Staurosporine (antibiotic AM-2282 or STS) is a natural product originally isolated in 1977 from the bacterium Streptomyces staurosporeus.

[3] The interest in these activities resulted in a large investigative effort in chemistry and biology and the discovery of the potential for anti-cancer treatment.

Tryptophan is converted to an imine by enzyme StaO which is an L-amino acid oxidase (that may be FAD dependent).

This is followed by a nucleophilic attack between the indole nitrogens resulting in cyclization and then decarboxylation assisted by StaC exclusively forming staurosporine aglycone or K252c.

The StaN enzyme reorients the sugar by attaching it to the 2nd indole nitrogen into an unfavored conformation to form intermediated O-demethyl-N-demethyl-staurosporine.

[8] When encapsulated in liposome nanoparticle, staurosporine is shown to suppress tumors in vivo in a mouse model without the toxic side effects which have prohibited its use as an anti-cancer drug with high apoptotic activity.

Researchers in UC San Diego Moores Cancer Center develop a platform technology of high drug-loading efficiency by manipulating the pH environment of the cells.