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4 páginas.- 1 figuras.-1 tabla.- 8 referencias.- Descripción del póster presentado en el 16th European Workshop on Lignocellulosics and Pulp (EWLP) Gothenburg, Sweden, June 28 – July 1, 2022, In the present work, the lignin from papyrus (Cyperus papyrus L.) pith and rind were isolated and studied in detail by two-dimensional nuclear magnetic resonance (2D-NMR) and derivatization followed by reductive cleavage (DFRC). The lignins from both parts of papyrus culms differed greatly in composition and structure. In the rind, the lignin was composed mainly of G-units, while the lignin in the pith was slightly enriched in Sunits. The differences in composition influenced the lignin interunit-linkage distribution. Moreover, 2D-NMR analyses revealed that the lignins from papyrus incorporated considerable amounts of cinnamates (p-coumarates and ferulates) and were highly acylated at the γ-OH. DFRC analyses proved that p-coumarates were the main acylating groups, predominantly acylating the S-lignin units. In addition, the rind lignin, and to a lesser extent the pith lignin, contained significant amounts of tricin and other flavonoids (naringenin chalcone, naringenin and dihydrotricin) incorporated into their structure., This work was supported by the project PID2020-118968RB-I00, funded by MCIN/AEI/ 10.13039/501100011033, and the project P20-00017 funded by the Regional Andalusian Government. MJR thanks the Spanish Ministry of Science, Innovation and Universities for a FPI fellowship (PRE2018-083267). The support by the Austrian Biorefinery Center Tulln (ABCT) is gratefully acknowledged

Póster PO2-04 en pdf y resúmen extendido de 4 páginas.- 2 figuras.- 8 referencias.- del póster PO2-04 presentado en el 16th European Workshop on Lignocellulosics and Pulp (EWLP) Gothenburg, Sweden, June 28 – July 1, 2022, In this study, we have found for the first time that various classes of flavonoids, namely naringenin chalcone, naringenin, dihydrotricin, and tricin, are incorporated into the lignin polymer of papyrus (Cyperus papyrus L.) rind. Identification of flavonoids was performed by analysis of the compounds released from the lignin by derivatization followed by reductive cleavage (the DFRC method), as well as by two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopic analysis, and comparing with authentic standards., This work was supported by the project PID2020-118968RB-I00, funded by MCIN/AEI/10.13039/501100011033, and the project P20-00017 funded by the Regional Andalusian Government, Consejería de Transformación Económica, Industria, Conocimiento y Universidades/FEDER. HK, VIT, JR are funded by DOE Office of Science DE-SC0018409.

Additional file 1: Figure S1. Transmission spectrum of the microscope slides used to mount the papyri during accelerated aging. Figure S2. FT-IR spectra of samples aged for up to 57 days with and without the influence of light. a Entire spectrum without the influence of light; b Entire spectrum with the influence of light; c Detail of the spectra (1750–1100 1/cm) aged in darkness. Figure S3. Chromatograms of aged samples without (left) and with (right) light influence, expressed as sample concentration (RI) vs. time, normalized to equal peak area. Note the different curve shapes—the “third peak”—for light aged samples after a longer aging treatment.

