(3S,6S,9S,15aR)-9-((S)-sec-butyl)-3-(6-hydroxyoctyl)-6-((1-methoxy-1H-indol-3-yl)methyl)octahydro-2H-pyrido[1,2-a][1,4,7,10]tetraazacyclododecine-1,4,7,10(3H,12H)-tetraone