and identifies at least six alkaloids that have not been previously characterized.

DOI

10.18122/td/1610/boisestate

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