Phthalate Derivatives Research Articles

Prepubertal phthalate exposure can cause histopathological alterations, DNA methylation and histone acetylation changes in rat brain.

Di-2-(ethylhexyl)phthalate (DEHP) is a phthalate derivative used extensively in a wide range of materials, such as medical devices, toys, cosmetics, and personal care products. Many mechanisms, including epigenetics, may be involved in the effects of phthalates on brain development. In this study, Sprague-Dawley male rats were obtained 21-23days after their birth (post-weaning) and were exposed to DEHP during the prepubertal period with low-dose DEHP (DEHP-L, 30mg/kg/day) and high-dose DEHP (DEHP-H, 60mg/kg/day, 37days) until the end of adolescence (PND 60). The rats in the study groups were sacrificed during adulthood, and histopathological changes, epigenetic changes, and oxidative stress parameters were evaluated in brain tissues. Histopathological findings indicating the presence of deterioration in brain tissue morphology were obtained, more prominently in the DEHP-H group. Examining the hippocampus under the light microscope, pyramidal neuron loss was detected only in CA1 of the DEHP-L group, while in DEHP-H rats, pyramidal neuron losses were detected in the CA1, CA2, and CA3 regions. No significant change was observed in brain lipid peroxidation levels with DEHP compared to control. Significant increases in total glutathione (GSH) in both dose groups were considered to be an adaptive response to DEHP-induced oxidative stress. The decrease in DNA methylation in the brain, although not statistically significant, and the increase in histone modification showed that exposure to DEHP may cause epigenetic changes in the brain and these epigenetic changes may also take place as one of the mechanisms underlying the damage observed in the brain. The results suggest that DEHP exposure during early development may have a significant effect on brain development.

Phthalic acid derivatives: Sources and effects on the human body

The review summarizes data on the sources of phthalates in the environment and the routes of their penetration into the human body (food and inhalation routes are described in detail). The article discusses methods for detecting phthalates in the human body and assessing adverse effects. Up-to-date information on the effects of phthalic acid derivatives on the human body is presented, potential health risks for people of different age groups are highlighted. Particular attention is paid to the adverse effects of phthalate derivatives on the respiratory system, especially in the context of inhalation of suspended particles contained in the atmospheric air.

Investigation of Potent Antifungal Metabolites from Marine Streptomyces bacillaris STR2 (MK045300) from Western Algeria

Fungal infections significantly threaten public health, and many strains are resistant to antifungal drugs. Marine Actinobacteria have been identified as the generators of powerful bioactive compounds with antifungal activity and can be used to address this issue. In this context, strains of Actinomycetes were isolated from the marine area of Rachgoun Island, located in western Algeria. The isolates were phenotypically and genetically characterized. The most potent antifungal isolate was selected, and its crude extract was purified and characterized by the GC/MS method. The results revealed that the STR2 strain showed the strongest activity against at least one target fungal species tested on a panel of fungal pathogens, including Candida albicans, Aspergillus fumigatus, Aspergillus niger, and Fusarium oxysporum. The molecular assignment of the STR2 strain based on the 16S rRNA gene positioned this isolate as a Streptomyces bacillaris species. The presence of safranal (2,3-dihydro-2,2,6-trimethylbenzaldehyde) in the crude chloroform extract of Streptomyces bacillaris STR2 strain was discovered for the first time in bacteria using chromatographic analysis of its TLC fractions. Moreover, certain molecules of biotechnological interest, such as phenols, 1,3-dioxolane, and phthalate derivatives, were also identified. This study highlights the potential of marine actinomycetes to produce structurally unique natural compounds with antifungal activity.

