To elucidate the molecular composition and sources of organic aerosols in Central Asia, carbonaceous compounds, major ions, and 15 organic molecular tracers of total suspended particulates (TSP) were analyzed from September 2018 to August 2019 in Dushanbe, Tajikistan. Extremely high TSP concentrations (annual mean ± std: 211 ± 131 μg m⁻³) were observed, particularly during summer (seasonal mean ± std: 333 ± 183 μg m⁻³). Organic carbon (OC: 11.9 ± 7.0 μg m⁻³) and elemental carbon (EC: 5.1 ± 2.2 μg m⁻³) exhibited distinct seasonal variations from TSP, with the highest values occurring in winter. A high concentration of Ca²⁺ was observed (11.9 ± 9.2 μg m⁻³), accounting for 50.8% of the total ions and reflecting the considerable influence of dust on aerosols. Among the measured organic molecular tracers, levoglucosan was the predominant compound (632 ± 770 ng m⁻³), and its concentration correlated significantly with OC and EC during the study period. These findings highlight biomass burning (BB) as an important contributor to the particulate air pollution in Dushanbe. High ratios of levoglucosan to mannosan, and syringic acid to vanillic acid suggest that mixed hardwood and herbaceous plants were the main burning materials in the area, with softwood being a minor one. According to the diagnostic tracer ratio, OC derived from BB constituted a large fraction of the primary OC (POC) in ambient aerosols, accounting for an annual mean of nearly 30% and reaching 63% in winter. The annual contribution of fungal spores to POC was 10%, with a maximum of 16% in spring. Measurements of plant debris, accounting for 3% of POC, divulged that these have the same variation as fungal spores.

Quinone is the important redox functional group for electron transfer capacity (ETC) of humic acid (HA). Lignin, as major component in corn straw, can be decomposed into phenol monomers, then oxidation into quinones for synthesis of HA during composting process. However, it is still unclear that the effects of type and variation characteristics of phenol monomers on redox characteristics of HA during straw composting process. In this study, p-hydroxybenzoic acid (P1), vanillic acid (P2), syringic acid (P3), p-hydroxy benzaldehyde (P4), 4-coumaric acid (P5), 4-hydroxyacetophenone (P6), ferulic acid (P7) and 4-hydroxy-3-methylacetophenone (P8) were recognized and clustered into three groups. The concentration of polyphenol presented a significant downward trend during the straw composting process. Based on the relationships among phenol monomers to ETC, electron donating capacity (EDC), electron accepting capacity (EAC) and quinone, we found that P1, P2, P3, P5 and P7 were significantly related to ETC, EDC and EAC of HA (P < 0.05). Furthermore, NH₄⁺-N and NO₃⁻-N were the main micro-environmental factors linking to ETC-related phenol monomers and redox characteristics of HA in straw composts (P < 0.05). Finally, two groups of core microflora that promoting the ETC-related phenol monomers and NH₄⁺-N, and ETC-related phenol monomers and NO₃⁻-N were identified by Mantel test, respectively. This study contributes a new insight for polyphenol way for redox capacity of HA in traditional composting and utilization of straw compost in contaminated environments.

Biomass burning (BB) is one of the largest sources of carbonaceous aerosols with adverse impacts on air quality, visibility, health and climate. BB emits a few specific aromatic acids (p-hydroxybenzoic, vanillic, syringic and dehydroabietic acids) which have been widely used as key indicators for source identification of BB-derived carbonaceous aerosols in various environmental matrices. In addition, measurement of p-hydroxybenzoic and vanillic acids in snow and ice cores have revealed the historical records of the fire emissions. Despite their uniqueness and importance as tracers, our current understanding of analytical methods, concentrations, diagnostic ratios and degradation processes are rather limited and scattered in literature. In this review paper, firstly we have summarized the most established methods and protocols for the measurement of these aromatic acids in aerosols and ice cores. Secondly, we have highlighted the geographical variability in the abundances of these acids, their diagnostic ratios and degradation processes in the environments. The review of the existing data indicates that the concentrations of aromatic acids in aerosols vary greatly with locations worldwide, typically more abundant in urban atmosphere where biomass fuels are commonly used for residential heating and/or cooking purposes. In contrast, their concentrations are lowest in the polar regions which are avoid of localized emissions and largely influenced by long-range transport. The diagnostic ratios among aromatic acids can be used as good indicators for the relative amounts and types of biomass (e.g. hardwood, softwood and herbaceous plants) as well as photochemical oxidation processes. Although studies suggest that the degradation processes of the aromatic acids may be controlled by light, pH and hygroscopicity, a more careful investigation, including closed chamber studies, is highly appreciated.

