Grandisines C-G, indolizidine alkaloids from the Australian rainforest tree Elaeocarpus grandis.
Five new indolizidine alkaloids, grandisines C, D, E, F, and G (4-8), and one known indolizidine alkaloid, (-)-isoelaeocarpiline (3), were isolated from the leaves of Elaeocarpus grandis and their structures determined by 1D and 2D NMR spectroscopy. Grandisine C (4) is isomeric with the known compound rudrakine (1). The absolute configuration of grandisine D (5) was deduced by its conversion to (-)-isoelaeocarpiline. Grandisine E (6) contains a novel tetracyclic ring system. Grandisine F (7) is the 14-amino analogue of grandisine C. Grandisine G (8) contains the novel combination of a piperidine attached to an indolizidine. Grandisines C, D, F, and G and (-)-isoelaeocarpiline showed receptor binding affinity for the human delta-opioid receptor with IC(50) values of 14.6, 1.65, 1.55, 75.4, and 9.9 microM, respectively.
Katavic
Peter L
PL
Natural Product Discovery, Eskitis Institute, Griffith University, Brisbane, Queensland, Australia 4111.
Venables
Debra A
DA
Forster
Paul I
PI
Guymer
Gordon
G
Carroll
Anthony R
AR
D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001315:Australia; D045467:Elaeocarpaceae / Q000737:chemistry*; D006801:Humans; D007212:Indolizines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D011957:Receptors, Opioid / Q000187:drug effects*; D014197:Trees / Q000737:chemistry*
D000470:Alkaloids; D007212:Indolizines; D011725:Pyridines; D011957:Receptors, Opioid; C581928:grandisine G