Production Of Organic Chemicals Research Articles

Global growth phase response of the gut bacterium Phocaeicola vulgatus (phylum Bacteroidota).

Phocaeicola vulgatus belongs to the intestinal microbiome, where it fermentatively breaks down of food-derived biopolymers , thereby, contributing to the gut metabolome. Moreover, due to its product range, P. vulgatus is a potential nonstandard platform organism for sustainable production of basic organic chemicals. Complementing a recent physiologic-proteomic report deciphering the strain's versatile fermentation network [1], the present study focuses on the global growth phase-dependent response. P. vulgatus was anaerobically cultivated with glucose in process-controlled bioreactors. Close sampling was conducted to measure growth parameters (OD, CDW, ATP content, substrate/product profiles) to determine growth stoichiometry. A coarser sampling (½ODmax, ODmax, and ODstat) served the molecular analysis of the global growth phase-dependent response, applying proteomics (soluble and membrane fractions, nanoLC-ESI-MS/MS) and targeted/untargeted metabolome analyses. The determined growth performance of features 1.74 h doubling time, 0.06 gCDW/mmolGlc biomass yield, 0.36 (succinate) and 0.61 (acetate) mmolP/mmolGlc as predominant fermentation product yields, and 0.43 mmolATP/mmolC as theoretically calculated ATP yield. The fermentation pathway displayed growth phase-dependent dynamics: the levels of proteins and their accompanying metabolites constituting the upper part of glycolysis peaked at ½ODmax, whereas those of the lower part of glycolysis and of the fermentation routes in particular towards predominant acetate and succinate were highest at ODmax and ODstat. While identified proteins of monomer biosynthesis displayed rather unspecific profiles, most of the intracellular amino acids peaked at ODmax. By contrast, proteins and metabolites related to stress response and quorum sensing showed increased abundances at ODmax and ODstat. The composition of the exometabolome expanded from 2,317 molecular formulas at ½ODmax via 4,258 at ODmax to 4,501 at ODstat, with growth phase-specific subsets increasing in parallel. The present study provides insights into the distinct growth phase-dependent behavior of P. vulgatus during cultivation in bioreactors. This could serve as a valuable knowledge base for further developing P. vulgatus as a non-conventional platform organism for biotechnological applications. In addition, the findings shed new light on the potential growth phase-dependent imprints of P. vulgatus on the gut microbiome environment, e.g. by indicating interactions via quorum sensing and by unraveling the complex exometabolic background against which fermentation products and secondary metabolites are formed.

Two-phase interfacial photocatalysis via amphiphilic Bi2WO6 to facilitate synchronous production and spontaneous separation of H2O2 and value-added organics

Photocatalytic synthesis of H2O2 from O2 reduction coupled with selective oxidation of organics into value-added chemicals is highly appealing; however, the troubling separation process presents a technical difficulty when both H2O2 and organic products are obtained in a homogeneous solution. Herein, an amphiphilic Bi2WO6 catalyst was synthesized through a facile solvothermal method based on the synergetic modification with both hydrophobic and hydrophilic groups, which enables the construction of Pickering emulsion interfacial photocatalysis systems in various organic/water mixtures to facilitate synchronous production and spontaneous separation of H2O2 and value-added organics. The amphiphilic Bi2WO6 catalyst exhibited significantly enhanced photocatalytic performance compared to its oleophilic and hydrophilic counterparts, resulting in remarkable generation rates of H2O2 and benzaldehyde reaching up to 121.53 and 99.25 mmol g−1 h−1, respectively, in a benzyl-alcohol/water biphasic system under simulated sunlight. The excellent photocatalytic performance could be maintained in a long-term reaction process. The photocatalytic mechanism was investigated through various control experiments and detailed characterizations. The interfacial photocatalysis played a crucial role in accelerating the redox reactions, showcasing its favorable applicability in various organic/water biphasic systems. This study provides guidelines for the realization of interfacial photocatalysis assisted by amphiphilic semiconductors, opening up a novel strategy to the simultaneous production of solar fuels and organic chemicals.