Isolation and identification of a novel phthalate derivative from Streptomyces sp. grown on peanut shells with antimicrobial activity

Isolation and identification of a novel phthalate derivative from Streptomyces sp. grown on peanut shells with antimicrobial activity

Phthalate Derivative from Non-Polar Fraction of Andaliman Stem Wood (Zathoxylum acanthopodium DC.) from North Sumatra

Phthalate Derivative from Non-Polar Fraction of Andaliman Stem Wood (Zathoxylum acanthopodium DC.) from North Sumatra

Effect of a phthalate derivative purified from Bacillus zhangzhouensis SK4 on quorum sensing regulated virulence factors of Pseudomonas aeruginosa

Pseudomonas aeruginosa causes life-threatening diseases and is resistant to almost all conventional antibiotics. The quorum sensing (QS) system of P. aeruginosa contributes to many pathogenic factors some of which are pigment production, motility, and biofilm. The disruption of quorum sensing system may be an impactful strategy to deal with infections. The present study investigates the anti-quorum sensing property of a bioactive molecule extracted from marine epibiotic bacteria present on the surface of seaweeds. Among all the isolates tested against monitor strain Chromobacterium violaceum (MTCC 2656), the one with the highest activity was identified as Bacillus zhangzhouensis SK4. The culture supernatant was extracted with chloroform which was then partially purified by TLC and column chromatography. The probable anti-QS compound was identified as 1,2-benzenedicarboxylic acid, bis (2-methylpropyl ester) by GC-MS and NMR analysis. The treatment of P. aeruginosa MCC 3457 with the lead compound resulted in the reduced production of pyocyanin, rhamnolipids, exopolysaccharide, biofilm, and motility. The observations of light and scanning electron microscopy also supported the biofilm inhibition. The lead compound showed synergism with the meropenem antibiotic and significantly reduced MIC. The molecular docking and pharmacokinetics study predicted 1, 2-benzenedicarboxylic acid, bis (2-methylpropyl ester), a phthalate derivative as a good drug candidate. The molecular dynamics study was also performed to check the stability of the lead compound and LasR complex. Further, lead compounds did not exhibit any cytotoxicity when tested on human embryonic kidney cells. As per our knowledge, this is the first report on the anti-QS activity of B. zhangzhouensis SK4, indicating that epibiotic bacteria can be a possible source of novel compounds to deal with the multidrug resistance phenomenon.

Diethylhexyl phthalate exposure amplifies oxidant and inflammatory response in fetal hyperglycemia model predisposing insulin resistance in zebrafish embryos.

Exposure of zebrafish embryos to glucose is a suitable model for the fetal hyperglycemia seen in gestational diabetes. Diethylhexyl phthalate (DEHP), which is considered an endocrine-disrupting chemical, is one of the most common phthalate derivatives used in stretching plastic and is encountered in every area where plastic is used in daily life. In the present study, the effects of DEHP on pathways related to insulin resistance and obesity were examined in zebrafish embryos exposed to glucose as a fetal hyperglycemia model. Zebrafish embryos were exposed to DEHP, glucose, and glucose + DEHP for 72 h post-fertilization (hpf), and developmental parameters and locomotor activities were monitored. At 72 hpf ins, lepa, pparγ, atf4a, and il-6 expressions were determined by RT-PCR. Glucose, lipid peroxidation (LPO), nitric oxide (NO) levels, glutathione S-transferase (GST), superoxide dismutase (SOD), and acetylcholine esterase (AChE) activities were measured spectrophotometrically. Compared with the control group, glucose, LPO, GST activity, il6, and atf4a expressions increased in all exposure groups, while body length, locomotor, and SOD activities decreased. While AChE activity decreased in the DEHP and glucose groups, it increased in the glucose + DEHP group. Although glucose exposure increased pparγ and lepa expressions, DEHP significantly decreased the expressions of pparγ and lepa both in the DEHP and glucose + DEHP groups. Our findings showed that DEHP amplified oxidant and inflammatory responses in this fetal hyperglycemia model, predisposing insulin resistance in zebrafish embryos.

