Common Constituents Research Articles

Essential oil variation in Melissa officinalis L. cultivated under industrial field conditions: effects of different harvesting times and plant materials

Melissa officinalis L. is a cosmopolitan aromatic and medicinal plant from the Lamiaceae family, which is necessary for pharmaceutical and cosmetic production. To evaluate the impact of different harvesting times and plant materials on the essential oil content and composition of M. officinalis 4-year-old plants, the present study was conducted in Fars province, Iran, under industrial field conditions. A randomized factorial experiment with three replications was used. Each replication contained six treatments [3 harvesting of M. officinalis × 2 treatments (shade drying + fresh state)]. Hydrodistillation was used to obtain the essential oils from each treatment, which were subsequently analyzed using GC-FID and GC-MS. The results demonstrated a significant influence of harvesting times and plant materials on the essential oil content and composition of M. officinalis. The average essential oil content was 0.028% to 0.095% (w/w). At different harvest times, the fresh plant yielded a higher content of essential oil compared to the dry plant. The number of chemical constituents in the essential oils was influenced by different harvesting times and plant materials. The predominant and common constituents in all harvested plant materials were the oxygenated monoterpenes geranial (28.7-43.2%) and neral (12.9-30.9%). Based on the major compounds, the essential oils from different harvesting times and plant materials were categorized into two chemotypes: chemotype I (geranial/thymol) and chemotype II (geranial/neral). It is recommended that drying operations not be used as a post-harvest processing method to achieve the highest essential oil yield from M. officinalis.

Rapid preparation of binary mixtures of sodium carboxylates as anodes in sodium-ion batteries.

Sodium-ion batteries are emerging as a sustainable solution to tackle the growing global energy demands. In this context, organic electrode materials complement such technologies as they are composed of earth-abundant elements. As organic anodes, sodium carboxylates exhibit promising applicability in a wide range of molecules. To harness the advantages of individual systems and to minimise their limitations, in this work, an approach to form binary mixtures of sodium carboxylates using one-pot, microwave-assisted synthesis is presented. The target mixtures were synthesised in 30 min with disodium naphthalene-2,6-dicarboxylate (Na-NDC) as a common constituent in all. Both components in all mixtures were shown to participate in the charge storage and had a considerable effect on the performance characteristics, such as specific capacity and working voltage, in half and full cell formats. This approach opens a new avenue for enabling organic materials to be considered as more competitive candidates in sodium-ion batteries and promote their use in other material classes to overcome their limitations.

The Uniqueverse, Natural selection as the unique model of evolutionary development of the Universe

The cosmological theories proposed so far do not postulate a common way of creation that can guide the entire line of growth of the universe, from elementary particles to living beings. But everything consists of the same basic components, combined and regulated differently: elementary particles, atoms and molecules make up celestial bodies, solar systems, single and pluricellular organisms, plants and animals. Common constituents are compatible with a common origin and with an incremental and selective development method. One possible common mode is that the Universe was formed according to an evolutionary method based on natural selection, the same process which then allowed the differentiation of biological species. This unique process may have guided from the beginning the development of the fundamental constituents of matter in the primitive universe and then created the other cosmic structures through the evolution of those elementary particles, up to organic molecules and biological beings. A process of this kind is a slow and gradual process, not based on a sudden event but on the progressive increase in the complexity of the structures present in the Universe, regulated by the selection of the most suitable and stable forms. For the relativistic relationship between energy, mass and velocity, we can think that the Universe was formed at the same time as the formation of elementary structures, slowly in a spacetime that was created in parallel: elementary particles created an initial infinitesimal spacetime system that then grew as more matter formed. The incremental creation of the cosmos would also concern forces and physical laws, which may have undergone the same evolutionary process from the most primordial and simple forms to the present, in proportion to the development of the whole system. This modality could justify the current simultaneous presence of quantum and relativistic laws at different levels (atomic and gravitational), as well as the coexistence of different species in different environments. This evolutionary modality is reflected in the fact that atoms, celestial bodies, chemical compounds, the general structure of the universe, physical laws and biological beings show the presence of stable entities selected among the many theoretically possible or unstable.