Organic Chemicals from Wood: Selective Depolymerization and Dearomatization of Lignin via Aqueous Electrocatalysis.

Replacing crude oil as the primary industrial source of carbon-based chemicals has become crucial for both environmental and resource sustainability reasons. In this scenario, wood arises as an excellent candidate, whilst depolymerization approaches have emerged as promising strategies to unlock the lignin potential as a resource in the production of high-value organic chemicals. However, many drawbacks, such as toxic solvents, expensive catalysts, high energy inputs, and poor product selectivity have represented major challenges to this task. Herein, we present an unprecedented approach using electrocatalysis for the simultaneous depolymerization and dearomatization of lignin in aqueous medium under ambient conditions. By employing water/sodium carbonate as a solvent system, we demonstrated a pathway for selectively depolymerizing lignin under reductive electrochemical conditions using carbon as an electrocatalyst. After reductive electrocatalysis, the presence of aromatic compounds was no longer detected via nuclear magnetic resonance (NMR) spectroscopy. Further characterization by NMR, FTIR spectroscopy, and mass spectrometry revealed the major presences of sodium levulinate, sodium 4-hydroxyvalerate, sodium formate, and sodium acetate as products. By achieving a complete dearomatization, valuable aliphatic intermediates with enhanced reactivity were selectively obtained, opening new avenues for further synthesis of many different organic chemicals, and contributing to a more sustainable and circular economy.

Internal model control of cumene process using analytical rules and evolutionary computation

Cumene is a precursor for producing many organic chemicals and is thinner in paints and lacquers. Its production process involves one of the large-scale manufacturing processes with complex kinetics. Different classical control strategies have been implemented and compared in this process for the cumene reactor. As a system with large degrees of freedom, a novel approach for extracting the state space model from the COMSOL Multiphysics implementation of the system is adopted here. Internal Modern Control (IMC) based PI and PID controllers are derived for the system. The system is reduced to the FOPDT and SOPDT model structure to derive the controller setting using Skogestad half rules. The integral time is modified for excellent set point tracking and faster disturbance rejection. From the analysis, it can be stated that the PI controller suits more for this specific process. The particle swarm optimization (PSO) algorithm, an evolutionary computation technique, is also used to tune the PI settings. The PI controllers with IMC, Zeigler Nichols, and PSO tuning are compared, and it can be concluded that the PSO PI controller settles at 45 s without any oscillations and settles down faster for the disturbance of magnitude 0.5 applied at t = 800 s. However, it is computationally intensive compared to other controller strategies.

Improvement of Current Efficiency of PEM Electrolyzer for Organic Chemical Hydride Energy Carrier Production with Water Electrolysis by Humidified Air Supply to Anode

