From Wood to Tetrahydro-2-benzazepines in Three Waste-Free Steps: Modular Synthesis of Biologically Active Lignin-Derived Scaffolds.
Ontology highlight
ABSTRACT:
SUBMITTER: Elangovan S
PROVIDER: S-EPMC6813559 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Phosphonates have garnered considerable attention for years owing to both their singular biological properties and their synthetic potential. State-of-the-art methods for the preparation of mixed phosphonates, phosphonamidates, phosphonothioates, and phosphinates rely on harsh and poorly selective reaction conditions. We report herein a mild method for the modular preparation of phosphonylated derivatives, several of which exhibit interesting biological activities, that is based on chemoselective activation with triflic anhydride. This procedure enables flexible and even iterative substitution with a broad range of O, S, N, and C nucleophiles.
| S-EPMC6175129 | biostudies-literature
Project description:The molecules of (2RS,4SR)-2-exo-(5-bromo-2-thienyl)-7-chloro-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, C(14)H(11)BrClNOS, (I), are linked into cyclic centrosymmetric dimers by C-H...pi(thienyl) hydrogen bonds. Each such dimer makes rather short Br...Br contacts with two other dimers. In (2RS,4SR)-2-exo-(5-methyl-2-thienyl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, C(15)H(15)NOS, (II), a combination of C-H...O and C-H...pi(thienyl) hydrogen bonds links the molecules into chains of rings. A more complex chain of rings is formed in (2RS,4SR)-7-chloro-2-exo-(5-methyl-2-thienyl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, C(15)H(14)ClNOS, (III), built from a combination of two independent C-H...O hydrogen bonds, one C-H...pi(arene) hydrogen bond and one C-H...pi(thienyl) hydrogen bond.
| S-EPMC2737428 | biostudies-literature
Project description:Phosphatidic acid (PA) is an important signaling lipid that plays roles in a range of biological processes including both physiological and pathophysiological events. PA is one of a number of signaling lipids that can act as site-specific ligands for protein receptors in binding events that enforce membrane association and generally regulate both receptor function and subcellular localization. However, elucidation of the full scope of PA activities has proven problematic, primarily due to the lack of a consensus sequence among PA-binding receptors. Thus, experimental approaches, such as those employing lipid probes, are necessary for characterizing interactions at the molecular level. Herein, we describe an efficient modular approach to the synthesis of a range of PA probes that employs a late stage introduction of reporter groups. This strategy was exploited in the synthesis of PA probes bearing fluorescent and photoaffinity tags as well as a bifunctional probe containing both a photoaffinity moiety and an azide as a secondary handle for purification purposes. To discern the ability of these PA analogs to mimic the natural lipid in protein-binding properties, each compound was incorporated into vesicles for binding studies using a known PA receptor, the C2 domain of PKCalpha. In these studies, each compound exhibited binding properties that were comparable to those of synthetic PA, indicating their viability as probes for effectively studying the activities of PA in cellular processes.
| S-EPMC5985520 | biostudies-literature
Project description:Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt % of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80 wt % of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83 %, haze of 75 %, thermal conductivity of 0.23 W mK-1 , and work-tofracture of 1.2 MJ m-3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings.
| S-EPMC5601211 | biostudies-literature
Project description:The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut community analysis of A. glabripennis identified a single species of fungus in the Fusarium solani/Nectria haematococca species complex. This is a soft-rot fungus that may be contributing to wood degradation. These results transform our understanding of lignin degradation by wood-feeding insects.
| S-EPMC2529026 | biostudies-literature
Project description:Plant lignin is regarded as an important source for soil humic substances (HSs). Nonetheless, it remains unclear whether microbial metabolism on lignin is related to the genesis of unique HS biological activities (e.g., direct plant stimulation). Here, selected white-rot fungi (i.e., Ganoderma lucidum and Irpex lacteus) and plant litter- or mountain soil-derived microbial consortia were exploited to structurally modify lignin, followed by assessing the plant-stimulatory activity of the lignin-derived products. Parts solubilized by microbial metabolism on lignin were proven to exhibit organic moieties of phenol, carboxylic acid, and aliphatic groups and the enhancement of chromogenic features (i.e., absorbance at 450 nm), total phenolic contents, and radical-scavenging capacities with the cultivation times. In addition, high-resolution mass spectrometry revealed the shift of lignin-like molecules toward those showing either more molar oxygen-to-carbon or more hydrogen-to-carbon ratios. These results support the findings that the microbes involved, solubilize lignin by fragmentation, oxygenation, and/or benzene ring opening. This notion was also substantiated by the detection of related exoenzymes (i.e., peroxidases, copper radical oxidases, and hydrolases) in the selected fungal cultures, while the consortia treated with antibacterial agents showed that the fungal community is a sufficient condition to induce the lignin biotransformation. Major families of fungi (e.g., Nectriaceae, Hypocreaceae, and Saccharomycodaceae) and bacteria (e.g., Burkholderiaceae) were identified in the lignin-enriched cultures. All the microbially solubilized lignin products were likely to stimulate plant root elongation in the order selected white-rot fungi > microbial consortia > antibacterial agent-treated microbial consortia. Overall, this study supports the idea that microbial transformation of lignin can contribute to the formation of biologically active organic matter. IMPORTANCE Structurally stable humic substances (HSs) in soils are tightly associated with soil fertility, and it is thus important to understand how soil HSs are naturally formed. It is believed that microbial metabolism on plant matter contributes to natural humification, but detailed microbial species and their metabolisms inducing humic functionality (e.g., direct plant stimulation) need to be further investigated. Our findings clearly support that microbial metabolites of lignin could contribute to the formation of biologically active humus. This research direction appears to be meaningful not only for figuring out the natural processes, but also for confirming natural microbial resources useful for artificial humification that can be linked to the development of high-quality soil amendments.
