Xenobe Research Institute

Laetirobin

Isolation efforts launched in 2006 have identified a novel natural product from specimens of Laetiporus sulphureus growing parasitically on Robina psudoacacia. Our studies were appeared in late 2009 in the Journal of Natural Products (read it now). (+/-)-Laetirobin was isolated as a cytostatic lead from Laetiporus sulphureus growing parasitically on the black locust tree, Robinia pseudoacacia, by virtue of a reverse-immunoaffinity system. Using an LC/MS procedure, milligram quantities of (+/-)-laetirobin were obtained, and the structure of +/-)-laetirobin was elucidated by X-ray crystallography and confirmed by NMR spectroscopy. Preliminary cellular studies indicated that (+/-)-laetirobin rapidly enters in tumor cells, blocks cell division at a late stage of mitosis, and invokes apoptosis. Studies led by the Lear group (National University of Singapore) now provide an effective gram-scale total synthesis (read it now). These materials are now being used to probe the mechanism(s) in which (+/-)-laetirobin alters cell division and blocks tumor cell growth.