Schelhammera pedunculata

The C-Homoerythrina alkaloids are a relatively recently identified group, the first examples being isolated and identified from Schelhammera pedunculata F. Muell. in 1968 (81). Homoerythrina alkaloids have been isolated from all three species of Schelhammera (Liliaceae), in which they constitute a further addition to the various biosynthetically related alkaloids within the family Liliacea (82-85)-, from the leaves of species of Phelline (Ilicacea), where their presence raises some doubts about the taxonomic classification of the genus (86-88)-, and from the roots and stems of species... 

Schelhammeridine.—Schelhammeridine (37), a major alkaloid of Schelhammera pedunculata, is structurally related to the Erythrina alkaloids, e.g. erythraline (38),... 

Five Homoerythrina alkaloids (3 R = Me, = H), (3 R + R = OCH2O), (3 R - R = Me), (4 R R = H, Me), and (4 R = R = Me) have been shown to co-occur with cephalotaxine (5 R = H) and its ester derivatives in Cephalotaxus harringtonia var. harringtoniaf The structures of the minor Homoerythrina alkaloids were established by spectroscopic studies and comparison with the known alkaloids (3 R = Me, R — H) and (3 R + R = OCHjO) which had been previously isolated from Schelhammera pedunculata and whose structures and absolute chemistry had been established. The co-occurrence of Homoerythrina and Cephalotaxus alkaloids makes it most attractive to propose that both types are derived from a common dienone (Scheme 1). An alternative biogenetic scheme for the formation of cephalotaxine (5 R = H) from an Erythrina precursor has been previously offered as speculation. Deoxyharringtonine (6), a new alkaloid with antileukemic activity of the same order of magnitude as the other known cephalotaxine alkaloids, has been... 

Johns SR, Kowala C, Lamberton JA, Sioumis AA, Wunderlich JA (1968) Homo-erythrina Alkaloids from Schelhammera pedunculata F.Muell. (Family Liliaceae). J Chem Soc Chem Commun 1102... 

The known Homoerythrina alkaloids B (3 R = Me, R = H) and E (3 R + R = OCHjO) have been isolated from Schelhammera undulata. These have been previously obtained from S. pedunculata and S. multiflora. 

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