Lamberto Tomassini

Iridoid glucosides from Viburnum rhytidophyllum

Abstract Three new Valeriana-type iridoid glucosides, 7,10,2′-triacetylpatrinoside; 7-p-coumarylpatrinoside and 10-acetylpatrinoside, have been isolated, together with decapetaloside, from the stem bark of Viburnum rhytidophyllum. The structures have been elucidated mainly by spectroscopic means.

Iridoid glucosides from Viburnum ayavacense

Abstract Nine new iridoid glucosides, all characterized by a β- d -glucopyranosyl moiety linked to the C-11 oxymethylene and either a 3-methylbutyroyl (isovaleroyl) or a 2-methylbutyroyl group at position 1, have been isolated from leaves and branches of Viburnum ayavacense , together with three related known compounds. The nine new structures (namely 7,10,2′,3′ tetra-acetylsuspensolide F, 7,10,2′,3′ tetra-acetylisosuspensolide F, 7,10,2′,6′ tetra-acetylisosuspensolide F, 2′,3′ diacetylvalerosidate, 2′,3′ diacetylisovalerosidate, isoviburtinoside II, isoviburtinoside III, isosuspensolide E and isosuspensolide F) have been elucidated by spectroscopic means.

Iridoid glucosides from Viburnum tinus

Abstract Five new iridoid glucosides, named viburtinosides I-V, together with suspensolide F, were isolated from leaves and branches of Viburnum tinus . All the iridoids contain a β- d -glucopyranosyl moiety linked to the oxymethylene at C-11 and an isovaleroyl at position 1, but differ for other acylating groups. The structures have been elucidated mainly by spectroscopic means.

Glycosidic monoterpenes from Linaria capraria.

During our systematic study on the species of genus Linaria (Scrophulariaceae) present in Italy, we examined the glycosidic fraction of Linaria capraria Moris et De Not., a species endemic of Tuscany archipelago. This fraction is particularly complex and we considered in this article only the medium polarity components. In accordance with previous studies, L. capraria shows acyl derivatives of antirrhinoside 1 as specific chemotaxonomic iridoidic markers. L. capraria exhibits a complex composition, with regard to iridoidic constituents, with several chromatographic problems to be resolved. We then isolated, besides the known antirrhinoside 1, two acyl derivatives of antirrhinoside, the 6′-O-senecioyl derivative, 2, and the 6′-O-angeloyl derivative, 3. In addition a glucoside of an acyclic monoterpene, 4, was also isolated, which may be correlated to the other monoterpenic glycosides isolated from other species of Scrophulariaceae.

Iridoid glucosides from Viburnum chinshanense

The phytochemical study of the aerial parts of Viburnum chinshanense Graebn., a species growing in Western and Central China, led to the isolation of six iridoid glucosides: the novel 10,2′-diacetylpatrinoside, 1, and the known 2′-acetyldihydropenstemide, 2′-trans- p-coumaroyl-dihydropenstemide, 2′-acetylpatrinoside, decapetaloside, and patrinoside. In addition, amentoflavone and rosarin were also isolated.

Phenylpropanoid glycosides in Italian Orobanche spp., sect. Orobanche

We studied the occurrence of phenylpropanoid glycosides (PhG) in five species of the genus Orobanche L., collected in the Latium region of Italy. The presence of orobanchoside and verbascoside in all four species confirms that these PhGs are taxonomic markers of the genus. The results suggest that O. gracilis form. citrina could be a diverse entity.

A C-methylated resacetophenone from Cistus monspeliensis L.

A new methylresacetophenone glucoside, named monspelioside, was isolated from Cistus monspeliensis, together with several diterpenes of labdane and clerodane types, a simple flavone and two methyl-inositols, one of them isolated for the first time from Cistus spp.

Iridoid glucosides from Viburnum sargenti

The phytochemical study of aerial parts of Viburnum sargenti Koehne, a species spontaneous in Mongolia and Northern China, led to the isolation of three iridoid glucosides of Valeriana-type: the novel 7,10,2′-triacetylsuspensolide F, 1, and the known viburtinoside IV and V. In addition, (+)-epicatechin was also isolated.

Iridoid glycosides from Escallonia species

Phytochemical study of Escallonia myrtoidea, E. illinita, E. alpina and E. pulverulenta led to the isolation of asperuloside and other C10-iridoid glycosides. From E. myrtoidea a new iridoid glycoside was isolated and identified as 6′-O-gb-d-glucosylasperuloside by spectroscopic means. The findings are in accordance with the inclusion of Escallonia in the Saxifragaceae.

Iridoids of Cruckshanksia verticillata and their Chemosystematic importance

Abstract From Cruckshanksia verticillata , an endemic Chilean species of the family Rubiaceae, a new secoiridoid was isolated in addition to asperuloside and secologanin and identified as 7-α-methoxysweroside by spectroscopic means. The importance of the isolated iridoids in subfamilial classification of the genus Cruckshanksia is discussed.