Introduciton To improve hydrogen energy carrier synthesis, we have studied toluene electrohydrogenation and water decomposition using proton exchange membrane (PEM) electrolysis. The cathode reaction is electrohydrogenation of toluene to synthesis methylcyclohexane instead of hydrogen evolution reaction of water electrolysis. Only side reaction of the cathode is hydrogen evolution reaction, which was affected by electroosmotic water from the anode to cathode. Sulfuric acid solution feeds as anolyte that is not only reactant reduces water transportation and increases current efficiency [1, 2]. As practical system, water transportation from anode to cathode should be suppressed without sulfuric acid utilizationIn this study, to improve current efficiency by water management, we have investigated humidified air feed to reduce water transfer to cathode compare with liquid water feed. Experimental A single cell electrolyzer made of titanium with 16 cm2 of projected electrode area was used. Figure 1 shows the schematic drawing of toluene direct hydrogenation electrolyzers with humidified air feed. Membrane-electrodes assembly was consisted of Nafion® 117 (DuPont), 0.6 mg cm-2 of PtRu/C (TEC61E54, TKK, I/C = 0.8) cathode catalyst layer and 2.0 mg cm-2 of IrOx (TEC77100, TKK, I/IrOx = 0.28). Cathode backing was a carbon paper (10BC, SGL) of 0.02 mg cm-2 of Pt loading, which works flow filed of toluene-methylcyclohexane, too. Anode baking as a Pt plated sintered Ti web (Bekaert), and anode flow filed was serpentine type. 10 mL min-1 of toluene or 10% toluene – methylcyclohexane was fed to cathode. 5.0 L min-1 (313 mL min-1 cm-2) of fully humidified air or liquid water was fed to cathode. Operation temperature was 80oC. Internal resistance was determined by high frequency intercept of real axis of the electrochemical impedance spectroscopy in the current density region between 0.1 to 0.6 A cm-2. The water transportation through the membrane was determined by separated water in outlet liquid from cathode during constant current electrolysis, and the Faraday efficiency was determined by generated gas volume from the cathode, simultaneously. Results and discussion Figure 2 shows the cell voltage and current efficiency as a function of the current density for 10% toluene-methylcyclohexane or 100% toluene to cathode and 5.0 L min-1 of fully humidified air or liquid water to anode feed. Cell voltages were almost same for all experiments in less than 0.3 Acm-2 of current density region, while cell voltages of humidified air feed were higher than that of liquid water feed in higher current density region. Here, internal resistance of humidified air and liquid water feed were 0.29 and 0.21 Ω cm2. Therefore, membrane condition of the humidified air feed was drier than that of the liquid water feed. Water transportation through the membrane around 0.2 mg min-1 cm-2, which was less than 1/10 of the liquid water or 1 M H2SO4 feed electrolysis. The current efficiency for 100% toluene feed was more than 95% at 1 A cm-2, and slightly decreased with current density. In this case, the current efficiency of the liquid water feed was a little higher than that of the humidified air feed. The current efficiency of the humidified air feed was more than 95% up to 0.5 Acm-2, while the current efficiency of the liquid water feed decreased 95% around 0.2 Acm-2. In addition, the current efficiency of 10% toluene-methylcyclohexane significantly decrease with current density.The current efficiency would be affected by the cathode potential and toluene transportation in the catalyst layer. For the 100% toluene feed, toluene transportation would less affect and cathode potential would much affect to the current efficiency. Larger internal resistance of the humidified air feed would correspond to dry condition of cathode ionomer, and it would decrease the cathode potential. Therefore, the current efficiency of humidified air was slightly lower than liquid water feed. On the other hand, the current efficiency of 10% toluene feed would be controlled by toluene transportation in the cathode catalyst layer and is significantly affected by the water transportation through the membrane. Therefore, the current efficiency of the humidified air feed significantly higher than that of the liquid water feed. Acknowledgement This study was based on results obtained from the Development of Fundamental Technology for Advancement of Water Electrolysis Hydrogen Production in Advancement of Hydrogen Technologies and Utilization Project (P14021) commissioned by the New Energy and Industrial Technology Development Organization (NEDO). References Nagasawa, K. Tanimoto, J. Koike, K. Ikegami, S. Mitsushima, J Power Sources, 439, 227070 (2019).Oi, K. Nagasawa, T. Takamura, Y. Misu, K. Matsuoka, S. Mitsushima, ECS Meeting s, MA2021-02, 1737 (2021). Figure 1

New visible-light-driven Bi2MoO6/Cs3Sb2Br9 heterostructure for selective photocatalytic oxidation of toluene to benzaldehyde

Herein, new Bi2MoO6/Cs3Sb2Br9 heterostructure (BiMo/CSB) was investigated for the first time as a visible-light-driven photocatalyst for C(sp3)–H bond activation using molecular oxygen as a green oxidant and toluene as a model substrate. The optimized BiMo/CSB photocatalyst exhibited enhanced toluene oxidation activity (2,346 μmol g-1h−1), which was almost two- and five-fold that of pristine CSB (1,165 μmol g-1h−1) and BiMo (482 μmol g-1h−1), respectively. The improved photocatalytic performance was essentially attributed to the formation of staggered band energy lineup in the BiMo/CSB hybrid, which promoted S-scheme charge transfer across the BiMo/CSB heterointerface as supported by ultraviolet photoelectron spectroscopy (UPS), density functional theoretical (DFT), time-resolve photoluminescence (TRPL), and photoelectrochemical studies. Spin–trapping electron paramagnetic resonance (EPR) and radical scavenging studies revealed that photoinduced hole, molecular oxygen, and superoxide radical are key active species in this photocatalytic system. The developed BiMo/CSB catalyst provided good selectivity toward benzaldehyde product (94–98 %), presumably due to the inhibiting effect of benzyl alcohol on benzaldehyde oxidation. No significant change in structure and morphology was observed for the spent catalyst, however small negative shift of Sb 3d and Bi 4f binding energy was found suggesting partial reduction of Sb3+ and Bi3+. This work not only provides a new visible-light-driven photocatalyst for C(sp3)–H bond activation but also opens the doors for exploitation of the conversion and functionalization of this inert bond toward the production of high value-added organic chemicals.