Biodegradation of phenanthrene-Cr (VI) co-contamination by Pseudomonas aeruginosa AO-4 and characterization of enhanced degradation of phenanthrene

Microorganisms capable of simultaneously remediating heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) pollution hold significant importance in bioremediation efforts. In this study, we investigated the ability of Pseudomonas aeruginosa AO-4 to simultaneously degrade phenanthrene (PHE) and reduce Cr (VI). Specifically, it has the ability to reduce 100 % of Cr (VI) (30 mg/L) while degrading 43.8 % of PHE (50 mg/L). In batch experiments, it was observed that the presence of Cr (VI) can enhance the degradation of PHE by strain AO-4. The solubility of PHE in soluble extracellular polymeric substances (S-EPS) was found to be related to the initial concentration of Cr (VI), which could explain why Cr (VI) promotes the degradation of PHE. Additionally, XPS analysis confirmed that Cr (VI) was reduced to Cr (III) with S-EPS produced by Pseudomonas aeruginosa AO-4. GC–MS analysis was conducted to analyze the degradation metabolites of phenanthrene, di(2-ethylhexyl) phthalate and 2TMS derivatives of salicylic acid were detected, indicating that Pseudomonas aeruginosa AO-4 is capable of degrading phenanthrene through two distinct pathways. These findings demonstrate the potential of Pseudomonas aeruginosa AO-4 in the treatment of co-contamination scenarios involving PAHs and HMs.

Antioxidant Activity of the Prunus mahaleb Seed Oil Extracts Using n-Hexane and Petroleum Ether Solvents: In Silico and In Vitro Studies

Prunus mahaleb L., also known as white mahaleb, and native to the Kurdistan region of Iraq, has significant nutraceutical and therapeutic ingredients. The seeds are rich in conjugated fatty acids with small quantities of cyanogenic glycosides, coumarin derivatives, and flavonoids. The contents of the seeds were extracted with the Soxhlet apparatus using n-hexane and petroleum ether solvents, separately. Gas chromatography-mass spectrometry (GC-MS) was used to recognize the chemical composition of the compounds. The radical scavenging activity was performed for the total extracts from n-hexane and petroleum ether solvents using 2,2-diphenyl-1 picrylhydrazyl (DPPH) assay and compared with quercetin as a positive control. Furthermore, molecular docking was performed for the identified compounds against five enzymes that have main roles in intracellular oxidation. Afterwards, drug-like properties and bioactivity predictions were applied for all compounds using Molinspiration software. The results showed four phthalate derivatives, six saturated fatty acids (SFAs), five monounsaturated fatty acids (MUFAs), and three polyunsaturated fatty acids (PUFAs). The n-hexane extract showed competitive antioxidant activity with quercetin and the in-silico studies suggested a notable antioxidant activity of the seed oil contents with apparent drug-likeness properties. Further studies are required to separate the extracts, then perform in vitro antioxidant activity on the compounds.

Production of galactan phthalates derivatives extracted from Gracilaria birdie: Characterization, cytotoxic and antioxidant profile

The present work explores the esterification reaction in the polysaccharide extracted from the seaweed Gracilaria birdiae and investigates its antioxidant potential. The reaction process was conducted with phthalic anhydride at different reaction times (10, 20 and 30 min), using a molar ratio of 1:2 (polymer: phthalic anhydride). Derivatives were characterized by FTIR, TGA, DSC and XRD. The biological properties of derivatives were investigated by assays of cytotoxicity and antioxidant activity (2,2-diphenyl-1-picrylhydroxyl - DPPH and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt - ABTS). The results obtained by FT-IR confirmed the chemical modification, there was a reduction related to the presence of carbonyl and hydroxyl groups when compared to the in nature polysaccharide spectrum. TGA analysis showed a change in the thermal behavior of the modified materials. X-ray diffraction, it was shown that the in nature polysaccharide appeared as an amorphous material, while the material obtained after the chemical modification process had increased crystallinity, due to the introduction of phthalate groups. For the biological assays, it was observed that the phthalate derivative was more selective than the unmodified material for the murine metastatic melanoma tumor cell line (B16F10), revealing a good antioxidant profile for DPPH and ABTS radicals.

