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1.
Molecules ; 29(12)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38930889

RESUMO

The Equisetaceae family, commonly known as horsetails, has been of scientific interest for decades due to its status as one of the most ancient extant vascular plant families. Notably, the corresponding species have found their place in traditional medicine, offering a wide array of applications. This study presents a comprehensive phytochemical analysis of polar secondary metabolites within the sterile stems of five distinct Equisetum species using HPLC-DAD-ESI-MSn. For this purpose, fresh plant material was extracted with acetone/water, and the resulting crude extracts were fractionated using dichloromethane, ethyl acetate, and n-butanol, respectively. The results reveal a complex array of compounds, including hydroxycinnamic acids, hydroxybenzoic acids, flavonoids, and other phenolic compounds. In addition, total phenolic contents (Folin-Ciocalteu assay) and antioxidant activities (DPPH assay) of the plant extracts were evaluated using spectrophotometric methods. The present comparative analysis across the five species highlights both shared and species-specific metabolites, providing valuable insights into their chemical diversity and potential pharmacological properties.


Assuntos
Antioxidantes , Equisetum , Compostos Fitoquímicos , Extratos Vegetais , Caules de Planta , Antioxidantes/química , Antioxidantes/farmacologia , Compostos Fitoquímicos/química , Extratos Vegetais/química , Equisetum/química , Caules de Planta/química , Cromatografia Líquida de Alta Pressão , Fenóis/química , Fenóis/análise , Flavonoides/química , Flavonoides/análise
2.
Molecules ; 27(23)2022 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-36500602

RESUMO

Matricaria recutita L., German chamomile, is one of the most widely used medicinal plants, whose efficacy has been proven in numerous studies. However, its roots have attracted only little interest so far, since mainly above-ground plant parts are used for medicinal purposes. To broaden the knowledge of chamomile roots, a profound phytochemical characterization was performed along with a bioactivity screening of corresponding root extracts. While volatile constituents such as chamomillol and polyynes were detected using GC-MS, HPLC-MSn analyses revealed the occurrence of four coumarin glycosides, more than ten phenolic acid esters and five glyceroglycolipids. Furthermore, the antioxidant activity of the extracts was evaluated. Polar extracts revealed IC50 values ranging from 13 to 57 µg/mL in the DPPH radical scavenging assay, which is in the same range as reported for chamomile flower extracts. In addition, superoxide radical scavenging potential and mild antibacterial effects against S. aureus und B. subtilis were demonstrated. Moreover, to assess interspecies variation in chamomile roots, extracts of M. recutita were compared to those of M. discoidea DC. Interestingly, the latter revealed stronger antioxidant activity. The presented results aim at the valorization of chamomile roots, previously discarded as by-product of chamomile flower production, as a sustainable source of bioactive phytochemicals.


Assuntos
Matricaria , Óleos Voláteis , Matricaria/química , Antioxidantes/farmacologia , Staphylococcus aureus , Óleos Voláteis/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química
3.
Molecules ; 27(3)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35164314

RESUMO

Age-related injuries are often connected to alterations in redox homeostasis. The imbalance between free radical oxygen species and endogenous antioxidants defenses could be associated with a growing risk of transient ischemic attack and stroke. In this context, a daily supply of dietary antioxidants could counteract oxidative stress occurring during ischemia/reperfusion injury (I/R), preventing brain damage. Here we investigated the potential antioxidant properties of coffee-derived circulating metabolites and a coffee pulp phytoextract, testing their efficacy as ROS scavengers in an in vitro model of ischemia. Indeed, the coffee fruit is an important source of phenolic compounds, such as chlorogenic acids, present both in the brewed seed and in the discarded pulp. Therefore, rat brain endothelial cells, subjected to oxygen and glucose deprivation (OGD) and recovery (ogR) to mimic reperfusion, were pretreated or not with coffee by-products. The results indicate that, under OGD/ogR, the ROS accumulation was reduced by coffee by-product. Additionally, the coffee extract activated the Nrf2 antioxidant pathway via Erk and Akt kinases phosphorylation, as shown by increased Nrf2 and HO-1 protein levels. The data indicate that the daily intake of coffee by-products as a dietary food supplement represents a potential nutritional strategy to counteract aging.


