Characterization of Phaseolus vulgaris L. landraces cultivated in Central Italy

Eight Phaseolus vulgaris L. landraces cultivated on farm in marginal areas of Central Italy (Lazio region) were investigated in order to evaluate chemical composition of storage proteins and secondary metabolites fractions. The total protein content showed some differences among landraces; the maximum value was next to 30 g for 100 g of dry weight. The seed storage proteins were screened by polyacrylamide gel electrophoresis (SDS/PAGE): seven landraces exhibited phaseolin patterns type S, one landrace showed a phaseolin pattern type T. A morphological analysis of cotyledon parenchyma performed by scanning electron microscopy (SEM) revealed differences in size of starch granules. Moreover the polyphenolic composition was investigated using HPLC-APCI; from the methanol extracts a flavonoid, kaempferol, and a coumarin, 5,7-dimethoxycoumarin, were identified. To our knowledge, this is the first tithe that 5,7-dimethoxycoumarin has been reported in P. vulgaris seeds

Gas chromatography-mass spectrometry analysis of phenolic compounds from Carica papaya L. leaf

Phenolic compounds are important components in vegetable foods, infusions and teas for their beneficial effects on human health. The presence of such compounds, evidenced for the first time in Carica papaya leaves, could partially explain the pharmacological properties of this plant and demonstrates its importance in alimentation and daily intake. C. papaya leaves were extracted with methanol in a Soxhlet apparatus and later with a liquid-liquid extraction (LLE) with the aim of identifying and quantifying secondary metabolites from this plant, using gas chromatography-mass spectrometry (GC-MS) in the selected ion-monitoring (SIM) mode. Derivatization procedure of the extract was necessary to analyze the polar compounds in GC-MS. 5,7-Dimethoxycoumarin and polar molecules such as protocatechuic acid, p-coumaric acid, caffeic acid, chlorogenic acid, kaempferol and quercetin were detected and identified in qualitative analysis. The quantitative analysis has shown the presence of phenolic acids as the main compound, while chlorogenic acid was found in trace amounts, compared to the flavonoids and coumarin compounds. The quantities detected were 0.25 mg/g (dry leaf) for caffeic acid, 0.33 mg/g for p-coumaric acid and 0.11 mg/g for protocatechuic acid. Kaetnpferol and quercetin were 0.03 and 0.04 mg/g, respectively, while that for 5,7-dimethoxycoumarin was 0.14 mg/g. (c) 2007 Elsevier Inc. All rights reserved

Inhibition of Mek 1/2 kinase activity and stimulation of melanogenesis by 5,7-dimethoxycoumarin treatment of melanoma cells

In this study, the processes of differentiation and melanogenesis induced by 5.7-dimethoxycoumarin in murine (B16) and human (A375) melanoma cells were investigated. Taking into account the previously demonstrated anti-proliferative and differentiation activities of this compound, we examined Ras/Raf/Mek/Erk mitogen-activated protein kinase activity following treatment; inhibition of Mek 1/2 kinase activity and Subsequent reduction in Erk 1/2 activation were detected in both cell types. We observed melanogenesis induction associated to an increase in cAMP-response element-binding protein (CREB) and microphthalmia-associated transcription factor (Mitf) expression, both involved in its regulation. Mitf is fundamental for development, survival and differentiation of melanocyte and melanoma, since it regulates transcription of genes encoding for proteins involved in cell cycle progression or in melanogenesis, such as the enzyme tyrosinase. A significant increase of tyrosinase activity was revealed following treatment in B16 but not in A375 cells. although a strong synthesis of melanin was induced by 5,7-dimethoxycoumarin in both cell lines. The treatment induced protoporphyrine IX accumulation involved in melanogenesis since it promotes stability of cAMP. Finally, the Mek 1/2 inhibitor U0126 significantly potentiated growth inhibition of B16 cells triggered by 5,7-dimethoxycoumarin, suggesting that down-regulation of Raf/Mek/Erk pathway sensitizes melanoma cells to 5,7-dimethoxycoumarin treatment

Micro-Raman study of copper hydroxychlorides and other corrosion products of bronze samples mimicking archaeological coins

Three bronze samples created by CNR-ISMN (National Research Council—Institute of Nanostructured Materials) to be similar to Punic and Roman coins found in Tharros (OR, Sardinia, Italy) were studied to identify the corrosion products on their surfaces and to evaluate the reliability of the reproduction process. Micro-Raman spectroscopy was chosen to investigate the corroded surfaces because it is a non-destructive technique, it has high spatial resolution, and it gives the opportunity to discriminate between polymorphs and to correlate colour and chemical composition. A significant amount of green copper hydroxychlorides (Cu2(OH)3Cl) was detected on all the coins. Their discrimination by Raman spectroscopy was challenging because the literature on the topic is currently confusing. Thus, it was necessary to determine the characteristic peaks of atacamite, clinoatacamite, and the recently discovered anatacamite by acquiring Raman spectra of comparable natural mineral samples. Clinoatacamite, with different degrees of order in its structure, was the major component identified on the three coins. The most widespread corrosion product, besides hydroxychlorides, was the red copper oxide cuprite (Cu2O). Other corrosion products of the elements of the alloy (laurionite, plumbonacrite, zinc carbonate) and those resulting from burial in the soil (anatase, calcite, hematite) were also found. This study shows that identification of corrosion products, including discrimination of copper hydroxychlorides, could be accomplished by micro-Raman on valuable objects, for example archaeological findings or works of art, avoiding any damage because of extraction of samples or the use of a destructive analytical technique