Lignin is a complex macromolecule structure found in plants. Through appropriate degradation of lignin it is possible to prepare chemicals with an added value. Therefore, it is important to use the best possible way for lignin... more
Lignin is a complex macromolecule structure found in plants. Through appropriate degradation of lignin it is
possible to prepare chemicals with an added value. Therefore, it is important to use the best possible way for
lignin degradation. Powerful method for characterization of the degradation is thermal analysis and the
combination of pyrolysis with gas chromatography coupled with mass spectrometry. In this work, different
commercial and prepared lignins were investigated.
Background: This study concerns the application of non-invasive and micro-invasive analyses for the study of a contemporary artwork entitled La Caverna dell’Antimateria (“The Cave of Antimatter”) which was created by Pinot Gallizio in... more
Background: This study concerns the application of non-invasive and micro-invasive analyses for the study of a contemporary artwork entitled La Caverna dell’Antimateria (“The Cave of Antimatter”) which was created by Pinot Gallizio in 1958–1959. The work represents one of the most significant examples of industrial painting. It consists of a total of 145 meters of painted canvas, designed in order to cover the entire floor plan of the René Drouin gallery in Paris, where it was displayed for the first time. Gallizio wanted to create an environment in which visitors could find themselves immersed in painting, in what he termed as a “work-environment”. Non-invasive (Fibre Optic Reflectance Spectroscopy) and micro-invasive analyses (Fourier Transform Infrared and micro-Raman Spectroscopies, Pyrolysis-Gas Chromatography and Gas Chromatography/Mass Spectrometry) were performed on three of the canvases which constitute this work of art in order to obtain information regarding the artistic materials used by Gallizio. Results: Pigments and unconventional materials (such as metal wires, sand) are present in the canvases that form the ceiling. The colours are unevenly distributed on the surface, thus revealing large areas of the white preparation below. In the canvas of the wall, instead, the paint is applied more uniformly and gives a dark colour cast. The analytical results led to the identification of many of the materials used by Gallizio. The pictorial palette consists of both inorganic and organic pigments, while polyvinylacetate, pure or mixed with a siccative oil, was identified as a binder thus confirming what was reported by the artist in his notes. Conclusions: The results of this research provide information concerning the artistic technique used by Pinot Gallizio. The analyses were successfully performed both in situ and on micro
Hardwickia binata Roxb. (Fabaceae) root bark exudate has been traditionally used by tribes of Chitteri hills to cure breast cancer. The main objective of this study is to give a scientific validation to the... more
Hardwickia binata Roxb. (Fabaceae) root bark exudate has been traditionally used by tribes of Chitteri hills to cure breast cancer. The main objective of this study is to give a scientific validation to the traditional use of H. binata. The root bark exudates of H. binatawas collected from Chitteri hills, shade dried, coarsely powdered and extracted with methanol using soxhlet apparatus. The Physico chemical properties, qualitative phytochemical studies, quantitative phytochemical studies and GC-MS analysis was carried out. The cytotoxic effect of methanol extract of H.binata root bark exudate was studied against cancer cell lines by MTT assay. The phytochemical studies indicated the presence of flavonoids, saponins, phenols and tannins. GC-MS study also revealed the presence of 22 organic compounds out of which 18 compounds were reported with various activities and five compounds reported to possess anticancer activity. In vitro cytotoxic activity on the cell lines showed more degree of inhibition against African Green Monkey Kidney Epithelial cells (Vero), Human cervical cancer cell lines (HeLa) and Human breast cancer cells (MCF-7).
For the first time, molecular evidence of the structural role played by succinic acid within the macromolecular structure of Class Ia and Class Id resinites is presented. Using a novel gas chromatographic methodology, communol (Class Ia)... more
For the first time, molecular evidence of the structural role played by succinic acid within the macromolecular structure of Class Ia and Class Id resinites is presented. Using a novel gas chromatographic methodology, communol (Class Ia) and ozol (Class Id) moieties within the polylabdane matrix are shown to be cross-linked with succinic acid. Samples were analysed using pyrolysis-gas chromatography-mass spectrometry with in situ HMDS derivatisation, using a thermal separation probe to perform the pyrolysis and sample introduction. The relatively slow rate of heating and prolonged pyrolysis of resinites using this new methodology, combined with the use of a mild derivatization reagent, allowed communol pyrolysates from Class Ia resinite and ozol pyrolysates from Class Id resinite to elute with unbroken succinyl ester cross-linkages. These results provide direct molecular evidence that the key role of succinic acid within Class Ia and Class Id resinite is to cross-link the macromolecular structure. In the Class Id resinite, the methodology also allowed the detection succinyl ester linkages between ozol pyrolysates and dehydroabietol, thus, demonstrating that non-polymerized diterpenes contribute structurally to the macromolecular structure of Class Id resinite.
Two cultural artefacts produced in Southeast Asia were analysed by Py-GC–MS with in situ silylation using HMDS. The page of a Burmese book (Kammavaca manuscript) from the early 20th century and a Cambodian wooden gilded sculpture... more
Two cultural artefacts produced in Southeast Asia were analysed by Py-GC–MS with in situ silylation using HMDS. The page of a Burmese book (Kammavaca manuscript) from the early 20th century and a Cambodian wooden gilded sculpture representing a Buddha from the 16th century were investigated for diagnostic purposes.
Burmese lacquer (thitsi) and a drying oil were identified. Benzoic acid and alkylphenylketones were detected, indicating that oxidation at the benzylic position of thitsi monomers occurred. Alkylphenylketones resulted from the pyrolysis of the polymeric network, and we believe they were the result of the oxidising environment generated by the drying oil during the curing. In the case of the Cambodian Buddha, the detection of alkylphenylketones was crucial for identifying the lacquer, as the marker pyrolysis products of thitsi were present at the trace level. Alkylphenylcarboxylic acids, alkyl-oxo-phenylcarboxylic acids and alkylphenols with a carboxylic group on the side chain were also detected. These compounds were identified as trimethylsilyl derivatives on the basis of their mass spectra interpretation, and were present as free acids or esters. Although their molecular structure might be ascribed to the oxidation of the original components of thitsi, the length of the alkyl chains did not make the association straightforward. Therefore, we propose that the oxidative cleavage of the aromatic ring may be responsible for the formation of these compounds.
