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1.
Pestic Biochem Physiol ; 168: 104643, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32711776

RESUMO

Essential oils are promising substitute for chemical pesticides with the inherent resistance by pests, environmental and health effects on humans. In this study, the chemical composition of essential oil extracted from Citrus sinensis peel was characterized, the insecticidal activities of the oil and its constituents against Callosobrunchus maculatus (Cowpea weevil) and Sitophilus zeamais (maize weevil) were investigated and the underlying insecticidal mechanism were elucidated. The essential oil was extracted by hydro-distillation and characterized using gas chromatography-mass spectrometry (GC-MS). Insecticidal activity was determined by contact and fumigant toxicity assay. The inhibitory effect of the oil and its constituents on acetylcholinesterase (AChE), Na+/K+-ATPase and glutathione-S- transferase (GST) activity were assayed using standard protocols. The total number of volatile compounds detected in C. sinensis essential oil was eighteen (18). d-limonene (59.3%), terpineol (8.31%) and linalool (6.88%) were the major compounds present in the essential oil. Among the tested essential oil compounds, terpineol showed highest contact toxicity against C. maculatus (LD50 =17.05 µg/adult) while 3-carene showed highest contact toxicity against S. zeamais (LD50 =26.01 µg/adult) at 24 h exposure time. Citral exhibited the highest fumigant toxicity against C. maculatus and S. zeamais with LC50 value 0.19 and 2.02 µL/L air at 24 h respectively. Acetylcholinesterase and Na+/K+-ATPase activities were significantly inhibited by C. sinensis oil and its constituents in both C. maculatus and S. zeamais as compared to control. This study indicates that C. sinensis essential oil and its constituents have potential to be developed into botanical pesticides.


Assuntos
Citrus sinensis , Inseticidas , Óleos Voláteis , Gorgulhos , Animais , Limoneno
2.
Environ Sci Technol ; 54(9): 5385-5390, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32243755

RESUMO

Recent studies have shown the potential of the photosensitizer chemistry of humic acid, as a proxy for humic-like substances in atmospheric aerosols, to contribute to secondary organic aerosol mass. The mechanism requires particle-phase humic acid to absorb solar radiation and become photoexcited, then directly or indirectly oxidize a volatile organic compound (VOC), resulting in a lower volatility product in the particle phase. We performed experiments in a photochemical chamber, with aerosol-phase humic acid as the photosensitizer and limonene as the VOC. In the presence of 26 ppb limonene and under atmospherically relevant UV-visible irradiation levels, there is no significant change in particle diameter. Calculations show that SOA production via this pathway is highly sensitive to VOC precursor concentrations. Under the assumption that HULIS is equally or less reactive than the humic acid used in these experiments, the results suggest that the photosensitizer chemistry of HULIS in ambient atmospheric aerosols is unlikely to be a significant source of secondary organic aerosol mass.


Assuntos
Poluentes Atmosféricos/análise , Substâncias Húmicas/análise , Aerossóis/análise , Luz , Limoneno , Compostos Orgânicos
3.
Arch Oral Biol ; 111: 104638, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31901573

RESUMO

OBJECTIVE: The purpose of this study was to investigate the effects of Lemon essential oil (LEO) and Limonene (LIM) in the progress of early caries. DESIGN: LEO and LIM were selected as experimental medicine, while sodium fluoride (NaF) and deionized water (DW) were positive and blank controls, respectively. Bovine incisors were used to establish enamel and dentin early caries models by demineralization method in vitro. Then specimens were subjected to pH cycling. Calcium and phosphate release of demineralizing solution were measured by an automatic biochemical analyzer; Surface microhardness tester and energy dispersive X-ray spectrometer were used to detect the surface microhardness recovery and calcium- phosphate ratio on tooth surface; Degraded collagen matrix by collagenase was investigated by assaying hydroxyproline. RESULTS: Calcium release of dentin demineralizing solution of LEO group was lower than DW group's and higher than NaF group's. Both of LEO and LIM groups, the surface microhardness recovery were significantly lower than those of NaF group, which were similar to DW group. Dentin surface calcium- phosphate ratio of LEO and LIM groups were lower than those of NaF group and higher than those of DW group. Hydroxyproline concentration in the remineralizing solution of LEO and LIM groups were lower than DW groups' and higher than NaF groups'. CONCLUSIONS: LEO and LIM have influence on the progress of dentin early caries, which can stabilize its structure by inhibiting collagen degradation. Meanwhile, these medicines may provide a new drug choice for the prevention and treatment of early root caries.