Para‐phenylenediamine hair dye and dry eye symptoms: A cross‐sectional study

Aims/Purpose: Para‐phenylenediamine is a common constituent in black hair dye which is well‐associated with irritant dermatitis. Ocular complications include blepharoconjunctivitis, dry eye disease and allergic eye disease (1), mostly reported in case studies. We conducted a cross‐sectional study to establish the prevalence of dry eye symptoms in black hair dye users, and its association with irritant dermatitis, sleeping position and frequency of hair dye use.Methods: This cross‐sectional study was conducted online among Facebook followers of an ophthalmology clinic based in Mauritius. 100 responses were gathered between November 2020 and May 2022. Participants included in the study were all users of black hair dye, over the age of 18 and of either sex. Patients with potential confounding causes of dry eye disease symptoms were not excluded from the study, but a separate analysis was conducted excluding them. Data was subsequently analysed using R statistical software.Results: Most participants were female (88%) and excluding those with confounding causes of dry eye disease, 57% of participants reported ocular symptoms, such as grittiness, blurry vision and red eyes. 34% of these patients also reported scalp dermatitis. Prevalence of ocular symptoms increased with duration of hair dye use. However, no association was found between either rates of irritant scalp dermatitis, sleeping position or frequency of hair dye use and ocular symptoms.Conclusions: We have found a high prevalence of dry eye symptoms among black hair dye users, compared to the prevalence previously described in the literature (28.2% by Golińska‐Zach et al.) (1), with a prolonged duration of hair dye use being a risk factor. Larger scale studies are needed to characterize the influence of para‐phenylenediamine hair dye on ocular surface disease, including assessment of tear film properties and meibomian gland dysfunction.Reference1. Golińska‐Zach A, Krawczyk‐Szulc P, Wiszniewska M, Nowakowska‐Świrta E, Świerczyńska‐Machura D, Tymoszuk D, et al. Sensitization to occupational allergens in hairdressing apprentices diagnosed already before entering vocational training. Med Pr [Internet]. 2016 [cited 2022 Apr 25]; 67(5): 567–75. Available from: https://pubmed.ncbi.nlm.nih.gov/27819696/

An interpretation of the new guidelines multilevel approach for a railway bridge

In the last years for European governments, like in Italy, has become important to increase the attention on the maintenance plan activities and its assessment, analyzing their infrastructures as highway bridges or viaducts and focusing in particular on their structural elements as prestressed precast beams, piles, supports and slabs; This concern due to the fact that the percentage of failures and partial collapses are strictly connected with the age of the infrastructure, timing exposure and deterioration status.With this end, the Italian government has decided to apply a new procedure analysis, based on a multilevel approach composed by five different levels, directly connected between them in order to obtain an attention class index, starting to the project parameters knowledge until the monitoring phase characterized by using accelerometers or similar instruments, cabled directly on the bridges for real time recording. Moreover, in particular for the development of the level nr.2 that must describe the infrastructure status presently, an abacus with a large number of principal defects was developed for the common materials constituents like masonry, concrete, steel and wood to estimate the deterioration levels of each infrastructure elements.The objective of that work is the application of Italian guidelines on a railway bridge, in order to increase the knowledge on this kind of bridges and analyze if and how the multilevel approach allows to understand critical aspects of railway typologies structures or if particular suggestions are necessary.

Understanding the impact of molecular structure on the formation of stable intermediates during the pyrolysis of monoalkylated cyclohexanes in a shock tube

Alkylcyclohexanes are common constituents of conventional jet fuels and are expected to be a vital molecular subclass in next-generation, sustainable aviation fuels (SAFs). In an effort to advance the current understanding of the combustion chemistry of these species at engine-relevant conditions, we measured the time-resolved evolution of key stable intermediates during the pyrolysis of cyclohexane (CH) and four monoalkylated cyclohexanes: methylcyclohexane (MCH), ethylcyclohexane (ECH), propylcyclohexane (PCH), and butylcyclohexane (BCH), using laser absorption spectroscopy (LAS) in a shock tube. These experiments were conducted using 2 % Fuel/Argon test mixtures at a nominal pressure of 2 atm over the temperature range 1150–1530 K. Simultaneous tracking of the mole fraction time histories of methane, ethylene, and larger alkenes (>C2) provided new, valuable insight into the high-temperature reactivity of the five fuels studied. Studying all five fuels under similar test conditions enabled us to observe clear trends in the yields of different pyrolysis products with varying molecular structure, specifically increasing the number of carbon atoms in the alkyl chain. The fuel structure effects investigated in this work are instrumental in characterizing the pyrolysis product distribution, and thereby the overall combustion behavior of cyclohexane derivatives with longer (>C4) alkyl chains. We believe the multi-wavelength speciation data presented in this work can significantly contribute towards the development of robust, simplified, and fuel-specific kinetic models for monoalkylated cyclohexanes.