| S-EPMC9769858 | biostudies-literature
Project description:Four previously undescribed drimane sesquiterpenoids were isolated from submerged cultures of the wood-inhabiting basidiomycete Dentipellis fragilis along with two compounds that were previously reported as synthetic or biotransformation compounds but not as natural products. The constitution and relative configuration of these compounds was determined based on high-resolution electrospray ionization mass spectrometry as well as by 1D and 2D nuclear magnetic resonance spectroscopy. The absolute configurations were established based on exemplary calculation of circular dichroism spectra and comparison with measured data as well as on biogenetic considerations. The biological activities of the isolated compounds were assessed in antimicrobial, cytotoxicity and neurotrophic assays. 10-Methoxycarbonyl-10-norisodrimenin (3) exhibited weak activity against the Gram-positive bacterium Staphylococcus aureus and the zygomycete Mucor hiemalis with minimal inhibitory concentrations of 66.7 μg mL-1. In addition, compound 3 showed weak inhibition of the mammalian cell line KB3.1 (human endocervical adenocarcinoma) with a half maximal inhibitory concentration of 21.2 μM. The neurotrophic activities of 15-hydroxyisodrimenin (1) and 10-carboxy-10-norisodrimenin (5) were assed in neurite outgrowth and real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) assays. When supplemented with 5 ng mL-1 nerve growth factor (NGF), the drimanes 1 and 5 induced neurite outgrowth in PC-12 (rat pheochromocytoma) cells compared to cells solely treated with NGF. As evaluated by RT-qPCR, compounds 1 and 5 also increased NGF and brain-derived neurotrophic factor expression levels in 1321N1 astrocytoma cells. Interestingly, the current study only represents the second report on neurotrophic activities of this widespread class of terpenoids. The only other available study deals with Cyathus africanus, another basidiomycete that can produce drimanes and cyathanes, but is only distantly related to Dentipellis and the Hericiaceae.
| S-EPMC10468952 | biostudies-literature
Project description:Engineering the microbial transformation of lignocellulosic biomass is essential to developing modern biorefining processes that alleviate reliance on petroleum-derived energy and chemicals. Many current bioprocess streams depend on the genetic tractability of Escherichia coli with a primary emphasis on engineering cellulose/hemicellulose catabolism, small molecule production, and resistance to product inhibition. Conversely, bioprocess streams for lignin transformation remain embryonic, with relatively few environmental strains or enzymes implicated. Here we develop a biosensor responsive to monoaromatic lignin transformation products compatible with functional screening in E. coli. We use this biosensor to retrieve metagenomic scaffolds sourced from coal bed bacterial communities conferring an array of lignin transformation phenotypes that synergize in combination. Transposon mutagenesis and comparative sequence analysis of active clones identified genes encoding six functional classes mediating lignin transformation phenotypes that appear to be rearrayed in nature via horizontal gene transfer. Lignin transformation activity was then demonstrated for one of the predicted gene products encoding a multicopper oxidase to validate the screen. These results illuminate cellular and community-wide networks acting on aromatic polymers and expand the toolkit for engineering recombinant lignin transformation based on ecological design principles.
| S-EPMC4104913 | biostudies-literature
Project description:In (2RS,4SR)-7-chloro-2-exo-(2-chloro-6-fluorophenyl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, C(16)H(12)Cl(2)FNO, (I), molecules are linked into chains by a single C-H...pi(arene) hydrogen bond. (2RS,4SR)-2-exo-(2-Chloro-6-fluorophenyl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, C(16)H(13)ClFNO, (II), is isomorphous with compound (I) but not strictly isostructural with it, as the hydrogen-bonded chains in (II) are linked into sheets by an aromatic pi-pi stacking interaction. The molecules of (2RS,4SR)-7-methyl-2-exo-(4-methylphenyl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, C(18)H(19)NO, (III), are linked into sheets by a combination of C-H...N and C-H...pi(arene) hydrogen bonds. (2S,4R)-2-exo-(2-Chlorophenyl)-2,3,4,5-tetrahydro-1H-1,4-epoxy-1-benzazepine, C(16)H(14)ClNO, (IV), crystallizes as a single enantiomer and the molecules are linked into a three-dimensional framework structure by a combination of one C-H...O hydrogen bond and three C-H...pi(arene) hydrogen bonds.
| S-EPMC2737425 | biostudies-literature
Project description:Despite the fact that they are not typically life-threatening, low-grade gliomas (LGGs) remain a significant clinical challenge in pediatric neuro-oncology due to comorbidities associated with these tumors and/or their treatments, and their propensity to multiply recurs. LGGs, in total the most common brain tumors arising in childhood, can often become a chronic problem requiring decades of management. The Second International Consensus Conference on Pediatric Low-Grade Gliomas held in Padua, Italy in 2016 was convened in an attempt to advance the pace of translating biological discoveries on LGGs into meaningful clinical benefit. Topics discussed included: the implications of our growing biological understanding of the genomics underlying these tumors; the assessment of the model systems available; the implications of the molecular and histopathologic differences between adult and pediatric diffuse gliomas; and steps needed to expedite targeted therapy into late-stage clinical trials for newly diagnosed cases. Methods for the diagnostic assessment of alterations in the Ras/mitogen-activated protein kinase pathway, typical for these tumors, were also considered. While the overall tone was positive, with a consensus that progress is being and will continue to be made, the scale of the challenge presented by this complex group of tumors was also acknowledged. The conclusions and recommendations of the meeting panel are provided here as an outline of current thinking and a basis for further discussion.
| S-EPMC5786244 | biostudies-literature