Streptocarpus dunnii

H. Inouye, S. Ueda, K. Inoue, H. Nayeshiro and N. Moritome, Biosynthesis of Prenylnaphthoquinones in cultured cells of Streptocarpus dunnii and Tabebuia argentea. Plant Tissue Culture, (1982) 375-376. 

Intact plants and cell cultures of Streptocarpus dunnii (Gesneriaceae) contain several 1,2-naphthoquinones with a reversed prenyl side chain, such as that in dunnione (66) (Fig. 6.16), l-Hydroxy-2-methylanthraquinone (67) and 1-hydroxy-2-(hydroxymethyl)anthraquinone (68) were also isolated from this culture. Administration of [1-carboxy- C]<9-succinylbenzoate revealed that was incorporated into the 1-position of dunnione and the 10-position of anthraquinones. These results, together with those of feeding experiments in which lawsone (41) and its 2-prenyl ether (69) were applied, suggested that dunnione (66) was formed by a Claisen-type rearrangement at the 2-position of 2-carboxy-4-oxotetralone (COT) (43), whereas anthraquinones were formed by prenylation at the 2-position of 2-carboxy-4-oxo-tetralone (COT) (43) or l,4-dihydroxy-2-naphthoic acid (40) (Inouye and Leistner, 1988). 

Biosynth. in Streptocarpus dunnii cell cultures. Yellow needles (MeOH aq.). Mp 69-70°. 

Biosynthesis of quinones of Streptocarpus dunnii cell cultures. J. Chem. Soc., Chem. Commun., 993-994. 

INOUYE. 1984. Biosynthesis of naphthoquinones and anthraquinones in Streptocarpus dunnii cell cultures. Phytochemistry 23 313-318. 

Stockigt, j., U. Srocka, and M.H. Zenk Structure and Biosynthesis of New Antra-quinone from Streptocarpus dunnii. Phytochemistry 12, 2389 (1973). 

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