Association Between Perceived Stress and Salivary Biomarkers of Allostatic Load Among Gender Minorities in Chennai: An Observational Cross-Sectional Study.

Background Transgender individuals in India experience immense psychosocial stressors, stigma, and violence. In response to stress, the body exhibits adaptive responses that necessitate the production of organic chemicals ensuing in the detection of blood serum and saliva.There are currently no laboratory tests that are confirmatory for the diagnosis of stress and facilitate necessary treatment to be carried out in a timely manner. Thus, potential salivary biomarkers could be a helpful tool in overseeing the efficacy of pharmacological treatment prescribed by a psychiatrist. Aim This study aimed to assess the correlation between perceived stress and salivary stress biomarker levels in transgender and gender nonconforming (TGNC) individuals in Chennai, India. Methodology Twenty-two TGNC individuals and 22 age-matched controls in Chennai were administered the Perceived Stress Scale-10 questionnaire. Following this, their saliva samples were collected using the passive drool technique and subjected to sandwich enzyme-linked immunosorbent assay (ELISA) technique for measuring salivary cortisol, salivary tumor necrosis factor-alpha (TNF-alpha), and salivary C-reactive protein (CRP). Independent t-test was used to compare salivary stress biomarker levels between the TGNC and age-matched control groups. Pearson's correlation test was done to correlate perceived stress and salivary stress biomarker levels in the TGNC group. Results Significant difference was seen between the TGNC and control groups with respect to salivary cortisol and salivary TNF-alpha levels, with the levels being higher in the TGNC group. A significant positive correlation was seen between perceived stress and salivary cortisol and between perceived stress and salivary TNF-alpha levels. Conclusion There is a significant correlation between perceived stress and salivary biomarkers of stress among TGNC people in Chennai.

Techno-economic and exergy analysis of e-methanol production under fixed operating conditions in Germany

Electric-based methanol (e-MeOH) has the potential to substitute fossil-based hydrocarbons as the prominent feedstock in the production of climate-neutral synthetic fuels and organic chemicals because e-MeOH can be fully produced from renewable energy sources, such as solar photovoltaic (PV) and wind energy. It is basically produced via direct CO2-hydrogenation from captured CO2 and electrolytic H2. Although the techno-economics of the e-MeOH production process have been extensively studied, the published results have not included direct comparison of the reactor design configuration, different kinetic models, and exergy analysis.To assess the process performance, the e-MeOH plant is modelled and simulated in Aspen Plus® on the basis of the state-of-the-art Lurgi MegaMethanol® technology. The in-house tool TEPET (Techno-Economic Process Evaluation Tool) assists with the techno-economic analysis, including a sensitivity analysis regarding CO2 and H2 costs and an exergy analysis of the e-MeOH plant.With the recommended process configuration, the e-MeOH plant could achieve energetic and exergetic Power-to-Fuel (PtF) efficiency of 52.4% and 56.4%, respectively. The e-MeOH can be produced in 2018 at NPC 1129–1481 €t−1 or 57–74 €GJ−1. These values would be doubled if the e-MeOH plant operates exclusively with the help of solar and wind energy in Germany. The study also investigates the impact of different published kinetic models of methanol synthesis, which alter the NPC by around 2.3%.

