Franco Cardini

Semi-β-carotenone from leaves of two cycads

Abstract A rare secocarotenoid, semi-β-carotenone, has been isolated from young leaves of Ceratozamia fuscoviridis (a form of C. mexicana Brongn.) and of C. kuesteriana. This is the first time that this carotenoid has been obtained from photosynthetic tissue. New data on the chromatographic behaviour and on the spectroscopic properties of the carotenoid are presented.

Carotenoids in ripe green and in autumn senescing leaves of apple tree: II - Seasonal changes of free carotenoids and xanthophyll esters and relationship between their content and senescing stage

Abstract Carotenoids (two carotenes, five free xanthophylls and seven xanthophyll esters previously isolated and identified, Cardini 1982) were measured in apple leaves from the early spring to autumn senescence; a detailed quantitative investigation on different senescence stages was also carried out. The xanthophyll esters were determinated by extinction coefficients (E1 cm 1%) experimentally obtained in this laboratory. α-carotene shows a clear character of « summer carotene », moreover for its sudden decrease in late summer it could perhaps be considered a biological indicator of early autumn. Violaxanthin shows a unique seasonal behaviour: a minimum during the summer maturity, a very marked biosynthesis in spring and a very intense esterification in autumn. In spring and in the first summer, violaxanthin shows a slight negative correlation with zeaxanthin in relationship with the « violaxanthin cycle », and also a negative correlation with neoxanthin; these correlations and the possible role of viola...

Occurrence of the very rare carotenoid triphasiaxanthin in leaves of two cycads

Abstract Triphasiaxanthin has been isolated for the first time from a photosynthetic tissue, in Ceratozamia kuesteriana and C. fuscoviridis . New data on the chromatographic behaviour and spectroscopic properties of this carotenoid are presented.

Alcuni aspetti del metabolismo di piante coltivate sia su un terreno serpentinoso sia in presenza di nichel

Abstract Effects of serpentine and Ni on some aspects of plant metabolism. — Results are here reported of a series of experiments on the metabolism of plants grown on a serpentine soil and in sand and water cultures with the addition of Ni. Variations in the content of citric and malic acid, chlorophylls, P, Ni, Fe (total and HCl soluble), Mn and Cu have been followed during plant growth in the leaves and roots. In Avena and Phaseolus the citric acid content greatly increases in both treatments (serpentine and Ni); the chlorophylls (a+b) markedly decrease; HCl sol. Fe is always reduced, particularly in the serpentine plants, total Fe accumulates in the roots in both treatments. The P content is particularly high in the Ni-treated plants, whilst on serpentine oats are always P-deficient, showing also a lower Mn and Cu content than plants grown in water cultures plus Ni. The relationships between citrate accumulation and scarce Fe translocation are discussed.

Carotenoids in ripe green and in autumn senescing leaves of apple tree: I - Qualitative composition of free carotenoids, xanthophyll esters and fatty acids of esters

Abstract By different chemical, spectral and chromatographic procedures seven carotenoids, two carotenes (α- and β-carotene) and five free xanthophylls (violaxanthin, lutein, antheraxanthin, zeaxanthin and neoxanthin) have been isolated and identified in green apple leaves. In autumn senescing leaves, besides the above seven carotenoids, the occurrence of at least seven xanthophyll esters has also been proved. Four esters, violaxanthin mono- and diester and lutein mono- and diester, (≥90% of total esters) and a minor component, neoxanthin triester, have been identified. Another minor component is most probably a monoester of antheraxanthin; the seventh, present in traces, has not been identified. The fatty acids combined with the above xanthophyll esters have been analysed by gas-chromatography. The unusual presence of low molecular weight fatty acids, C7-C11, has been registered (1,5-8% of the total); caprilic and capric acids have been identified. Lauric acid with three minor homologous (2-7% and myrist...

Occurrence of a mixture of ketocarotenoids in chloroplast plastoglobules of young leaflets of a Cycad

Summary An investigation was carried out on chloroplast plastoglobules in young leaflets of “forma fuscoviridis” of Ceratozamia mexicana Brongn., a cycad characterized by a transitory red-brown colour in the first stages of developing leaves. Plastoglobules were isolated by several ultracentrifugations and the contents of the different “rings” were compared on silica gel layers with natural standards obtained in our laboratory from fully ripe fruits of Murraya exotica L. and of Triphasia trifolia (Burm. f.) P. Wilson, (the two very rare semi-s-carotenone and triphasiaxanthin) and from the leaflets of the same “forma fuscoviridis” (the novel ceratoxanthin). The results pointed out that the red-brown coloration is due to the presence of a mixture of eight ketocarotenoids in the plastoglobules densely packed around the prolamellar body of young chloroplasts.

Il Contenuto di Rame e di Altri Microelementi in Alcune Piante Della Zona Mineraria di Montecatini Val di Cecina (Livorno)

Abstract Copper and other microelements in some plants of a mining area at Montecatini Val di Cecina (Leghorn). — Copper, iron, manganese, boron, nickel and cobalt have been evaluated in some specimens of the vegetation cover of an old copper mine placed at Montecatini Val di Cecina. The copper content is not high, sign of an almost complete exhaustion in the utilization of the mine now no more in use. The high pH level of the soil (7.5–7.9) hinders remarkably the absorption of manganese, which though very abundant in the parent rock, is almost lacking in the cation exchange complex. Therefore the plants are unable to absorb it. The other microelements content does not show anything particular.