Search results for "DPPH"
showing 10 items of 137 documents
Polish Yellow Sweet Clover (Melilotus officinalis L.) Honey, Chromatographic Fingerprints, and Chemical Markers
2017
A case study of Polish Melilotus officinalis honey was presented for the first time. Gas chromatography–mass spectrometry (GC-MS) (after steam distillation, Soxhlet extraction, ultrasonic solvent extraction, and solid phase extraction (SPE)) and targeted high performance liquid chromatography with a photodiode array detector (HPLC-PAD) were applied to determine the characteristic components of honey. While ubiquitous in most honeys, carbohydrates, terpene derivatives, and phenylacetic acid dominated in the Soxhlet extracts (25.54%) and in the application of SPE (13.04%). In addition, lumichrome (1.85%) was found, and may be considered as a marker of this honey. Due to the presence of these …
Chromatographic fingerprint, antioxidant activity, and colour characteristic of polish goldenrod (Solidago virgaurea L.) honey and flower
2018
In recent times, the nutraceutical and pharmaceutical interest in honey due to its well-known health properties has increased. Consumers need clear and precise information, so that they can make informed choices about their diet and the foods they buy. Therefore, gas chromatography–mass spectrometry (GC–MS) and high-performance liquid chromatography with a photodiode array detector (HPLC-PAD) was revealed a general characteristic fingerprint of polish monofloral goldenrod honey and flowers. In addition, high-performance thin-layer chromatography (HPTLC) has proven to be a useful tool for determining similarity patterns of common bands among honey from the same floral source and thus can be …
Phytochemical Constituents, Antioxidant Activity, and Toxicity Assessment of the Aerial Part Extracts from the Infraspecific Taxa of Matthiola frutic…
2021
In a project designed to investigate the specific and infraspecific taxa of Matthiola endemic to Sicily (Italy) as new potential sources of bioactive compounds in this work, the infraspecific taxa of Matthiola fruticulosa were studied, namely, subsp. fruticulosa and subsp. coronopifolia. HPLC–PDA/ESI–MS and SPME–GC/MS analyses of hydroalcoholic extracts obtained from the aerial parts of the two subspecies led to the detection of 51 phenolics and 61 volatile components, highlighting a quite different qualitative–quantitative profile. The antioxidant properties of the extracts were explored through in vitro methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power and Fe2+ chelating activ…
Phytochemical profile and bioactivity of traditional ayurvedic decoctions and hydro-alcoholic macerations of Boerhaavia diffusa L. and Curculigo orch…
2015
Decoctions (DECs) and hydro-alcoholic extracts (HEs) prepared from roots of Boerhaavia diffusa L. (Nyctaginaceae) and Curculigo orchioides Gaertn. (Hypoxidaceae) were phytochemically characterised by HPLC-DAD and profiled for their antioxidant, antigenotoxic and cytotoxic activities. B. diffusa DEC was rich in ferulic acid and vanillin, while the HE also contained boeravinone B and eupalitin. Both C. orchioides HE and DEC displayed the main occurrence of orcinol-β-d-glucoside and curculigoside A. Antioxidant activity was assayed through spectrophotometric DPPH, ABTS and β-carotene bleaching test, and using (HP)TLC bioautographic strategies. For both crude drugs, HE was the best performing p…
Chemical analysis and antioxidant activity of the essential oils of three Piperaceae species growing in the central region of Cuba.