Valorisation of the residual aqueous phase from hydrothermally liquefied black liquor by persulphate-based advanced oxidation

Hydrothermal liquefaction of Kraft black liquor is a promising method for the production of valuable organic chemicals. However, the separation of the biochar and biocrude leaves a residual aqueous phase in large volumes, which needs to be properly managed to make the process profitable. In this work, the persulphate-based advanced oxidation was assessed, for the first time ever, as a pretreatment of this aqueous phase to reduce its content of phenolic compounds and alcohols, which hinder further valorisation strategies. Results revealed that the phenolic compounds and the alcohols were oxidised in presence of low persulphate anion concentrations (<50 mM), mainly to quinone-like compounds and organic acids. At higher oxidant concentrations, these intermediates were subsequently oxidised to valuable acetic acid. When Fe (II) was added as the catalyst, low concentrations (<9 mM) enhanced the degradation of both phenolic compounds and alcohols due to the increase of the sulphate radicals, consequently reducing persulphate requirements for their removal. Nevertheless, higher Fe (II) doses produced the sequestration of sulphate radicals, thus decreasing the oxidation performance and generating undesired parallel reactions.

In-situ reduced ultrathin molybdenum oxide nanorods-Au heterojunction for boosted catalytic oxidation performance of cyclohexane

The production of cyclohexane oxidation to cyclohexanol and cyclohexanone (KA oil) in the chemical industry is still constrained by low conversion, low selectivity, and drastic reaction conditions. To address this, we have developed MoO3-x ultrafine nanorods-Au nanoparticles composite by in situ uniform growth for the boosted photocatalytic oxidation of cyclohexane. The resulting MoO3-x-Au Schottky heterojunction possesses significantly improved catalytic performance in cyclohexane oxidation, achieving a conversion rate of 9.99% and the KA oil selectivity of 96.37%. Using the Finite-Difference Time-Domain (FDTD) method, we interpreted the enhanced electric field distribution of the composite. Moreover, the photocatalytic mechanism was validated by H2O2 production and in-situ FTIR characterization. The adsorption experiments validated that the high selectivity of KA oil is originated from the superior adsorption capability of MoO3-x-Au for cyclohexane over cyclohexanol and cyclohexanone. Our study showcases the potential of MoO3-x ultrafine catalysts in the green synthesis of industrial organic chemical products.

Optimizing Strategies for Bio-Based Ethanol Production Using Genome-Scale Metabolic Modeling of the Hyperthermophilic Archaeon, Pyrococcus furiosus.

A genome-scale metabolic model, encompassing a total of 623 genes, 727 reactions, and 865 metabolites, was developed for Pyrococcus furiosus, an archaeon that grows optimally at 100°C by carbohydrate and peptide fermentation. The model uses subsystem-based genome annotation, along with extensive manual curation of 237 gene-reaction associations including those involved in central carbon metabolism, amino acid metabolism, and energy metabolism. The redox and energy balance of P. furiosus was investigated through random sampling of flux distributions in the model during growth on disaccharides. The core energy balance of the model was shown to depend on high acetate production and the coupling of a sodium-dependent ATP synthase and membrane-bound hydrogenase, which generates a sodium gradient in a ferredoxin-dependent manner, aligning with existing understanding of P. furiosus metabolism. The model was utilized to inform genetic engineering designs that favor the production of ethanol over acetate by implementing an NADPH and CO-dependent energy economy. The P. furiosus model is a powerful tool for understanding the relationship between generation of end products and redox/energy balance at a systems-level that will aid in the design of optimal engineering strategies for production of bio-based chemicals and fuels. IMPORTANCE The bio-based production of organic chemicals provides a sustainable alternative to fossil-based production in the face of today's climate challenges. In this work, we present a genome-scale metabolic reconstruction of Pyrococcus furiosus, a well-established platform organism that has been engineered to produce a variety of chemicals and fuels. The metabolic model was used to design optimal engineering strategies to produce ethanol. The redox and energy balance of P. furiosus was examined in detail, which provided useful insights that will guide future engineering designs.

