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In our previous studies, Prunus spinosa fruit (PSF) ethanol extract was showed to exert antioxidant, antimicrobial, anti-inflammatory and wound healing activities. In the present study, an integrated bioinformatics analysis combined with experimental validation was carried out to investigate the biological mechanism(s) that are responsible for the reported PSF beneficial effects as an antioxidant during a pro-inflammatory TLR4 insult. Bioinformatics analysis using miRNet 2.0 was carried out to address which biological process(es) the extract could be involved in. In addition, Chemprop was employed to identify the key targets of nuclear receptor (NR) signaling and stress response (SR) pathways potentially modulated. The miRNet analysis suggested that the PSF extract mostly activates the biological process of cellular senescence. The Chemprop analysis predicted three possible targets for nine phytochemicals found in the extract: (i) ARE signaling, (ii) mitochondrial membrane potential (MMP) and (iii) p53 SR pathways. The PSF extract antioxidant effect was also experimentally validated in vitro using the human monocyte U937 cell line. Our findings showed that Nrf2 is modulated by the extract with a consequent reduction of the oxidative stress level. This was confirmed by a strong decrease in the amount of reactive oxygen species (ROS) observed in the PSF-treated cells subjected to lipopolysaccharide (LPS) (6 h treatment, 1 µg/mL). No visible effects were observed on p53 and MMP modulation.

The nuclear RNA surveillance mechanism is essential for cancer cell survival and is ensured by the RNA nuclear exosome including some co-factors, such as the RNA helicase MTR4. Recent studies suggest an involvement of DNA repair proteins such as apurinic/apyrimidinic (AP) endodeoxyribonuclease 1 (APE1), a major endodeoxyribonuclease of Base Excision Repair (BER), in RNA metabolism and RNA decay of oxidized and abasic RNA. Cisplatin (CDDP) and 5-fluorouracil (5-FU) are commonly used for the treatment of solid tumours. Whether APE1 is involved in the elimination of CDDP- or 5-FU-damaged RNA is unknown, as is its possible interaction with the nuclear exosome complex. Here, by using different human cancer cell models, we demonstrated that: (a) APE1 is involved in the elimination of damaged-RNA, upon CDDP- and 5-FU-treatments, in a MTR4-independent manner; (b) the interaction between APE1 and MTR4 is stimulated by CDDP- and 5-FU-treatments through lysine residues in the APE1 N-terminal region and is, in part, mediated by nucleic acids and (c) APE1- and MTR4-depletion lead to the generation of R-loop formation causing the activation of the DNA damage response (DDR) pathway through the ATM-p53-p21 axis. Our data demonstrate a role of MTR4 in DDR underpinning the function of APE1 in controlling the RNA quality upon genotoxic treatments with possible implications in chemoresistance.

Prunus spinosa fruits (PSF) contain different phenolic compounds showing antioxidant and anti-inflammatory activities. Innovative drug delivery systems such as biomimetic nanoparticles could improve the activity of PSF extract by promoting (i) the protection of payload into the lipidic bilayer, (ii) increased accumulation to the diseased tissue due to specific targeting properties, (iii) improved biocompatibility, (iv) low toxicity and increased bioavailability. Using membrane proteins extracted from human monocyte cell line THP-1 cells and a mixture of phospholipids, we formulated two types of PSF-extract-loaded biomimetic vesicles differing from each other for the presence of either 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dioleoyl-sn-glycero-3-phospho-(1&prime, rac-glycerol) (DOPG). The biological activity of free extract (PSF), compared to both types of extract-loaded vesicles (PSF-DOPCs and PSF-DOPGs) and empty vesicles (DOPCs and DOPGs), was evaluated in vitro on HUVEC cells. PSF-DOPCs showed preferential incorporation of the extract. When enriched into the nanovesicles, the extract showed a significantly increased anti-inflammatory activity, and a pronounced wound-healing effect (with PSF-DOPCs more efficient than PSF-DOPG) compared to free PSF. This innovative drug delivery system, combining nutraceutical active ingredients into a biomimetic formulation, represents a possible adjuvant therapy for the treatment of wound healing. This nanoplatform could be useful for the encapsulation/enrichment of other nutraceutical products with short stability and low bioavailability.