Urban agglomeration: developing approaches to a new phenomenon

Object: the article studies the essence and features of urban agglomerations (hereinafter referred to as UA), the system of interrelation with neighbouring districts and cities. In addition, the authors of the article considered scientific and theoretical approaches to the concept of urban agglomerations, different stages of development and factors affecting them.Methods: the study was conducted using the following methods: general scientific dialectical method of cognition, which was chosen to determine the essence of urban agglomerations in general and the factors affecting their economic development — system approach, since urban agglomerations are a set of interconnected and mutually conditioned territories with a certain centre, i.e. shows signs of coherence;The comparative approach is central and necessary in this study to identify the common constituents of urban agglomerations.Findings: the research showed that UAs are a product of human activity. They are created by people who prefer to live, work and rest in close proximity to each other. UAs are also formed due to economic-political, and social norms of society development, but they can differ from each other depending on the specific territory, which is influenced in a complex by specific factors of a certain region. The factors can include political-economic, cultural-social, communication innovation-technological, transport, infrastructure, housing and utilities, production, natural-climatic, environmental and other factors that attract the population and improve the quality and conditions of living.Conclusions: Foreign authors tend to emphasize economic and demographic aspects of UAs. They often define urban agglomerations as a continuous territory consisting of one or more cities, towns, villages and neighboring territories, focusing on physical aspects. Kazakh scientists believe that UA is an association of territories based on political, economic, production, social, cultural, national, religious, and environmental attributes or factors. However, despite the divergence in scientific circles, many scientists come to a common opinion that UA should be studied in a complex and systematic way depending on the territory under study. Each scientist has his or her own opinion and this topic has not been fully explored yet, today there is no single definition of the essence, and features of UA, so this topic always causes disputes and disagreements and is the object of current research.

Global Profiling of the Antioxidant Constituents in Chebulae Fructus Based on an Integrative Strategy of UHPLC/IM-QTOF-MS, MS/MS Molecular Networking, and Spectrum-Effect Correlation.

An integrative strategy of UHPLC/IM-QTOF-MS analysis, MS/MS molecular networking (MN), in-house library search, and a collision cross-section (CCS) simulation and comparison was developed for the rapid characterization of the chemical constituents in Chebulae Fructus (CF). A total of 122 Constituents were identified, and most were phenolcarboxylic and tannic compounds. Subsequently, 1,3,6-tri-O-galloyl-β-d-glucose, terflavin A, 1,2,6-tri-O-galloyl-β-d-glucose, punicalagin B, chebulinic acid, chebulagic acid, 1,2,3,4,6-penta-O-galloyl-β-d-glucose, and chebulic acid, among the 23 common constituents of CF, were screened out by UPLC-PDA fingerprinting and multivariate statistical analyses (HCA, PCA, and OPLS-DA). Then, Pearson's correlation analysis and a grey relational analysis were performed for the spectrum-effect correlation between the UPLC fingerprints and the antioxidant capacity of CF, which was finally validated by an UPLC-DPPH• analysis for the main antioxidant constituents. Our study provides a global identification of CF constituents and contributes to the quality control and development of functional foods and preparations dedicated to CF.

Risk Assessment of Isoeugenol in Food Based on Benchmark Dose-Response Modeling.

Isoeugenol has recently been evaluated as possibly carcinogenic (Group 2B) by the WHO International Agency for Research on Cancer (IARC). In light of this evaluation, an updated risk assessment of this common food constituent was conducted using the benchmark dose (BMD) approach as recommended by the European Food Safety Authority (EFSA) for point of departure (POD) determination, as an alternative to the no observed adverse effect level (NOAEL). This approach was specifically chosen, as for the relevant neoplastic endpoints only lowest observed adverse effect level (LOAEL) values are available. The toxicological endpoint from the animal studies with the most conservative BMD lower confidence limit (BMDL) value was identified. Using the obtained BMDL value of 8 mg/kg body weight/day as POD, an acceptable daily intake (ADI) of 16 µg/kg body weight/day was obtained, which-despite being more conservative than previous approaches-is still clearly above the estimated daily exposure level to isoeugenol in the USA and in Europe. These results confirm a low risk of the estimated daily exposure levels of isoeugenol.