Assuntos
Cariostáticos/farmacologia , Cárie Dentária , Esmalte Dentário/efeitos dos fármacos , Limoneno/farmacologia , Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Animais , Bovinos , Concentração de Íons de Hidrogênio , Fluoreto de Sódio/farmacologia , Desmineralização do Dente , Remineralização Dentária
4.
Bioresour Technol ; 300: 122666, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31901556

RESUMO

To satisfy the growing demand for limonene, novel pathways for microbial production of limonene have been sought. A techno-economic analysis is carried out for one such process producing limonene from sugar at an industrial plant scale to assess potential economic viability. A conceptual design of the process is developed, in which a gas stripping-solvent scrubbing method is chosen for recovering limonene from bioreactors based on consideration of payback time and process operability. Minimum limonene selling prices are estimated over a range of fermentation productivity based on the calculation of net present value using discounted cash flow method. Under 45% of the maximum theoretical yield, the selling price reaches $19.9/kg, which could be competitive with established production processes when fermentation productivity is above 0.7 kg/(m3·h). Reduction of cost could be realised through improvement of microbial strains, utilisation of cheaper feedstocks, reduction in capital investment and strategic business planning.


Assuntos
Reatores Biológicos , Limoneno , Análise Custo-Benefício , Fermentação , Açúcares
5.
Food Chem Toxicol ; 136: 111023, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31866146

RESUMO

The present study evaluated the effect of the essential oil of Mikania cordifolia (EOMc) and its major constituent limonene alone or associated with antibacterial drugs against Multidrug Resistant Bacteria (MDR). To evaluate the antibacterial activity, the minimum inhibitory concentrations (MIC) of the oil and limonene against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus were determined. The antibiotic-modulating activity was assessed using subinhibitory concentrations (MIC/8) of these substances in combination with conventional antibacterial drugs. Although no relevant antibacterial activity of the natural products was detected, both substances modulated the action of antibiotics against resistant bacteria. The EOMc demonstrated the best modulating effect against P. aeruginosa, presenting synergistic effects when associated with gentamicin and norfloxacin. In addition, the oil reduced the MIC of norfloxacin against E. coli as well as reduced the MIC of gentamicin against S. aureus. On the other hand, the best effect of limonene was obtained against S. aureus. Thus, it is concluded that the essential oil Mikania cordifolia and the isolated compound limonene do not have clinically significant antibacterial effect, but modulate the action of antibiotics against MDR bacteria.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Limoneno/farmacologia , Mikania/química , Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Gentamicinas/farmacologia , Testes de Sensibilidade Microbiana , Norfloxacino/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
6.
Plant Dis ; 104(2): 414-422, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31841378

RESUMO

The fungus Austropuccinia psidii is a major pathogen of Eucalyptus spp. that damages mainly early-stage leaves. Resistant clones are the most widely used control measure for the rust disease caused by A. psidii. Essential oils produced in the plant-host cells are associated with resistance. However, the chemical characteristics of Eucalyptus leaves at different stages of maturity, associated with resistance or susceptibility to A. psidii, need to be determined. The aims of this study were to characterize the chemical composition of essential oils in Eucalyptus leaves at three developmental stages of clones of three E. urophylla × E. grandis hybrids that exhibit different resistance levels to rust and to identify probable resistance-related compounds from them. The rust severity following inoculation and the quantity and quality of the essential oil extracted by hydrodistillation were determined at the first, third, and fifth leaf stages of the three clones. Identification of the compounds present in the essential oil was determined by gas chromatography coupled with mass spectrometry. No rust was observed on the three leaf stages of the resistant clone or on the fifth leaf stage of the susceptible clones. Limonene was found at high percentages in essential oils from the three leaf stages of the resistant clone and at low percentages in the susceptible clones. In vitro and in vivo tests indicated that low limonene percentages stimulated A. psidii urediniospore germination and were not fungitoxic, whereas high percentages caused complete inhibition of germination and degenerative changes in fungal reproductive structures. The limonene present in Eucalyptus leaves can be considered a chemical compound related to the rust resistance of Eucalyptus spp.


