Cheng, Yi-Qiang2021-12-202021-12-202021-08https://hdl.handle.net/20.500.12503/30780This project aimed to explore a new approach to microbial natural product discovery through collection of soil samples from strategically determined geographic sites in the State of Texas. Morphologically distinctive bacterial and fungal isolates were obtained from the soil samples and a pilot-size, semi-fractionated natural product library was constructed and screened for cytotoxicity against human cancer cell lines. Subsequently, activity-guided purification and structural identification were performed to characterize naturally occurring bioactive small molecules. Through a pilot fungal-derived natural product study, the library construction methodology was validated and known cytotoxic compounds malformin, palmitic acid, aspergillin PZ, and trichoderone B were isolated and re-identified. Their structural data and previously unknown cytotoxicity against various cancer cell lines were studied and are reported herein.application/pdfenmicrobial natural productsdrug discoverynatural product libraryBiological Products / therapeutic useNeoplasms / drug therapyFungi / isolation and purificationDrug Discovery / methodsThesis