A novel triamino monoterpene indole alkaloid with an unprecedented skeleton, gelstriamine A (1), four new monoterpene indole alkaloids (2−5), and 12 known analogues (6−17) were isolated from Gelsemium elegans. The structures of 1−5 were established using extensive spectroscopic techniques, NMR calculations with iJ/dJ-DP4 and 2D C−H COSY ANNs analysis, ECD calculations, chemical methods, and single crystal Xray diffraction analysis. Gelstriamine A (1) possesses an unprecedented 6/5/7/6/6/5 heterohexacyclic scaffold bearing a unique hexahydrooxazolo[4,5-b]pyridin-2(3H)-one motif, and a plausible biosynthetic pathway was proposed. All the isolated alkaloids 1−17 showed discernible analgesic activities in an acetic acidinduced writhing test in mice, and N-desmethoxyhumantenine N 4 -oxide (3) exhibited more potent analgesic activities than those of morphine at doses of 0.04 and 0.2 mg/kg.