The structure of the spermine alkaloid aphelandrine from Aphelandra squarrosa NEES The new spermine alkaloid aphelandrine (2) has been isolated from Aphelandra squarrosa NEES. By oxidation of 2 with KMnO4 followed by methylation (CH2N2) 12 and 14 could be prepared (Scheme 2). Fusion of 2 with KOH yielded spermine (1) whereas hydrolysis of 2 in hot hydrochloric acid results in lacton 17, the structure of which could be elucidated by comparison with a synthetically prepared model compound (Scheme 3). The benzylic bonds N (10), C(11) as well as O(16), C(17) of 2 could be cleaved by hydrogenolysis (compare 23 and 26; Scheme 4). The elucidation of the correct linkage of the spermine moiety with the aromatic dicarboxylic acid is based mainly on chemical and spectroscopic evidence of the tetrahydro derivative 26, the Hofmann‐degradation products 28, 30 and 31 (Scheme 6) as well as the ester 35, prepared by partial hydrolysis of 2 (Scheme 7). Copyright © 1978 Verlag GmbH & Co. KGaA, Weinheim