Myocardial infarction is the acute condition of myocardial necrosis that occurs as a result of imbalance between coronary blood supply and myocardial demand. Air pollution increases the risk of death from cardiovascular diseases (CVDs). The aim of this study was to investigate the effects of particulate matter (PM) on oxidative stress, the expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) messenger RNA (mRNA) level induced by ischemia–reperfusion injury, and the protective effects of vanillic acid (VA) in the isolated rat heart. Male Wistar rats were randomly divided into eight groups (n = 10), namely control, VAc, sham, VA, PMa (0.5 mg/kg), PMb (2.5 mg/kg), PMc (5 mg/kg), and PMc + VA groups. Particles with an aerodynamic diameter <10 μm (PM₁₀) was instilled into the trachea through a fine intubation tube. Two days following the PM₁₀ instillation, the animal’s hearts were isolated and transferred to a Langendorff apparatus. The hearts were subjected to 30 min of global ischemia followed by 60 min of reperfusion. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), xanthine oxidase (XOX), and lactate dehydrogenase (LDH) were measured using special kits. Reverse transcription polymerase chain reaction (RT-PCR) was used to determine levels of iNOS and eNOS mRNA. An increase in left ventricular end-diastolic pressure (LVEDP), S–T elevation, and oxidative stress in PM₁₀ groups was observed. Ischemia–reperfusion (I/R) induction showed a significant augment in the expression of iNOS mRNA level and a significant decrease in the expression eNOS mRNA level. This effect was more pronounced in the PM groups than in the control and sham groups. Vanillic acid caused a significant decrease in LVEDP, S–T elevation, and also a significant difference in eNOS mRNA expression level, antioxidant enzymes, iNOS mRNA expression level, and oxidative stress occurred on myocardial dysfunction after I/R in isolated rat hearts. This study showed that PM₁₀ exposure had devastating effects on the myocardial heart, oxidative stress, and eNOS and iNOS mRNA expression levels. Vanillic acid was able to improve these parameters. Vanillic acid as a potent antioxidant could also provide protection against particulate matter-induced toxicity.

Acacia jacquemontii possess has numerous traditional therapeutic uses. The rationale of this study was to investigate the role of Acacia jacquemontii ethyl acetate extract (AJEAE) in the downregulation of hyperglycemia. The current study was performed in two parts, in vitro, through characterization (high-performance liquid chromatography), estimation of total phenolic content, total flavonoid content, antioxidant (2,2-diphenyl-1-picrylhydrazylassay), and α-amylase inhibitory activities of the studied extract, and in vivo using Wistar rats in which animals were divided into five groups NC, DC, GL, AJEAE 250 mg/kg, and AJEAE 500 mg/kg. The effects of AJEAE on fasting plasma glucose, plasma insulin, HOMA-IR, oral glucose tolerance test, glycated hemoglobin (HBA1c), lipid profile, inflammatory cytokines (Interleukin-6, tumor necrosis factor-alpha), and oxidative stress markers (lipid peroxidation, nitic oxide, superoxide dismutase, catalase, glutathione peroxidase) were evaluated. Our findings confirmed the presence of quercetin, kaempferol, gallic acid, vanillic acid, syringic acid, M-coumaric acid, sinapic acid, chlorogenic acid, cinnamic acid, and ferulic acid in AJEAE. Total flavonoid and phenolic contents in AJEAE were 83.83 mg GAE/g and 77.06 mg QE/g, respectively. Significant inhibition of DPPH (69.470%/1 mg/ml) and α-amylase (71.8%/1 mg/ml) activities were exhibited by AJEAE. Alloxan-injected rats showed marked hyperglycemia and hypoinsulinemia, and increased inflammatory marker levels as compared to normal control (p < 0.001). Additionally, raised levels of triglyceride (139.7 ± 2.771), total cholesterol (198.7 ± 1.856), very low-density lipoprotein (33.43 ± 0.2728), low-density lipoprotein (155.5 ± 2.754), lipid peroxidation, and nitric oxide (p < 0.001) and decreased levels of high-density lipoprotein (17.20 ± 0.1732), superoxide dismutase, catalase, and glutathione peroxidase were observed in diabetic rats (p < 0.001). AJEAE significantly (p < 0.05) improved the aforementioned parameters and the protective efficacy was comparable to glibenclamide. Histopathological findings also evidenced the anti-hyperglycemic properties of AJEAE through regeneration of pancreatic β cells. Conclusively, our findings demonstrated the antihyperglycemic, antihyperlipidemic, antioxidant, anti-inflammatory, and pancreatic beta β cell regenerative properties of AJEAE against alloxan-induced diabetes.