Assuntos
Antioxidantes/farmacologia , Coffea/química , Fator 2 Relacionado a NF-E2/agonistas , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Traumatismo por Reperfusão/terapia , Animais , Antioxidantes/química , Isquemia Encefálica/metabolismo , Isquemia Encefálica/terapia , Linhagem Celular , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenóis/química , Extratos Vegetais/química , Ratos , Traumatismo por Reperfusão/metabolismo
4.
Molecules ; 26(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299566

RESUMO

Citrus fruits are a rich source of high-value bioactive compounds and their consumption has been associated with beneficial effects on human health. Red (blood) oranges (Citrus sinensis L. Osbeck) are particularly rich in anthocyanins (95% of which are represented by cyanidin-3-glucoside and cyanidin-3-6″-malonyl-glucoside), flavanones (hesperidin, narirutin, and didymin), and hydroxycinnamic acids (caffeic acid, coumaric acid, sinapic, and ferulic acid). Lemon fruit (Citrus limon) is also rich in flavanones (eriocitrin, hesperidin, and diosmin) and other polyphenols. All of these compounds are believed to play a very important role as dietary antioxidants due to their ability to scavenge free radicals. A standardized powder extract, red orange and lemon extract (RLE), was obtained by properly mixing anthocyanins and other polyphenols recovered from red orange processing waste with eriocitrin and other flavanones recovered from lemon peel by a patented extraction process. RLE was used for in vivo assays aimed at testing a potential beneficial effect on glucose and lipid metabolism. In vivo experiments performed on male CD1 mice fed with a high-fat diet showed that an 8-week treatment with RLE was able to induce a significant reduction in glucose, cholesterol and triglycerides levels in the blood, with positive effects on regulation of hyperglycemia and lipid metabolism, thus suggesting a potential use of this new phytoextract for nutraceutical purposes.


Assuntos
Citrus , Hiperglicemia/tratamento farmacológico , Hiperlipidemias/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Hipolipemiantes/uso terapêutico , Extratos Vegetais/uso terapêutico , Animais , Antocianinas/química , Antocianinas/uso terapêutico , Antioxidantes/química , Antioxidantes/uso terapêutico , Citrus/química , Dieta Hiperlipídica/efeitos adversos , Flavanonas/química , Flavanonas/uso terapêutico , Hiperglicemia/etiologia , Hiperlipidemias/etiologia , Hipoglicemiantes/química , Hipolipemiantes/química , Masculino , Camundongos , Extratos Vegetais/química
5.
Am J Otolaryngol ; 41(5): 102564, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32593046

RESUMO

Acute rhinosinusitis (ARS) can be characterized as bacterial (ABRS) and require antibiotic therapy only in 0.5-5% of cases. In most cases, the disease is in a viral and post-viral form, which requires pathogenetic and symptomatic treatment. The study objective was to determine the efficacy of BNO 1012 extract in the technology of delayed antibiotic prescribing in children with acute rhinosinusitis. METHODS: 292 children aged 6 to 11 years with ARS were randomized in the multicenter, comparative study. They received an extract of five medicinal plants in addition to standard symptomatic therapy or standard therapy only. EVALUATION CRITERIA: reduction of the sinusitis severity according to a 4-point medical assessment scale (nasal congestion, severity of anterior and posterior rhinorrhea) at each visit, dynamics of self-scoring of rhinorrhea and headache (according to a 10-point visual analogue scale), "therapeutic benefit" in days, frequency of antibiotic prescriptions due to the use of an extract of five plants. RESULTS: The use of the 5-plant extract BNO 1012 in addition to the standard symptomatic treatment of acute rhinosinusitis provides a clinically significant, adequate reduction in the severity of rhinorrhea, nasal congestion and post-nasal drip, assessed by a physician at V2 (p < 0.005). Significant differences are noted in the patient's self-scoring of rhinorrhea on the second or third day in viral RS, and from the fourth to the eighth day in post-viral RS. Symptoms of similar intensity in control group were observed at V3. Thus, in the first week of treatment, the treatment group compared to the control one showed a "therapeutic benefit" of three days. The use of BNO 1012 in patients with acute rhinosinusitis can 1.81-fold reduce the prescription of antibacterial drugs. CONCLUSION: The combination of five medicinal plants is effective for the treatment of acute rhinosinusitis in children aged 6 to 11 years. Its use provides a significant "therapeutic benefit" when administered in addition to standard symptomatic therapy, reducing the need for antibiotic use.


