25 research outputs found
A structural characterization of the lignins from sugarcane (Saccharum spp. L) bagasse and straw
The structure of the lignins of sugarcane bagasse and straw was investigated. The lignins were characterized both in situ and in isolated preparations (Milled-Wood Lignin, MWL, and Cellulolytic Lignin, CEL) by Py-GC/MS and 2D-NMR. It was concluded that they are p-hydroxyphenyl-guaiacyl-syringyl lignins with associated p-coumarates and ferulates. 2D-NMR indicated that the main substructures present are β–O–4´-ethers, followed by β–5´ phenylcoumarans and with lower amounts of β–β´ resinols and β–1´ spirodienones.This study has been funded by the EU project LIGNODECO (KBBE-244362) and the Spanish project AGL2011-25379 (co-financed by FEDER funds). Jorge Rencoret thanks the CSIC for a JAE-DOC contract of the program “Junta para la Ampliación de Estudios” co-financed by Fondo Social Europeo (FSE). Funding provided by the Minas Gerais State Research Foundation (FAMEPIG) from the Brazilian National Council for Science and Technology Development (CNPq), and from the Coordination for the Improvement of Higher Education Personnel (CAPES) is greatly appreciated.N
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
Brazilian legislation on genetic heritage harms biodiversity convention goals and threatens basic biology research and education
ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest
Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
Differences in the chemical structures of the lignins from sugarcane bagasse and straw
Two major residues are produced by the sugarcane industry, the fibrous fraction following juice extraction (bagasse), and the harvest residue (straw). The structures of the lignins from these residues were studied by pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC/MS), nuclear magnetic resonance (NMR), and derivatization followed by reductive cleavage (DFRC). Whereas the lignin from bagasse has a syringyl-rich p-hydroxyphenyl:guaiacyl:syringyl (H:G:S) molar composition of 2:38:60, the lignin from straw is guaiacyl-rich (H:G:S of 4:68:28). The compositional differences were also reflected in the relative abundances of the different interunit linkages. Bagasse lignin was primarily β–O–4′ alkyl-aryl ether units (representing 83% of NMR-measurable units), followed by minor amounts of β–5′ (phenylcoumarans, 6%) and other condensed units. The lignin from straw has lower levels of β-ethers (75%) but higher relative levels of phenylcoumarans (β–5′, 15%) and dibenzodioxocins (5–5/4–O–β, 3%), consistent with a lignin enriched in G-units. Both lignins are extensively acylated at the γ-hydroxyl of the lignin side-chain (42% and 36% acylation in bagasse and straw), predominantly with p-coumarates (preferentially on S-units) but also with acetates (preferentially on G-units) to a minor extent. Tetrahydrofuran structures diagnostically arising from β–β-coupling (dehydrodimerization) of sinapyl p-coumarate or its cross-coupling with sinapyl alcohol were found in both lignins, indicating that sinapyl p-coumarate acts as a monomer participating in lignification. The flavone tricin was also found in the lignins from sugarcane, as also occurs in other grasses.This study has been funded by the Spanish projects AGL2011-25379, AGL2014-53730-R and CTQ2014-60764-JIN (co-financed by FEDER funds), the CSIC project 2014-40E-097 and the EU-projects LIGNODECO (KBBE-2009-3-244362) and INDOX (KBBE-2013-7-613549). John Ralph was funded through the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science DE-FC02-07ER64494). Jorge Rencoret thanks the CSIC for a JAE-DOC contract of the program “Junta para la Ampliación de Estudios” co-financed by Fondo Social Europeo (FSE). A.G. Lino thanks CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) for financial support. C.F. Lima and J.L. Colodette are grateful to National Council for Scientific and Technological Development (CNPq) for research fellowships. We also thank Dr. Manuel Angulo for performing the NMR analyses that were acquired on a Bruker Avance III 500 MHz instrument from the NMR facilities of the General Research Services of the University of Seville (SGI-CITIUS).Peer reviewe
Structural characteristics of the lignins from sugarcane bagasse and straw
4 páginas.-- 1 figuras.-- 5 referencias.-- Comunicación oral presentada en el 14th European Workshop on Lignocellulosics and Pulp June 28-30, 2016 - Autrans, France.Sugarcane (Saccharum spp.) is a perennial monocotyledonous plant from the Gramineae family that is the main feedstock for the production of sugar and also ethanol. Two major residues are produced by the sugarcane industry, the fibrous fraction following juice extraction (named bagasse), and the harvest residue (straw). Sugarcane bagasse and straw are lignocellulosic resides basically composed of cellulose, hemicelluloses, and lignin, and are attractive feedstocks for the production of second-generation ethanol and other bio-based products, in the context of the so-called lignocellulosic biorefinery. Converting bagasse and straw to ethanol requires an enzymatic saccharification of the polysaccharides to reducing sugars and their subsequent fermentation to ethanol. However, the presence of recalcitrant lignin reduces the accessibility of the enzymes to the cellulose, and decreases the efficiency of the hydrolysis. Costly and harsh pretreatment processes are therefore needed to circumvent cell-wall recalcitrance by removing, or cleaving and redistributing, the lignin polymer. The efficiency of the pretreatment process is highly dependent on both the lignin content and structure, and therefore the knowledge of the structure of the lignin is important to develop appropriate pretreatment methods for delignification, as well as for potentially higher-value utilization of the lignin.
