Natural products chemistry. Part 124. Revised structure and synthesis of a new acridone alkaloid, hallacridone from Ruta graveolens tissue cultures

Secondary metabolites produced by callus cultures of various Ruta species

“…Gravacridonol was detected in callus of R. bracteosa and R. macrophylla. 1-Hydroxy-3-methoxy-N-methyl-acridone has been previously isolated from various Rutaceae species [11] including Ruta graveolens tissue cultures [13]. We could show that this simple acridone alkaloid is also present in R. chalepensis callus cultures.…”

“…Rutacridone and its derivatives are the main alkaloids in the investigated cell lines. Recently [1,11] hallacridone was found in tissue cultures of R. graveolens. It is now documented that this acetylfuroacridone alkaloid is also synthesized in R. bracteosa, R. macrophylla and R. chalepensis.…”

Naturstoffchemie, 174. Mitt. [1]: Oxidation von Acronycin mit Kaliumpermanganat

“…Hierbei gilt besonderes Interesse den Epoxiden von Acronycin (1) und Rutacridon, sowie den entsprechenden Folgeprodukten nach Hydrolyse. In unserer Arbeitsgruppe [3], [4], [5], [6] ftihrten umfangreiche Oxidationsversuche unter anderem zu dem aus Ruta graveolens isolierten Naturstoff Rutagravin [7], sowie zu einem potentiellen Naturstoff Dihydrohallacridon [8], vermutlich eine biosynthetische Vorstufe von Hallacridon [9]. Die Synthese von Dihydrohallacridon und Rutagravin erfolgte durch Oxidation von Rutacridon mit Kaliumpermanganat [4].…”

Biosynthesis of acridone alkaloids formation of rutacridone by cell‐free extracts of Ruta graveolens cell suspension cultures

“…The anthranilic acid-derived acridones and furoquinolines occur frequently concomitantly in various rutaceous species. A number of furoacridones including rutacridone (7) has been found in Ruta graveolens L. Their possible biosynthetic relationship was recently discussed [1].…”