Silica extraction from bamboo leaves using alkaline extraction method

The silica is most common constituent of bamboo leaves mainly varies from 75.90 to 82.86 %.In this study, silica was extracted from bamboo leaves using an alkaline extractionprocess. In proximate analysis, bamboo leaves were found to contain significantly more ash (24.5 %) containing 79.28 % silica and low levels of fixed carbon. However, in ultimate analysis, bamboo leaves were found to contain 57.56 % oxygen.The yield and quality of silica were improved by extracting silica from bamboo leaves ash under various operating conditions.A higher concentration of NaOH (2.5 N) resulted in a greater yield of silica (97.73 %).During the alkaline process, an acid leaching treatment was used toremove metal impurities either from bamboo leaves ash or extracted silica. The silica yield increased from 97.73 % to 98.86 % after acid leaching of feed. In an FTIR analysis, Si-O-Si, Si-O, and Si-OH bonds were identified. Modern characterization techniques such as XRF were used to determine the purity of silica. There is a significant difference between the maximum purity of acid leached silica samples (96.13 %) and that of commercial silica samples (95.52 %).As a result of this study, silica that has a wide range of applications in the food and nutrition industries, the pharmaceutical industry, and as a nano-catalyst could be produced.

Steam gasification of char derived from refuse-derived fuel pyrolysis: adsorption behaviour in phenol solutions

ABSTRACT The increasing waste generation trends resulted in growing attention to the technologies that aim to reduce or prevent landfilling. The pyrolysis and gasification of refuse-derived fuel (RDF) allow waste to be turned into new raw materials, like pyrolysis gas and syngas. However, the wet gas cleaning processes result in the production of highly contaminated liquid waste. Phenolic compounds are common constituents of this wastewater and often appear in the wastewater of other industries as well. In this research, the laboratory-scale steam gasification of an RDF char was performed to produce syngas and adsorbent simultaneously. The RDF was previously pyrolyzed at 700 °C maximum temperature in a Hungarian pyrolysis pilot plant with approximately 120 kg h−1 capacity. In this thermal waste processing plant, the pyrolysis gas is already utilised by burning, but currently, the char ends up in landfills. The gasification of char samples was examined with different steam-to-carbon ratios (0.56, 0.84, and 1.12) and duration (30, 60, and 120 min) at 900 °C. Following gasification, the phenol removal capability of the solid by-products was investigated. The results show that its composition and energetic properties make the produced syngas more suitable to use as a raw material in the chemical industry rather than a fuel. At lower concentrations, the effectiveness of the solid by-product for phenol removal was comparable to commercial activated carbon. These are promising results about producing activated carbon from waste without any chemical treatment.

Cobalt-catalyzed aminoalkylative carbonylation of alkenes toward direct synthesis of γ-amino acid derivatives and peptides

γ-Amino acids and peptides analogues are common constituents of building blocks for numerous biologically active molecules, pharmaceuticals, and natural products. In particular, γ-amino acids are providing with better metabolic stability than α-amino acids. Herein we report a multicomponent carbonylation technology that combines readily available amides, alkenes, and the feedstock gas carbon monoxide to build architecturally complex and functionally diverse γ-amino acid derivatives in a single step by the implementation of radical relay catalysis. This transformation can also be used as a late-stage functionalization strategy to deliver complex, advanced γ-amino acid products for pharmaceutical and other areas.

The Application of Metal Oxide Nanoparticles in Sunscreen and Their Potential Risks

Nanoparticles are extremely small particles with at least one dimension between 1 and 100 nanometers (nm). These nanoparticles consist of many disparate elements such as metal and polymers. Nanoparticles like zinc oxide and titanium dioxide play an important role in sunscreens. Zinc oxide and titanium dioxide are common active constituents found in many sunscreens. They are utilised in physical sunscreen because of their ability to protect skin from UV light. Being exposed to sunlight for a long time may rise the peril of skin diseases and lead to skin lesions. The nanoparticles have an negative effect on human and environment. These potential risks should be concerned by the public and these risks still need to be researched by the scientists. Nanoparticles have the potential to impact the environment. For instance, silver and copper nanoparticles used in consumer products can be released into the environment via wastewater and accumulate in soil and water bodies.