In der vorliegenden Arbeit wurden 6 Proben historischer Gem��lde - davon 3 von Peter Paul Rubens ��� mit Mikro-R��ntgendiffraktometrie (��-XRD) im Labor untersucht. Die verwendeten Strahlquerschnitte wurden hierbei durch Beschneiden des Strahls unter Verwendung von Schlitzen auf eine Breite bis >100 ��m begrenzt. Es sollte untersucht werden, ob bei einem Laborger��t mit sehr geringen Spaltbreiten noch verwertbare Informationen zum Auftreten kristalliner Phasen in Malschichten erhalten werden k��nnen. Das Hauptaugenmerk der Arbeit lag darauf, den Malschichtaufbau durch Abscannen der Probe in definierten Abst��nden (50 ��m bzw. 100 ��m) durch R��ntgenbeugung abbilden zu k��nnen. Zur Optimierung der Messparameter wurden alle Messbereiche mit Parallelstrahlspiegel und fokussierendem Spiegel untersucht und die Resultate verglichen. Allen untersuchten Proben konnte klar mindestens eine kristalline Phase zugewiesen werden, in der Regel zur Grundierung geh��rend (Calcit, Kalziumsulfat-Dihydrat). Die d��nnste, zusammenh��ngende Schicht, die detektiert werden konnte, war im Durchschnitt 30 ��m dick und bestand aus Quecksilbersulfid (Zinnoberrot). Obwohl die chemische Analyse hohe Siliziumanteile in einigen Malschichten ergab, konnte keine silicathaltige Phase mit der verwendeten Technik detektiert werden. Die r��umliche Zuordnung der Diffraktionsdaten zu Messbereichen auf der Probe war mit fokussierendem Spiegel in der Regel pr��ziser m��glich, auf Kosten der Intensit��t der Reflexe. Bei dieser Optik wurden dominante Phasen aus einem anderen Messbereich bestenfalls dann nicht mehr detektiert, wenn sich der Fokus des R��ntgenstrahls ��ber 100 ��m von der Grenze der Malschichten entfernt befand. Gro��fl��chig aufgetragene Pigmente wie Bleiwei��, Eisenoxide (H��matit) und Zinnoberrot konnten sehr gut detektiert werden, weitere Bestandteile wie Mennige und Aragonit nur mit sehr geringer Intensit��t. F��r alle Proben der Gem��lde von Peter Paul Rubens wurde Cerussit (Bleicarbonat) als Begleitphase der Bleiwei��schichten gefunden, dies erweitert die durch andere Analysetechniken - wie z.B. Infrarot- oder Ramanspektroskopie, sowie R��ntgenfluoreszenzanalyse - erzielbaren Informationen. In den Grundierungen der Rubens-Gem��lde wurden keine Unterschiede bez��glich der kristallinen Phasen festgestellt, ausschlie��lich Calcit wurde detektiert., This work comprises the analysis of six samples of historic paintings ��� including three by Peter Paul Rubens ��� by applying micro X-Ray diffraction (��-XRD). It was examined whether useful XRD data of paint layers could still be obtained, if the beam width is limited to 100 ��m using laboratory equipment. The focus of this work was to represent the arrangement of the paint layers by XRD-data through measurements every 50 ��m or 100 ��m. To optimize the measuring parameters, all areas were detected using parallel and focusing mirrors and comparing the results. At least one crystalline phase was detected for every sample, mostly parts of the ground, such as calcite and gypsum. The smallest coherent layer detected was on average 30 ��m thick and consisted of mercury sulfide. No phase containing silicon could be detected, although being a main component of some investigated areas, as shown by chemical analysis. Area resolution of the obtained diffraction data was more precise using the focusing mirror, having less intensity on the downside. At best, no intensity was detected for areas containing strong X-Ray scattering elements that were more than 100 ��m away from the beam focus. Pigments like lead white, hematite and vermilion could be detected very well, especially if applied in a coherent area. Other phases like vermilion and aragonite showed only very small intensities. The Rubens samples exhibited cerussite accompanied by the lead white phases, an information that adds to the information obtained by other methods, e.g. Raman/infrared spectroscopy or X-Ray fluoresecence spectroscopy. No differences could be detected regarding the groundings of the artworks by Rubens, all showing only calcite as crystalline compound.

20 páginas.- 10 figuras.- 2 tablas.- 59 referencias.- Supplementary Information The online version contains supplementary material available at https://doi.org/10.1007/s10570-022-04573-y, Papyrus, produced from the white pith of Cyperus papyrus L., has been used for millennia as the major writing support by ancient cultures, but there was no continuous papyrus production until modern times. Therefore, papyrus production had to be rediscovered. Modern Egyptian papyrus producers claim that their sheets possess 'the same physical and chemical properties as ancient papyri'. To study if this is accurate, commercially available papyrus sheets were compared to ancient papyri and papyri produced according to Pliny's historic description. Material characterization was performed with a focus on the potentially color-bearing lignin. Two-dimensional nuclear magnetic resonance spectroscopy, derivatization followed by reductive cleavage, and pyrolysis-gas chromatography/mass spectrometry were complemented with microscopy and tests for surface pH and sodium content. The lignin data in the native pith and commercial sheets were compared to 10 ancient samples from the Papyrus Museum Vienna. The analytical data clearly show the involvement of a strong alkaline treatment followed by chlorine bleaching for commercial papyri, as expressed by higher pH values, altered lignin structures, and chlorinated lignin compounds. The inclusion of an alkaline step in ancient papyrus manufacture is discussed but dismissed, since the alkali-treatment causes a huge decrease in lignin content, that was not found for the analysed ancient specimen. We assume that this additional treatment was introduced to obtain yellowish papyrus sheets meeting optical expectations of modern spectators. Linguistic and art historic evidence indicates that such a step would not have made sense in antiquity, since it was desired to produce white papyri., Open access funding provided by University of Natural Resources and Life Sciences Vienna (BOKU). The authors acknowledge the financial support from the Austrian Biorefinery Centre Tulln (ABCT), the County of Lower Austria, the Spanish State Research Agency, the European Regional Development Fund (project AGL2017-83036-R) and the Junta de Andalucia (project P20-00017).

