Chemical compositions and related total antioxidant capacities of twelve spice essential oils were analyzed. To enable a comparison of their relative antioxidant potentials, essential oils were ...extracted by hydrodistillation from selected spice plants and their chemical compositions were determined by the GC-MS system on two fused-silica capillary columns of different polarity. Antioxidant effectiveness was examined by four different methods: the 2,2'-diphen-yl-1-picrylhydrazyl (DPPH) radical scavenging method, determination of ferric reducing antioxidant power (FRAP), determination of antioxidant activity with thiobarbituric acid reactive species (TBARS) and automatic determination of the oxidative stability of fat (RANCIMAT). Based on their antioxidant capacity, twelve spice essential oils can be sorted in descending order: Clove (Syzygium aromaticum L.) > Basil (Ocimum basilicum L.) > Laurel (Laurus nobilis L.) > Coriander (Coriandrum sativum L.) > Nutmeg (Myristica fragrans Houtt.) > Black Pepper (Piper nigrum L.) > Everlast (Helichrysum italicum G. (Roth) Don) > Mint (Mentha piperita L.) > Marjoram (Marjorana hortensis Moench.) > Cinnamon (Cinnamornum zeylanicum Nees) > Sage (Salvia officinalis L.) > Fennel (Foeniculum vulgare Muller).
A study of antioxidant activity and acetylcholinesterase (ACNE) inhibitory activity of aqueous tea infusions prepared from walnut (Juglans regia L.), peppermint (Menthaxpiperita L.), strawberry ...(Fragariaxananassa L.), lemon balm (Melissa officinalis L.), sage (Salvia offici nalis L.), and immortelle (Helichrysum arenarium (L.) Moench.) is presented here. Chemical composition of selected aqueous tea infusions was determined by high-performance liquid chromatography with photodiode-array method (HPLC-PDA), and the following phenolic compounds were identified as dominant: rosmarinic acid, gallic acid (not identified in walnut and sage), caffeic acid (in sage and peppermint), neochlorogenic acid, 3-p-coumaroylquinic acid and quercetin 3-galactoside (in walnut) and luteolin 7-O-glucoside (in sage). Antioxidant activity of the selected aqueous tea infusions was measured using low-density lipoprotein (LDL) oxidation method, 2,2'-diphenyl-l-picrylhydrazyl (DPPH) radical scavenging test, R-carotene bleaching method, and Rancimat method (induction period of lard oxidation). Strawberry and lemon balm aqueous infusions completely inhibited LDL oxidation at the concentration of 0.005 g/L in the reacting system. Very long prolongation of the lag phase was achieved with peppermint and sage aqueous infusions. All tested infusions in the concentration range of 0.05-2.85 g/L showed very pronounced effect of DPPH scavenging activity (90-100 %) as well as the inhibition of β-carotene bleaching (89-100 %). In pure lipid medium, used in Rancimat method, sage and immortelle at the concentration of 0.16 % (by mass) had the highest ability to inhibit lipid peroxidation process. Screening of the ACNE inhibitory activity by Ellman's method showed that the strongest inhibition was obtained with walnut and strawberry aqueous infusions at the concentration of 1.36 g/L in the reacting system. The presented results suggest that natural antioxidants could be useful and merit further investigations in the treatment and prevention of Alzheimer's disease. Key words: antioxidant activity, acetylcholinesterase inhibiting activity, aqueous tea infusion, phenolic compounds
The results obtained show that Bosnian pine is richin glycosidically bound volatile compounds with strong free radical scavengingproperties. Since volatiles can be released from nonvolatile ...glycosideprecursors, these compounds can be considered as a hidden potential source ofantioxidant substances and may contribute to the total free radical scavengingability of Bosnian pine.
The methanol, ethyl acetate and chloroform extracts of selected Croatian plants were tested for their acetylcholinesterase (AChE) inhibition and antioxidant activity. Assessment of AChE inhibition ...was carried out using microplate reader at 1 mg mL
−1
. Antioxidant capacities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test and ferric reducing/antioxidant power assay (FRAP). Total phenol content (TPC) of extracts were determined using Folin-Ciocalteu colorimetric method.
Out of 48 extracts, only methanolic extract of the Salix alba L. cortex exerted modest activity towards AChE, reaching 50.80% inhibition at concentration of 1 mg mL
−1
. All the other samples tested had activity below 20%. The same extract performed the best antioxidative activity using DPPH and FRAP method, too. In essence, among all extracts used in the screening, methanolic extracts showed the best antioxidative activity as well as highest TPC.
The results obtained show that Bosnian pine is rich in glycosidically bound volatile compounds with strong free radical scavenging properties. Since volatiles can be released from nonvolatile ...glycoside precursors, these compounds can be considered as a hidden potential source of antioxidant substances and may contribute to the total free radical scavenging ability of Bosnian pine.
Ispitana su antioksidacijska svojstva eteričnih ulja dvaju kemotipova timijana ovisno o njihovoj katalitičkoj transformaciji. Katalitička transformacija je provedena s kalijevim ...hidrogentrioksoperoksosulfatom(VI) i FeIII mezo-tetrafenilporfirin katalitičkim sustavom, poslije čega je kemijski sastav eteričnih ulja izmijenjen. Antioksidacijska aktivnost ispitana je s dvije različite metode (2,2'-diphenyl-1-picrylhydrazyl radical scavenging i Ferric Reducing / Antioxidant Power). Obje su metode pokazale da fenolni kemotip posjeduje jača antioksidacijska svojstva od nefenolnoga tipa. Poslije katalitičke oksidacije, eterična ulja obaju kemotipova timijana pokazivala su jači antioksidacijski učinak.
The paper examines the chemical composition and antioxidant activity of free volatile aglycones
from laurel (Laurus nobilis L.) as compared to its essential oil. Comparison of the chemical
...composition of volatile aglycones with the chemical composition of essential oil showed there
was no similarity between the free compounds found in the essential oil and the corresponding
volatile aglycones. Only eugenol was found to be identical. To evaluate the said antioxidant
activities, two different methods were applied: 2,2’-diphenyl-1-picrylhydrazyl radical scavenging
method (DPPH) and ferric reducing/antioxidant power assay (FRAP). The results obtained
in vitro with both methods showed that volatile aglycones from laurel possess lower reducing
power and free radical scavenging ability compared to essential oil as well as the well-known
synthetic antioxidant butilated hydroxytoluene (BHT).
Chemical compositions and related total antioxidant capacities of twelve spice essential oils were analyzed. To enable a comparison of their relative antioxidant potentials, essential oils were ...extracted by hydrodistillation from selected spice plants and their chemical compositions were determined by the GC-MS system on two fused-silica capillary columns of different polarity. Antioxidant effectiveness was examined by four different methods: the 2,2'-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging method, determination of ferric reducing antioxidant power (FRAP), determination of antioxidant activity with thiobarbituric acid reactive species (TBARS) and automatic determination of the oxidative stability of fat (RANCIMAT). Based on their antioxidant capacity, twelve spice essential oils can be sorted in descending order: Clove (Syzygium aromaticum L.) > Basil (Ocimum basilicum L.) > Laurel (Laurus nobilis L.) > Coriander (Coriandrum sativum L.) > Nutmeg (Myristica fragrans Houtt.) > Black Pepper (Piper nigrum L.) > Everlast (Helichrysum italicum G. (Roth) Don) > Mint (Mentha piperita L.) > Marjoram (Marjorana hortensis Moench.) > Cinnamon (Cinnamomum zeylanicum Nees) > Sage (Salvia officinalis L.) > Fennel (Foeniculum vulgare Muller).
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