The whole plants of Solanum nigrum L. have been used traditionally2) as a remedy for various cancers in the Shanghai region of China. We analyzed the constituents of the immature fruits of this plant and found the steroidal glycosides, SN-O, SN-1, SN-4 together with SN-2 (solamargine) and SN-3 (solasonine).3) Now, we have isolated six components, SN-a - f (1 - 6), from the uncrushed berries immersed in cold MeOH for two years. Five of them have been shown to be the steroidal alkaloids oxidized selectively at C-12 and/or C-27. These are derived from solamargine and solasonine, probably by the reactions of included enzymes. Here we deals with the structural characterizations of SN-a - f (1 - 6).