Abstract: Thechemicalcompositionoftheessentialoil from the aerial parts ofThymushaussknechtiiVelen. was analyzed by using gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The major component oftheessentialoil was thymol (52.2%). Total phenolic content oftheessentialoil was determined as 132.9 µg gallic acid equivalent. Theantioxidantcapacity was evaluated by DPPH free radical, superoxide anion radical and hydrogen peroxide scavenging activities along with ferrous ion-chelating power test, ABTS radical cation decolorization assay and ferric thiocyanate methods. In addition to antioxidant activity, anticholinesterase activity oftheessentialoil was also evaluated. It exhibited inhibitoryactivities on AChE and BuChE which play an important role in Alzheimer’s disease, along with significant antioxidant activity.
Coffee pulp is produced in large quantities, and its disposal can pollute the environment. However, the nutritional value andantioxidant content of coffee pulp make it a good option for animal feed. Therefore, the objective of this study was to determine thechemicalcomposition, the phenolic compounds andtheantioxidantcapacityof coffee pulp using fresh (FCP), ensiled (ECP), and ensiled and sun-dried (EDCP) coffee pulp. The study design was completely randomized with three treatments (n=4). Dry matter (DM), crude protein (CP), ash, acid detergent fiber (ADF), neutral detergent fiber (NDF), lignin, phenolic compounds andantioxidantcapacity were determined. Data were analyzed by analysis of variance, and means were compared with the Tukey test. The percentage of CP, NDF and ADF was higher in ECP and EDCP than in FCP. There were no changes in lignin content. Ensiling and sun drying did not decrease (P>0.05) caffeine or tannins. No differences were found in caffeic acid (2.031±2.873, 5.103±0.391, 4.913±0.018 mg g -1 DM in FCP, ECP,
Wang et al. (1996) demonstrated that plums are rich source of antioxidants, and they had 4.4 times higher total antioxi- dant capacities than apples, the latter being one ofthe most commonly consumed fruits in our diet. So, the results of this study imply that dietary phytochemicals from plums may supply substantial antioxidants, which, in turn, may provide health-promoting ef ects to consumers. Also, it needs to be stressed that antioxidantcapacity is tightly correlated with specii c phenolics compounds (Chun et al., 2003; Stintzing et al., 2002). But in this study we did not achieve nor analyses nor identii cation of these individual phenolic compounds.
This study concludes that theantioxidantand radical scavenging activity oftheessentialoiland organic extracts of P. integrifolia leaves indicate towards its strong protective role against oxidative diseases and possible use of P. integrifolia leaves as a natural antioxidant for potential pharmaceutical application. Theoil showed higher antioxidantactivities than organic extracts, whereas methanol extract had potent antioxidant activity than other extracts as compared to three tested methods. Further work is needed to fully understand the variables that can affect the evaluation oftheantioxidantcapacity by different methodologies.
Theantioxidant activity assay was carried out by the Trolox equivalent antioxidantcapacity (TEAC) method andthe radical ABTS ˙+ (2,2-azino- bis-3-ethylbenzoline-6-sulfonic acid) was captured in agreement with the procedure described by Rufino et al. (2007b). Preparation ofthe radical ABTS ˙+ was based on the reaction between 5mL ABTS ˙+ aqueous solution (7 mM) and 88 µL potassium persulfate solution (140 mM), which was left for 16 hours in the dark. Afterwards, the mixture was diluted with ethanol to reach absorbance of 0.70 nm ± 0.05 at 734 nm. An aliquot of 30 µL of every dilution ofessential oils from leaves and flowers (from 2000 to 10000 mg/L) was added to 3 mL ofthe radical ABTS ˙+ in test tubes and left for 6 minutes in the dark. Absorbance was read at 734 nm by a spectrophotometer whose blank was ethanol. A Trolox curve at different concentrations (from 100 to 2000 µM) was prepared and used as the standard. The ABTS ˙+ calibration curve obtained the following correlation coefficient: R² = 0.99. Results were expressed as Trolox micromole per gram ofoil (µM trolox/g).
Free radical scavenging activity (DPPH): The time- course evaluation ofthe free radical scavenging capacityofthe different concentrations oftheessential oils, isolated using different hydrodistillation periods, from the dried aerial parts of fennel (Figure 1 A-D), showed, in all cases, that the higher concentrations oftheessential oils (12-24 g/L) attained the steady-state faster and had better DPPH free radical scavenging ability. However, steady-state, as well as 85-95% of activity, was only attained at the end of 30 min. In general, at the highest concentrations assayed (12-24 g/L), theessential oils from the different distillation periods showed similar DPPH free radical scavenging capacity. Whereas at the highest concentrations assayed (12-24 g/L), theantioxidantcapacity was >85%, for the lowest concentrations (2-6 g/L), only theessential oils isolated during 2 h and 3 h of hydrodistillation showed an antioxidantcapacity >60%, and only after 6 h of reaction.