Biostimulants improve yield, quality, and stress acclimation in crops. In this work, we tested the possibility of using phenolics-rich extracts from spelt (Triticum dicoccum L.) husks to attenuate the effects of salt stress (100–200 mM NaCl) in maize. Two methanolic extracts were prepared from the soluble-conjugated (SC), and the insoluble-bound (IB) phenolic acid fractions of the spelt husk, and their effects were investigated on several stress-associated biochemical parameters, such as proline, lipid peroxidation, H2O2, GSH levels, and ion content. Results show that SC and IB fractions of husk extracts behaved very differently, no doubt due to their greatly divergent chemical composition, as revealed by both GC-MS and HPLC analyses. The efficacy of treatments in mitigating salt stress was also dose- and timing-dependent. IB, even at the lower concentration tested, was able to recover the performance of stressed plants in terms of growth, photosynthetic pigments content, and levels of salt stress markers. Recovery of shoot growth to control levels and reduction of stress-induced proline accumulation occurred regardless of whether plants were pre-treated or post-treated with IB, whereas only pre-treatment with the higher dose of IB was effective in mitigating oxidative stress. Although in some cases SC and even methanol alone exerted some positive effects, they could also be deleterious whereas IB never was. Overall, results indicate that a polyphenol-containing extract obtained from spelt by-products can behave as biostimulant in maize plants and can mitigate their response to salt stress, by acting on different biochemical targets.

Jatropha curcas L. is an inedible plant whose seed oil is an interesting source for biodiesel production. Seed cake, the main byproduct remaining (about 70% w/w) after the oil extraction process, has a high nutritional value but the presence in Jatropha curcas seed of phorbol esters (PEs), a family of toxic compounds with a tigliane skeleton, prevents application of seed cake and other byproducts (e.g. glycerin) in animal feed without an efficient detoxification. Considering the high toxicity of PEs, it is important to have a sensitive analytical method to evaluate the presence of these compounds in Jatropha curcas derivatives. In this paper we present the study of the ESI-MS/MS fragmentation pattern of the [M+Na]+ ion at m/z 733.5 of the six known PEs, namely Jatropha factors (JFs) C1-C6, which allowed to tentatively identify a series of characteristic and specific fragment ions useful to reveal the presence of JFs in Jatropha curcas seed oil, distinguish them from each other, and identify new PEs (J1-J4). Moreover, the substitution of the usual acetonitrile/water as mobile phase with a mixture of methanol/water (85:15, v/v) allowed to increase the signal of the sodium adduct of about 50-fold during the HPLC-ESI-MS/MS analysis.

The sterols and triterpene dialcohols composition is an important parameter to assess the authenticity of the high value and prone to adulteration extra virgin olive oil. The official methods used to carry out this analysis are time-consuming, labor-intensive and require a high amount of solvents. In this work a simple and time-saving method, based on two solid phase extraction (SPE) steps was developed. After oil saponification, the unsaponifiable matter was purified by polymeric SPE and then the sterols and triterpene dialcohols were isolated by an in-house packed small particle silica gel SPE and analyzed by GC-FID. Results obtained analyzing a sample of extra virgin olive oil, olive oil and refined olive pomace oil with the proposed method showed a good agreement with those obtained with the International Olive Council (IOC) official method. Thus, the use of the proposed method allows a rapid screening for extra virgin olive oils authentication.

