Amaranzoles B−F, Imidazole-2-carboxy Steroids from the Marine Sponge Phorbas amaranthus. C24-N- and C24-O-Analogues from a Divergent Oxidative Biosynthesis
摘要:
Five new steroidal imidazoles, amaranzoles B-F, were isolated from extracts of the marine sponge Phorbas amaranthus along with the known amaranzole A. The C24-N-(4-p-hydroxyphenyl)imidazol-5-yl constitution found in amaranzoles A, C, and D is replaced by a C24-O-(4-p-hydroxyphenyl)imidazole-2-carboxylate motif in amaranzoles B, E, and F. The structures were elucidated by interpretation of spectroscopic data. The C24 side chain configuration was assigned by synthesis of a model ester followed by chiroptical comparisons of its CD spectrum with that of an amaranzole B derivative.
Amaranzoles B−F, Imidazole-2-carboxy Steroids from the Marine Sponge Phorbas amaranthus. C24-N- and C24-O-Analogues from a Divergent Oxidative Biosynthesis
摘要:
Five new steroidal imidazoles, amaranzoles B-F, were isolated from extracts of the marine sponge Phorbas amaranthus along with the known amaranzole A. The C24-N-(4-p-hydroxyphenyl)imidazol-5-yl constitution found in amaranzoles A, C, and D is replaced by a C24-O-(4-p-hydroxyphenyl)imidazole-2-carboxylate motif in amaranzoles B, E, and F. The structures were elucidated by interpretation of spectroscopic data. The C24 side chain configuration was assigned by synthesis of a model ester followed by chiroptical comparisons of its CD spectrum with that of an amaranzole B derivative.
Amaranzoles B−F, Imidazole-2-carboxy Steroids from the Marine Sponge <i>Phorbas amaranthus</i>. C24-<i>N</i>- and C24-<i>O</i>-Analogues from a Divergent Oxidative Biosynthesis
作者:Brandon I. Morinaka、Joseph R. Pawlik、Tadeusz F. Molinski
DOI:10.1021/jo1000324
日期:2010.4.16
Five new steroidal imidazoles, amaranzoles B-F, were isolated from extracts of the marine sponge Phorbas amaranthus along with the known amaranzole A. The C24-N-(4-p-hydroxyphenyl)imidazol-5-yl constitution found in amaranzoles A, C, and D is replaced by a C24-O-(4-p-hydroxyphenyl)imidazole-2-carboxylate motif in amaranzoles B, E, and F. The structures were elucidated by interpretation of spectroscopic data. The C24 side chain configuration was assigned by synthesis of a model ester followed by chiroptical comparisons of its CD spectrum with that of an amaranzole B derivative.