23402-09-7 Brevianamide A NSC208423 Spiro[5H,6H-5a,9a-(iminomethano)-1H-cyclopent[f]indolizine-7(8H),2'-[2H]indole]-3',5,10(1'H)-trione, 2,3,8a,9-tetrahydro-8,8-dimethyl-