Assuntos
Basidiomycota , Eucalyptus , Limoneno , Doenças das Plantas , Folhas de Planta
7.
N Engl J Med ; 382(8): 697-705, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31860793

RESUMO

BACKGROUND: The causative agents for the current national outbreak of electronic-cigarette, or vaping, product use-associated lung injury (EVALI) have not been established. Detection of toxicants in bronchoalveolar-lavage (BAL) fluid from patients with EVALI can provide direct information on exposure within the lung. METHODS: BAL fluids were collected from 51 patients with EVALI in 16 states and from 99 healthy participants who were part of an ongoing study of smoking involving nonsmokers, exclusive users of e-cigarettes or vaping products, and exclusive cigarette smokers that was initiated in 2015. Using the BAL fluid, we performed isotope dilution mass spectrometry to measure several priority toxicants: vitamin E acetate, plant oils, medium-chain triglyceride oil, coconut oil, petroleum distillates, and diluent terpenes. RESULTS: State and local health departments assigned EVALI case status as confirmed for 25 patients and as probable for 26 patients. Vitamin E acetate was identified in BAL fluid obtained from 48 of 51 case patients (94%) in 16 states but not in such fluid obtained from the healthy comparator group. No other priority toxicants were found in BAL fluid from the case patients or the comparator group, except for coconut oil and limonene, which were found in 1 patient each. Among the case patients for whom laboratory or epidemiologic data were available, 47 of 50 (94%) had detectable tetrahydrocannabinol (THC) or its metabolites in BAL fluid or had reported vaping THC products in the 90 days before the onset of illness. Nicotine or its metabolites were detected in 30 of 47 of the case patients (64%). CONCLUSIONS: Vitamin E acetate was associated with EVALI in a convenience sample of 51 patients in 16 states across the United States. (Funded by the National Cancer Institute and others.).


Assuntos
Lesão Pulmonar Aguda/patologia , Líquido da Lavagem Broncoalveolar/química , Sistemas Eletrônicos de Liberação de Nicotina , Vaping/efeitos adversos , Vitamina E/análise , Lesão Pulmonar Aguda/etiologia , Adolescente , Adulto , Idoso , Fumar Cigarros , Óleo de Coco/análise , Feminino , Humanos , Limoneno/análise , Masculino , Pessoa de Meia-Idade , Estados Unidos , Adulto Jovem
8.
Anal Sci ; 35(12): 1385-1391, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827038

RESUMO

This study deals with the application of different monoterpenes as relatively green bio-based solvents for low density-dispersive liquid-liquid microextraction (LD-DLLME) of different non-steroidal anti-inflammatory drugs (NSAIDs) from aqueous samples in comparison with conventional halogenated solvents. Results indicated that D-limonene could extract the hydrophobic compounds with higher %recovery compared with other bio-based and halogenated solvents. The LD-DLLME procedure was optimized by applying one-factor-at-a-time (OFAT) followed by central composite face-centered design (CCF) of the response surface methodology (RSM). Under the optimal conditions, the method exhibited good linearity with r ≥ 0.9950 with low LOD as well as LOQ levels in the range of 0.11 to 0.81 and 0.36 to 2.69 ng/mL, respectively. The method was efficiently applied to a variety of real aqueous samples. Finally, the green aspect of our procedure was compared with some reported methods using two green metric tools.


Assuntos
Limoneno/química , Microextração em Fase Líquida/métodos , Preparações Farmacêuticas/isolamento & purificação , Solventes/química , Poluentes Químicos da Água/isolamento & purificação , Água/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Preparações Farmacêuticas/análise , Preparações Farmacêuticas/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
10.
Molecules ; 25(1)2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31861877

