In our previous work on the biosynthesis of Veratrwn alkaloids,it was found that solanidine (V) that accumulated in the etiolated Veratrum was converted to jervine and veratramine under illuminated cultivation with white light. 1 This evidence suggests the participation of light on the reaction of C-nor-D-homo rearrangement in the biosynthesis of Veratrum alkaloids and further possibility of the detection of intermediates in the process of C-nor-D-home rearrangement from solanidine by a definite condition of illumination. In our detailed experiments on steroidal alkaloids which accumulate particularly in illuminated plants but not found in etiolated plants, two new cevanine alkaloids, shinonomenine (Ia) and veraflorizine (IIa) were isolated from the tertiary base fraction of rhizome of Veratrwn grandiflorwn (Max.) Loesen that was cultivated under illuminated condition, red fluorescent light, maximum energy at 660 nm, for 4 days, and a new cevanidane alkaloid, procevine (IIIa) was isolated from the aerial part of the Veratrum plant that was cultivated under sunlight lamp, maximum 30,000 lux, for 2 days, and procevine (IIIa) was accompanied with isorubijervine (IV) from this plant. Shinonomenine (Ia), named after the Japanese name for the Veratrum plant shinonomes8, C27H430N, mp 95-96O, [olD -90.7" (c 0.33, CHC13), MS: m/e 397 (M+) and 112 (base peak), PMR: 6 1.04 (3H, s, 19-Me), 0.84 and 1.12 (3H each, d, J = 6 Hz, 21 and 27-Me), 6 3.52 (lH, m, 3a-H, this signal shifted downfield to 6 4.60 on acetylation), d 5.42 (vinyl proton at C-6), Ib : R=Ac I Ib : R=Ac