Phenols, essential oils and carotenoids of Rosa canina from Tunisia and their antioxidant activities

The antioxidant activity of leaf extracts of Rosa canina from diverse localities of Tunisia were evaluated by ABTS and DPPH methods, whereas in those of essential oils and carotenoids extracts such activity was determined only by the ABTS method. Total phenols determined by the Folin method revealed that at Aindraham, samples showed a great variability of phenol content in contrast to those from Feija. After chemical analysis of the essential oils by gas chromatography (GC) and gas chromatography coupled to mass spectra (GC-MS), revealed that the oils of Feija were predominantly composed of palmitic acid, vitispirane, linoleic acid, lauric acid, myristic acid and phytol acetate, while in thosesamples from Aindraham predominated vitispirane, palmitic acid, linoleic acid and phytol acetate. Higher concentrations of b-carotene and lycopene were found in the samples from Aindraham after determination by high performance liquid chromatography (HPLC). All samples possess antioxidant activity, nevertheless much more significant in phenol extracts in contrast to the carotenoid extracts, which possess the lowest activity

Phenols, essential oils and carotenoids of Rosa canina from Tunisia and their antioxidant activities

The antioxidant activity of leaf extracts of Rosa canina from diverse localities of Tunisia were evaluated by ABTS and DPPH methods, whereas in those of essential oils and carotenoids extracts such activity was determined only by the ABTS method. Total phenols determined by the Folin method revealed that at Aindraham, samples showed a great variability of phenol content in contrast to those from Feija. After chemical analysis of the essential oils by gas chromatography (GC) and gas chromatography coupled to mass spectra (GC-MS), revealed that the oils of Feija were predominantly composed of palmitic acid, vitispirane, linoleic acid, lauric acid, myristic acid and phytol acetate, while in those samples from Aindraham predominated vitispirane, palmitic acid, linoleic acid and phytol acetate. Higher concentrations of beta-carotene and lycopene were found in the samples from Aindraham after determination by high performance liquid chromatography (HPLC). All samples possess antioxidant activity, nevertheless much more significant in phenol extracts in contrast to the carotenoid extracts, which possess the lowest activity

Extraction of neuroprotective compounds from Eucalyptus leaves using green technologies. Ternary mixture design

Resumen del trabajo presentado al 19th European Meeting on Supercritical Fluids: Budapest, Hungary, 21–24 May 2023.Authors thank projects PID2020-113050RB-I00, and PDC2021-120814-I00 funded by MCIN/AEI /10.13039/501100011033 and The European Union Next GenerationEU/ PRTR, also INCGLO0019 (Bioprospection of local agricultural resources, a way to achieve the Objectives of Sustainable development) and COOPA22033 (Bioprospecting Algerian native plants by means of sustainable extraction techniques to find bioactive compounds) both financed by the CSIC.N

Chemical variability of the essential oils from Rosa canina L. and Rosa sempervirens L. flowers collected at Tunisia

The chemical variability of the essential oils of Rosa canina L. and R. sempervirens L. flowers collected at seven localities from northern Tunisia was investigated by gas chromatography (GC) and GC-mass spectrometry (GC-MS). The essential oils yields ranged between 0.7% and 1.4% (v/f.w.) for R. canina and R. sempervirens, respectively. Forty-one components were identified in R. canina and twenty-six in R. sempervirens oils. Rosa canina essential oil, from plants collected at Ain Draham, was dominated by beta-caryophyllene (32%) and geraniol (21%), whereas in the oils from plants collected at Boussalem n-heneicosane (29%), p-cymene (12%) and beta-caryophyllene (11%) predominated. However, the oil isolated from the samples collected at Fernana was dominated by 2,4,6-trimethyl-octane (9%), n-undecane (8%) and geraniol (8%). p-Cymene (14%), limonene (11%) and gamma-terpinene (11%) were the main components of the oil isolated from Feija samples. Rosa sempervirens oils, from plants collected at Ain Draham and Fernana, were characterized by a high 2-phenylethyl alcohol content (29% and 93%, respectively). The major components of the oil isolated from Tabarka samples were p-cymene (16%) and gamma-terpinene (12%). Cluster analysis of the essential oils composition from the studied populations, confirmed the major chemical variability

Phenolic profile, antioxidant capacity of five Z<i>iziphus spina</i>-<i>christi</i> (L.) Willd provenances and their allelopathic effects on <i>Trigonella foenum</i>-<i>graecum</i> L. and <i>Lens culinaris</i> L. seeds

<p>The aim of this work was to evaluate some secondary metabolites, antioxidant activity of methanolic leaf extracts of five <i>Ziziphus spina</i>-<i>christi</i> provenances (INRGREF, Tozeur, Degueche, Nafta and Kebelli) and their allelopathic effects on <i>Trigonella foenum</i>-<i>graecum</i> and <i>Lens culinaris</i>. Leaves were collected during 2013 and 2014. Total phenols, flavonoids, tannins and antioxidant activity were evaluated using the Folin ciocalteux, Aluminum trichloride, vanillin and scavenging activity on 22-diphenyl-1-picrylhydrazyl (DPPH) radical methods, respectively. Total phenols, tannins and flavonoids were present, at levels of 57.41 mg GAE/g DW, 31.98 mg RE/g DW and 14.68 μg CE/g DW, respectively. The high antioxidant activity (0.086 μg/mL) was noted in kebelli provenance (2013). The highest germination, plumule and radicle lengths of tested species were observed in INRGREF provenance. <i>Z. spina</i>-<i>christi</i> leaf extracts may be suggested in foods and pharmaceutical industries. Leaf extracts could also provide a natural herbicide with a positive impact on the environment.</p

Chemical composition, antioxidant and cytotoxic activities of Onopordum acanthium L. Crude oil and defatted meal

In the present study, the seed oil from Onopordum acanthium. L and methanolic extract of the defatted meal were evaluated for their cytotoxic effect and antioxidant potential. The phenolic composition of the defatted meal was determined with RP-HPLC-UV and tocopherols levels in the crude oil were also assessed. Overall, the methanolic extract exhibited the best amount of total phenolics and flavonoids content (78.06±0.55 mg GAE/g on DW basis and 20.38±0.21 mg RE/g on DW basis, respectively).Seven phenolic compounds were identified with cinnamic acids as the major components (67.2%) and epicatechin was the dominant flavan-3-ol. Additionally, three individual tocopherols were determined and α-tocopherol was the main isomer (914.8±0.02mg/kg). Data of antioxidant performance showed superior antioxidant capacity in methanol extract. Moreover methanolic extract from defatted seeds was more active towards HepG2 cancer cells than the crude oil(IC50 of 44.05±3.54µg/ml) and showed less cytotoxicity towards AML12 normal hepatocytes in comparison to doxorubicin indicating at least some tumor-specific action