Assuntos
Antibacterianos/administração & dosagem , Uso Excessivo dos Serviços de Saúde/prevenção & controle , Fitoterapia , Extratos Vegetais/administração & dosagem , Rinite/tratamento farmacológico , Sinusite/tratamento farmacológico , Doença Aguda , Administração Oral , Criança , Feminino , Humanos , Masculino , Obstrução Nasal/tratamento farmacológico , Obstrução Nasal/etiologia , Avaliação de Resultados da Assistência ao Paciente , Estudos Prospectivos , Rinite/complicações , Rinite/microbiologia , Rinite/virologia , Sinusite/complicações , Sinusite/microbiologia , Sinusite/virologia
6.
J Food Sci Technol ; 52(10): 6230-41, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26396369

RESUMO

The effect of combination of phyto-extracts (sea buckthorn extract (SBTE), grape seed extract (GSE)) on different physico-chemical, oxidative stability, instrumental colour and texture, sensory and microbiological properties of pork patties were investigated under aerobic and MAP (50 % CO2: 50 % N2) packaging conditions. Treatments viz. T-1 (aerobic packaged control), T-2 (aerobic packaged containing 0.3 % SBTE+ 0.1 % GSE), T-3 (MAP packaged control) and T-4 (MAP packaged containing 0.3 % SBTE+ 0.1 % GSE) at 4 ± 1 °C for 35 days and samples were drawn at 7 days interval. The pH decreased initially up to 21 days and thereafter increased on further storage whereas water activity followed a decreasing trend throughout the storage period, irrespective of the treatment and packaging conditions. Results of oxidative stability parameters revealed that peroxide value, TBARS and FFA followed an increasing trend in both the packaging groups during storage however, the rate of increase was significantly lower (P < 0.05) in MAP packaged products than aerobic packaged products and phyto extracts incorporated products than their respective control. Instrumental colour and texture profiles were best maintained in MAP packaged treated products (T-4) which has higher redness (a*) value whereas lightness (L*) and yellowness (b*) showed lower (P < 0.05) value. MAP packaging resulted in superior sensory properties of pork patties as compared to aerobic packaged products. Standard plate count, psychrophiles and Coliforms were significantly (P < 0.05) lower in treated products than control and microbial count was better maintained in MAP than aerobic condition. Results concluded that the combined use of antioxidants and MAP packaging would be a useful method to control the oxidative and microbial quality changes of pork patties and it can be successfully stored for 35 days.

7.
Animals (Basel) ; 13(3)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36766219

RESUMO

Grains are major farm animals' diet ingredients, and one of the main concerns is when are mycotoxin (MyT) contaminated, compromising animals' health, performance, and product safety. Among the natural phytocompounds that are being used to prevent MyT damage, silymarin (SIL), an extract from the seed of the milk thistle (MT) is a suitable candidate. This review aims to examine the scientific evidence concerning the anti-MyT toxicity effects of MT/SIL in poultry and livestock. In vitro and in vivo studies (n = 27) showed that MT whole plant, seed, or SIL-standardized extract had positive effects on animal health, performance, and restoring the hepatic activity, with a reduction of organ lesions caused by MyT. Furthermore, showed utility for combating MyT-immunodepression, improving intestinal health, and limiting the excretion of toxins residues in food of animal origin, although in some cases, MT/SIL supplementation does not produce appreciable effects. The use of MT in animal nutrition can be useful since the bioactive compounds, also if present in variable amounts, can help the animals to counteract the effects of MyT. The use of the phytoextract of SIL, due to its cost, can be useful if it reported the specific bioactive compounds, recognize for their pharmacological activities.

