552 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
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* | DD | ORGANIC COMPOUNDS (Class 532, subclass 1) {11} |
271 | DF | .~ Polycyclo ring system containing anthracene configured ring system having at least one double bond between ring members and having oxygen single bonded or any atom double bonded direct at the 9- or 10-position (e.g., anthrones, anthranois, etc.) {10} |
274 |  | .~.~ The polycyclo ring system is attached indirectly by nonionic bonding to an additional polycyclo ring system having a least three cyclos (e.g., plural anthracene configured ring systems bonded directly to the same nitrogen, etc.) |