In the HMBC spectral data. the assignment of c-8 was obtained by correltions between 5-oH. c-6, and
c-10 :and H-6 / c-5 and c-8 .In addition, the proton signal of H-11 correlated with c-12 , c-7 , and
c-9, the proton of H-12 correlated with c-8 ,c-11 and c-1 , while H-1 correlated with c-12. thus, the double bond was located at c-8, and the rhamnosyl