Antonio Dini

Chemical composition of Lepidium meyenii

Abstract Lepidium meyenii Walpers, a tuber of Andine origin still cultivated in Peru for local preparation, was studied. The carbohydrate, lipid, protein, fibre and also the amino-acid, fatty acid, mineral and sterol fractions were determined. The results show that the tuber is nutritionally interesting. Alkaloid-like compounds were also found. It is concluded that this tuber can be a food source in countries, where economic and technological conditions are inadequate to combat malnutrition.

Phenolic constituents of Kancolla seeds

Chemical investigation of Kancolla seeds revealed the presence of an array of polyphenols which were dominated by kaempferol and quercetin glycosides. Also isolated was a glucoside of vanillic acid. This is the first report of quercetin 3-O-β-d-apiofuranosyl-(1‴→∼2″)-O-[a-l-rhamnopyranosyl-(1⁗→6″)]-∼3-d-galactopyranoside-3′,4′-dimethyl ether. All structures were elucidated by chemical and spectroscopic methods, namely NMR (1H, 13C, COSY, HMQC, HMBC), mass data (FAB–MS, HRFAB–MS, GC–MS), IR and UV.

Glucosinolates from Maca (Lepidium meyenii)

Maca (Lepidium meyenii Walp) is a food plant belonging to the Cruciferae family. It is very interesting because it has one of the highest frost tolerances of any cultivated plant and can be grown at high altitudes (3800–4800 m) (Bonnier, 1986). Maca dry tubers were bought from INIA (Instituto National de Investigation Agroindustrial de Huancayo, Peru); a sample has been deposited in the Herbarium Neapolitanum the Dipartimento di Biologia Vegetale Universita degli Studi ‘Federico II’ of Naples (herbarium code NAP).

S-Alkenyl Cysteine Sulfoxide and Its Antioxidant Properties from Allium cepa var. tropeana (Red Onion) Seeds

A new cysteine sulfoxide, (S(S)R(C))-S-(3-pentenyl)-L-cysteine sulfoxide (1), was identified from the seeds of Allium cepa var. tropeana, together with the known methiin, etiin, alliin, isoalliin, propiin, and butiin. The structure of compound 1 was established by analysis of its physical and spectroscopic data. The antioxidant activity of an extract containing cysteine sulfoxides and compound 1 was evaluated using the FRAP and DPPH tests.

Starfish saponins VI - unique 22,23-epoxysteroidal cyclic glycosides, minor constituents from Echinaster sepoeitus

Abstract On the basis of comparative 1H− and 13C-n.m.r. data, the structures of the minor saponins from the starfish Echinaster sepositus have been elucidated to be 2-4. They closely resemble 1, the major saponin from the same starfish, and, in addition to the cyolic trisaccharide moiety bridging C-3 and C-6 of the steroid, include epoxide functionalities in the steroidal side-chains.

Starfish saponins VII. Structure of luzonicoside, a further steroidal cyclic glycoside from the pacific starfishEchinaster luzonicus

On the basis of comparative chemical and spectral data, the structure of the major saponin, luzonicoside, from the starfishEchinaster luzonicus has been elucidated as2. This is a further example of a novel class of steroidal cyclic glycoside from starfish of the genusEchinaster. Its structure includes a Δ7, 3β,6β-dioxygenated-23-oxosteroidal moiety, already found in the saponins ofEchinaster sepositus, and a trisaccharide moiety, β-D-galactopyranosyl-(1→2) α-L-arabinopyranosyl-(1→2)-β-D-glucuronopyranosyl, bridging C-3 and C-6 of the steroid.

Chemical constituents of some Tricholomataceae

Sterols, fatty acids and free amino acids of four species of Tricholomataceae were investigated. They contained ergosterol in high amount and the related sterols, fucosterol, sitosterol, cholesterol and brassicasterol. Linoleic and palmitic are the main unsaturated and saturated fatty acids respectively. The most abundant free amino acids were alanine, valine and proline.

Flavonol glycosides from Eupatorium tinifolium

Abstract Two new flavonol glycosides, 3′-methylquercetagetin 3- O -galactoside and 3′-methylquercetagetin 3- O -glucoside, have been isolated from the ethyl acetate extract of Eupatorium tinifolium . The structure of these compounds has been established on the basis of chemical and spectral data.

Oligosaccharides in Five Different Vicia faba L. Cultivars

Abstract The oligosaccharide composition in seeds of some bean cultivars (two of Vicia faba L. and three of V. faba minor) have been examined. The sugars were isolated by solvent extraction and the concentrated extracts were analysed by PC and HPLC analyses. Characterization was also performed by thin-layer chromatography, enzymatic hydrolysis assays, GC determination of alditol acetate derivatives obtained after complete acid hydrolysis and FAB-MS of individual sucrose α- d galactosides. Although sucrose, raffinose, stachyose and verbascose were always identified, great differences in the total sugar content were found among the five cultivars. Sucrose and verbascose were the major components. Their contents were highest in the Muchamiel cv. (2.30 and 3.05 g/100g of dry bean, respectively). The selection of cultivars is the best way to improve the V. faba quality

Sterols from the sponge Agelas oroides

Abstract 1. 1. The sponge Agelas oroides contains Δ7-sterols and their nuclear-saturated analogues as shown by GC-MS and 1H NMR spectroscopy. 2. 2. The major component of the sterol mixture is 24-ethylcholest-7-en-3β-of followed by cholestanol and cholest-7-en-3β-ol. 3. 3. A rare marine sterol with Δ8(9)-unsaturation, identified as 4α-methyl-5α-cholest-8-en-3β-ol, is also present.