8 figuras.- refefencias.- Versión aceptada del artículo.- Supplementary data kiab469_Suppl. https://academic.oup.com/plphys/advance-article/doi/10.1093/plphys/kiab469/6400262#supplementary-data, Recent studies demonstrate that several polyphenolic compounds produced from beyond the canonical monolignol biosynthetic pathways can behave as lignin monomers, participating in radical coupling reactions and being incorporated into lignin polymers. Here, we show various classes of flavonoids, the chalconoid naringenin chalcone, the flavanones naringenin and dihydrotricin, and the flavone tricin, incorporate into the lignin polymer of papyrus (Cyperus papyrus L.) rind. These flavonoids were released from the rind lignin by DFRC, a chemical degradative method that cleaves the β-ether linkages, indicating that at least a fraction of each was integrated into the lignin as β-ether linked structures. Due to the particular structure of tricin and dihydrotricin, whose C-3ʹ and C-5ʹ positions at their B-rings are occupied by methoxy groups, these compounds can only be incorporated into the lignin through 4ʹ–O–β bonds. However, naringenin chalcone and naringenin have no substituents at these positions and can therefore form additional carbon-carbon linkages, including 3ʹ– or 5ʹ–β linkages that form phenylcoumaran structures not susceptible to cleavage by DFRC. Furthermore, NMR analysis indicated that naringenin chalcone can also form additional linkages through its conjugated double bond. The discovery expands the range of flavonoids incorporated into natural lignins, further broadens the traditional definition of lignin, and enhances the premise that any phenolic compound present at the cell wall during lignification could be oxidized and potentially integrated into the lignin structure, depending only on its chemical compatibility. This study indicates that papyrus lignin has a unique structure as it is the only lignin known to date that integrates such a diversity of phenolic compounds from different classes of flavonoids. This discovery will open up new ways to engineer and design lignins with specific properties and for enhanced value., This work was funded by the Spanish State Research Agency and the European Regional 51 Development Fund (project AGL2017-83036-R), the Consejería de Transformación 52 Económica, Industria, Conocimiento y Universidades, Junta de Andalucía (project P20-53 00017), the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science DE54 SC0018409), and the Austrian Biorefinery Center Tulln (ABCT). MJR thanks the Spanish 55 Ministry of Science, Innovation and Universities for a FPI fellowship (PRE2018-083267).

11 páginas.- 6 figuras.- 5 tablas.- 57 referencias, Papyrus (Cyperus papyrus L.) is a plant with high productivity rate that is considered an interesting raw material for obtaining biofuels and biomaterials. In the present work, the composition and structural features of the lignins present in the rind and pith of papyrus culms have been studied. The analyses revealed that the lignins from both parts of papyrus culms differed greatly not only in their contents but also in composition and structure. In the rind, the lignin represented up to 27.0% (dry-matter) and was composed mainly of G-units (H:G:S composition of 4:63:33), while the lignin in the pith (15.7% dry-matter) presented a slightly higher amount of S-units (H:G:S composition of 8:43:49). These lignins also presented considerable amounts of cinnamates (p-coumarates and ferulates) incorporated. The differences in composition influenced the content of the lignin inter-unit linkages. Thus, the rind lignin presented lower amounts of β–O–4′ ether linkages (77% of all identified linkages) and higher content of condensed structures, such as phenylcoumarans (15%), resinols (2%), dibenzodioxocins (3%), and spirodienones (2%), while the pith lignin contained more β–O–4′ ethers (85% of all identified linkages) and lower amounts of phenylcoumarans (11%), tetrahydrofurans (2%), and spirodienones (2%). Moreover, 2D NMR analyses revealed that the lignins from papyrus were highly acylated at the γ-OH (40% acylation in the rind, and 60% acylation in the pith). DFRC analyses proved that p-coumarates were the main acylating groups, and that they were predominantly acylating the S-lignin units. Finally, the analyses also showed the presence of important amounts of the flavanone tricin in the rind lignin and, at lower amounts, in the pith lignin. © 2021 The Authors, This work was partially funded by the Spanish Project AGL2017-83036-R (financed by Agencia Estatal de Investigación, AEI and Fondo Europeo de Desarrollo Regional, FEDER) and by Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucía, Spain (project P20_00017). MJR thanks the Spanish Ministry of Science, Innovation and Universities for a FPI fellowship (PRE2018-083267). FB, TR, and AP were funded by the Austrian Biorefinery Center Tulln (ABCT).