In this paper, we report a detailed characterization of the lignins in sugarcane bagasse and straw by using different analytical techniques (Py-GC/MS, 2D-NMR, DFRC). The analyses indicate that the lignin from sugarcane bagasse is S-rich (H:G:S molar ratio of 2:38:60) whereas the lignin from sugarcane straw is G-rich (4:68:28). The compositional differences are also reflected in differences in the relative abundances of the various interunit linkages. Thus, the lignin from bagasse is mostly made up by ß¿O¿4¿ alkyl-aryl ether units (83% of all linkages), followed by minor amounts of phenylcoumarans (6%) and other condensed units. The lignin from straw, on the other hand, has lower amounts of alkyl-aryl ether units (75% of all linkages) and has higher amounts of condensed structures such as phenylcoumarans (15%) and dibenzodioxocins (3%). The differences observed in the lignins of the two sugarcane residues suggest that the bagasse material will pretreat more easily (because of its higher S-content and lower condensation degree) than the straw (with a higher content of condensed structures). In addition, the two residues contain significant levels of p-coumarate, ferulate, and tricin that might also be valuable to extract as commodity chemicals.This study has been funded by the projects AGL2014-53730-R and CTQ2014-60764-JIN (cofinanced by FEDER funds), and CSIC project 2014-40E-097. J. Ralph was funded through the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science DE-FC02-07ER64494). AGL thanks CAPES, and CFL and JLC thank CNPq for financial support.Peer Reviewe
Lipophilic phytochemicals from sugarcane bagasse and straw
9 páginas.-- 6 figuras.-- 2 tablas.-- 37 referenciasThe composition of lipophilic phytochemicals in sugarcane bagasse and straw, the two major residues of sugarcane processing, was investigated in detail by gas chromatography and mass spectrometry. The composition of the lipids from sugarcane bagasse and straw were completely different from each other. While the extracts of sugarcane bagasse were dominated by n-aldehydes (ca. 48% of all identified lipids) and n-fatty alcohols (ca. 23%) with lower amounts of n-fatty acids (10%) and steroid ketones (14%), the extracts from sugarcane straw were strongly dominated by n-fatty acids (accounting for ca. 60% of all identified compounds) with significant amounts of steroid compounds, particularly sterols (10%) and steroid ketones (14%). Tocopherols and triterpenols were also found, being particularly abundant among the extractives of sugarcane straw. Sugarcane bagasse and straw can thus be considered as promising feedstocks for obtaining highly valuable phytochemicals of nutraceutical or pharmaceutical interest.This study has been funded by the Spanish projects AGL2011-25379 and AGL2014-53730-R (co-financed by FEDER funds), the CSIC project 2014-40E-097 and the EU-project INDOX (KBBE-2013-7-613549). Alessandro G. Lino thanks CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) for financial support. C.F. Lima and J.L. Colodette are grateful to National Council for Scientific and Technological Development (CNPq) for research fellowships.Peer reviewe
Laparoscopia no abdome agudo não traumático: estudo retrospectivo
Os autores analisaram, retrospectivamente, 117 pacientes portadores de abdome agudo não-traumático, submetidos à laparoscopia diagnóstica e/ou terapêutica, na Casa de Saúde Santa Martha, em Niterói. A precisão diagnóstica do exame laparoscópico foi de 96,6%. Com relação à terapêutica, 74,4% dos pacientes foram tratados por laparoscopia, 21,4% por laparotomia e 4,3% foram tratados clinicamente. A precocidade na realização da laparoscopia relacionou-se à maior taxa de sucesso com o tratamento laparoscópico (valor p < 0,05). Analisando-se a recuperação pós-operatória, os pacientes submetidos a intervenções laparoscópicas iniciaram a dieta oral e receberam alta mais precocemente que os submetidos à laparotomia (valor p < 0,05 e p < 0,01 respectivamente). A taxa de complicação foi de 13,7%, com mortalidade de 2,6%. Os autores concluem que a laparoscopia é um excelente método diagnóstico, permite um manejo terapêutico satisfatório associado a uma recuperação pós-operatória mais precoce
Structural characterization of the lignins from sugarcane bagasse and straw
The structure of the lignins of sugarcane bagasse and straw was investigated. The lignins were characterized both in situ and in isolated preparations (Milled-Wood Lignin, MWL, and Cellulolytic Lignin, CEL) by Py-GC/MS and 2D-NMR. It was concluded that they are p-hydroxyphenyl-guaiacyl-syringyl lignins with associated pcoumarates and ferulates. 2D-NMR indicated that the main substructures present are β–O–4´-ethers, followed by β–5´ phenylcoumarans and with lower amounts of β–β´ resinols and β–1´ spirodienones.This study has been funded by the Spanish project AGL2011-25379 (co-financed by FEDER funds). Jorge Rencoret thanks the CSIC for a JAE-DOC contract of the program “Junta para la Ampliación de Estudios” cofinanced by Fondo Social Europeo (FSE). AGL thanks CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) for financial support.Peer reviewe