The revised structures of luteoskyrin,rubroskyrin and rugulosin

✍ Scribed by Shoji Shibata; Yukic Ogihara; Nobuko Kobayashi; Shujiro Seo; Isao Kitagawa

• Publisher: Elsevier Science
• Year: 1968
• Tongue: French
• Weight: 345 KB
• Volume: 9
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)89582-9

✦ Synopsis

In our earlier studies (1), we proposed to formulate (-) luteoskyrin, C30H22012,m.p. 281°(decomp.),[q/D -880'. a hepatotoxic yellow pigment of Penicillium islandicum Soap (NRRL 1036, UD and E strains) as (I), and (+)rugulosin, C30H22010,m.p. 290°(decomp.),1dD +492*, a yellow pigment isolated from P,. rugulosum Thorn and some other fungi as (II). The formulations were based mainly on the negative quinonic colour reactions, the formation of bianthraquinones, iridoskyrin (III) and dianhydrorugulosin(IV), respectively, by dehydration reaction, and the IR snectra showing chelated carbonyl (1620 cm-') in luteoskyrin an3 rugulosin, and non-chelated carbonyl (1690 cm") in rugulosin. The nresence of phenolic or enolic hydroxyls and alcoholic hydroxyls in the both nigments was proved by the IR spectral absorptions of acetate carbonyl at 1773 and 1751 cm", respectively in 0-hexaacetylrugulosin and 0-octaacetylluteoskyrin. The NMR spectral analysis which was not available at the time of the earlier investigation has now been performed to reexamine the structures of the above compounds. The NMR(in d6-DMSO) signals of aromatic methyls ((R)** 2.42t;(L)***2.28J), nhenolic hydroxyls ((R)ll.37J;(L)l1.28J,l2.38Q, enolic hydroxyls ((R)l4.546;(L)l4.53J) and aromatic orotons ((R)7.16J(d),7.43r(d): (L)7.28&(s)) of the both compounds agreed well with the aromatic cart of the * Present address: Faculty of Pharmaceutical Sciences, Osaka University.