echinacoside and loganic-acid

In this study, we report the first phytochemical analysis of polar fraction of Pedicularis kerneri Dalla Torre growing in Dolomites, Italy. Several iridoid glucosides were isolated, namely aucubin (1), monomelittoside (2), plantarenaloside (3), euphroside (4), mussaenosidic acid (5) and 8-epiloganic acid (6), showing a composition in accordance with previous study on this genus. The studied samples, collected from Dolomites, presented a chemotype already recognised in species from North America, characterised by euphroside (4) and aucubin (1) as main components, but the main character was the presence of monomelittoside (2) never reported in this genus. The identification of verbascoside (7), leucosceptoside A (9) and echinacoside (10) complete the systematic framing of this species since is ascertained the co-occurrence of phenylethanoid glycosides with iridoids in Lamiales species.

Topics: Glucosides; Glycosides; Iridoid Glucosides; Iridoids; Italy; Molecular Structure; Pedicularis; Phenols; Plant Extracts

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