Two New Hydronaphthoquinones from Sinningia aggregata (Gesneriaceae) and Cytotoxic Activity of Aggregatin D

Abstract Two new hydronaphthoquinones, aggregatins E and F ( 1 and 2 , resp.) were isolated from the tubers of Sinningia aggregata ( Ker‐Gawl .) Wiehler (Gesneriaceae), along with twelve known compounds aggregatin D ( 3 ), tectoquinone ( 4 ), 1‐hydroxy‐2‐methylanthraquinone ( 5 ), icosyl ferulate ( 6 ), pustuline ( 7 ), 1,6‐dihydroxy‐2‐methylanthranquinone ( 8 ), 6‐hydroxy‐2‐methylanthraquinone ( 9 ), 7‐hydroxy‐2‐methylanthraquinone ( 10 ), tyrosol ( 11 ), halleridone ( 12 ), calceolarioside B ( 13 ), and cornoside ( 14 ). All compounds were identified by analysis of spectroscopic and spectrometric data. Compounds 3, 4 , and 10 had already been reported in this species. Compounds 2 and 3 were evaluated against several tumor cell lines, but only 3 exhibited activities against UACC‐62, 786‐0 and OVCAR‐3 cell lines, with IC 50 values of 12.3, 12.8 and 0.3 μg/ml, respectively, without toxic effects on non‐cancer cell line HaCat (human keratinocyte).