Furanic and phenolic compounds are problematic compounds resulting from the pretreatment of lignocellulosic biomass for biofuel production. Microbial electrolysis cell (MEC) is a promising technology to convert furanic and phenolic compounds to renewable H₂. The objective of the research presented here was to elucidate the processes and electron equivalents flow during the conversion of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; 4-hydroxybenzoic acid, HBA) compounds in the MEC bioanode. Cyclic voltammograms of the bioanode demonstrated that purely electrochemical reactions in the biofilm attached to the electrode were negligible. Instead, microbial reactions related to the biotransformation of the five parent compounds (i.e., fermentation followed by exoelectrogenesis) were the primary processes resulting in the electron equivalents flow in the MEC bioanode. A mass-based framework of substrate utilization and electron flow was developed to quantify the distribution of the electron equivalents among the bioanode processes, including biomass growth for each of the five parent compounds. Using input parameters of anode efficiency and biomass observed yield coefficients, it was estimated that more than 50% of the SA, FF, and HMF electron equivalents were converted to current. In contrast, only 12 and 9% of VA and HBA electron equivalents, respectively, resulted in current production, while 76 and 79% remained as fermentation end products not further utilized in exoelectrogenesis. For all five compounds, it was estimated that 10% of the initially added electron equivalents were used for fermentative biomass synthesis, while 2 to 13% were used for exoelectrogenic biomass synthesis. The proposed mass-based framework provides a foundation for the simulation of bioanode processes to guide the optimization of MECs converting biomass-derived waste streams to renewable H₂.

Root exudates (REs) of Scirpus triqueter were extracted from the rhizosphere soil in this study. The components in the REs were identified by GC-MS. Many organic acids, such as hexadecanoic acid, pentadecanoic acid, vanillic acid, octadecanoic acid, citric acid, succinic acid, glutaric acid, and so on, were found. Batch simulated experiments were conducted to evaluate the impacts of different organic acids, such as citric acid, artificial root exudates (ARE), succinic acid, and glutaric acid in REs of S. triqueter on desorption of pyrene (PYR) and lead (Pb) in co-contaminated wetland soils. The desorption amount of PYR and Pb increased with the rise in concentrations of organic acids in the range of 0–50 g·L⁻¹, within shaking time of 2–24 h. The desorption effects of PYR and Pb in soils with various organic acids treatments decreased in the following order: citric acid > ARE > succinic acid > glutaric acid. The desorption rate of PYR and Pb was higher in co-contaminated soil than in single pollution soil. The impacts of organic acids in REs of S. triqueter on bioavailability of PYR and Pb suggested that organic acids enhanced the bioavailability of PYR and Pb in wetland soil, and the bioavailability effects of organic acids generally followed the same order as that of desorption effects.

Plants in Brassica genus have been found to possess strong allelopathic potential. They may inhibit seed germination and emergence of subsequent crops following them in a rotation system. Series of laboratory and greenhouse experiments were conducted to determine the allelopathic impacts of Brassica napus L. against mung bean. We studied (1) the effects of aqueous extract (5%) of different plant parts (root, stem, leaf, flower, and whole plant) of B. napus, (2) the effects of leaf and flower extracts of B. napus at 0, 1, 2, 3, and 4% concentrations, and (3) the effect of residues of different B. napus plant parts and decomposition periods (0, 7, 14, and 21 days) on germination and seedling growth of mung bean. Various types of phenolics including quercitin, chlorogenic acid, p-coumeric acid, m-coumaric acid, benzoic acid, caffeic acid, syringic acid, vanillic acid, ferulic acid, cinamic acid, and gallic acid were identified in plant parts of B. napus. Among aqueous extracts of various plant parts, leaf and flower were found to have stronger inhibitory effects on germination and seedling growth traits of mung bean, higher concentrations were more toxic. The decomposition period changed the phtotoxic effect of residues, more inhibitory effect was shown at 14 days decomposition while decomposition for 21 days reduced inhibitory effect. The more total water-soluble phenolic was found in 5% (w/v) aqueous extract and 5% (w/w) residues of B. napus flowers at 14 days of decomposition (89.80 and 10.47 mg L⁻¹), respectively. The strong inhibitory effects of B. napus should be managed when followed in rotation.