Cannabis Sativa L. has been used for a long time to obtain food, fiber and as a medicinal and psychoactive plant. Today the nutraceutical potential of C. Sativa is being increasingly reappraised; however, C. Sativa roots remain poorly studied, despite citations in the scientific literature. In this direction, we identified and quantified the presence of valuable bioactives (namely β-sitosterol, stigmasterol, campesterol, friedelin and epi-friedelanol) in the root extracts of C. Sativa, a finding which might pave the way to the exploitation of the therapeutic potential of C. Sativa in all its parts. To facilitate roots harvesting and processing, aeroponic (AP) and aeroponic elicited cultures (AEP), have been set up and compared to soil-cultivated plant (SP): interestingly a considerable overgrowth of the plants - particularly of roots - and a significant increase (up to 20 fold in the case of β-sitosterol) in the total content of the above roots’ bioactive molecules have been observed in AP and AEP. In conclusion aeroponics, an easy, standardised, free of contaminant cultivation tecchnique, allows an ease harvesting/processing of roots along with a greater production of their secondary bioactive metabolites which could be utilized in the formulation of health promoting and health care products.

Conventional (CB) and apple-pomace-reformulated (RB) biscuits were administered to healthy rats. Although the areas under curve (AUC) of glucose concentration were comparable between samples, differences in the glycaemic profile of CB and RB were observed. RB caused an initial steeper increase in glycaemia but a shift in the glycaemic peak from 45 to 60 min, as compared to CB. When CB or RB was ingested with apple juice (AJ) no differences were observed as compared to their ingestion with a soft drink (SD) simulating AJ sugar content, indicating that reformulation, more than the presence of AJ, was crucial in affecting the glycaemic response. Consumer acceptability towards reformulation was assessed through conjoint analysis, by simulating labels reporting information on reformulation. Consumers preferred information generally referring to the health-promoting effect (i.e. “low sugar” and “high fibre” contents), despite directly relating to a specific disease (i.e. “suitable for diabetics” and “low glycaemic index”).

A rapid and sensitive HPLC-APCI-MS/MS method for the determination of cholesterol oxidation products (COPs) in milk powder based foods is reported. The method consists in the direct saponification of the sample and purification of oxysterols by reversed phase C18-SPE followed by HPLC-MS/MS analysis. By this procedure, the extraction and enrichment of oxysterols are combined in a unique step, reducing sample manipulation and the possible formation of artifacts. LOD and LOQ were in the concentration ranges of 2-8ngg-1 and 8-30ngg-1, respectively. The precision (CV%) was in the range 10-36% in fresh samples with a total COPs amount from 212 to 645ngg-1 and 6-14% for an oxidized sample with a higher amount (3651ngg-1). The recovery ranged from 74±8% for 7-ketocholesterol to 101±12% for 7α-hydroxycholesterol at 200ngg-1 and from 82±2% for 7-ketocholesterol to 117±10% for 5α,6α-epoxycholesterol at 500ngg-1 spiked levels, respectively.

Thermal (T) and ultrasound (US) pasteurization processes were applied to apple juice and the phenolic compounds (TPC) were quantified before and after in vitro digestion by HPLC-DAD-ESI-MSn, with their bioaccessibility ascertained. Digested samples were analysed for their inhibitory capacity against α-glucosidase. Since some of the compounds exhibit fluorescence, both steady state and time-resolved fluorescence methods were used to investigate the binding to a blood transport protein, human serum albumin (HSA). It was found that processing induced an increase in the TPC content, which was more pronounced when US was applied. In contrast, digestion reduced the TPC content, evening out the overall effect. Still T and US pasteurized juices exhibited a higher quantity of TPC upon digestion as compared to the raw sample. No correlation was found between the TPC content and α-glucosidase inhibition, as the T and US pasteurized juices showed the highest and lowest inhibitory capacities against the enzyme, respectively. This is indicative that other compounds, such as those formed upon thermal treatment, may be involved in the antidiabetic effect of apple juice. The fluorescence study showed that binding occurred to HSA, at slightly different rates for different species present in the US treated extract. Considering energy consumption, US pasteurization is the most power consuming treatment despite its shorter duration. Overall, no univocal indication on the best pasteurization process can be gathered. Thus, it is necessary to define the desired target in order to drive technological interventions by a customized approach.