8.
Arch Physiol Biochem ; 129(6): 1219-1228, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34270371

RESUMO

CONTEXT: The effect of Eucalyptus globulus in diabetic cardiac dysfunction and the possible mechanisms involved have not been explored. OBJECTIVE: To evaluate the effect of ethanol leaf extract of E. globulus (NEE) on the cardiac function of fructose/streptozotocin-induced diabetic rats. MATERIALS AND METHODS: Type-2 diabetes was induced in rats with 10% fructose feeding for 14 days and an intraperitoneal administration of 40 mg/kg streptozotocin. Diabetic animals were treated with NEE (100-400 mg/kg) or 5 mg/kg glibenclamide orally for 21 days. Biochemical assays, histopathological examination and analyses of PCSK9, Rho kinase and Cardiac troponin expression were performed. RESULTS: The untreated diabetic group showed decreased expression of the genes, oxidative stress, dyslipidemia, increased activities of creatine kinase MB and lactate dehydrogenase, reduced nitric oxide level, and depletion of cardiomyocytes, which were reversed in NEE treated groups. CONCLUSIONS: Eucalyptus globulus ameliorated diabetic cardiac dysfunction through increased PCSK9, Rho kinase and Cardiac troponin expression.


Assuntos
Diabetes Mellitus Experimental , Eucalyptus , Cardiopatias , Ratos , Animais , Eucalyptus/metabolismo , Pró-Proteína Convertase 9/metabolismo , Pró-Proteína Convertase 9/farmacologia , Estreptozocina/toxicidade , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Regulação para Cima , Quinases Associadas a rho/metabolismo , Quinases Associadas a rho/farmacologia , Estresse Oxidativo , Extratos Vegetais/farmacologia , Troponina/metabolismo , Troponina/farmacologia
9.
Pharmaceutics ; 15(7)2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37514079

RESUMO

This work focuses on the synergetic effect obtained by immobilization of Rhamnus frangula L. (RfL) phytoextract in layered double hydroxides (LDHs) matrixes and their subsequent encapsulation into biocompatible hydrogels (HG). In this respect, the LDHs were used as hosts for the immobilization of the phytoextract by a reconstruction method, after which the LDHsRfL were embedded into biocompatible hydrogel (HG) matrixes, based on polyethylene glycol diacrylate (PEGDA), by a radical polymerization reaction. The resulted biocompatible hydrogel composites were characterized by modern methods, while the swelling and rheology measurements revealed that the HG composites steadily improved as the content of RfL phytoextract immobilized on LDHs (LDHsRfL) increased. The following in vitro sustained release of the RfL phytoextract was highlighted by measurements at pH 6.8, in which case the composite HGs with LDHsRfL presented an improved release behavior over the LDHsRfL, thus, underlining the synergistic effect of PEGDA network and LDH particles on the slow-release behavior. The kinetic models used in the RfL release from composite HGs clearly indicate that the release is diffusion controlled in all the cases. The final composite HGs described here may find applications in the pharmaceutical field as devices for the controlled release of drugs.

10.
Front Chem ; 11: 1118454, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36959877

RESUMO

Medicinal plants are long known for their therapeutic applications. Tinospora cordifolia (commonly called gulancha or heart-leaved moonseed plant), a herbaceous creeper widely has been found to have antimicrobial, anti-inflammatory, anti-diabetic, and anti-cancer properties. However, there remains a dearth of reports regarding its antibiofilm activities. In the present study, the anti-biofilm activities of phytoextractof T. cordifolia and the silver nanoparticles made from this phytoextract were tested against the biofilm of S.taphylococcus aureus, one of the major nosocomial infection-producing bacteria taking tetracycline antibiotic as control. Both phytoextract from the leaves of T. cordifolia, and the biogenic AgNPs from the leaf extract of T. cordifolia, were found successful in reducing the biofilm of Staphylococcus aureus. The biogenic AgNPs formed were characterized by UV- Vis spectroscopy, Field emission Scanning Electron Microscopy (FE- SEM), and Dynamic light scattering (DLS) technique. FE- SEM images showed that the AgNPs were of size ranging between 30 and 50 nm and were stable in nature, as depicted by the zeta potential analyzer. MIC values for phytoextract and AgNPs were found to be 180 mg/mL and 150 µg/mL against S. aureusrespectively. The antibiofilm properties of the AgNPs and phytoextract were analyzed using the CV assay and MTT assay for determining the reduction of biofilms. Reduction in viability count and revival of the S. aureus ATCC 23235 biofilm cells were analyzed followed by the enfeeblement of the EPS matrix to quantify the reduction in the contents of carbohydrates, proteins and eDNA. The SEM analyses clearly indicated that although the phytoextracts could destroy the biofilm network of S. aureuscells yet the biogenicallysynthesizedAgNPs were more effective in biofilm disruption. Fourier Transformed Infrared Radiations (FT- IR) analyses revealed that the AgNPs could bring about more exopolysaccharide (EPS) destruction in comparison to the phytoextract. The antibiofilm activities of AgNPs made from the phytoextract were found to be much more effective than the non-conjugated phytoextract, indicating the future prospect of using such particles for combatting biofilm-mediated infections caused by S aureus.