A novel oxygen-deficient core–shell ZA@ZnO1-X nanocomposite for enhanced degradation of multiple polyaromatic hydrocarbons

Persistent organic pollutants such as polyaromatic hydrocarbons (PAHs) are one of the emerging micropollutants present in several industrial effluents. Being trace refractory organics, its treatment by conventional method is very challenging. Thus, we report a novel core–shell zeolite A@oxygen-deficient ZnO (ZA@ZnO1-X) nanocomposite for degradation of PAHs mixture containing fluorene, phenanthrene, and anthracene. The hierarchical structure helps to reduce the recombination of photogenerated electron and holes pair, thereby availing more active species for photodegradation. The enhanced photodegradation efficacy is due to the synergistic effect of oxygen-defect sites in ZA@ZnO1-X and photoactive species. Core-shell ZA@ZnO1-X shows improved catalytic properties with a band gap value of 2.65 eV lower than the sole ZnO nanosheet (3.03 eV). The porous shell of the ZnO1-X structure provides an enhanced adsorption site and fully utilizes photon energy (visible light) with no aggregation because of ZA support. The maximum photocatalytic degradation is achieved by optimizing reaction parameters of 96%, 95.1%, and 93% of fluorene (0.02436 min−1), phenanthrene (0.02421 min−1), and anthracene (0.02102 min−1), respectively in 2 h at neutral pH and catalyst load 1 g/l. The primary active species responsible for PAHs degradation is h+, followed by HO•, O2•- radicals analyzed by quenching experiment. The degradation intermediates, and degraded products analysis by GC–MS gives a plausible general reaction pathway of PAHs and reveals primary intermediate is a phthalate derivative. Finally, the regeneration of active catalytic sites in the ZA@ZnO1-X photocatalyst shows its stability and reusability over five consecutive cycles.

The effect of citrate plasticizers on the properties of nitrocellulose granules

AbstractNitrocellulose granules containing the proposed new eco‐friendly inert plasticizers, substitutes for phthalate derivatives, such as acetyl triethyl nitrate (ATEC) and tributyl citrate (TBC) were obtained. The single‐base propellants were obtained using safe granulation process (water method). Diethylene glycol dinitrate (DEGDN) was used as an energetic modifier in obtained propellants. It was found that the addition of citrate plasticizers reduced the heat of combustion and dynamic vivacity of powders. At the same time DEGDN increased the heat of combustion of tested materials. Citrate derivatives did not affect the density and thermal decomposition of granules. It was concluded based on pyrostatic analysis that the TBC plasticizer influenced the kinetics of nitrocellulose gelatinization by DEGDN. The kinetic model [nth order with autocatalysis (CnB) reaction] was adjusted based on the process of thermal decomposition. The presence of DEGDN in granules reduces the activation energy and increases the constant heat cumulative rate. The prepared propellants are characterized by excellent thermal stability in accordance with the STANAG 4582 standard. The obtained propellants can be potentially used in small calibre ammunition.

Cyclic Phthalate Esters as Liver X Receptor Antagonists with Anti-hepatitis C Virus and Anti-severe Acute Respiratory Syndrome Coronavirus 2 Properties.

The liver X receptor is a nuclear hormone receptor that regulates lipid metabolism. Previously, we had demonstrated the antiviral properties of a liver X receptor antagonist associated with the hepatitis C virus and severe acute respiratory syndrome coronavirus 2. In this study, we screened a chemical library and identified two potential liver X receptor antagonists. Spectroscopic analysis revealed that the structures of both antagonists (compounds 1 and 2) were cyclic dimer and trimer of esters, respectively, that consisted of phthalate and 1,6-hexane diol. This study is the first to report the structure of the cyclic trimer of phthalate ester. Further experiments revealed that the compounds were impurities of solvents used for purification, although their source could not be traced. Both phthalate esters exhibited anti-hepatitis C virus activity, whereas the cyclic dimer showed anti-severe acute respiratory syndrome coronavirus 2 activity. Cyclic phthalate derivatives may constitute a novel class of liver X receptor antagonists and broad-spectrum antivirals.

