Zum Bufadienolidmuster der roten „Meerzwiebel”¹

Abstract

Red coloured bulbs of plants of the Urginea maritima aggregate from the northern and southern Mediterranean area were shown to exhibit different bufadienolide compositions. Therefore, the bufadienolide complex of “red squill” samples from Tunesia and from Sardegna was investigated. Twelve bufadienolides were isolated from bulbs of tetraploid squill from Tunesia, sixteen from tetraploid samples from Sardegna. The Compounds were identified by means of FAB-MS, ¹H-NMR, and ¹³C-NMR studies or comparison with authentic substances. Both of the samples contained scilliroside (14), scillarenin 3-O-β-D-glucoside (2), proscillaridin A (1), scilliphaeosidin 3-O-β-D-glucoside (5), scilliglaucoside (17), scilliphaeoside (4), and 12-epi-scilliphaeoside (7); the bulbs from Tunesia contained additionally glucoscilliphaeoside (6) and the four new bufadienolides 12-epi-glucoscilliphaeoside (10), 12β-hydroxyscilliglaucosidin 3-O-β-D-glucoside (21), 12-epi-scilliphaeosidin 3-O-β-D-glucoside (8), and 12-epi-scilliphaeosidin 3-O-α-L-rhamnosido-α-L-rhamnoside (9). In the bulbs from Sardegna scülaren A (3), gamabufotalin 3-O-α-L-rhamnoside (20), scilliglaucoside (17), scillirubrosidin 3-O-α-L-rhamnoside (11), scillirubroside (12), 12β-hydroxyscilliroside (15), 5α-4,5-dihydroscillirosidin 3-O-α-L-thevetosido-β-D-glucoside (19), and deacetyl-scilliroside (8) besides the new Compounds 10-carb-oxy-5β,14β-dihydroxybufa-3,20,22-trienolide 5-O-β-D-glucoside (18) and scilliglaucogenin (16) were found in addition. Not only quantitative but even qualitative differences in the bufadienolide pattern between the samples of the northern and the southern Mediterranean area were proved. By now it is not clear whether the investigated samples belong to different chemodemes of Urginea numidica or are two different species of the Urginea maritima aggregate.

Key words

Urginea maritima aggregate - Urginea numidica (Jord. & Fourr.) Grey - Hyacinthaceae - bufadienolides - cardiac glycosides