Rhazya stricta, -strictosidine

Isolation of the stereospecific strictosidine s)mthase (STS) and formation of strictosidine with the 3a-(S) configuration proved conclusively that this was the natural precursor of the terpenoid indole alkaloids. Strictosidine occurs naturally in Rhazya stricta and the synthase has been isolated from a number of other species Amsonia salicifolia, A. tabemaemontam, Catharanthus pusillus, C. roseus, Rauvolfia verticillata, R. vomitoria, R. serpentina, Rhazya orientalis and Voacanga africana. The enzyme has been purified to homogeneity from R. serpentina (Hampp and Zenk, 1988). A comparison of the activity of STS from C. roseus roots, the only portion of the plant to contain ajmalicine, with that present in plant cell cultures producing the same alkaloid demonstrated that the plant cell cultures are far more metabolically active (Ziegler and Facchini, 2008). 

Macro-isolation and radiochemical dilution analysis based upon the incorporation of [5- H]loganin proved that both vincoside and isovincoside are present in Vinca rosea plants, and N-acetylvincoside was also isolated. Independently and simultaneously with the above work, strictosidine was isolated from Rhazya stricta, was proved to be present by dilution analysis in... 

The isolation and characterisation of vincoside " (39a), isovincoside " (39b), and N(4)-acetylvincoside from Vinca rosea, and of strictosidine [same overall structure as (39) but not yet stereochemically defined] from Rhazya stricta, have certainly provided the most exciting and significant new structures in this... 

Studies on strictosamide (27a) from Rhazya stricta (which may be an artefact for it is formed from strictosidine under mild conditions) and vincoside lactam (27b) have also been adduced in support of the revised formulations. 

Strictosidine (104) is produced by the plant Rhazya stricta. A crude enzyme preparation from the plant was used to produce labelled strictosidine this, when incubated with Catharanthus enzyme, again gave the three alkaloids (105), (106), and (107). ° Cell-free preparations of cell-suspension cultures of Amsonia tabernaemontana, Rhazya orientalis, and Vinca minor were also observed to convert (102) plus (103) into strictosidine (104) with fair efficiency the formation of vincoside (109) was never observed. ... 

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