Antimicrobial Activities of Several Argemone mexicana-Inspired Phytocompounds

Level of Education of Students Involved


Faculty Sponsor

Danielle Orozco-Nunnelly


Arts and Sciences



ORCID Identifier(s)


Presentation Type

Poster Presentation

Symposium Date

Spring 4-27-2023


The creation of novel antimicrobial agents is currently at the forefront of modern healthcare due to a stark decrease in antimicrobial drug development in recent years and rise of “superbugs” that are resistant to more than one type of antimicrobial treatment, which are predicted by 2050 to cause 10 million deaths per year. Our research is focused on testing bacterial and fungal pathogens against methanolic and hexane extracts of various medicinal plants, such as Argemone mexicana. From previous work by our group, several antimicrobial compounds were isolated from the roots and leaves of A. mexicana, including berberine, chelerythrine and sanguinarine (work published in PLOS ONE in 2021). Since then, we have synthesized multiple rationally-designed variants of these original phytocompounds (fourteen berberine and four chelerythrine variants) and have tested these A. mexicana-inspired phytocompounds for altered antimicrobial activities. Interestingly, several of these variant compounds show increased antibacterial effects against gram-positive bacteria, yet reduced toxicity against the eukaryotic fungal cell lines tested. Moreover, based on an alkaline phosphatase (ALP) assay, it appears that the altered antimicrobial actions of some of these unique variants may be due to changes in the permeability of the cell envelope, resulting in the leakage of intracellular proteins. A manuscript is being prepared to publish these exciting findings in a peer-reviewed scientific journal. Our current work is focused on testing additional poorly-explored medicinal plants, as well as designing and synthesizing new variants of bioactive molecules in the hopes of discovering new, more effective drugs.

Biographical Information about Author(s)

We are a group of undergraduate biology students working in the lab of Dr. Orozco-Nunnelly. Our research focuses on testing plant extracts against various bacteria and fungi of interest to identify novel antimicrobial compounds. The research process involves macerating plant material, incubating it with a solvent (usually hexane or methanol), purifying the extract, and testing it using an antimicrobial disc diffusion assay against over a dozen unique prokaryotic and eukaryotic cell lines. Our lab partners with Dr. Pruet's organic chemistry lab to help analyze the compounds within the plant extracts and to produce derivative compounds based on specific phytocompounds we have previously identified.

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