The effects of packaging type and storage temperature on some of UHT milk quality indexes.

The objective of the present study was to illustrate the changes in physicochemical properties in ultra-high temperature (UHT) milk packed into a pouch and Tetra Brik during storage. UHT milk samples were kept at 5 and 25 °C for 3 months and regularly analyzed monthly. During storage, significant increases (p < 0.05) in titratable acidity (TA), water-soluble nitrogen (WSN), and non-protein nitrogen (NPN) when UHT milk was packed into pouch versus Tetra Brik and stored at 25 versus 5 °C. Neither type of packaging nor storage temperature affect pH values during storage. Spore-forming bacterial (SFB) count was always higher in UHT milk packed into pouch versus Tetra Brik. Refrigerated storage kept UHT milk without detectable SFB compared to UHT milk held at 25 °C. Pouch packages were responsible for the migration of phthalate derivatives [dimethyl phthalate "DMP", diethyl phthalate "DEP", dibutyl phthalate "DBP", and di-(2-Ethylhexyl) phthalate "DEHP"] into milk with significantly greater levels than milk filled into Tetra Brik. The total sensory scores were decreased significantly during storage, which was more pronounced in UHT milk filled into pouch versus Tetra Brik or stored at 25 °C versus 5 °C. It is concluded that UHT milk filled into Tetra Brik stored at 5 and 25 °C is better in terms of quality and safety indexes than such filled into a pouch.

In Vitro Antibacterial and Antioxidant Activities and Molecular Docking Analysis of Phytochemicals from Cadia purpurea Roots.

Phytochemicals and antibacterial and antioxidant activities of Cadia purpurea roots were investigated herein for the first time. The phytochemical study led to the isolation of two compounds, di-(2-methylheptyl) phthalate (1) and 13-O-pyrrolecarboxyl lupanine (2), from methanol roots extract of C. purpurea. The antibacterial activity results revealed that the n-hexane extract presented a better inhibitory value (13.8 ± 0.0 mm) followed by chloroform (11.1 ± 0.4 mm) and chloroform : methanol (1 : 1) (10.7 ± 0.1 mm) extracts against E. coli at the maximum dose of 100 mg/mL. While, methanolic and ethanolic extracts displayed a mild activity against same bacterium at same dose. The methicillin resistant S. aureus was found with almost total resistance to all extracts up to the 100 mg/mL. The chloroform : methanol (1 : 1), chloroform, and n-hexane extracts recorded inhibition zone values (8.0 ± 0.0–10.0 ± 0.1 mm, 7.7 ± 0.0–9.8 ± 0.1 mm, and 7.3 ± 0.2–8.9 ± 0.2 mm, respectively) better than chloramphenicol (7.2 ± 0.6 mm at 30 μg dose) against P. aeruginosa. The alcoholic extracts also exhibited an activity better than chloramphenicol up to 25 mg/mL against same bacterium. Compound 2 produced a comparable inhibition value (9.6 ± 0.0 mm to 18.5 ± 0.0 mm) to that of chloramphenicol (21.5 ± 0.3 mm) against E. coli at doses up to 1.0 mg/mL; whereas, compound 1 showed a slight activity (7.1 ± 0.1 mm–10.3 ± 0.0 mm). Both compounds were found generally inactive against S. aureus, while they provided an activity better than chloramphenicol (7.2 ± 0.6 mm) against P. aeruginosa with inhibition zones ranging from 7.1 ± 0.0 mm to 9.0 ± 0.1 mm for compound 1 and 7.2 ± 0.0 mm to 10.6 ± 0.0 mm for compound 2. Ethanolic and methanolic extracts exhibited a better DPPH radical scavenging activity (IC50 values of 12.9 and 16.03 μg/mL, respectively) and strong ferric ion reducing power (with absorbance of 0.788 ± 0.000 and 0.810 ± 0.001, respectively) at a concentration of 500 μg/mL compared to the other extracts. Compound 1 also possessed a better anti-DPPH trapping activity (IC50, 7.99 μg/mL) than compound 2 (IC50, 58.34 μg/mL). The compounds, however, indicated a weak ferric ion reduction power even at higher amount. In general, the observed antibacterial and antioxidant activities of isolated compounds and extracts were found to be dose-dependent. Conducting further biochemical investigations on all parts of this plant could provide opportunities of finding extra alkaloidal compounds and other phthalate derivatives with better biological activity.