Leaching tests reveal fast aluminum fluoride release from ashfall accumulated in La Palma (Canary Islands, Spain) after the 2021 Tajogaite eruption

Leaching tests conducted on fresh ashfall samples taken soon after the onset of the 2021 Tajogaite eruption occurred at the Northwest flank of the Cumbre Vieja Volcanic Ridge in La Palma (Canary Islands) have revealed relevant geochemical trends which have important environmental significance and practical implications. The ashfall deposited on most of the island during the eruptive episode (9/19/2021–12/13/2021) contains, in addition to common constituents in volcanic tephra (e.g. volcanic glass, silicates like olivine, amphibole or pyroxene, magnetite, etc.) a significant amount of very fine-grained (diameter range of 10–500 μm) crystals of highly soluble salts like AlF3, NaCl, KCl or CaSO4. These salts likely crystallized at high temperature by interaction of acid volatile phases (e.g., HF, HCl, SO2) with volcanic glass and silicate minerals during the ascending flow of the eruptive plume, though some adsorption of marine aerosols on ash surfaces during the subsequent descending flow and transport to more distal areas could have also taken place. The dissolution of these salts in the leaching tests (conducted with ultrapure distilled water during 90 min) reveals a fast release of important amounts of F−, Cl− and SO42− as major anions, and Al3+, Na+, K+, Ca2+, Mg2+ and Si4+ as major cations, in addition to minor amounts of trace metals like Mn2+, Zn2+, Ba2+ or Sr2+. The release of F− and Al3+, both potentially toxic and travelling together as aluminum fluoride species (AlF3, AlF2+, AlF4−) is particularly noteworthy and represents a potential threat for the environment (including soils, surface waters or groundwater existing beneath the ashfall layers covering the island) as well as for food safety (e.g. banana plantations) and/or human health (exposure to F- or Al-contaminated water). On the other hand, the tephra does not represent an environmental hazard as regards to other toxic elements traditionally reported for ashfall released in other volcanic eruptions, such as As, Pb, Hg or Se, which were always close to or below the limit of quantification. Besides, the Tajogaite 2021 ashfall shows a significant acid-neutralizing capacity as a result of the partial dissolution of volcanic glass in the F-rich solutions. This study presents a discussion of geochemical and mineralogical controls on element mobility during ashfall/water interaction in the environment which may be worth considering in any future restoration or land management plans for the island.

Integration of Deep Learning and Sequential Metabolism to Rapidly Screen Dipeptidyl Peptidase (DPP)-IV Inhibitors from Gardenia jasminoides Ellis.

Traditional Chinese medicine (TCM) possesses unique advantages in the management of blood glucose and lipids. However, there is still a significant gap in the exploration of its pharmacologically active components. Integrated strategies encompassing deep-learning prediction models and active validation based on absorbable ingredients can greatly improve the identification rate and screening efficiency in TCM. In this study, the affinity prediction of 11,549 compounds from the traditional Chinese medicine system's pharmacology database (TCMSP) with dipeptidyl peptidase-IV (DPP-IV) based on a deep-learning model was firstly conducted. With the results, Gardenia jasminoides Ellis (GJE), a food medicine with homologous properties, was selected as a model drug. The absorbed components of GJE were subsequently identified through in vivo intestinal perfusion and oral administration. As a result, a total of 38 prototypical absorbed components of GJE were identified. These components were analyzed to determine their absorption patterns after intestinal, hepatic, and systemic metabolism. Virtual docking and DPP-IV enzyme activity experiments were further conducted to validate the inhibitory effects and potential binding sites of the common constituents of deep learning and sequential metabolism. The results showed a significant DPP-IV inhibitory activity (IC50 53 ± 0.63 μg/mL) of the iridoid glycosides' potent fractions, which is a novel finding. Genipin 1-gentiobioside was screened as a promising new DPP-IV inhibitor in GJE. These findings highlight the potential of this innovative approach for the rapid screening of active ingredients in TCM and provide insights into the molecular mechanisms underlying the anti-diabetic activity of GJE.

