Two new C20-diterpenoid alkaloids named naviculine A (1) and naviculine B (2), were isolated from Aconitum naviculare STAPF. Their structures were established by spectral methods, especially 2D-NMR spectra ( 1H,1H-COSY, HMQC, HMBC, and NOESY) and DFT methods (at the B3LYP/6-311++ G(2d,p)//B3LYP/6-31G(d) level), respectively. They were assayed for their anti-HIV-1 activity. © 2008 Verlag Helvetica Chimica Acta AG.