STRUCTURE OF ACRIGNINE-A, THE FIRST NATURALLY OCCURRING ACRIDONOLIGNOID FROM CITRUS PLANTS

The chemical structure of acrignine-A (1), an acridone alkaloid carrying lignan moiety, from roots of Citrus plants (Rutaceae) have been elucidated by spectrometric studies using 1H-13C long-range COSY and NOE experiments. The structure was confirmed by single crystal X-ray analysis. This is the first example of an acridonolignoid isolated from natural sources.