T h e a n t i o x i d a n t a c t i v i t y t h r o u g h t h e phosphomolybdenum complex reduction method was performed using the standard solutions of ascorbic acid and rutin, that were prepared at the concentration of 200 μg / mL in methanol and 0.5% DMSO, as well as the samples (Prieto, Pineda, Aguilar, 1999). Aliquots of 0.3 mL were added to 3 mL ofthe phosphomolybdenum reagent (0.1 M tribasic sodium phosphate (28 mL), 0.03 M ammonium tetrahydrate molybdate solution (12 mL), 3 M sulfuric acid (20 mL) and water until complete 100 mL). The tubes were closed and brought to the thermostated bath at 95 ºC for 90 min. After cooling, the absorbances were obtained in 96-well microplates with round bottoms by reading in the Multiskan FC spectrophotometer, Thermo Scientific® at wavelength 695 nm. Theantioxidantcapacityofthe samples was expressed in relative antioxidant activity (AAR%), in relation to the standards, using the equation: AAR% = [(Sample Absorbance - Absorbance of White)/ (Absorbance of Standard - Absorbance of White)] X 100 The variance ofthe obtained results was evaluated by the ANOVA test andthe difference between the means verified by the test (t) by Scott and Knott (p <0.05).
et al., 1995) was also used to measure the potential antioxidantcapacityof T. capitatus essential oils. Egg yolk homogenate was used as lipid-rich media. An aliquot of yolk material was made up to a concentration of 10% (w/v) in KCl (1.15%, w/v). The yolk was then homogenised for 30 s, followed by ultrasonication for further 5 min. Five hundred µl of 10% (w/v) homogenate and 100 µl of sample, solubilised in methanol, were added to a test tube and made up to 1 ml with distilled water, followed by addition of 1.5 ml of 20% acetic acid (pH 3.5) and 1.5 ml of 0.8% (w/v) 2-thiobarbituric acid (TBA) in 1.1% (w/v) sodium dodecyl sulphate (SDS). Each essentialoil sample and tested substance was assayed at concentrations of 100, 500 and 1000 mg l –1 . This mixture was stirred in a vortex, and heated at 95 °C for 1 h. After cooling at
The decrease in the absorption at 560 nm suggested superoxide radicals’ scavenging, being most significant when theessentialoil was added to the reaction mixture – 95.93 %. Superoxyde dismutase 100 U/mL with inhibiting effect 77.8 % was used as a standard. The results achieved in the study revealed two ways of influence ofessentialoiland eugenol on xanthine-xanthine oxidase function – they acted as xanthine oxidase inhibitors and superoxide scavengers, thus confirming the interpretation of (Jubert et al., 2004).The evaluation ofantioxidant activity in a linoleic acid model system was as follows: For the task of evaluating theinhibitory effect ofessentialoil on lipid peroxidation, a model system of linoleic acid emulsion was applied. Theantioxidantcapacity was estimated both at the early stages of linoleic acid autoxidation and later, after the emergence of secondary oxidation products, expressed as malonic aldehyde content. Two indicators were referred to, corresponding to a different degree of lipid peroxidation – conjugated diene formation and TBARS. The effect oftheessential Murraya koenigii leaf oil on lipid peroxidation was assayed at body temperature, 37°C.
Abstract: Theessentialoil from the aerial parts of Salvia chrysophylla Staph (Lamiaceae), endemic to Turkey, was investigated by using GC and GC-MS. Fifty-four of 55 components, represented 99.52% ofthe total oil, were identified. The major components oftheessentialoil were found to be -terpinenyl acetate (36.31%), - caryophyllene (15.29%), linalool (8.12%) and -elemene (4.26%). Theantioxidant activity oftheoil was investigated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and -carotene/linoleic acid tests. Anticholinesterase activity was screened against acetylcholinesterase andbutyrylcholinesterase which are the chief enzymes of Alzheimer s disease. Theessentialoil showed weak antioxidant activity. However, at 1 mg/mL concentration, theessentialoil exhibited mild acetylcholinesterase (52.5±2.0%) and moderate butyrylcholinesterase (76.5±2.7%) inhibitory activity
Propolis is a resinous substance collected, transformed and used by bees to seal holes in their honeycombs, smooth out the internal walls and protect the hive entrance against intruders. Honeybees (Apis mellifera L.) collect the resin from tree bark and leaf buds. Resin is masticated, salivary enzymes are added andthe partially digested material is mixed with beeswax and used in the hive (1, 2).
The findings ofthe present studies, therefore, suggest the use ofthe whole essentialoil from the seeds of Z. armatum as a local resource in controlling mosquito larvae. The source constraint may not allow their practical utility in larger breeding habitat; however, the plant source may be utilised by local people for controlling mosquito larvae in small breeding places like water coolers, tree holes, abandoned wells, drums and containers in and around the rural/subur- ban dwellings. Such practice would not only reduce thechemical burden on the environment but also promote sustainable utilisation of locally available bioresource by rural communities. Further studies may be directed towards enhancing the efficacy of such oils with the use of potentiating/synergistic agents, developing suitable formulations and their bioefficacy evaluation in real field conditions.
