The aqueous MeOH extract of the leaves and root of Xanthocercis zambesiaca (Leguminosae) and eight structurally related nitrogen-containing sugars, fagomine (1), 4-O-beta-D-glucopyranosylfagomine (2), 3-O-beta-D-glucopyranosylfagomine (3), 3-epifagomine (4), 2,5-dideoxy-2,5-imino-D-mannitol (5),