Figure 1: Two-dimensional structure of alkaloids used in this study (a) nitidine (b) magnoflurine (c) toddaline (d) toddaquinoline (e) toddasin (f) toddanol (g) toddanone (h) toddalenone (i) flindersine (j) toddacoumalone (k) toddacoumaquinone and (l) toddalenol