A Spatial Analysis of Urban Streets under Deep Learning Based on Street View Imagery: Quantifying Perceptual and Elemental Perceptual Relationships

Measuring the human perception of urban street space and exploring the street space elements that influence this perception have always interested geographic information and urban planning fields. However, most traditional efforts to investigate urban street perception are based on manual, usually time-consuming, inefficient, and subjective judgments. This shortcoming has a crucial impact on large-scale street spatial analyses. Fortunately, in recent years, deep learning models have gained robust element extraction capabilities for images and achieved very competitive results in semantic segmentation. In this paper, we propose a Street View imagery (SVI)-driven deep learning approach to automatically measure six perceptions of large-scale urban areas, including “safety”, “lively”, “beautiful”, “wealthy”, “depressing”, and “boring”. The model was trained on millions of people’s ratings of SVIs with a high accuracy. First, this paper maps the distribution of the six human perceptions of urban street spaces within the third ring road of Wuhan (appearing as Wuhan later). Secondly, we constructed a multiple linear regression model of “street constituents–human perception” by segmenting the common urban constituents from the SVIs. Finally, we analyzed various objects positively or negatively correlated with the six perceptual indicators based on the multiple linear regression model. The experiments elucidated the subtle weighting relationships between elements in different street spaces and the perceptual dimensions they affect, helping to identify the visual factors that may cause perceptions of an area to be involved. The findings suggested that motorized vehicles such as “cars” and “trucks” can negatively affect people’s perceptions of “safety”, which is different from previous studies. We also examined the influence of the relationships between perceptions, such as “safety” and “wealthy”. Finally, we discussed the “perceptual bias” issue in cities. The findings enhance the understanding of researchers and city managers of the psychological and cognitive processes behind human–street interactions.

Preparation of β-Cyclodextrin Functionalized Platform for Monitoring Changes in Potassium Content in Perspiration.

The monitoring of potassium ion (K+) levels in human sweat can provide valuable insights into electrolyte balance and muscle fatigue non-invasively. However, existing laboratory techniques for sweat testing are complex, while wearable sensors face limitations like drift, fouling and interference from ions such as Na+. This work develops printed electrodes using β-cyclodextrin functionalized reduced graphene oxide (β-CD-RGO) for selective K+ quantification in sweat. The β-CD prevents the aggregation of RGO sheets while also providing selective binding sites for K+ capture. Electrodes were fabricated by screen printing the β-CD-RGO ink onto conductive carbon substrates. Material characterization confirmed the successful functionalization of RGO with β-CD. Cyclic voltammetry (CV) showed enhanced electrochemical behavior for β-CD-RGO-printed electrodes compared with bare carbon and RGO. Sensor optimization resulted in a formulation with 30% β-CD-RGO loading. The printed electrodes were drop-casted with an ion-selective polyvinyl chloride (PVC) membrane. A linear range from 10 μM to 100 mM was obtained along with a sensitivity of 54.7 mV/decade. The sensor showed good reproducibility over 10 cycles in 10 mM KCl. Minimal interference from 100 mM Na+ and other common sweat constituents validated the sensor's selectivity. On-body trials were performed by mounting the printed electrodes on human subjects during exercise. The K+ levels measured in sweat were found to correlate well with serum analysis, demonstrating the sensor's ability for non-invasive electrolyte monitoring. Overall, the facile synthesis of stable β-CD-RGO inks enables the scalable fabrication of wearable sensors for sweat potassium detection.

An aldehyde as a rapid source of secondary aerosol precursors: theoretical and experimental study of hexanal autoxidation

