Giovanna Palazzino

Biological activities of the plant-derived bisindole voacamine with reference to malaria.

The in vivo antiplasmodial activity of voacamine was assessed in a 4‐day test. It was shown to exhibit in vivo activity with 25.4% and 43.4% inhibition of parasitaemia with 2.5 and 10 mg/kg, respectively. In synchronized cultures, it was found to act on trophozoite and schizont stages of Plasmodium falciparum. Using the FMC29 strain of Plasmodium falciparum as parasite and the isobologram curve as a method to assess interaction in drug combination, it was shown to lack any chloroquine‐enhancing activity and its in vitro antiplasmodial effect was not potentiated by the chemosensitizer malagashanine. Copyright

Chemical fingerprinting of Equisetum arvense L. using HPTLC densitometry and HPLC

Equisetum arvense L. is a herbaceous medicinal plant, commonly known as horsetail, whose extracts have been reported to possess diuretic and haemostatic properties. The aim of this study was to evaluate the use of fingerprint chromatographic methods on commercially available raw materials or preparations of E. arvense L. in order to ascertain their quality and identify possible adulterants using HPLC and HPTLC densitometry. Two chromatographic methods were used to determine the chemical fingerprints of E. arvense and other allied species. The first was based on HPTLC identification followed by densitometric measurement at 350 nm. The second was based on HPLC separation. The ease of sample preparation and the possibility of simultaneous analysis of several samples in a short time make HPTLC a method of choice for the comprehensive quality evaluation of herbal products.

Two prenylated isoflavanones from Millettia pervilleana

Abstract From the root bark of Millettia pervilleana , which showed high cytotoxic activity, two prenylated isoflavanones were isolated. Their structures were determined by means of chemical and spectroscopic properties to be (3 R )-2′,7-dihydroxy-3′,4′-dimethoxy-5′- α , α -dimethylallylisoflavanone, named pervilleanone, and its 3′- O -demethyl derivative.

Benzylbenzoate and norlignan glucosides from Curculigo pilosa: structural analysis and in vitro vascular activity

From the rhizomes of Curculigo pilosa, two benzylbenzoate diglucosides, piloside A and piloside B, and a glucosyl-fused norlignan, pilosidine, previously obtained only as the tetra-O-methyl derivative, were isolated. Pilosidine showed facilitating effect on adrenaline evoked contractions in rabbit aorta isolated preparations.

The Modern Analytical Determination of Botanicals and Similar Novel Natural Products by the HPTLC Fingerprint Approach

Abstract Efficient, useful and sensitive analytical devices for the quality control of complex mixtures of natural products are urgently needed. Controls should be based on simple, viable, comprehensible and low cost methods. High Performance Thin Layer Chromatography (HPTLC) the last evolution of planar chromatography, is a reliable candidate for analysis of botanicals. Although HPLC remains the best choice for organic substances, HPTLC can solve several problems in a quicker, simpler and easier method. Furthermore, the visualization and the analysis of similar products performed exactly in the same conditions, allow an evident, good and safe result of comparison. The paper is dedicated to HPTLC application on selected market products, in order to evidence benefits and limits of the HPTLC fingerprint approach.

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.

Traceability in Multi-Ingredient Botanicals by HPTLC Fingerprint Approach

A high-performance thin-layer chromatography (HPTLC) method was developed for simple and rapid chemical analyses of multi-ingredient botanicals. The method was based on comparison of the fingerprint of the marketed multi-ingredient botanical with the fingerprints of the extracts of its component plants and of a handmade mixture of the constituent extracts in a ratio as similar as possible to that of the market product, when labeled. Planar chromatography analysis was completed by a densitometric scansion. The analyses revealed a good correspondence between the market products and the handmade mixture of standard extracts.

Plants and parts of plants used in food supplements: an approach to their safety assessment

In Italy most herbal products are sold as food supplements and are subject only to food law. A list of about 1200 plants authorised for use in food supplements has been compiled by the Italian Ministry of Health. In order to review and possibly improve the Ministrys list an ad hoc working group of Istituto Superiore di Sanità was requested to provide a technical and scientific opinion on plant safety. The listed plants were evaluated on the basis of their use in food, therapeutic activity, human toxicity and in no-alimentary fields. Toxicity was also assessed and plant limitations to use in food supplements were defined.

Minor Nb,C(21)-secocuran alkaloids of Strychnos myrtoides

Abstract From the stem bark of Strychnos myrtoides in addition to strychnobrasiline and malagashanine, four minor alkaloids, viz. malagashanol, 12-hydroxy-19-epi-malagashanine, myrtoidine and 11-demethoxymyrtoidine were isolated and their structures were established by 2-D NMR techniques. They belong to the series Nb,C(21)-secocuran and the two last show an additional α–β unsaturated γ-lactonic ring among C(18)–C(21). The biogenesis of these alkaloids is also discussed.

Acridones of Vepris sclerophylla : Their 13C-NMR data

Abstract The isolation and 13 C-NMR data of four acridones from Vepris sclerophylla are reported.