Antonio Ventrone

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.

Two new non-glycosidic iridoids from Sambucus ebulus

Two new ‘Valeriana-type’ non-glycosidic iridoids were isolated from the aerial parts (leaves and young branches) of Sambucus ebulus L., a perennial herbaceous species widespread in Europe. The structures were elucidated, by spectroscopic means, as 7-O-acetylpatrinoside aglycone (1) and 10-O-acetylpatrinoside aglycone (2).

In vitro shoot regeneration of Centranthus ruber DC from hairy roots induced by Agrobacterium rhizogenes, and determination of valepotriate content

ABSTRACT Hairy roots were induced by infection with Agrobacterium rhizogenes strain LBA 9402 containing the plasmid 1855 from the valepotriate-producing medicinal plant Centranthus ruber. Plants were regenerated from callus derived from the hairy roots. The induction of shoot domes was obtained when hairy root calli, after a period of 3 months of dark incubation in MS (Murashige & Skoog, 1962) medium without growth regulators, were transferred for one week on the same medium under a 16-h light / 8-h dark photoperiod. Shoot regeneration increased with benzyladenine alone applied monthly at 2.5 µM concentration after the 3 months period of dark incubation. No bud formation was observed in untransformed tissues grown under the same light and hormonal conditions. Callus cultures of non-transformed plants was obtained by using leaves and roots as source material in the presence of 10.7 µM NAA and 1 µM kinetin as growth regulators, and 9 µM BA and 2.6 µM NAA for the next phase of shoot regeneration. BA and NAA together were not used for plant regeneration from transformed tissue. The morphological characteristics of the transgenic plants were analysed during two years of ex vitro growth. In the greenhouse, the transgenic plants showed pale pink flowers, heterostyly, leaves smaller than those of wild type plants, and a larger amount of roots. Roots of transgenic plants continued to produce valepotriates.

Lignans and secoiridoid glycosides from the stem barks of Jasminum tortuosum

Abstract This paper reports on the first phytochemical analysis ever performed on Jasminum tortuosum Willd. This analysis, mainly carried out by means of column chromatography separation, NMR spectroscopy and mass spectrometry, led to the isolation and the identification of four compounds, namely the lignans ginkgool (1) and olivil-4′-O-β-glucopyranoside (2) and the secoiridoids oleoside dimethyl ester (3) and oleoside 11-methyl ester (4). The presence of these compounds is significant from a chemotaxonomic point of view, confirming the correct botanical classification of the species and, from a phytochemical standpoint, may suggest its possible use in the ethno-medicinal field.

New Dihydrostilbene Derivatives from Chloraea chrysantha

The study of the main components of the alcoholic extract obtained from Chloraea chrysantha Poepp. led to the isolation of two new dihydrostilbene derivatives together with the known gavilein (3). The new compounds have been assigned as 3‐methoxy‐5‐{2‐[3‐methoxy‐2‐(3‐methylbut‐2‐en‐1‐yl)phenyl]ethyl}phenol (1) and 1‐[2‐(3,5‐dimethoxyphenyl)ethyl]‐3‐methoxy‐2‐(3‐methylbut‐2‐en‐1‐yl)benzene (2). The presence of compounds 1–3 is perfectly in accordance with the current botanical classification of the genus.

A new iridoid diglucoside from Antirrhinum siculum

Abstract A new iridoid diglucoside has been isolated from an ethanolic extract of Antirrhinum siculum, together with five-known compounds. Its structure has been assigned as 5-O-glucopyranosyl-7α-hydroxyharpagide by spectroscopic means.

A new iridoid diglucoside from Harpagophytum procumbens

A new iridoid diglucoside has been isolated from an aqueous extract of Harpagophytum procumbens secondary roots, together with six known compounds. Its structure has been assigned as 6′-O-glucopyranosyl-8-O-trans-coumaroylharpagide by spectroscopic means.

Iridoid glycosides from Alonsoa meridionalis

A new iridoid glucoside has been isolated from the Chilean native Alonsoa meridionalis (L.f.) Kuntze. Its structure has been assigned as 6′-O-β-d-glucopyranosyl-8-O-acetylharpagide (1) by using spectroscopic methods. Harpagoside (2), laterioside (3) and verbascoside (4) were also identified.

New acylated salicin bis-glucosides from Viburnum veitchii

The phytochemical study of aerial parts of Viburnum veitchii C.H. Wright, a deciduous species originary of Central China, led to the isolation of three salicin derivative bis-glucosides, i.e. henryoside (1), and the new structures 2′b-acetyl-3′b-(3-methylbutyryl)-henryoside (2) and 2′b,6′b-diacetyl-3′b-(3-methylbutyryl)-henryoside (3). In addition, luteolin, lonicerin, robustaflavone and eugenyl-β-D-glucopyranoside were also isolated.