Background, aim, and scope Olive oil mill wastewater (OOMW) environmental impacts minimization have been attempted by developing more effective processes, but no chemical or biological treatments were found to be totally effective to mitigate their impact on receiving systems. This work is the first that reports simultaneously the efficiency of three different approaches: biological treatment by two fungal species (Trametes versicolor or Pleurotus sajor caju), enzymatic treatment by laccase, and chemical treatment by photo-Fenton oxidation on phenols removal. Materials and methods Those treatments were performed on OOMW with or without phenol supplement (p-coumaric, vanillin, guaiacol, vanillic acid, or tyrosol). OOMW samples resulted from treatments were extracted for phenols using liquid-liquid extraction and analyzed by gas chromatography coupled to mass spectrometry. Results Treatment with T. versicolor or P. sajor caju were able to remove between 22% and 74% and between 8% and 76% of phenols, respectively. Treatment by laccase was able to reduce 4% to 70% of phenols whereas treatment by photo-Fenton oxidation was responsible for 100% phenols reduction. Discussion Range of phenol degradation was equivalent between T. versicolor, P. sajor caju and laccase for p-coumaric, guaiacol, caffeic acid, and tyrosol in supplemented OOMW, which enhances this enzyme role in the biological treatment promoted by these two species. Conclusions Phenols were removed more efficiently by photo-Fenton treatment than by biological or enzymatic treatments. Recommendations and perspectives Use of fungi, laccase, or photo-Fenton presents great potential for removing phenols from OOMW. This should be further assessed by increasing the application scale and the reactor configurations effect on the performance, besides a toxicity evaluation of treated wastewater in comparison to raw wastewater.

Particulate matter (PM) inhalation is an established trigger of cardiovascular events such as cardiac arrhythmias that occur within hours to days after exposure. Higher daily PM levels are related to acute increases in systemic arterial blood pressure (BP). The aim of the present study was to evaluate the effects of PM₁₀ on electrocardiogram (ECG) parameters, blood pressure, lipid peroxidation (MDA), xanthine oxidase, and antioxidant enzyme in healthy rats and also to examine the protective effects of vanillic acid (VA) in this respect. Eighty male Wistar rats were divided into eight groups (n = 10), namely control (normal saline, gavage), VAc (10 mg/kg), sham (normal saline, intratracheal instillation), VA (10 mg/kg VA, 10 days gavage +0.1 ml normal saline, intratracheal instillation), PM1 (0.5 mg/kg), PM2 (2.5 mg/kg), PM3 (5 mg/kg), PM3 + VA (5 mg/kg, intratracheal instillation + 10 mg/kg VA, 10 days, gavage) groups. The rats were anesthetized and 0.1 ml of saline as well as a certain concentration of PM₁₀ was instilled into the trachea and it was repeated after 48 h, then 30 min after that, PR interval, QTc, and systolic blood pressure were measured. The activities of antioxidant enzymes, xanthine oxidase (XOX), and malondialdehyde (MDA) were measured in plasma by special Kits. A significant increase in blood pressure (BP), PR interval, QTc, MDA, and XOX and a significant decrease in antioxidant enzyme (CAT, SOD, and GPx) occurred in PM₁₀ groups. Vanillic acid ameliorated blood pressure, QTc, PR interval, XOX, MDA, and increased antioxidant enzymes (SOD, CAT, and GPx) significantly. In the present study, it was shown that PM₁₀ had devastating effects on the heart and blood pressure, probably due to the increased oxidative stress in healthy rats. Vanillic acid could improve the symptoms of PM₁₀ exposure and can be used as an antioxidant agent against the harmful effects of PM₁₀.