Tetrahedron, vol: 58,32 (2002)
New polyoxygenated steroids exhibiting reversal of multidrug resistance from the gorgonian Isis hippuris
Tanaka J., Trianto A., Musman M., Issa H.H., Ohtani I.I., Ichiba T., Higa T., Yoshida W.Y., Scheuer P.J.
Abstract
Eleven new (5-15) and one known (4) polyoxygenated steroids have been isolated from two collections of the gorgonian Isis hippuris and their structures determined by spectroscopic analysis and X-ray diffraction study. Except for 15 all others were polyoxygenated gorgosterols. X-Ray study of the previously reported compound 4 demonstrated the stereochemistry of the side chain moiety to be identical with that of gorgosterol. Compound 15 was a deacetyl derivative of the known steroid 16 having a spiroketal and a lactone function. The stereochemistry of 15 was confirmed by X-ray analysis, which also established the C-22 configuration of 16 which had remained unsolved. These compounds have been tested for reversal of multidrug resistance (MDR) with cancer cells expressing P-glycoprotein (P-gp). Some of them showed moderate activity. © 2002 Elsevier Science Ltd. All rights reserved.
Keyword: Gorgosterols; Hippuristanols; Octocoral; X-ray analysis