Biotechnological Approaches to Generate Biogenic Solvents and Energy Carriers from Renewable Resources

Abstract Background: Current threats connected to the ongoing depletion of fossil resources and elevated levels of greenhouse gases accelerating climate change and global warming provoke a renaissance of biotechnological production of various organic bulk chemicals, which, particularly during the second half of the 20th century, were almost exclusively produced from fossil resources via chemosynthetic processes. Scope: Besides the manufacture of bioethanol, a product obtained by microbial fermentation, biogenic production of solvents and energy carriers like acetone, isopropanol, 2,3-butanediol, or 1-butanol, hence, processes known since the beginning of the last century, experiences now a substantial revival. Summary of new synthesis and conclusions reached in the review: The review illustrates how to produce these products by resorting to fossil raw materials instead of petrochemical production processes, and how this can be accomplished by the cultivation of anaerobic organisms, namely facultatively anaerobic yeasts and bacteria (production of ethanol or 2,3-butanediol), and strictly anaerobic Clostridia (1-butanol, acetone, or isopropanol) on renewable resources. Moreover, novel methods for producing biodiesel-like methyl-esters of aerobically produced bacterial polyhydroxyalkanoate biopolyester building blocks combine the synthesis of microbial biopolyesters from wastewater with the progress of innovative renewable energy carriers. The biochemical background, the current state of research and development, and the status of industrialization of these processes are reviewed. Conclusion: Challenges to make these bioprocesses, based on inexpensive renewable resources, competitive with or even superior to petrochemical production routes in terms of sustainability, scalability, and economic feasibility still exist: however, they can be overcome by the concerted action of various scientific disciplines.

Electrochemical Manufacturing Routes for Organic Chemical Commodities.

Electrochemical synthesis of organic chemical commodities provides an alternative to conventional thermochemical manufacturing and enables the direct use of renewable electricity to reduce greenhouse gas emissions from the chemical industry. We discuss electrochemical synthesis approaches that use abundant carbon feedstocks for the production of the largest petrochemical precursors and basic organic chemical products: light olefins, olefin oxidation derivatives, aromatics, and methanol. First, we identify feasible routes for the electrochemical production of each commodity while considering the reaction thermodynamics, available feedstocks, and competing thermochemical processes. Next, we summarize successful catalysis and reaction engineering approaches to overcome technological challenges that prevent electrochemical routes from operating at high production rates, selectivity, stability, and energy conversion efficiency. Finally, we provide an outlook on the strategies that must be implemented to achieve large-scale electrochemical manufacturing of major organic chemical commodities.

Effects of ethoxyquin on metabolism and composition of active marine microbial communities

Salmon culture has the potential to generate environmental impacts due to the release of organic matter and chemical products into the water column. Ethoxyquin (EQ) is a food additive widely used as an antioxidant in fish feed, but due to the scarce evidence on its safety for the environment it has been banned by the European Food Safety Authority. To evaluate and compare responses of marine microbial communities to EQ additions (10, 100 and 1000 μg L−1), we carried out 20 L seawater microcosm experiments in two distinct areas, Achao and Coliumo Bay, where the first is influenced by salmon farming. We estimated metabolic response (respiration, extracellular enzymatic activity and ECOplates) for two size fractions (< 1 μm and < 63 μm) and changes in the active microbial community diversity. The results revealed different responses associated with study sites and size fractions. For the < 1 μm fraction (bacterioplankton), the addition of EQ increased both oxygen consumption and the degradation of proteinaceus compounds, while for the entire community (< 63 μm), the addition of EQ decrease respiration and the capacity to degrade carbohydrates and lipids. The carbon substrates utilization was variable, decreasing in the 100 and 1000 μg EQ. L−1 treatments, suggesting that high EQ concentrations may limit the capacity to process different carbon sources, producing a preference for amino acids and carboxylic acids in the first hours of exposition in Achao. In the area without salmon farming (Coliumo Bay) substrates utilization, mainly carbohydrates and carboxylic acids, was stimulated by the addition of EQ. A shift was observed in the active microbial community between treatments at different taxonomic levels, especially associated with Alphaproteobacteria, which presented lower activity when exposed to EQ. Gammaproteobacteria (KI89A), Bacteroidea (NS10, NS3b clade) and MGII showed higher activity associated with EQ additions. Overall, our study indicates that EQ may generate both changes in the metabolism (respiration, enzymatic extracellular activity, carbon sources preferences) and composition of the active microbial community in the water column altering the degradation of organic matter.