RESUMO

Limonene is a monoterpenoid compound, which is founded in a lot of plants' essential oils with good antibacterial activity against food-borne pathogens, but it has an ambiguous antimicrobial susceptibility and mechanism against Listeria monocytogenes (L. monocytogenes). In this study, the antimicrobial susceptibility of Limonene to L. monocytogenes was studied, and some new sights regarding its antibacterial mechanism were further explored. Scanning electron microscopy (SEM) verified that limonene caused the destruction of the cell integrity and wall structure of L. monocytogenes. The increase in conductivity and the leakage of intracellular biomacromolecules (nucleic acids and proteins) confirmed that limonene had an obvious effect on cell membrane permeability. The results of Propidium Iodide (PI) fluorescence staining were consistent with the results of the conductivity measurements. This indicated that limonene treatment caused damage to the L. monocytogenes cell membrane. Furthermore, the decrease in ATP content, ATPase (Na+K+-ATPase, Ca2+-ATPase) activity and respiratory chain complex activity indicated that limonene could hinder ATP synthesis by inhibiting the activity of the respiratory complex and ATPase. Finally, differential expression of proteins in the respiratory chain confirmed that limonene affected respiration and energy metabolism by inhibiting the function of the respiratory chain complex.


Assuntos
Antibacterianos/farmacologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Limoneno/farmacologia , Listeria monocytogenes/metabolismo , Óleos Voláteis/química , Antibacterianos/química , Limoneno/química
11.
Toxicol Ind Health ; 35(10): 638-646, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31771499

RESUMO

The guanidine family of antimicrobial agents, which includes polyhexamethylene guanidine phosphate (PHMG) and oligo(2-(2-ethoxy)ethoxyethyl) guanidinium chloride (PGH), and chlorophenol biocidal chemicals such as 2,4,4'-trichloro-2'-hydroxydiphenyl ether (triclosan) are used in various occupational and environmental biocidal applications. The excipient propylene glycol (PG) is used to dissolve the active ingredients. The skin sensitization (SS) potential of these substances has not been systemically investigated and is still debated. Moreover, mixtures of PHMG, PGH, or triclosan with PG have not been evaluated for SS potency. An in vivo assay known as the local lymph node assay: 5-bromo-2-deoxyuridine-flow cytometry method (LLNA: BrdU-FCM) was recently adopted as an alternative testing method and was used to address these issues. Via the LLNA: BrdU-FCM, PHMG, PGH, and triclosan were predicted to be sensitizers, while PG was predicted to be a nonsensitizer. In addition, d-limonene, which is used as a flavoring in various consumer products, was also predicted to be a sensitizer, although no unanimous conclusion has been reached regarding its SS potential. Mixtures of PHMG, PGH, triclosan, or d-limonene with PG at ratios of 9:1, 4:1, and 1:4 (w/w) were all positive in terms of SS potential, indicating that the PG excipient does not influence the SS predictions of these chemicals. Since humans can be occupationally and environmentally exposed to mixtures of excipients with active ingredients, the present study may give insight into further investigations of the SS potentials of various chemical mixtures.


Assuntos
Guanidinas/efeitos adversos , Hipersensibilidade Imediata/induzido quimicamente , Polímeros/efeitos adversos , Propilenoglicóis/efeitos adversos , Pele/efeitos dos fármacos , Triclosan/efeitos adversos , Animais , Relação Dose-Resposta a Droga , Excipientes/efeitos adversos , Excipientes/química , Feminino , Guanidinas/química , Limoneno , Ensaio Local de Linfonodo , Camundongos , Camundongos Endogâmicos BALB C , Polímeros/química , Propilenoglicóis/química , Triclosan/química
12.
Bioresour Technol ; 294: 122180, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31606595

RESUMO

The biotransformation of R-(+)-limonene into high concentrations of R-(+)-α-terpineol by Sphingobium sp. was investigated in order to optimize the main process variables (pH, biocatalyst concentration, substrate concentration, temperature and agitation). This strategy comprised the screening of variables by a Plackett-Burman design followed by a Central Composite Design. The statistical analysis showed that the optimal α-terpineol production were at 28 °C and pH 7.0, with a limonene concentration of 350 g/L of organic phase agitation of 200 rpm and a biocatalyst concentration of 2.8 g/L of aqueous phase (OD600 = 8). Further trials showed that the R-(+)-α-terpineol concentration was higher (240 g/L after 96 h) when using a ratio of 1:3 (v.v-1) of organic:aqueous phases. However, the total production and yield (in terms of biomass) of α-terpineol would be maximized for an aqueous:organic ratio of 1:1. The experimental design optimization adopted herein was an effective tool for this type of study.