Cars as a Method for the Detection of Toxic Pollutants in MIBA: The Case of Phthalates on Danio renio’s Larva

Living organisms (eggs and larvae of Danio rerio) have been incubated in an innovative microincubator MIBA with various concentrations of Di-N-Butyl Phthalate (DBP) derivatives for different times. Images were acquired with a macromultiphoton or CARS microscope and probe DBP (control) and its derivative N3-aDBP were detectable thanks to the signal emitted by the alkyne and a signal possible thanks to the auto-fluorescence of the aromatic ring. Using fluorescence imaging and CARS microscopy methods, we investigated the value of Raman-CARS that could vibrate unnatural groups (N3 or C≡C) previously grafted onto the DBP molecule in zebrafish. Contrary to other products, N3-aDBP probe has been detected continuingly by macro-fluorescence in larva but CARS signal was only detected in FLIM mode (Fluorescence Lifetime Imaging Microscopy). To conclude, CARS microscopy can be used to image toxic pollutants even by integrating photo-activatable probes. In our case, photo-physical reactions following the irradiation of the probe lead to new photoproducts that are not identified and difficult to characterize in fluorescence and specific CARS signal.

Exposure to DEHP induces testis toxicity and injury through the ROS/mTOR/NLRP3 signaling pathway in immature rats

As the most abundantly used phthalate derivative, di-(2-ethylhexyl) phthalate (DEHP) leads to reproductive disorders, especially in males. Testicular injury can be triggered when the testis is exposed to DEHP during the immature stage. However, the potential mechanism is largely unclear. In the present study, Sprague-Dawley rats were exposed to 0, 250 and 500 mg/kg/day DEHP from postnatal day (PND) 20 to PND 30. The spermatogonia cell line GC-1 and spermatocyte cell line GC-2 were exposed to different doses of monoethylhexyl phthalate (MEHP), a metabolite of DEHP. Testicular injury was observed. Oxidative stress was evaluated both in vivo and in vitro. Our results showed that after DEHP exposure, the testicular structure was damaged and spermatogenesis was disturbed. We also found that oxidative stress was increased, as indicated by the upregulation of the important factors in the antioxidant pathway. Furthermore, the expression of autophagy-related proteins was significantly downregulated. Autophagy inhibition led to activation of the pyroptosis pathway. Nucleotide-binding and oligomerisation (NOD) domain-like receptor (NLR) family pyrin domain (PYD)-containing 3 (NLRP3), Caspase-1 and cytokine interleukin-1β (IL-1β) were significantly upregulated. Additionally, an imbalance in self-renewal and differentiation was observed in germ cells after DEHP exposure, causing the cessation of germ cell development. In summary, these data suggest that DEHP exposure enhances oxidative stress, downregulates autophagy, induces NLRP3 inflammasome activation and subsequently triggers pyroptosis in vivo and in vitro, which provides novel insight into DEHP-related injury in immature testes in the context of pyroptosis.

Antimicrobial Activity, in silico Molecular Docking, ADMET and DFT Analysis of Secondary Metabolites from Roots of Three Ethiopian Medicinal Plants.