The aim of this work was the study of the best conditions for obtaining a callus culture from the pulp of Acca sellowiana, and to perform a quali-quantitative analysis of the secondary metabolites yielded by the in vitro callus culture. To this end, callus was induced on both Murashige and Skoog and Gamborg B5 media containing various combinations of growth regulators. Three previously undescribed ursane-type triterpenoids, 2α,3β,6α,23-tetrahydroxy-18α,19α-urs-20-en-28-oic acid, 2α,3β,23-trihydroxy-18α,19α-urs-20-en-28-oic acid and 2α,3β,6β,23-tetrahydroxy-18α,19α-urs-20-en-28-oic acid were isolated from the methanolic extract of A. sellowiana culture and characterized by 1D and 2D NMR experiments. Moreover, the quali-quantitative analysis (ESI-MSn and GC-MS) also showed the presence of β-sitosterol, phloridzin, oleanolic, ursolic, 3β-hydroxy-18α,19α-urs-20-en-28-oic, maslinic, corosolic, 2α,3β-dihydroxy-18α,19α-urs-20-en-28-oic, and tormentic acid.

Introduction Very rarely fruit pulp has been used in in vitro culture to produce secondary metabolites useful in promoting health. Objectives The aims of this work were the study of the best conditions to obtain the callus cultures from the pulp of two varieties of apples, Golden Delicious (GD) and “Mela Rosa Marchigiana” (MRM), and the quali-quantitative analysis of secondary metabolites produced by the two in vitro callus cultures. Methodology Callus was induced on both Murashige and Skoog and Gamborg B5 media containing various combinations of supplements. To achieve the maximum recovery of secondary metabolites produced, preliminary extraction tests were carried out on GD apple culture using two different organic solvents (MeOH and EtOAc). The quali-quantitative analysis of the methanolic extract of both cultures was carried out by ESI-MSn and GC–MS techniques. Results The GC–MS analysis revealed the presence of triterpenic acids, in particular, oleanolic, ursolic, maslinic, pomolic, tormentic, corosolic and annurcoic acid along with a phytosterol, β-sitosterol. In addition, GD callus culture produced phloridzin, absent in the MRM culture. In this last culture, however, the total amount of secondary metabolites was markedly higher. The in vivo production of these bioactive compounds were also quantified in the GD and MRM apple pulps. Conclusion Apple pulps produced higher amounts of triterpenic acids in vitro than in vivo. The present work can be considered a method to amplify the production of important secondary metabolites which exert beneficial effects on human health. Copyright © 2016 John Wiley & Sons, Ltd.

This paper aims to identify causes and processes of an undesired age-related optical phenomenon in which two kinds of paper – a white paper and a green one – and an iron-gall ink are involved together with unavoidable environmental agents. Documents under examination are dated 1893 and come from the Trieste cadastral system archive (Ufficio del catasto tavolare di Trieste). The green paper, with a high content of lignin and kaolin is a pre-printed payment order used in accounting operations and it is adjacent to a white lignin-free paper. Diffused brown stains appear on the white paper mainly from being in prolonged contact with the green one which was handwritten using iron-gall ink. The green page induces a strong browning effect on the contact side of the white one, except for inked areas. The manuscript black lines of the lignin-containing page seem to protect the adjacent surface, where a mirror image appears. A particular type of mirror effect, which we propose to call negative mirror effect, is clearly evidenced. Micro-XRF (micro-X-ray fluorescence spectroscopy) and FT-IR ATR (attenuated total reflectance Fourier transform infrared spectroscopy) techniques were used to achieve information on both diagnostic inorganic and organic components. By way of our chemical model we can hypothesise the migration of oxidised brown low molecular weight extra-cellulose compounds (from lignin and/or hemicelluloses) from green recto to white verso pages. The browning process is only hindered in sharp correspondence with the areas of the green recto folio written with the iron-gall ink: this ink acts as a physical barrier to the migration or, as a second hypothesis, it is able to withhold the mobile organic compounds by way of a specific but still unknown interaction. In the field of scientific research on metal-gall ink corrosion this is a novel, interesting and surprising case of the reverse, in which the ink itself is not the cause of the corrosion, but the unforeseen preventive agent.