11.
Nat Prod Res ; 36(8): 2140-2144, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33118389

RESUMO

This study is aimed at valorizing artichoke (Cynara cardunculus var. scolymus L.) by-products as source of inulin, a fiber showing relevant prebiotic properties, through the realization of a waste value chain. Starting from artichoke by-products, the inulin fraction was assessed both in terms of total amount and degree of polymerization as a function of the harvest season and storage conditions. These parameters have been found significant at influencing inulin yield of extraction. For the first time, artichoke wastes were proposed to be exploited taking into account the optimal conditions to preserve their high-added chemical value. Our data suggest that Italian farms could obtain from their wastes a total amount of 16 t/year of inulin with an average polymerization degree higher than 40 and would allow the development of a circular economy process within the artichoke supply chain, by exploiting its wastes representing 70% of the total artichoke biomass.


Assuntos
Cynara scolymus , Cynara , Scolymus , Cynara scolymus/química , Inulina/química , Polimerização , Prebióticos
12.
Nucleus (Calcutta) ; 65(3): 303-320, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36407558

RESUMO

The positive effect of herbal supplements on aging and age-related disorders has led to the evolution of natural curatives for remedial neurodegenerative diseases in humans. The advancement in aging is exceedingly linked to oxidative stress. Enhanced oxidative stress interrupts health of humans in various ways, necessitating to find stress alleviating herbal resources. Currently, minimal scientifically validated health and cognitive booster resources are available. Therefore, we explored the impact of plant extracts in different combinations on oxidative stress, life span and cognition using the multicellular transgenic humanized C. elegans, and further validated the same in Mus musculus, besides testing their safety and toxicity. In our investigations, the final product-the HACBF (healthy ageing cognitive booster formulation) thus developed was found to reduce major aging biomarkers like lipofuscin, protein carbonyl, lipid levels and enhanced activity of antioxidant enzymes. Further confirmation was done using transgenic worms and RT-PCR. The cognitive boosting activities analyzed in C. elegans and M. musculus model system were found to be at par with donepezil and L-dopa, the two drugs which are commonly used to treat Parkinson's and Alzheimer's diseases. In the transgenic C. elegans model system, the HACBF exhibited reduced aggregation of misfolded disease proteins α-synuclein and increased the health of nicotinic acetylcholine receptor, levels of Acetylcholine and Dopamine contents respectively, the major neurotransmitters responsible for memory, language, learning behavior and movement. Molecular studies clearly indicate that HACBF upregulated major genes responsible for healthy aging and cognitive booster activities in C. elegans and as well as in M. musculus. As such, the present herbal product thus developed may be quite useful for healthy aging and cognitive boosting activities, and more so during this covid-19 pandemic. Supplementary Information: The online version contains supplementary material available at 10.1007/s13237-022-00407-1.

13.
Plants (Basel) ; 10(11)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34834903

RESUMO

A study was carried out to evaluate the effectiveness of sugar beet extract (SBE) and glycine betaine (GB) in mitigating the adverse effects of drought stress on two maize cultivars. Seeds (caryopses) of two maize cultivars, Sadaf (drought-tolerant) and Sultan (drought-sensitive) were sown in plastic pots. Plants were subjected to different (100%, 75% and 60% field capacity (FC)) water regimes. Then, different levels of SBE (3% and 4%) and GB (3.65 and 3.84 g/L) were applied as a foliar spray after 30 days of water deficit stress. Drought stress significantly decreased plant growth and yield attributes, chlorophyll pigments, while it increased relative membrane permeability (RMP), levels of osmolytes (GB and proline), malondialdehyde (MDA), total phenolics and ascorbic acid as well as the activities of superoxide dismutase (SOD) and peroxidase (POD) enzymes in both maize cultivars. Exogenous application via foliar spray with SBR or GB improved plant growth and yield attributes, chlorophyll pigments, osmolyte concentration, total phenolics, ascorbic acid and the activities of reactive oxygen species (ROS) scavenging enzymes (SOD, POD and catalase; CAT), but reduced leaf RMP and MDA concentration. The results obtained in this study exhibit the role of foliar-applied biostimulants (natural and synthetic compounds) in enhancing the growth and yield of maize cultivars by upregulating the oxidative defense system and osmoprotectant accumulation under water deficit conditions.

