Studies in the biochemistry of micro-organisms

Abstract

A NUMBER of polyhydroxyanthraquinones, all of which are derivatives of 2methylanthraquinone, have been reported from these laboratories as metabolic products of different species of moulds. They are: helminthosporin, 4:5:8-trihydroxy-2-methylanthraquinone, from Helminthosporium gramineum Rabenhorst [

Xanthones and Oxepino[2, 3‐b]chromones from Three Endophytic Fungi

“…The two known anthraquinones citreorosein (4) [42] and emodin (5), [42] the known palmarumycine C 11 [43] (bipendenin) [44] (6), ergosterol, [47] and 5a,8a-epidioxyergosterol [48] were identified by comparison of their spectra with reported data. The co-occurrence of the ring-extended xanthones 1-3 with anthraquinones 4 and 5 is very interesting from a biosynthetic point of view; the latter compounds are putative precursors of xanthones.…”

“…We now report on the isolation of bioactive metabolites from the cultures of these productive fungi. Three new oxepinoA C H T U N G T R E N N U N G [2,3-b]chromen-6-ones (a very rare class of ring-enlarged xanthones), namely, microsphaeropsones A-C (1-3); a known oxepinoA C H T U N G T R E N N U N G [2,3-b]chromen-6-one, fusidienol A (8 a); [40,41] the new 3,4-dihydrofusidienol A (8 b); the two known anthraquinones citreorosein (4) [42] and emodin (5); [42] the known palmarumycine C 11 (6) [43] (bipendensin); [44] two known aromatic xanthones 9 a and 9 b; [45,46] and two new aromatic xanthones, namely, microxanthone (9 c) and seimatoxanthone A (10) were isolated in addition to the common fungal metabolites ergosterol and 5a,8a-epidioxyergosterol (Scheme 1 and 2). [47,48] A semisynthetic dihydrooxepinoA C H T U N G T R E N N U N G [2,3-b]chromen-6-one 7 was prepared by oxidation of the allylic alcohol 1 with manganese dioxide.…”

Synthesen von Emodinaldehyd [1] / Synthesis of Emodine Aldehyde [1]

“…[20]) zur Ermittlung des Substituentenmusters heranzuziehen. Im vorliegenden Fall lassen sich die chemischen Verschiebungen der aromatischen Protonen 2-, 4-, 5-und 7-H der Komponente 10, von denen 5-und 7-H mit 7(5,7) ~ 2,5 Hz als saubere Dubletts erscheinen und 2-sowie 4-H mit 7(2,4) ~ 1,6 Hz wegen der Fernkopplungen zu den Protonen im Substituenten an C-3 breitere Signale aufweisen, mit denen ihrer unblockierten Stammverbindungen, dem Citreorosein 11 [21,22] …”

Studies in the biochemistry of micro-organisms. 115. Metabolites of Penicillium frequentans Westling: isolation of sulochrin, asterric acid, (+)-bisdechlorogeodin and two new substituted anthraquinones, questin and questinol

“…229-231°, and the substance was later identified with teloschistin (Neelakantan, Rangaswami, Seshadri & Subramanian, 1951) and fallacinol (Murakami, 1956). All these melting points are well below that of questinol (280(282°), and the non-identity was confirmed by differences in the infrared-absorption spectrum between questinol and a sample prepared by Anslow et al (1940) and by the solubility of questinol in aqueous sodium carbonate. Questinol is therefore c-hydroxyquestin, or cohydroxyemodin 5-methyl ether (4,7-dihydroxy-2-hydroxymethyl-5-methoxyanthraquinone) (IX;…”

“…236-237°. The compound was also prepared by methylation ofhydroxyemodin with methyl iodide and sodium methoxide in methanol (Anslow, Breen & Raistrick, 1940): the authors record m.p. 229-231°, and the substance was later identified with teloschistin (Neelakantan, Rangaswami, Seshadri & Subramanian, 1951) and fallacinol (Murakami, 1956).…”