Assuntos
Limoneno , Terpenos , Biotransformação , Monoterpenos Cicloexânicos , Cicloexenos , Monoterpenos
13.
Bioresour Technol ; 293: 122105, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31514116

RESUMO

This work aimed to develop a green protocol for chemical processing of spent aromatic biomass to obtain xylose, levulinic acid, and lignin in good yields via treatment with p-cymene-2-sulphonic acid (p-CSA), a Brønsted acid synthesised from d-limonene as a renewable feedstock from citrus waste. Chemical processing of palmarosa biomass with p-CSA under heating in an autoclave resulted in hydrolysate containing xylose (~16% yield). Further processing of pre-treated biomass with p-CSA in presence of aq. HCl under refluxing caused a selective degradation of cellulose to levulinic acid (~22% yield with respect to biomass). The residual biomass was used to afford lignin in good yields.


Assuntos
Citrus , Lignina , Biomassa , Ácidos Levulínicos , Limoneno , Xilose
14.
Molecules ; 24(18)2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31547401

RESUMO

Volatile compounds in flowers of Rhododendron delavayi, R. agastum, R. annae, and R. irroratum were analyzed using comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC) coupled with high-resolution quadrupole time-of-flight mass spectrometry (QTOFMS). A significantly increased number of compounds was separated by GC×GC compared to conventional one-dimensional GC (1DGC), allowing more comprehensive understanding of the volatile composition of Rhododendron flowers. In total, 129 volatile compounds were detected and quantified. Among them, hexanal, limonene, benzeneacetaldehyde, 2-nonen-1-ol, phenylethyl alcohol, citronellal, isopulegol, 3,5-dimethoxytoluene, and pyridine are the main compounds with different content levels in all flower samples. 1,2,3-trimethoxy-5-methyl-benzene exhibits significantly higher content in R. irroratum compared to in the other three species, while isopulegol is only found in R. irroratum and R. agastum.


Assuntos
Flores/química , Odorantes/análise , Rhododendron/química , Compostos Orgânicos Voláteis/análise , Monoterpenos Acíclicos/análise , Aldeídos/análise , Cromatografia Gasosa , Monoterpenos Cicloexânicos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Limoneno/análise , Espectrometria de Massas , Microextração em Fase Sólida , Especificidade da Espécie
15.
Arq Bras Cardiol ; 113(5): 925-932, 2019 11.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31482987

RESUMO

BACKGROUND: D-limonene (DL) is a monoterpene and is the major component in the essential oil of citrus fruit. It presents antihyperglycemic and vasodilatation activities. OBJECTIVES: This study evaluated the cardiovascular effects and potential antiarrhythmic of DL in rats. METHODS: Hemodynamic and electrocardiographic (ECG) parameters were measured in male Wistar rats, which under anesthesia had been cannulated in the abdominal aorta and lower vena cava and had electrodes subcutaneously implanted. In the in vitro approach, the heart was removed and perfused using the Langendorff technique. The significance level adopted was 5% (p < 0.05). RESULTS: DL, in doses of 10, 20, and 40 mg/kg (i.v), produced intense and persistent bradycardia associated with hypotension. Bradycardia with prolonged QTc was observed in the ECG in vivo recording. In the in vivo model of arrhythmia induced by Bay K8644, DL (10 mg/kg) decreased the arrhythmia score from 15.33 ± 3.52 to 4.0 ± 2.64 u.a (p < 0.05, n = 4). In isolated perfused hearts, DL (10-3 M) promoted significant reductions in heart rate (from 228.6 ± 8.5 ms to 196.0 ± 9.3 bpm; p < 0.05) and left ventricular development pressure (from 25.2 ± 3.4 to 5.9 ± 1.8 mmHg; n = 5, p < 0.05). CONCLUSIONS: DL produces bradycardia and antiarrhythmic activity in rat heart.