2013
The present study describes the phytochemical profile and antioxidant activity of the essential oils of three Piperaceae species collected in the central region of Cuba. The essential oils of Piper aduncum, P. auritum and P. umbellatum leaves, obtained by hydrodistillation, were analyzed by gas chromatography-mass spectrometry. The main components of P. aduncum oil were piperitone (34%), camphor (17.1%), camphene (10.9%), 1,8-cineol (8.7%) and viridiflorol (7.4%), whereas that of P. auritum and P. umbellatum was safrole (71.8 and 26.4%, respectively). The antioxidant properties of the essential oils were also evaluated using several assays for radical scavenging ability (DPPH test and redu…
Isolation and identification of new anthraquinones from Rhamnus alaternus L and evaluation of their free radical scavenging activity
2018
From the butanolic and the ethyl acetate extracts of Rhamnus alaternus L root bark and leaves, three new anthraquinone glycosides, alaternosides A-C (1,4,6,8 tetrahydroxy-3 methyl anthraquinone 1-O-ß-D-glucopyranosyl-4,6-di-O-α-L-rhamnopyranoside (1); 1,2,6,8 tetrahydroxy-3 methyl anthraquinone 8-O-ß-D-glucopyranoside (2) and 1, 6 dihydroxy-3 methyl 6 [2′-Me (heptoxy)] anthraquinone (3)) were isolated and elucidated together with the two known anthraquinone glycosides, Physcion-8-O-rutinoside (4) and emodin-6-O-α-L-rhamnoside (5) as well as with the known kaempferol-7-methylether (6), β-sitosterol (7) and β-sitosterol-3-O-glycoside (8). Their chemical structures were elucidated using spectr…
Traditionally used Thai medicinal plants: in vitro anti-inflammatory, anticancer and antioxidant activities.
2009
In order to assess traditional Thai claims about the therapeutic potential of medicinal plants and to select plants for future phytochemical research, nine plant species with anti-inflammatory uses were selected from Thai textbooks and assessed for their in vitro anti-inflammatory, antiproliferative and antioxidant activities.Nuclear factor-kappaB (NF-kappaB) inhibitory effects in stably transfected HeLa cells were determined by luciferase assay, and effects on LPS-induced pro-inflammatory mediators prostaglandin E2 (PGE2), interleukin (IL)-6, IL-1beta, and tumour necrosis factor (TNF)alpha in primary monocytes were assessed by ELISA. Cytotoxic activities were examined against HeLa cells, h…
Caffeate and piperidine-3-ol derivatives from the stem bark of Cassia sieberiana
2019
A new caffeate derivative from the ethanol extract of the stem bark of Cassia sieberiana DC. is described herein along with the known secondary metabolites spectaline (2), iso-6-cassine (3), 3-O-methyl-chiro-inositol (4), monobehenin (5), octyl nonadecyloate (6), β-sitosterol (7), stigmasterol (8) and sitosterol 3-O-β-D-glucopyranoside (9). The chemical structures were elucidated by means of various spectroscopic and spectrometric techniques. Extract and isolated compounds were devoid of inhibitory action against the herein selected bacterial strains (MICs > 256 μg/mL) but showed capacities to reduce 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (EC50 < 3 μg/mL) considerably better than the …
Antioxidant properties of polyphenol-rich cocoa products industrially processed
2010
Fermentation and roasting are the main causes of polyphenol degradation during the process for obtaining cocoa products. In the present study, a process for obtaining polyphenol-rich cocoa products on an industrial scale is described. The process avoids the fermentation and roasting steps and includes a step for the inactivation of the enzyme Polyphenol Oxidase (PPO), which helps preserve the polyphenol content present in the raw cocoa bean. In addition, our study evaluates the antioxidant capacity and characterizes the flavonoid profile of the polyphenol-rich cocoa products obtained from the natural polyphenolrich cocoa cake. Using different protocols, we have obtained three cocoa extracts…
Chemistry and functional properties in prevention of neurodegenerative disorders of five Cistus species essential oils.
2013
The chemical composition of Cistus creticus, Cistus salvifolius, Cistus libanotis, Cistus monspeliensis and Cistus villosus essential oils has been examined by GC and GC–MS analysis. Height-nine constituents were identified in C. salvifolius oil, sixty in C. creticus, fifty-six in C. libanotis, fifty-four in C. villosus, forty-five in C. monspeliensis. Although the five species belong to the same genus, the composition showed interesting differences. Essential oils were screened also for their potential antioxidant effects (by DPPH, ABTS, FRAP and b-carotene bleaching test) and their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity, useful for prevention and …