N-Boc/Fmoc/Z-N′-formyl-gem-diaminoalkyl derivatives, intermediates particularly useful in the synthesis of partially modified retro-inverso peptides, have been characterized by both positive and negative ion electrospray ionization (ESI) ion-trap multi-stage mass spectrometry (MSn). The MS2 collision induced dissociation (CID) spectra of the sodium adduct of the formamides derived from the corresponding N-Fmoc/Z-amino acids, dipeptide and tripeptide acids show the [M + Na-NH2CHO]+ ion, arising from the loss of formamide, as the base peak. Differently, the MS2 CID spectra of [M + Na]+ ion of all the N-Boc derivatives yield the abundant [M + Na-C4H8]+ and [M + Na-Boc + H]+ ions because of the loss of isobutylene and CO2 from the Boc protecting function. Useful information on the type of amino acids and their sequence in the N-protected dipeptidyl and tripeptidyl-N′-formamides is provided by MS2 and subsequent MSn experiments on the respective precursor ions. The negative ion ESI mass spectra of these oligomers show, in addition to [M-H]−, [M + HCOO]− and [M + Cl]− ions, the presence of in-source CID fragment ions deriving from the involvement of the N-protecting group. Furthermore, MSn spectra of [M + Cl]− ion of N-protected dipeptide and tripeptide derivatives show characteristic fragmentations that are useful for determining the nature of the C-terminal gem-diamino residue. The present paper represents an initial attempt to study the ESI-MS behavior of these important intermediates and lays the groundwork for structural-based studies on more complex partially modified retro-inverso peptides. Copyright © 2013 John Wiley & Sons, Ltd.

A simple, efficient two-step synthesis of N-protected N′-formyl-gem-diaminoalkyl derivatives is reported. The procedure involves the unprecedented reduction of the carbamoyl azide of α-N-Boc/Fmoc/Z-protected amino acids and dipeptides (Boc = tert-butoxycarbonyl, Fmoc = 9-fluorenylmethoxycarbonyl, Z = benzyloxycarbonyl) by treatment with NaBH4 at room temperature. The reaction proceeds rapidly (45 min) without detectable epimerization (by HPLC-ESI-MS analysis) and is not influenced by the nature of the starting carbamoyl azide. The 1H and 13C NMR analyses of the synthesized N-protected N′-formamides were carried out in [D6]DMSO. The spectra exhibited the presence of two rotameric forms in solution as a result of the restricted rotation around the N–CO formyl bond. The integration of the N–CH–N protons of the two isomers showed that the cis isomer (rotamer B) was the more abundant conformer by 60 to 78 %. The reported synthesis represents the potential value of carbamoyl azides as versatile chiral starting materials for many synthetic purposes.

Very rarely fruit pulp has been used in in vitro culture to produce secondary metabolites useful in promoting health.The aims of this work were the study of the best conditions to obtain the callus cultures from the pulp of two varieties of apples, Golden Delicious (GD) and "Mela Rosa Marchigiana" (MRM), and the quali-quantitative analysis of secondary metabolites produced by the two in vitro callus cultures.Callus was induced on both Murashige and Skoog and Gamborg B5 media containing various combinations of supplements. To achieve the maximum recovery of secondary metabolites produced, preliminary extraction tests were carried out on GD apple culture using two different organic solvents (MeOH and EtOAc). The quali-quantitative analysis of the methanolic extract of both cultures was carried out by ESI-MSThe GC-MS analysis revealed the presence of triterpenic acids, in particular, oleanolic, ursolic, maslinic, pomolic, tormentic, corosolic and annurcoic acid along with a phytosterol, β-sitosterol. In addition, GD callus culture produced phloridzin, absent in the MRM culture. In this last culture, however, the total amount of secondary metabolites was markedly higher. The in vivo production of these bioactive compounds were also quantified in the GD and MRM apple pulps.Apple pulps produced higher amounts of triterpenic acids in vitro than in vivo. The present work can be considered a method to amplify the production of important secondary metabolites which exert beneficial effects on human health. Copyright © 2016 John WileySons, Ltd.