9 páginas.- 4 figuras.- 1 tabla.- 27 referencias, Papyri belong to the oldest writing grounds in history. Their conservation is of the highest importance in preserving our cultural heritage, which is best achieved based on an extensive knowledge of the materials’ constituents to choose a tailored conservation approach. Thermogravimetric Analysis (TGA) has been widely employed to quantify cellulose and lignin in papyrus sheets, yielding reported lignin contents of 25% to 40%. In this work, the TGA method conventionally used for papyrus samples was repeated and compared to other lignin determination approaches (Klason-lignin and acetyl bromide-soluble lignin). TGA can lead to a large overestimation of the lignin content of commercial papyrus sheets (~27%) compared to the other methods (~5%). A similar overestimation of the lignin content was found for the pith and rind of the native papyrus plant. We concluded that the TGA method should, therefore, not be used for lignin quantification., Funding by the Austrian Biorefinery Center Tulln (ABCT) and the County of Lower Austria is greatly acknowledged. J.C.d.R., J.R. and M.J.R were funded by the Spanish State Research Agency and the European Regional Development Fund (project AGL2017-83036-R), and by the Junta de Andalucía (project P20-00017).

19 páginas.- 9 figuras.- 1 tabla.- 55 referencias.- The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fpls.2022.1097866/full#supplementary-material, Papyrus (Cyperus papyrus L.) is a sedge plant with a high rate of biomass productivity that represents an interesting raw material to produce chemicals, materials and fuels, which are currently still obtained from fossil resources, in the context of a lignocellulosic biorefinery. In this work, the content and chemical composition of the lipids present in papyrus stems were thoroughly studied. For this, the papyrus stems were separated into the rind and the pith. The lipid content accounted for 4.1% in the rind and 4.9% in the pith (based on dry matter). The main compounds identified in both parts of the papyrus stem were hydrocarbons, n-fatty acids, 2-hydroxyfatty acids, alcohols, alkylamides, mono- and diglycerides, steroids (sterols, ketones, hydrocarbons, esters and glycosides), tocopherols, tocopherol esters, phytol, phytol esters, alkyl ferulates, ω-carboxyalkyl ferulates (and their monoglycerides), and acylglycerol glycosides. The rind presented a predominance of n-fatty acids (6790 mg/kg; that represented 28.6% of all identified compounds), steroid compounds (6255 mg/kg; 26.3%), phytol and phytol esters (4985 mg/kg; 21.0%), and isoprenoid hydrocarbons, namely phytadiene and squalene (2660 mg/kg; 11.2%), while the most abundant lipids in the pith were steroids (8600 mg/kg; 44.4% of all identified compounds) and fatty acids (6245 mg/kg; 32.2%). Due to the great diversity and significant abundance of the compounds identified in papyrus, it can be considered as a potential raw material for biorefineries to obtain valuable phytochemicals of interest to various industrial sectors., This work has been funded by the projects AGL2017-83036-R and PID2020-118968RB-I00 (financed by MCIN/AEI/ 10.13039/501100011033 and, as appropriate, by “ERDF A way of making Europe”), and the project P20_00017 (financed by the Regional Andalusian Government, Consejería de Transformación Económica, Industria, Conocimiento y Universidades, and co-financed by FEDER). MJR acknowledges the Spanish Ministry of Science, Innovation and Universities for a FPI fellowship (PRE2018-083267). FB, TR, and AP were supported by the Austrian Biorefinery Center Tulln (ABCT).