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Sandra Loesgen with Cassandra Lew holding beakers in their lab

From dirt to drugs

By Srila Nayak

Sandra Loesgen with Cassandra Lew

Chemist Sandra Loesgen’s lab researches the discovery and evaluation of natural products that can be developed into drugs.

Loesgen, an assistant professor of chemistry, mentors and leads a group of student researchers who investigate and develop new screening techniques to better understand the antibiotic, anti-tumor and anti-viral activity found in metabolites produced by fungi and bacteria.

“Drugs from dirt is a big theme in the community,” says Loesgen, whose students investigate microbes from soil samples found in diverse locales, ranging from Oregon to Africa. “We have some microbes from OSU’s Memorial Union that might be interesting in the future.”

Cassandra Lew, a junior chemistry major and research assistant in Loesgen’s lab, uses many instrumentation and spectroscopic techniques to isolate and study pathogens in soil samples from Bend, Oregon, in order to determine their cytotoxicity, or how toxic they are to cells, and their antibiotic properties.

Her research experiences have deepened her love for science and she plans to pursue a Ph.D. in organic chemistry to develop therapeutic applications. Lew is supported by a URISC scholarship (Undergraduate Research Innovation, Scholarship & Creativity).

Lew is assisting on a research project led by Loesgen that involves testing strains of abacteria and fungus against colon cancer cells. "We basically do an assay to see if the microbes kill the cells or not. I am specifically working with a strain right now that has killed cancer cells and trying to find the actual molecule that is killing the cancer cells," explains Lew.

Elizabeth Kaweesa in lab

Elizabeth Kaweesa, a first-year chemistry doctoral student

The newest member of Loesgen’s research team is Elizabeth Kaweesa, a first-year chemistry doctoral student. She grew up in a fishing village near Lake Victoria in Uganda, where she developed an early interest in medicine and healthcare.

Drawn to the Loesgen lab’s pioneering research in drug development, Kaweesa has rapidly established her niche—she is currently analyzing a bacterial strain that has shown potent cytotoxicity toward colon carcinoma cells. Her research focuses on screening bacteria isolated from soil samples collected from Mount Kilimanjaro in Tanzania for anticancer and antibacterial activity.