Three secoiridoid glucosides from Ligustrum japonicum

Studies on the Constituents of Syringa Species. X. Five New Iridoid Glycosides from the Leaves of Syringa reticulata (BLUME) HARA.

“…From a biosynthetic point of view, it is interesting to note that (8Z)-oleoside-type secoiridoid was isolated from a natural source. Previous biosynthetic investigations (bold lines) of (8E)-oleoside-type secoiridoid reported by Inouye et al 13,14) and our structural studies described above presume that these type secoiridoids are biosynthesized by the route depicted in Fig. 4.…”

Phenylethanoid and secoiridoid glycosides from the leaves of Ligustrum purpurascens

“…In addition to the above assigned signals, there were three carbonyl groups (d C 175.6, 174.1 and 170.0) in 16. Comparison of NMR data of 16 with those of Ligustaloside B (Inoue et al, 1982) revealed that the signals of the two compounds were very similar, except for the absence of the aldehydic proton and the methoxy group in 16, suggesting that the structure of 16 possessed carboxyl groups at C-10 and C-11. With the aid of 2D NMR experiments, all of the 1 H and 13 C NMR signals of 16 were assigned ( Table 2).…”

Secoiridoid glucosides with free radical scavenging activity from the leaves of Syringa dilatata

“…A portion (38.6 mg) of fraction D2 (between 36 and 51 mL; 60 mg) was subjected to HPLC (a gradient from 20 to 35% CH 3 CN in H 2 O over 35 min, then 100% CH 3 CN for 10 min) to yield syringopicroside ( 2 ; t r 19.96 min; 6.0 mg; w/w% = 0.23) and oleuropein ( 3 ; t r 21.29 min; 5.0 mg; w/w% = 0.19). The structures of 1 (Damtoft et al , 1992) and 3 (Inoue et al , 1982) C-, and 2D-NMR data. Although 2 was previously isolated from S. vulgaris L. (Asaka et al , 1970), its NMR spectroscopic data have not been reported to our knowledge.…”