| 552 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, subclass 1) {11} |
| 502 | DF | .~ Cyclopentanohydrophenanthrene ring system containing {21} |
| 540 | DF | .~.~ Carbon bonded directly at the 17 beta-position of the cyclopentanohydrophenanthrene ring system is a member of an acyclic chain of six or more uninterrupted carbons (e.g., sterols, etc.) {4} |
| 542 | ![]() | .~.~.~ Oxygen bonded directly at the 6- or 7-position |