Assuntos
Antiarrítmicos/uso terapêutico , Arritmias Cardíacas/tratamento farmacológico , Bradicardia/tratamento farmacológico , Limoneno/uso terapêutico , Animais , Antiarrítmicos/farmacologia , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/diagnóstico , Pressão Sanguínea/efeitos dos fármacos , Bradicardia/diagnóstico , Eletrocardiografia , Frequência Cardíaca/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Hipotensão , Preparação de Coração Isolado , Limoneno/farmacologia , Masculino , Modelos Animais , Ratos Wistar , Pressão Ventricular/efeitos dos fármacos
16.
Molecules ; 24(17)2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484421

RESUMO

Pinus eldarica (Pinaceae), an evergreen plant, is distributed across the warm and dry climates of western Asia, including Asia Minor, the Middle East, and land surrounding the Caspian Sea. Essential oils (EOs) from different aerial parts of this tree have been used in traditional medicine. We aimed to investigate the chemical profile and antimicrobial activity of the EO from P. eldarica grown in northwestern Iran. EO from the needles, bark, and pollen were extracted with boiling water using a Clevenger apparatus at yield of 0.7-1.2 cm3/100 g of dry plant material. The main chemical components of the EO from the needles were D-germacrene (18.17%), caryophyllene (15.42%), γ-terpinene (12.96%), and ß-pinene (10.62%); those from the bark were limonene (16.99%), caryophyllene oxide (13.22%), and drimenol (13.2%); and those from the pollen were α-pinene (25.64%) and limonene (19.94%). In total, 83 constituents were characterized in the EOs, using gas chromatography mass spectrometry analysis; mainly, sesquiterpene hydrocarbons in needle EO and monoterpene hydrocarbons in pollen and bark EOs. ß-Pinene, ß-myrcene, limonene, and caryophyllene were identified in the EOs from all three plant parts. The antibacterial and antifungal properties of the EOs were examined: pollen EO exhibited antibacterial activity against Escherichia coli; bark EO inhibited the growth of Candida albicans and Staphylococcus aureus; and the needle EO inhibited the growth of S. aureus. Thus, the EOs from aerial parts of P. eldarica can benefit the EO industry and antibiotic development.


Assuntos
Óleos Voláteis/química , Pinus/química , Componentes Aéreos da Planta/química , Monoterpenos Acíclicos/química , Monoterpenos Acíclicos/farmacologia , Monoterpenos Bicíclicos/química , Monoterpenos Bicíclicos/farmacologia , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Irã (Geográfico) , Limoneno/química , Limoneno/farmacologia , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos
17.
J Cosmet Sci ; 70(3): 137-147, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31398102

RESUMO

The antimicrobial properties of natural limonene and the compounds obtained after isomerization of limonene (α-terpinene, γ-terpinene, terpinolene, and p-cymene) were studied. The following microorganisms were selected for the tests: Gram-negative bacteria Escherichia coli K12 (ACCT 25922), Gram-positive Staphylococcus epidermidis (ACCT 49461), yeast fungi Candida albicans, and fungi Trichophyton rubrum, Aspergillus niger, Penicillium commune, Trichoderma viride, and Cladosporium cladosporioides. During the studies, terpinolene showed the highest activity, and therefore, this compound was chosen for the preparation of therapeutic creams (content of terpinolene: 0.5 and 2 wt%). The obtained creams were active in the microbiological tests even at the lowest content of terpinolene. The mixture of products obtained after the isomerization of limonene also showed antimicrobial activity. Probably, in the future, this mixture of products can be used as a potential and relatively inexpensive ingredient in therapeutic and protective creams that can be applied for the relief of skin lesions and in the treatment of acne or atopic dermatitis.


Assuntos
Limoneno/química , Catálise , Monoterpenos Cicloexânicos , Cimenos , Isomerismo , Monoterpenos , Dióxido de Silício , Terpenos
18.
J Photochem Photobiol B ; 198: 111577, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31376573

