By the NOE method using13C NMR and UV spectra we have confirmed the structures of four new alkaloids isolated previously: 10-hydroxycanthin-6-one (ervine), 10-methoxycanthine-6-one (methylervine), 10-β-D-glucopyranosyloxycanthin-6-one (ervoside), and 6-methoxy-β-carbolin-l-ylpropionic acid (ervolanine). © 1992 Plenum Publishing Corporation.