14.
Curr Med Chem ; 28(33): 6730-6752, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-33761849

RESUMO

Several clinical studies have shown that exposure of skin to solar ultraviolet (UV) radiation causes adverse effects, such as inflammation, oxidative stress and DNA damage. As a result, different skin disorders can arise, among which are skin cancer, including non-melanoma skin cancer (NMSC) and melanoma (MM). Phenolic compounds are plant-derived secondary metabolites with a well-known antioxidant activity, able to counteract the negative effects of UV radiation. In this review, we discuss the effects of some selected phenols on NMSC and MM, demonstrating that they can be useful in the prevention and in the treatment of these types of tumors. Moreover, we report the mechanisms by which these phenols carry out their antitumor action. In vitro and in vivo studies have highlighted that many phenols are capable of inducing photoprotection, apoptosis and autophagy. They can also reduce DNA methylation, tumorigenesis, tumor incidence and proliferation. Moreover, we describe some examples of plant extracts, whose anticancer activity appears to be better than that of single phenols. A great concordance of results emerged, despite the differences in experimental methods. Therefore, the knowledge compiled here could provide the basis for conducting some well-organized clinical trials to validate the chemopreventive and the therapeutic potential of some phenolic compounds in patients with NMSC and MM.


Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Melanoma/tratamento farmacológico , Melanoma/prevenção & controle , Fenóis/uso terapêutico , Pele , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/prevenção & controle , Raios Ultravioleta
15.
3 Biotech ; 10(8): 364, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32832325

RESUMO

In this study, biological deoxygenation of graphene oxide (GO) using an Eclipta prostrata phytoextract was performed via the infusion method. The presence of oxide groups on the surface of graphene and removal of oxides groups by reduction were characterized through morphological and structural analyses. Field emission scanning electron microscopy images revealed that the synthesized GO and rGO were smooth and morphologically sound. Transmission electron microscopy images showed rGO developing lattice fringes with smooth edges and transparent sheets. Atomic force microscopy images showed an increase in the surface roughness of graphite oxide (14.29 nm) compared with that of graphite (1.784 nm) due to the presence of oxide groups after oxidation, and the restoration of surface roughness to 2.051 nm upon reduction. Energy dispersive X-ray analysis indicated a difference in the carbon/oxygen ratio between GO (1.90) and rGO (2.70). Fourier-transform infrared spectroscopy spectrum revealed peak stretches at 1029, 1388, 1578, and 1630 cm-1 for GO, and a decrease in the peak intensity after reduction that confirmed the removal of oxide groups. X-ray photoelectron microscopy also showed a decrease in the intensity of oxygen peak after reduction. In addition, thermogravimetric analysis suggested that rGO was less thermally stable than graphite, graphite oxide, and GO, with rGO decomposing after heating at temperatures ranging from room temperature to 600 °C.

16.
Braz. arch. biol. technol ; 54(6): 1093-1098, Nov.-Dec. 2011.
Artigo em Inglês | LILACS | ID: lil-608429

RESUMO

The antifungal activity of aqueous extract of Cannabis sativa, Parthenium hysterophorus, Urtica dioeca, Polystichum squarrosum and Adiantum venustum was investigated against Alternaria solani, Alternaria zinniae, Curvularia lunata, Rhizoctonia solani and Fusarium oxysporum at different concentrations (5, 10, 15 and 20 percent). At 20 percent, maximum antifungal potential was observed with the extracts of C. sativa, which recorded excellent inhibitory activity against C. lunata (100 percent), A. zinniae (59.68 percent), followed by leaf extract of P. hysterophorus (50 percent) against A. solani. The application of botanical extracts for disease management could be less expensive, easily available, non-polluting and eco-friendly.

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