The production of sesquiterpene-type phytoalexins with a vetispyradiene skeleton by Hyoscyamus albus hairy roots induced by methyl jasmonate (MeJA) was reported in a previous paper. The production pattern on co-treatment with cupper sulfate and MeJA (CuSO₄–MeJA) showed a TLC profile differing from that on treatment with MeJA. Thus, we studied the production of phytoalexins on hairy root culture involving co-treatment with CuSO₄–MeJA. In the experiment, many sesquiterpene-type phytoalexins with a vetispyradiene skeleton were isolated, most of which were different from the products reported in the previous paper. Here, we isolated four new phytoalexins (1—4) along with known compounds 5—10 from the culture medium of H. albus hairy roots co-treated with MeJA–CuSO₄. The structures of the new compounds (1—4) were determined as: (3R,4S,5R,7S,9R)-3-acetoxy-9-(2-methylpropionyloxy)solavetivone (1), (3R,4S,5R,7S,9R)-3-hydroxy-9-(3-methylbutanoyloxy)solavetivone (2), (3R,4S,5R,7S,9R)-3-acetoxy-9-(3-methyl-butanoyloxy)solavetivone (3), and (3R,4S,5R,7S,9R)-3-acetoxy-9-(3-methyl-2-butenoyloxy)-solavetivone (4) based on MS and NMR including 2D-NMR data. These findings indicated that the production of phytoalexins in H. albus hairy roots yielded different products based on treatment with different chemicals (CuSO₄, MeJA, and MeJA–CuSO₄).