RESUMO

Lippia rotundifolia Cham. is in the family Verbenaceae and is endemic to the Cerrado. This species is aromatic and characterized by the presence of glandular trichomes on its leaves that are rich in monoterpenes. The objective of this study was to evaluate the growth, photosynthetic pigment production, and chemical composition of L. rotundifolia grown in vitro under different light wavelengths and intensities. The light intensities consisted of five treatments using cool white fluorescent lamps at 20, 54, 78, 88, and 110 µmol m-2 s-1. The light quality consisted of six treatments using light-emitting diodes (LEDs) in different light wavelengths, namely, white, red, blue, and their interactions: 1R:1B, 2.5R:1B, and 1R:2.5B. After 45 days, the biometric parameters, photosynthetic pigment content, and volatile compounds were evaluated. The lower light intensities of 20 and 54 µmol m-2 s-1 generated higher growth, photosynthetic pigment content, and biomass accumulation. Myrcene and pentadecane were highest under light intensities of 88 and 110 µmol m-2 s-1, respectively. The highest limonene and ocimenone levels were obtained at 20 and 54 µmol m-2 s-1 intensity, respectively, and the highest myrcenone content was obtained at 78 µmol m-2 s-1 intensity. Regarding the light wavelengths, the combination of red and blue spectra further stimulated plantlet growth, and the 2.5R:1B combination obtained the best biometric data and total chlorophyll content. The z-ocimenone chemical compound contents were highest under the 1R:2.5B light spectrum. The monochromatic blue spectrum increased the myrcene and limonene content but decreased the myrcenone content, which was increased by red light. The highest pentadecane contents were obtained with the white spectrum and the red and blue combinations.


Assuntos
Luz , Lippia/metabolismo , Fotossíntese/efeitos da radiação , Compostos Orgânicos Voláteis/metabolismo , Clorofila/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Limoneno/metabolismo , Lippia/química , Lippia/crescimento & desenvolvimento , Folhas de Planta/química , Folhas de Planta/metabolismo , Análise de Componente Principal , Compostos Orgânicos Voláteis/análise
19.
Indoor Air ; 29(6): 956-967, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31461792

RESUMO

Ozone (O3 ) chemistry is thought to dominate the oxidation of indoor surfaces. We consider the hypothesis that reactions taking place within indoor boundary layers result in greater than anticipated hydroxyl radical (OH) deposition rates. We develop models that account for boundary layer mass-transfer phenomena, O3 -terpene chemistry and OH formation, removal, and deposition; we solve these analytically and by applying numerical methods. For an O3 -limonene system, we find that OH flux to a surface with an O3 reaction probability of 10-8 is 4.3 × 10-5 molec/(cm2 s) which is about 10 times greater than predicted by a traditional boundary layer theory. At very low air exchange rates the OH surface flux can be as much as 10% of that for O3 . This effect becomes less pronounced for more O3 -reactive surfaces. Turbulence intensity does not strongly influence the OH concentration gradient except for surfaces with an O3 reaction probability >10-4 . Although the O3 flux dominates OH flux under most conditions, OH flux can be responsible for as much as 10% of total oxidant uptake to otherwise low-reactivity surfaces. Further, OH chemistry differs from that for ozone; therefore, its deposition is important in understanding the chemical evolution of some indoor surfaces and surface films.


Assuntos
Poluentes Atmosféricos/química , Poluição do Ar em Ambientes Fechados/análise , Radical Hidroxila/análise , Ozônio/química , Limoneno/análise , Oxirredução , Terpenos/análise
20.
J Agric Food Chem ; 67(25): 7087-7097, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31199132

RESUMO

Limonene, a cyclic monoterpene, is widely used in food and cosmetics industries as well as in agriculture. In the work described herein, employing a systematic optimization strategy, we constructed an efficient platform for producing limonene via the heterologous mevalonate pathway in Escherichia coli. By site-directed mutation of EfMvaS and tuning the initial translation of EfMvaE and EfMvaSA110G through ribosome binding site engineering, the upstream module for overproducing mevalonate was obtained. Expression of MmMK with ScPMK, ScPMD, and ScIDI under FAB80 promoter resulted in an efficient midstream module to produce 181.73 mg/L of limonene. Subsequently, coexpression of SlNPPS and MsLS in the downstream module led to a great improvement of limonene production to 694.61 mg/L. Finally, metabolically engineered strain ELIM78 produced 1.29 g/L of limonene in 84 h by fed-batch fermentation in a shake-flask. This is the first report on limonene biosynthesis in E. coli using neryl pyrophosphate synthase, which has promising potential for producing other monoterpenes.


Assuntos
Escherichia coli/genética , Escherichia coli/metabolismo , Limoneno/metabolismo , Técnicas de Cultura Celular por Lotes , Fermentação , Engenharia Metabólica , Ácido Mevalônico/metabolismo , Monoterpenos/metabolismo
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