In this study, several deteriorated pressure sensitive adhesive tapes (PSATs) applied in the past for repairing ripped paper documents of 19th century and books of 20th century were analyzed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy technique. The comparison of FTIR spectra of the old tapes with those of some commercially available tapes subjected to accelerated aging allowed us to identify, in a fast and nondestructive way, the main classes of old tapes on the basis of their backing (cellophane, cellulose acetate, polyvinyl chloride and polypropylene) and adhesive (natural rubber, synthetic rubber and acrylic polymer) compositions. This procedure's results were very useful to the paper restorers and conservators, who will have the possibility of choosing the most appropriate conservation treatment for the removal of pressure sensitive adhesive tapes that can be found on many paper documents.

The kinetics of periodate oxidation of cellulose was followed by exploiting the β-alkoxy degradation of oxidised units in alkaline medium, that brings about a decrease of viscometric degree of polymerisation. The parallel strong weight loss after NaOH treatment indicates a non-random mechanism of oxidation. The obtained results are interpreted on the basis of an appositely derived kinetic model that can be applied to other mechanisms of bulk and surface degradation.

The in vitro antifungal activity was determined of an ethanolic extract of Vitis vinifera L. tendrils (TVV) against ten plant pathogenic fungi, using the agar dilution method; activity was shown against all tested fungi. Fusarium species were the most sensitive with MIC values ranging from 250 to 300 ppm, while the basidiomycete fungus Rhizoctonia solani was the most resistant, with a MIC value of 500 ppm. Electrospray ionization tandem mass spectrometry (ESI-MSn) was used to obtain qualitative information on the main components of TVV. The high amount of polyphenolic compounds contained in TVV is likely to contribute significantly to its antifungal activity.

Paper lamination is a widely used method to consolidate fragile documents. Previous studies have presented a new method of lamination that allows the consolidation of documents before undertaking aqueous treatments. In this method a thin Japanese paper coated with an acrylic resin is applied on the fragile document by means of a heated press. In this work we optimised the preparation of the lamination sheets as well as the working procedures, and we were able to establish that our laboratory-made specimens are chemically stable, easily reversible and permeable to aqueous solutions. The latest property is of particular importance, since it allows a subsequent aqueous deacidification even for fragile documents. The laminated paper documents were further analysed by means of colorimetry and FTIR spectroscopy before and after accelerated ageing as well as by determination of the alkali reserve left on the coated paper, in order to compare our lamination method with other commercially available lamination sheets.

The reaction products are prepared in a three step sequence and achieved as a mixture of two rotamers.

The ring forming condensation between some natural α-amino acid phenylhydrazides (1) and aqueous formaldehyde (2) has opened a novel synthetic route to hexahydro-1,2,4-triazin-6-one derivatives (3). Polycyclic systems were obtained from the same reaction carried out with L-aspartic acid 1,4-bis(2-phenylhydrazide) (1d), L-histidine phenylhydrazide (1e) and L-tryptophan phenylhydrazide (1f) which gave perhydro-4,6-dioxo-2,8-diphenyl[1,2,4]triazino[4,5-d][1,2,4]triazepine (5) perhydro-1-oxo-3-phenylimidazo[5,4-d][1,2,4]triazino[4,5-a]pyridine (7) and 1,2,3-H-3-(2-phenylcarbazoyl)-β-carboline (8), respectively. Substrates 1 were conveniently obtained by direct reaction of phenylhydrazine with L-α-amino acid esters retaining the original chirality.

