With the help of an SBIR grant (NCI R43CA128144-01A1) and in collaboration with Dr. Leslie Gunatilaka of the University of Arizona, Dr. Gunailaka has produced a newly available library of 25,000 samples – 5,000 natural product extracts and 20,000 fractions of these extracts. The natural product library was derived from Sonoran desert plants and associated microorganisms recently catalogued by the Southwest Center for Natural Product Research and Commercialization, at the University of Arizona.
The variety of plant species of the Sonoran desert is impressive. In Arizona alone there are over 3,430 recorded species of flowering plants, ferns, and fern allies in about 907 genera and 132 families. Approximately, 5% of these species are endemic to Arizona. Arizona is unique in the number of Cactus (family: Cactaceae) species. No other state except Texas can boast so many species of this highly specialized family. Twelve of the 71 species of Cacti are endemic to Arizona.
A significant characteristic of plants that grow in the Sonoran desert is their high photosynthetic capacity to produce a variety of secondary metabolites, often in large quantities, which are essential for the survival of these plants exposed to a harsh, hot, and dry environment. Thus, contained in plants of the Sonoran desert may be a wealth of pharmacologically important small molecule natural products. The library contains Sonoran desert plant and plant-associated fungal extracts and fractions derived from these extracts. These organisms are unique and the extracts derived from them have never been subjected to gene expression analysis for cancer therapeutics. The University of Arizona library consists of over 2000 plant (mostly above ground parts) and 3000 fungal extracts. Each plant extract is derived from an identified plant species. Thus, 2000 extracts represent 2000 plants collected in and around the Sonoran desert, extracted with procedures that tend to preserve bioactivity. In fact, two important compounds that inhibit HS90 (heat shock protein 90, implicated in cancer) have been discovered from this library. One is Radicicol and the other is Monocillim 1.
We used the library to find and develop a lead compound for Recurrent Prostate Cancer, NR067.