A Comprehensive Review of the Pharmacological Properties and Bioactive Components of Retama monosperma.

Retama monosperma L. (Boiss.) or Genista monosperma L. (Lam.), known locally as "R'tam", is a spontaneous and annual herb that belongs to the Fabaceae family. It is native to the Mediterranean regions, specifically in the desert areas and across the Middle Atlas in Morocco. This plant has been extensively used in folk medicine and it is rich in bioactive compounds, including polyphenols, flavonoids, and alkaloids. Current research efforts are focusing on the development of novel natural drugs as alternatives to various organic and non-organic chemical products from Retama monosperma. In addition, extract, and isolated compounds obtained from different parts of the chosen plant have been described to exhibit multiple biological and pharmacological properties such as antioxidant, anti-aging, anti-inflammatory, antihypertensive, anti-helminthic, disinfectant, diuretic, and hypoglycemic effects. The plant-derived extract also acts as an antimicrobial agent, which is highly efficient in the treatment of bacterial, viral, and fungal infections. Its antiproliferative effects are associated with some mechanisms, such as the inhibition of cell cycle arrest and apoptosis. In light of these assessments, we critically highlight the beneficial effects of the flowers, stems, seeds extracts, and isolated compounds from R. monosperma (L.) Boiss in human health care, industrial, and other applications, as well as the possible ways to be employed as a potential natural source for future drug discovery.

Recent Trends, Opportunities and Challenges in Sustainable Management of Rice Straw Waste Biomass for Green Biorefinery

Waste rice straw biomass and its burning in open fields have become a serious issue of greenhouse gases emission and air pollution, which has a negative impact on public health and the environment. However, the environmental impact of burning this agro-waste can be mitigated by diverting it towards green biorefinery through the sustainable production of energy, biofuels, organic chemicals, and building blocks for various polymers. This will not only help to reduce the reliance on limited fuels and various chemicals derived from petroleum, but also help in the restoration of the environment in a sustainable manner through its complete utilization. To maximize the inherent conversion potential of rice straw biomass into valuable products, this agriculture waste biomass requires a comprehensive analysis and a techno-economic review for its sustainable management. This review article focuses on the sustainable management of rice straw waste biomass via innovative valorization approaches, as well as the opportunities and challenges encountered in this sector for meeting the demand of current and future green biorefineries.

Probing the Role of Individual OH Sites in Carbohydrate Conversion Suggests Strategies for Increasing Product Selectivity and Avoiding Humins

Carbohydrates will likely play a central role in the future production of organic chemicals, but the understanding of pathways that are accessible in carbohydrate upgrading has remained unsatisfactory. The polyfunctionality of carbohydrates and their complex appearance in linear and cyclic forms with different stereochemistries can lead to diverse and interconverting pools of isomers along the entire reaction pathway. Here, we identify avoidable pathways toward byproducts and humins using an experimental high-resolution investigation into the routes of carbohydrate conversion with an emphasis on the conversion of C5 carbohydrates by Lewis acidic SnCl4 in dimethyl sulfoxide (DMSO)/water. Reaction tracking with C5 carbohydrates and deoxy variants was used to evaluate the effects of loss of individual functional groups on the pathways that are accessible in carbohydrate conversion. Especially, the removal of the hydroxy group at C5 enhances (and accelerates) the selectivity of carbohydrate conversion through an acyclic pathway, not only relative to the formation of furanic compounds but also relative to the formation of humins. Blocking the primary alcohol in xylose may hence benefit future biomass conversion strategies. Even in the absence of intermolecular reactions toward humins, the conversion of pentose follows second-order kinetics.

Solar Light Responsive Graphitic Carbon Nitride Coupled Porphyrin Photocatalyst that Uses for Solar Fine Chemical Production.