BackgroundUvaria scheffleri (Annonaceae), Clematis burgensis (Ranunculaceae), and Euphorbia schimperiana (Euphorbiaceae) are medicinal plants traditionally used to treat cough, tuberculosis, asthma, sore throat and skin infections.MethodsSilica gel column chromatographic separation was used to isolate compounds. Crude extract and isolated compounds were evaluated for antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans via the broth dilution method. Docking studies were performed with E. coli DNA-Gyrase B and human DNA topoisomerase IIα by using AutoDock Vina. ADMET were predicted by SwissADME, PreADMET, and OSIRIS Property predictions. The optimized structures and molecular electrostatic potential surface of the isolated compounds were predicted by DFT analysis using B3LYP/6-31G basis levels.ResultsSilica gel column chromatographic separation afforded five compounds 1–5 of which N-methyl-2,3-bis(2-hydroxybenzyl)-1Н-indol (1) is reported herein for the first time, along with known C-benzylated dihydrochalcone uvaretin (2), bis(2-ethylheptyl) phthalate (3), lupeol (4) and suberosin derivative (5). Dichloromethane roots extract of U. scheffleri showed potent antibacterial activity against S. aureus (MIC = 6.25 µg/mL) compared to gentamicin (MIC=5 µg/mL). In silico, molecular docking analysis of compounds (1and 3–5) showed strong interaction with E. coli DNA gyrase B with a binding energy value ranging from −6.9 to −6.0 kcal/mol compared to ciprofloxacin −7.2 kcal/mol, whereas analysis against human topoisomerase IIα showed binding energy value ranging from −5.9 to −5.3 kcal/mol compared to vosaroxin (−6.2 kcal/mol).ConclusionThe results obtained suggest that N-methyl-2,3-bis(2-hydroxybenzyl)-1Н-indol (1) and coumarin (5) are potential topoisomerase II α inhibitors and might be used as anticancer agents. The ADMET studies showed the highest drug-likeness properties for studied compounds other than bis(2-ethylheptyl) phthalate (3). DFT calculations suggested that studied compounds showed the lowest gap energy and were chemically reactive, and isolated compounds may serve as potential drug candidates that corroborate with the traditional uses of studied plants.

English

The essential oils of Eugenia uniflora leave possess several biological activities but a great variability in their chemical composition is observed. In the present study, gas chromatography and mass spectrometry were applied to examine the essential oil from leaves of four different specimens over the seasons of the year, two of which are located in a habitat of a Brazilian metropolis, and the other two in a natural reserve. The collected data allowed identifying twenty-nine compounds; an aliphatic ketone, sesquiterpenes, fatty acids, hydrocarbons, and phthalate derivatives. Sesquiterpene hydrocarbons and oxygenated sesquiterpenes were the chemical classes prevailing in most samples. The curzerene was observed in higher content (10.5-53.4%) in all samples in which the presence of sesquiterpenes class was confirmed. Phthalate derivatives were identified for the first time in the essential oil of E. uniflora leaves. The occurrence of a common chemical marker for four specimens was not observed. Besides, no compound was observed in the same specimen throughout the seasons, and specimens of the same habitat exhibited different essential oil chemical profiles. According to the multivariate analysis applied to the chemical profile for all individuals in different seasons, four different clusters were identified without dependence on season or location. Key word: Eugenia uniflora, seasonality, location, essential oil, chemical composition.

Towards the design of ideal electrochromic materials with low driving voltage based on phthalate derivatives

Small molecular organic electrochromic materials have gradually attracted the attention from academia. Although ester organic electrochromic materials show unique advantages such as significant color change, wide color adjustment range and low cost, their electrochromic mechanisms are still unclear, keeping their driving voltage and stability issues unsolved. In this article, the absorption spectra of phthalate derivatives under different conditions are calculated with time-dependent density functional theory to understand the influences on the electrochromic properties by the electronic and steric effects. By the increased conjugation and reduced steric hindrance, carbonyl linking group is found capable to enhance the absorption in the visible region and exhibit low driving voltages. Further, a new electrochromic compound is designed to improve the luminous effect and lower the driving voltage.