Alessia Ramunno

Phenolic components of Olea europaea--isolation of tyrosol derivatives.

A new tyrosol derivative, the oleic ester of tyrosol, was isolated from fruits of Olea europaea, Cassanese cultivar. Salidroside, the known glucosyl derivative of thyrosol, was isolated from the Carolea cultivar.

Monoterpenoids from Stachys glutinosa L.

The iridoidic composition of Stachys glutinosa L. was examined in comparison with the results obtained in the phytochemical studies on S. corsica Pers. The presence of the known harpagide and acetyl-harpagide were showed together with that of a new di-glycosidic iridoid. The structure of this new compound, the 5-allosyloxy-aucubin, was demonstrated by comparison with the spectroscopical data of monomelittoside and of its 5-O-glucosyl-derivative, the melittoside. The presence of allose in Stachys genus seems to be a chemotaxonomical character.

The Chemistry of Olea Europaea

ABSTRACT: This review summarises the chemistry of Olea europaea, in particular of hydrophilic components, which are seen as the key compounds responsible for several properties, identified as the organoleptic characteristics of foods derived from O. europaea and as the biological properties attributed to this plant, like ipotensive, anti-oxidising, etc. In fact, two groups of polar compounds can be identified in O. europaea: terpenenoids, as oleuropein; phenols, as hydroxy-phenyl ethanol derivatives; and compounds related to these two categories. Oleuropein and its metabolites are terpenoids present in all parts of plant and represent the chemotaxonomic markers of O. europaea. Tyrosol, hydroxytyrosol and related compounds represent the main characteristic phenolic fraction of O. europaea and are recognised as very powerful anti-oxidising agents. The chemistry of oleuropein and of other phenolic components of O. europaea is described, in relation also with the biological activity of these compounds. O. europaea represents, in fact, a key plant in the economy of Mediterranean region, and olives are the key component of Mediterranean diet. Olives, olive oil in particular, represent a unique food in the scenario of Mediterranean region and they certainly have contributed to the evolution of civilisation of this part of the world.

Flavonoids and iridoids from Stachys corsica

Two flavonoid glycosides containing acetylated allose, and two iridoid glucosides were obtained from a EtOH extract of Stachys corsica, an endemic plant of Sardinia and Corsica. All the compounds have previously been isolated from other species of Stachys.

Iridoidic pattern in endemic Sardinian plants: the case of Galium species

The monoterpenoid fractions of three endemic Galium ssp. (Rubiaceae) from Sardinia Island were examined and compared with the iridoidic pattern yet known in Galium species. This comparison evidenced theirs endemic characters. In particular, in G.corsicum and in G. glaucophyllum loganic acid was isolated and identified for the first time in Galium genus. In G. schmidii a rare iridoid is present, 10-hydroxy-loganin, whose presence in this genus was evidenced only in G. mollugo and loganin isolated for the first time.

The occurrence of phenyl propanoid glycosides in endemic Teucrium species

The phenyl propanoid fraction of Teucrium subspinosum Pourrette ex Willd. (Lamiaceae) from Baleari Island, was examined together with the same fraction of T. subspinosum from Sardinia. In T. subspinosum, besides verbascoside as main component, a new phenyl-propanoid-glycoside was isolated and identified by 1H- and 13C-NMR spectra analysis. Comparison with molecular composition of T. marum confirmed the differences between these species and evidenced their endemic character.

Taxonomical markers in two endemic plants of Sardinia: Verbascum conocarpum and Scrophularia trifoliata

The monoterpenoid composition of Verbascum conocarpum and Scrophularia trifoliata, both endemic plants of Sardinia, was examined. The main chemotaxonomic markers of Scrophulariaceae, the iridoids aucubin, verbascoside and catalpol, were isolated.

Iridoids from Seeds of Gentiana Lutea

In the seeds of Gentiana lutea L. there were also detected, in addition to the known sweroside and getiopicroside, loganic acid 3 and trifloroside 4 that is present as main glycosidic component. The structures of 3 and 4 were established by spectroscopic studies.

Phytochemical characters of teucrium marum from Sardinia: an endemic plant

In this work the iridoidic fraction of Teucrium marum from Sardinia, was examined. A new clerodane, teumarin B, was isolated and identified by 1H- and 13C-NMR spectra analysis. The endemic character of this plant was further confirmed. Teumarin B showed cytotoxic properties.

Iridoid glucosides from Lamium garganicum flowers.

In the flowers of Lamium garganicum L. a single iridoid is present, as main glycosidic component, the 8-acetyl-shanzhiside methyl ester, 1. The structure of 1 was established by spectroscopic studies and chemical evidence.