Photocatalysis is a defendable manner for production of several organic chemicals, energy and its storage from solar energy. For the evolution of metal free, cost-effective catalyst a 2D composite has been appear as a photocatalyst. Here, we had reported the synthesis of a light harvesting composite as a photocatalyst which was assembled by a poly-condensation mechanism between graphitic carbon nitride and tetrakis(4-nitrophenyl) porphyrin and the resulting composite manifest the excellent light harvesting properties, suitable energy band and low charge recombination. The photocatalyst [(NO2 )4 TPP@g-C3 N4 ] enables the efficient photocatalytic production of nicotinamide adenine dinucleotide (NADH) from consumed NAD+ also the production of organic chemicals like 4-methoxybenzylimines from 4-methoxybenzylamines. The photocatalytic efficiency of the photocatalyst was estimated by the percentage of NADH regeneration and the percentage yield of organic transformations. It shows the tetrakis(4-nitrophenyl) porphyrin could enhance the charge transfer capacity of graphitic carbon nitride which shows excellent photocatalysis activities and organic transformations.

Waste cooking oil and crude glycerol as efficient renewable biomass for the production of platform organic chemicals through oleophilic yeast strain of Yarrowia lipolytica

Organic acids like succinic and citric acids are of great interest as platform organic products that play important roles as precursors for a wide range of bio-based materials. Succinic and citric acids can be successfully produced biotechnologically from renewable resources of both hydrophilic and hydrophobic nature through efficient microbiological conversion. Yarrowia lipolytica represents one of the most versatile microbial factories in terms of organic acids production, as it easily develops and produced metabolites starting from glucidic-based and/or lipid-based substrates. The purpose of this work was to investigate the ability of Y. lipolytica to adapt to hydrophilic and hydrophobic sources and to biosynthesize important platform chemicals like succinic and citric acids. The selected strain was monitored during a batch cultivation for 192 h on 100 g/L carbon source: pure glycerol as a hydrophilic source, sunflower waste cooking oil as a hydrophobic source, and crude glycerol deriving from biodiesel production as a mixture of hydrophilic and hydrophobic sources. Cellular viability, biomass accumulation, and metabolites formation in terms of succinic acid and citric acid was monitored, and the highest results were registered for cultivations performed on waste cooking oil [10.35 ± 0.29 (log 10 ) CFU/mL, 8.15 g/L cell dry weight, 3.50 ± 0.04 g/L citric acid, and 21 ± 0.16 g/L succinic acid]. The results obtained in this work outline the industrial potential of the oleaginous yeast strain of Y. lipolytica to bioconvert the lipidic residual biomass with negative environmental implications into valuable organic compounds with wide-range applicability. • Sunflower waste cooking oil is a renewable biomass for biotechnological approaches. • Y. lipolytica produces up to 21 g/L succinic acid and 3.5 g/L citric acid from SWCO. • Y. lipolytica produces up to 14 g/L succinic acid and 4.9 g/L citric acid from CG. • Y. lipolytica produces organic acids from both hydrophilic and hydrophobic sources.

Fine Tuning the Pore Surface in Zirconium Metal–Organic Frameworks for Selective Ethane/Ethylene Separation

Ethylene is an important chemical feedstock for production of polymers and high-value organic chemicals, and yet its conventional purification process is plagued with high consumption of energy. Metal–organic frameworks (MOFs) provide a suitable adsorption platform for selective ethane/ethylene separation thanks to their structural diversity, tunable pore characteristics, designable pore sizes, and high pore volumes. Although there are empirical design rules like avoiding open metal sites and creating nonpolar pore surfaces for development of adsorptive MOFs, it is still challenging to design robust MOFs that can realize direct ethane-selective separation. Herein, we systematically designed and synthesized three Zr-MOFs based on the assembly of angular ligands and 12-connected Zr6 clusters that feature the pcu network structure. By changing the size and flexibility of the substituent on the angular ligand, we were able to prevent interpenetration and identified NPF-802, which exhibits good C2H6/C2H4 separation performance that is attributed to the bulky and inert tert-butyl groups of its carbazole ligand. This work provides insights for design of ligands of MOFs with suitable pore environments to address important and challenging gas separations.