EFFICIENT SYNTHESIS OF INDOLACTAM-TYPE PKC ACTIVATORS

PROTEIN KINASE C (PKC) PLAYS A CRUCIAL ROLE IN SIGNAL TRANSDUCTION FOR A VARIETY OF BIOLOGICALLY ACTIVE SUBSTANCESTHAT ACTIVATE CELLULAR FUNCTIONS AND PROLIFERATION. SEVERALCLASSES OF NATURALLY OCCURRING COMPOUNDS, INCLUDING DIACYLGLYCEROLS, PHORBOL ESTERS, AND INDOLACTAMS, HAVE BEEN SHOWN TO ACTIVATE PKC. THE LAST-NAMED COMPOUNDS INCLUDE TELEOCIDIN B, LYNGBYATOXIN, AND INDOLACTAM V. SINCE NONE OF THESE ARE READILY AVAILABLE TO RESEARCHERS, THE STUDY OF THIS CLASS OF ACTIVATORS HAS NOT PROGRESSED AS RAPIDLY AS FOR THE OTHERS. THIS PROJECT WILL PROVIDE AN EFFICIENT SYNTHESIS OF A POTENT INDOLACTAM ACTIVATOR OF PKC. THIS IN TURN WILL PROVIDE THE RESEARCH COMMUNITY WITH A RELIABLE SOURCE OF THIS CLASS OF ACTIVATORS AT REASONABLE PRICES. THE PROJECT WILL ALSO DEVELOP A SUITABLE SUBSTRATE FOR THE PREPARATION OF A ((3)H)-LABELED INDOLACTAM ACTIVATOR OF VERY HIGH SPECIFIC ACTIVITY FOR USE IN RECEPTOR-BINDING STUDIES. THE EFFICIENT SYNTHESIS WILL PROVIDE A STARTING MATERIAL FOR FURTHER STRUCTURAL MODIFICATIONS THAT MAY LEAD TO NEW INDOLACTAM-BASED COMPOUNDS WITH ALTERED AND POSSIBLY USEFUL BIOLOGICAL PROPERTIES. THE EXCITATORY AMINO ACID (EAA) NEUROTRANSMITTERS, SUCH AS GLUTAMATE AND ASPARTATE, HAVE BEEN IMPLICATED IN THE PATHOLOGY OF A NUMBER OF NEUROLOGICAL DISORDERS, INCLUDING EPILEPSY, STROKE/ANOXIA, AND NEURODEGENERATIVE DISEASES. DRUGS THAT ANTAGONIZE EAA NEUROTRANSMISSION OFFER A NOVEL APPROACH TO TREATING THESE DISORDERS. THE GOAL OF THIS PROJECT IS TO ISOLATE NOVEL AND SPECIFIC GLUTAMATE RECEPTOR ANTAGONISTS FROM PREVIOUSLY UNCHARACTERIZED SPIDER VENOMS. SPIDERS ARE A GOOD POTENTIALSOURCE OF THERAPEUTICALLY USEFUL EAA RECEPTOR ANTAGONISTS BECAUSE THEIR VENOMS CONTAIN ANTAGONISTS OF THE GLUTAMATE RECEPTOR OF THE NEUROMUSCULAR JUNCTION OF THEIR INSECT PREY. PREVIOUS STUDIES SUGGEST THAT MANY SPIDER VENOMS CONTAIN ANTAGONISTS OF MAMMALIAN EAA RECEPTORS. IN PHASE I, SIX SPIDER VENOMS WILL BE FRACTIONATED BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND SCREENED FOR NEUROACTIVE COMPONENTS. NEXT, THE MECHANISM OF ACTION OF THE ACTIVE COMPONENTS WILL BE DETERMINED USING ELECTROPHYSIOLOGICAL AND RECEPTOR-BINDING ASSAYS AS WELL AS AN IN VITRO EXCITOTOXICITY ASSAY. FINALLY, PRELIMINARY STRUCTURE ANALYSES WILL BE PERFORMED OF THOSE COMPOUNDS THATAPPEAR TO BE EAA RECEPTOR ANTAGONISTS. IN PHASE II, THE COMPLETE CHEMICAL STRUCTURE AND CHEMICAL SYNTHESIS ROUTE OF PROMISING COMPOUNDS WILL BE DETERMINED, AND FURTHER STUDIES OF THEIR IN VIVO EFFICACY, TOXIC EFFECTS, AND BIOAVAILABILITY WILL BE PERFORMED.