Compound W2 absorbs at λ max (MeOH) 267, 350 nm, the NaOMe spectrum exhibited a bathochromic shift of + 49 nm (table 4)
indicated the presence of 4`
-OH and absence of 3-OH. The results of UV shift and 1H-NMR elucidate the structure feature of
compound w2 in (figure: 2).