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Tingenone, an unusual new quinonoid triterpene related to celastrol and pristimerin, has been isolated from various plants of the Cetastraceae and Hippocrateaceae families. It has been shown to be 20-decarboxy-21 -oxocelastrol by chemical and spectroscopic methods.WE have previously reported I-4 the isolation, from various plants of the Celastraceae and Hippocrateaceae families, of a bright red pigment with antitumour activity, named maitenin.t Maitenin was shown to be a quinonoid triterpene related to pristimerin (1) and celastrol (2), found previously in other Celastraceae,6-8 and a partial structure (3) was p r~p o s e d .~ Subsequently maitenin, m.p. 228-2229", was found to be identical with tingenone, m.p. 182--183', an orange pigment from Euonymus tingens, to which an incorrect structure had been previously assigned.lo The difference in m.p., despite identical spectroscopic properties, was attributed to retention of solvent, and the problem posed by this observation was overcome by the preparation of two derivatives (a leucodiacetate and a toluene-9-thiol adduct) from each pigment; the products were identical on the basis of spectroscopic parameters, m.p., and mixed m.p.We now report chemical studies which establish that the ketone group in structure (3) is at C-21. Reduction of tingenone with sodium borohydride, followed by acetylation, yielded tri-0-acetyltingenol (4) and di-0t The name Maitenin should not be confused with Maytenin, an alkaloid from Mayteizzts chztchuhuasca.5 0. Gmqalves de Lima, I

Neben den bekannten Cumarinen Xanthyletin und seinem 3‐(0:,oz‐Dimethyl‐allyh‐Derivat wurden aus Hortia arborea drei weitere Cumarine isoliert.

Während Isocordoin (2′,4′‐Dihydroxy‐3′‐(7,7‐dimethylallyl)‐chalcon) in Eisessig/ H2SO4 zwei isomere Chromanchalcone vom Typ (II) liefert, ergibt Cordoin(I) unter gleichen Bedingungen neben drei Isomeren vom Typ (II) auch ein Dichroman‐chalcon (III).

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