Amaryllidaceae and Sceletium alkaloids

Chapter 3 Chemical and Biological Aspects of Narcissus Alkaloids

“…Thus, in those alkaloids in which the two-carbon bridge (C-11 and C-12) is cis to the substituent at C-3, H-1 shows an allylic coupling with H-3 (J 1,3 �1-2 Hz) and H-2 shows a smaller coupling with H-3 (J 2,3 �0-1.5 Hz), as it occurs in crinamine (57). The alkaloids of the Narcissus genus are exclusively of the hemanthamine type, while in genera such as Brunsvigia, Boophane, etc., the crinine type alkaloids are predominant.…”

“…The history of the Amaryllidaceae alkaloids, their structural elucidation, and their biological profiles, as well as their synthesis, have been summarized on several occasions (20,33,(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48) which, together with the regular publications in the journal Natural Product Reports (34,(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63)(64)(65)(66), represent a valuable source of information.…”

“…Hemanthamine (53), hemanthidine (55), crinamine (57), maritidine (44), and papyramine (48) display pronounced cell growth inhibitory activities against a va riety of tumor cells, such as Rauscher viral leukemia, Molt 4 lymphoma, BL6 mouse melanoma, HepG2 human hepatoma, HeLa, LNCaP human prostate cancer, or HT (298,336,341,424,462,463,500). Some of these alkaloids, namely crinamine, hema nthamine, and papyramine, also present a cytotoxic effect against non-tumoral fib roblastic LMTK cells (463).…”

Biosynthesis and Biological Activities of Newly Discovered Amaryllidaceae Alkaloids

“…To date, more than 650 AAs have been reported, and their chemical library is still expanding [1,[12][13][14][15][16][17][18][19][20][21][22][23][24]. Although diverse in structure, this plethora of AAs are categorized together as they share a common initial synthesis pathway.…”

“…Among the six new galantamine-type alkaloids only 9-de-O-methyl-11β-hydroxygalantamine (13) showed a weak AChE inhibitory activity with IC 50 value 168.7 µM. The SAR of new galantamine derivatives alkaloids (11)(12)(13)(14)(15)(16) and known alkaloids isolated from the same plant species revealed that the 4,4a double bond and 9-OH are required for the AChE inhibitory activity, while the presence of the 11-OH group dramatically decreases AChE inhibitory activity [66].…”