Abstract. Aldehydes are common constituents of natural and polluted atmospheres, and their gas-phase oxidation has recently been reported to yield highly oxygenated organic molecules (HOMs) that are key players in the formation of atmospheric aerosol. However, insights into the molecular-level mechanism of this oxidation reaction have been scarce. While OH initiated oxidation of small aldehydes, with two to five carbon atoms, under high-NOx conditions generally leads to fragmentation products, longer-chain aldehydes involving an initial non-aldehydic hydrogen abstraction can be a path to molecular functionalization and growth. In this work, we conduct a joint theoretical–experimental analysis of the autoxidation chain reaction of a common aldehyde, hexanal. We computationally study the initial steps of OH oxidation at the RHF-RCCSD(T)-F12a/VDZ-F12//ωB97X-D/aug-cc-pVTZ level and show that both aldehydic (on C1) and non-aldehydic (on C4) H-abstraction channels contribute to HOMs via autoxidation. The oxidation products predominantly form through the H abstraction from C1 and C4, followed by fast unimolecular 1,6 H-shifts with rate coefficients of 1.7×10-1 and 8.6×10-1 s−1, respectively. Experimental flow reactor measurements at variable reaction times show that hexanal oxidation products including HOM monomers up to C6H11O7 and accretion products C12H22O9−10 form within 3 s reaction time. Kinetic modeling simulations including atmospherically relevant precursor concentrations agree with the experimental results and the expected timescales. Finally, we estimate the hexanal HOM yields up to seven O atoms with mechanistic details through both C1 and C4 channels.

Spondias mombin: biosafety and GC–MS analysis of anti-viral compounds from crude leaf extracts

Essential oils are combinations of naturally occurring phytochemicals that, alone or in synergy with other compounds, can therapeutically attenuate disease-causing viral infections such as SARS-CoV-2, Ebola, and Marburg viruses. This study aimed to investigate the biosafety of and identification of antiviral phytochemicals of Spondias mombin (Linn) leaf crude extracts by GC–MS analysis. GC–MS analysis showed that the compound concentrations were dependent on the polarity of extracting solvent SMH (34), SMDCM (36), SMEA (12), SME (50) and SMM (36). Toluene (15.13%) and di-isooctyl phthalate (14.21%) were identified as the basic constituents of SMH. In SMDCM, n-nonadecanol-1 (19.64%) and eicosane (13.93%) were the main compounds, while in SMEA it was ethanol, 2-butoxy-(83.29%). Both SME and SMM showed the presence of Tetradecyl trifluoroacetate (15.43%). Pentadecanoic acid (12.18%), Propane, 2,2-diethoxy- (33.83%) and o-Xylene (15.87%). The identified antiviral compounds in the crude extracts, were d-Limonene (1.33%), p-Cymene (1.31%), Thymol (0.50%) and Carvacrol (0.87%) in SMM and SMH extracts, with Phytol, acetate being a common constituent in all the essential oils, except SMEA. In vitro cytotoxicity studies of crude S. mombin leaf extracts were performed using the MTT method in three cell lines: MCF-7, A-549 and HEK-293, with IC50 values between 15.91 and 178.5 μg/mL. Therefore, the results indicated that crude extracts from S. mombin leafs had low toxicity and could be used safely. Compared with hexane extracts (1), methanol extracts have more compounds with antiviral properties (3) and can be used as reusable therapeutic candidates, natural dietary supplements or in the fight against SARS-CoV-2, Ebola and Marburg viruses. This can be valuable in pharmaceutical preparations of drug candidates for the treatment of these viruses.

Removal of the chemotherapeutic drugs 5-fluorouracil and cyclophosphamide by UV/peracetic acid: Reaction kinetics and mechanism

5-Fluorouracil and cyclophosphamide, the two most commonly used chemotherapeutic drugs, are widely detected in aquatic environments and cause cytotoxic and other adverse effects in ecosystems. In this work, UV/peracetic acid (UV/PAA) treatment was investigated for the first time for 5-fluorouracil and cyclophosphamide removal. The results showed that 5-fluorouracil and cyclophosphamide can be efficiently removed via UV/PAA within 20 min, with pseudo-first-order rate constants (kobs) of 0.197 and 0.135 min−1, respectively. The influences of PAA dosage, initial compound concentration, solution pH and common water constituents (Cl−, HCO3−, NO3− and dissolved organic matter) were systematically studied. OH was the predominant species involved in the degradation of the two pharmaceuticals, while direct UV photolysis and R–C were also involved in removing 5-fluorouracil. Two and five byproducts were detected in UV/PAA degradation of 5-fluorouracil and cyclophosphamide, respectively, and the possible degradation pathways were proposed. Although total organic carbon was not completely removed during the reaction, the Microtox® toxicity trend (an increase and further decrease) implied further detoxification of the byproducts. Additionally, UV/PAA treatment applied to real water samples (river water and effluent from a wastewater treatment plant) still exhibited good efficiency for removing the two compounds, revealing its applicability in water/wastewater treatment.