The ring forming condensation between some natural α-amino acid phenylhydrazides (1) and aqueous formaldehyde (2) has opened a novel synthetic route to hexahydro-1,2,4-triazin-6-one derivatives (3). Polycyclic systems were obtained from the same reaction carried out with L-aspartic acid 1,4-bis(2-phenylhydrazide) (1d), L-histidine phenylhydrazide (1e) and L-tryptophan phenylhydrazide (1f) which gave perhydro-4,6-dioxo-2,8-diphenyl[1,2,4]triazino[4,5-d][1,2,4]triazepine (5) perhydro-1-oxo-3-phenylimidazo[5,4-d][1,2,4]triazino[4,5-a]pyridine (7) and 1,2,3-H-3-(2-phenylcarbazoyl)-β-carboline (8), respectively. Substrates 1 were conveniently obtained by direct reaction of phenylhydrazine with L-α-amino acid esters retaining the original chirality.

The study of polymer behavior over time represents the crucial stage in the setup of innovative methodologies for paper restoration. In this research, a series of laboratory simulations by accelerated aging and characterization tests by chemical and physical measurements were carried out on paper samples consolidated both by grafting polymerization with acrylic copolymers and by coating with waterborne polyurethanes with the aim of determining their harmlessness and long-term effectiveness. In this way, our purpose was not only to verify possible risks for the paper materials but also to determine the advantages and potentialities of new restoration methods through an appropriate and essential working plan of investigations. From our evaluation, both the selected consolidation methods appeared unsuitable to be used in paper restoration because of the damage that they could cause on the paper materials because of their limited durability over time. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The kinetics of cellulose degradation was analysed by means of a two-stage model, characterised by an autoretardant and autocatalytic regime, later tempered by the consumption of glycosidic bonds in the amorphous regions. The proposed model explains the effects on the kinetic equations of different modes of ageing (acid hydrolysis, ageing in ventilated oven or sealed vessels), initial oxidation of cellulose and experimental procedures (with or without reduction of oxidised groups). The autoretardant branch can be analysed in a quantitative way, while the integration of the non-linear autocatalytic branch is allowed in some cases, characterised by the decrease of pH and/or emission of acid volatile organic compounds (VOCs). Most of the controversial results of the literature can be easily explained, but the proposed model offers also a guide for further studies on the kinetics of cellulose degradation.

Afin de determiner les facteurs cles responsables de la deterioration du papier place dans un environnement clos, ou range dans des rayons, un modele autocatalyctique de degradation en conteneurs scelles a ete cree. En raison de la non-linearite du modele une solution analytique ne peut etre trouvee si facilement mais une simulation sur ordinateur indique de facon qualitative que l'acidite initiale du papier exerce une une influence sur la forme du deroulement cinetique alors que l'ampleur d'un accroissement de composes acides volatiles (VOCs) provoque un accroissement de la deterioration. Nos resultats demontrent que l'acidite initiale et le mecanisme chimique d'oxydation devraient etre pris en consideration dans les recherches, plutot que le degre de polymerisation, tant en ce qui concerne le processus de vieillissement accelere que celui du vieillissement naturel du papier dans des environnements clos, c'est-a-dire non ventiles (non aeres).

La cinetique de la degradation du papier a ete brievement reconsideree et remise a jour afin de mettre en evidence les facteurs essentiels qui avaient ete (et qui sont encore) largement negliges lors de l'interpretation des resultats experimentaux. Un simple re-examen des donnees de la litterature revele le caractere discutable de maintes declarations faites dans le domaine de la recherche relative a la conservation du papier. On a demontre en particulier que les techniques du vieillissement accelere ne permettent pas de predire l'esperance de vie du papier, comme le met en evidence la structure exponentielle de l'equation d'Arrhenius. Il apparait par ailleurs que certains resultats obtenus lors d'analyses viscosimetriques aient ete mal interpretes car lors de la planification des experiences aucune difference n'avait ete faite entre la degradation actuelle (hydrolytique) et la degradation potentielle (oxydative) de la cellulose. Enfin l'ordre pseudo-zero de la cinetique de la degradation conduit a des declarations discutables car la plupart des mecanismes de degradation du papier ne se conforment pas a ce modele simple. Les resultats de la recherche dans le domaine de la conservation du papier devraient etre partiellement revises.