The leishmanicidal potential ofessential oils has been well studied (Cardoso et al. 2015), andthe leaf essentialoilof C. aschersoniana displayed high leishmanicidal activity when tested against L. amazonensis promastigote forms. Increase in parasite lysis was observed with increase in essentialoil concentration, with IC 50 = 4.46 μg/mL (Table II). The leaf essentialoilof C. aschersoniana inhibited parasite growth in a concentration/dose-dependent manner. As positive control was used amphotericin B (IC 50 = 1.88 μg/mL), an antifungal with broad spectrum of action that is used as second-line drug against leishmaniasis and that show a high toxicity in the host (Bastos et al. 2016, Fernández-García et al. 2017).
The leaf oil evaluated in this study showed a great percentage of oxygenated monoterpenes (52.5%) (Table 1, Figure 2). The main constituents were terpinen-4-ol, 1,8 cineole and γ-terpinene (Table 1, Figure 1) (Victório, 2008; Victório et al., 2009a). These constituents were found in studies on theessentialoil from other samples of A. zerumbet (Zoghbi et al., 1999; Ali et al., 2002; Elzaawely et al., 2007; Victório et al., 2009b). Caryophyllene oxide was also found in low amounts (Figure 1). Essential oils from A. zerumbet present a great variety of compounds involved in the antimicrobial activity. Terpinen-4-ol and 1,8 cineole have been reported to inhibit several microorganisms (Janssen & Scheffer, 1985; Matasyoh et al., 2007).
Among many essential oils, those from plants within the Lamiaceae family have received considerable attention in the search for biologically active natural products against agricultural as well as stored products pests. In a recent study, was investigated the antifeedant properties of several Lamiaceae essential oils and some of their volatile constituents against onion thrips Thrips tabaci. This raised questions about possible other biological effects of these phytochemicals in thechemical ecology ofthe onion thrips 5-7 .
As the multinomial model is non-linear, the marginal effect ofthe treatment in a DID model is not the marginal impact ofthe interaction between time and treatment, but the difference ofthe cross-differences, as described by Puhani (2012). The results of Table 7 (in terms of marginal effects) show that the BVJ has a significant effect on the probability studying and working at the same time, but not on the other outcome variables. The estimated marginal effects mean that the probability of a youngster studying and working increases by 4.2 percentage points with the BVJ, compared with a baseline of 30% in the control group in 2006. The estimated coefficients for the categories ‘studying only’ and ‘working only’ were negative but not statistically significant. It seems, therefore, that treated adolescents do not quit their jobs to study because ofthe program, but do both activities at the same time. This raises questions about the long run impacts ofthe program, since the quality ofthe night classes is notoriously low in Brazil.
Essence of modification of silumins boils to change of form or size of silicon crystals present as eutectic or primary ones. Perfect sliding properties and high abrasion resistance of hypereutectoid silumins result from their structure, which can be characterized by precipitations of primary crystals of silicon in soft eutectic groundmass. Primary crystals of silicon are unfavorable due to their impact on machinability of material. They bring about considerable wear of tools and have negative effect on conditions of machined surface (big roughness). In case of hypereutectic silumins, by introduction of active nucleuses of crystallization are refined mainly a brittle, hard precipitations of primary silicon . High content o silicon results in necessity of superheating ofthe alloy in limits of 850 – 900 C and keeping it
In the middle ofthe many families of plants investigated, the Myrtaceae family deserves some special interest. This family consists of approximately 3,800 species and 130 genera distributed worldwide (Lucas et al., 2005). In Brazil, this family is represented by about 1,000 species and 26 genera (Sobral et al., 2010), including many which are used owing their medicinal properties and importance as food sources (Agra et al., 2008). The genus Psidium has approximately 92 species distributed from Mexico to Uruguay and northern Argentina. In Brazil, it occurs from the Amazon region to the State of Rio Grande do Sul (Landrum, 2003). Among the species ofthe genus Psidium, Psidium cattleianum Sabine, popularly known as “strawberry guava” stands out for the commercial importance attributed to its fruit used in the food industry (Santos et al., 2007). However, although there are studies on the quality of their seeds (Silva et al., 2011), theantioxidantand antimicrobial activity of extracts obtained from its fruit (Medina et al., 2011), thechemical characteristics of its juice (Santos et al., 2007), andthechemicalcompositionoftheessentialoil (Marques et al., 2008), there aren’t reports about the phytochemical compositionand their biological activities. The present study is the first record on the subject.
Gas chromatography – mass spectrometry (GC- MS) analysis was carried out by a Shimadzu QP2010 with an AOC-20i auto-injector and a DB-5MS column (30 m x 0.25 mm, 0.25 mm in thickness). The carrier gas was He with pressure of 57.4 kPa and flow rate of 1.00 mL/ min. The split ratio was 1/30, the injector temperature was 250 °C andthe injected volume was 1 µL. Temperature programming was the following : 60 – 240 °C, increasing 3 °C/min. MS were recorded on the electron ionization (EI) mode, with ionization energy of 70 eV (scan time: 2 scans/s). Identification ofthe constituents was based on the retention indices (the calculation used from C 9 to C 22 alkanes) and on the comparison ofthe mass spectra with libraries (Wiley 7 and Nist 62) and references to previously published data (ADAMS, 2007).