.beta.-Longilobine 12,18-Dihydroxy-senecionan-11,16-dione 480-54-6 Longilobine NSC107659 RETRORSINE Retrorsin Retrosine Senecionan-11,16-dione, 12,18-dihydroxy- WLN: T55-12- 1A Q EN IOVY OVO BUTJ KU2 M1 NQ N1Q cis-Retronecic acid ester of retronecine