Cellulose paper (Whatman no.1, chromatographic grade) was oxidised with 0.1 M sodium metaperiodate at different oxidation levels (0–11 days at room temperature), and analysed with FTIR before and after chemical treatments (reduction, further oxidation, alkaline hydrolysis). The deconvolution of infrared data allowed us to verify that periodate oxidises cellulose in isolated domains, leading to the decrease of crystallinity, in agreement with the results of wide angle X-ray scattering (WAXS). In particular, the alkaline hydrolysis (β-alkoxy fragmentation) followed by mild acid treatment removed the oxidised groups and recovered most of the crystallinity of cellulose, as determined by the FTIR crystallinity index.

Paper lamination is a widely known method to consolidate fragile and brittle documents. Since the loss of mechanical strength of paper documents is almost completely due to their acidity, the procedure generally adopted by restorers consists of an aqueous treatment of deacidification followed by consolidation. The drawback of this method is due to the loss of paper fragments during the deacidification step, that must be therefore accurately controlled. Some preliminary experiments showed that a better and faster practice would be the lamination of paper documents with a water-resistant sheet before their immersion in the deacidification bath. The aim of this work is to evaluate the permeability, chemical stability and reversibility of the lamination sheets coated with two commercially available acrylic resins. From both gravimetric and FTIR analyses it appeared that slight modifications of the acrylic monomers led to different properties, and this behaviour can be exploited to improve the properties of lamination sheets in order to set up a reliable method of aqueous mass deacidification.

Les spectres infrarouges des echantillons de papier montrent souvent de nombreuses bandes qui se chevauchent de facon tres significative aux alentours de 1400-1900 cm. La deconvolution numerique revele les informations sous-jacentes comme l'ont demontre certains exemples de deconvolution effectuee sur des echantillons anciens de papier original ainsi que sur des echantillons de papier specialement prepares. Grâce a la technique de deconvolution numerique il est possible de detecter l'absorption d'infrarouge par les groupes oxydes (conjugues ou non conjugues) dans la molecule de cellulose, ainsi que dans la gelatine, la colophane et la lignine et ceci meme en presence de larges bandes provoquees par absorption d'eau a -1630 cm. La technique de deconvolution permet d'identifier approximativement le mecanisme de degradation qui entraine le jaunissement et le brunissement des echantillons de papier.

Des echantillons de papier de cellulose contenant du FeCl 3 et du CuCl 2 ont ete soumis a une analyse FTIR avant et apres le vieillissement accelere a 90+/-10°C (technique des tubes scelles). On a pu constater qu'une forte hydrolyse et une deshydratation des chaines cellulosiques avec formation de liaison double de C4-C5 et d'une oxydation de C6 sont les phenomenes essentiels observes lors de la degradation de FE(III). Cu(II) oxyde les groupes C2- et C3-OH en aldehydes et carboxyles en entrainant une cassure des composes cycliques qui hydrolyse et oxyde le groupe C4-OR avec formation de C4-C6 β-ceto-aldehyde ou β-ceto-acide. Parmi les bandes de deconvolution FTIR du domaine situe entre 1250 et 1850 cm -1 on attribue le signal 1660 cm -1 au groupe insature de C=C-cO et le signal 1612-1622 cm -1 au groupe CO-C-CO (forme chelatee de tautomerie ceto-enolique). Ces bandes qui ne peuvent etre detectees qu'a l'aide de la technique de deconvolution apparaissent plus distinctement que celles de groupes libres (non-lies) au-dela de 1700 cm -1 .