oleuropein and loganin

We propose the cell culture approach to investigate oleuropein (1) biogenesis in Olea europaea L. We suggest employing olive callus cultures to identify the iridoidic precursor of oleuropein. In fact, we confirmed that callus cells from olive shoot explants are able to produce key secoiridoid as 1. To enable this approach, we synthesised and characterised deuterium-labelled iridoidic precursors belonging both to the loganin and the 8-epiloganin series. These iridoids are [7,8-(2)H2]-7-deoxy-8-epi-loganin (2(D)), [8,10-(2)H2]-8-epi-loganin (4(D)) and [7,8-(2)H2]-7-deoxy-loganin (3(D)).

Topics: Deuterium; Iridoid Glucosides; Iridoids; Molecular Structure; Olea; Tissue Culture Techniques

In our continued investigation of plants from the family Oleaceae we have now investigated Picconia azorica endemic to the Azores. Like most species within the family it contains the oleoside-based secoiridoid glucosides ligstroside and oleuropein as the main compounds and in addition verbascoside and echinacoside. As with the previously investigated Picconia excelsa, it also contained the carbocyclic iridoid glucosides involved in the biosynthetic pathway to the oleoside derivatives. However, while P. excelsa contained loganin esterified with some monoterpenoid acids, P. azorica contains similar esters of 7-epi-loganic acid named Picconioside A and B. In addition were found the two 7-O-E/Z-cinnamoyl esters of 7-epi-loganic acid named Picconioside C and D.

Topics: Azores; Glucosides; Glycosides; Iridoid Glucosides; Iridoids; Molecular Structure; Oleaceae; Phenols; Pyrans