Isolation of 4‐Hydroxy‐5‐methoxycanthin‐6‐one from Picrasma quassioides and Revision of a Previously Reported Structure

Abstract

<jats:title>Abstract</jats:title><jats:p>A new alkaloid, 4‐hydroxy‐5‐methoxycanthin‐6‐one (<jats:bold>1</jats:bold>), has been isolated from <jats:italic>Picrasma quassioides</jats:italic> (Simaroubaceae), and its structure has been determined by high‐field <jats:sup>1</jats:sup>H‐ and <jats:sup>13</jats:sup>C‐NMR, <jats:sup>13</jats:sup>C,<jats:sup>1</jats:sup>H‐HETCOR, <jats:sup>1</jats:sup>H,<jats:sup>1</jats:sup>H‐2D‐COSY, and NOE‐difference spectra. Previous data, interpreted by other workers as being from this compound, is instead tentatively reassigned to another new alkaloid structure, 4‐hydroxy‐3‐methylcanthine‐5,6‐dione (<jats:bold>2</jats:bold>).