scholarly journals Phenolic Thiazoles with Antioxidant and Antiradical Activity. Synthesis, In Vitro Evaluation, Toxicity, Electrochemical Behavior, Quantum Studies and Antimicrobial Screening

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1707
Author(s):  
Gabriel Marc ◽  
Anca Stana ◽  
Ana Horiana Franchini ◽  
Dan Cristian Vodnar ◽  
Gabriel Barta ◽  
...  

Oxidative stress represents the underlying cause of many chronic diseases in human; therefore, the development of potent antioxidant compounds for preventing or treating such conditions is useful. Starting from the good antioxidant and antiradical properties identified for the previously reported Dihydroxy-Phenyl-Thiazol-Hydrazinium chloride (DPTH), we synthesized a congeneric series of phenolic thiazoles. The radical scavenging activity, and the antioxidant and chelation potential were assessed in vitro, a series of quantum descriptors were calculated, and the electrochemical behavior of the synthesized compounds was studied to evaluate the impact on the antioxidant and antiradical activities. In addition, their antibacterial and antifungal properties were evaluated against seven aerobic bacterial strains and a strain of C. albicans, and their cytotoxicity was assessed in vitro. Compounds 5a-b, 7a-b and 8a-b presented remarkable antioxidant and antiradical properties, and compounds 5a-b, 7a and 8a displayed good Cu+2 chelating activity. Compounds 7a and 8a were very active against P. aeruginosa ATCC 27853 compared to norfloxacin, and proved less cytotoxic than ascorbic acid against the human keratinocyte cell line (HaCaT cells, CLS-300493). Several phenolic compounds from the synthesized series presented excellent antioxidant activity and notable anti-Pseudomonas potential.

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Razmik Sargsyan ◽  
Arsen Gasparyan ◽  
Gohar Tadevosyan ◽  
Hovik Panosyan

AbstractDue to wide range of secondary metabolites, lichens were used from antiquity as sources of colorants, perfumes and medicaments. This research focuses on exploring the antioxidant, antimicrobial and cytotoxic activities of methanol, ethanol, acetone extracts and aqueous infusions of corticolous lichens sampled from Armenia. Methanol, ethanol and acetone extracts from all tested lichens were active against Gram-positive bacterial strains. The most effective solvent to retrieve antimicrobial compounds was methanol. Aqueous infusions of tested lichens didn’t show any significant antibacterial and antifungal activity. The highest antimicrobial activity was observed for methanol extract of Ramalina sinensis. The minimum inhibitory concentration of methanol extract of Ramalina sinensis were 0.9–1.8 mg mL− 1. Pseudevernia furfuracea demonstrated antifungal activity (Ø 12 mm). Methanol extract of Parmelia sulcata demonstrated largest 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity (71 %). The cytotoxicity was measured on human HeLa (cervical carcinoma) cell lines using microculture tetrazolium test assay. The IC50 values estimated for methanol extracts of Peltigera praetextata, Evernia prunastri, Ramalina sinensis and Ramalina farinacea species in HeLa cell line were within 1.8–2.8 mg mL− 1 and considered as non-cytotoxic. Obtained results suggest that studied lichens can be prospective in biotechnologies as alternative sources of antimicrobial and antioxidant substances.


2008 ◽  
Vol 63 (7-8) ◽  
pp. 483-491 ◽  
Author(s):  
Mortada M. El-Sayed ◽  
El-Sayed S. Abdel-Hameed ◽  
Wafaa S. Ahmed ◽  
Eman A. El-Wakil

The methanol extract of the leaves of Buddleja asiatica Lour. (Loganiaceae) showed antioxidant activity toward the well known in vitro antioxidant tests such as total antioxidant capacity by the phosphomolybdenum method, free radical scavenging activity by the 1,1- diphenyl-2-picrylhydrazyl scavenging assay (DPPH assay) and hydrogen peroxide scavenging methods. Due to the high scavenging activity of the n-butanol successive fraction toward DPPH and H2O2 (SC50 = 11.99 and 18.54 μg/ml, respectively), this extract was subjected to chromatographic separation and isolation. Four non-phenolic compounds were isolated and identified on the basis of spectroscopic and chemical analyses: 1-O-ß-D-glucopyranosyl- 2-methoxy-3-(2-hydroxy-triaconta-3,12-dienoate)-glycerol (1), 3-O-[α-l-rhamnopyranosyl- (1→4)-ß-d-glucopyranosyl-(1→3)]-[ß-d-glucopyranosyl-(1→2)]-ß-d-fucopyranosyl-olean- 11,13(18)-diene-3ß,23,28-triol (2), 3-O-[α-l-rhamnopyranosyl-(1→4)-ß-d-glucopyranosyl- (1→4)-ß-d-glucopyranosyl-(1→3)]-ß-d-fucopyranosyl-olean-11,13(18)-diene-3ß,23,28-triol (3), and 3-O-[α-l-rhamnopyranosyl-(1→4)-ß-d-glucopyranosyl-(1→3)]-[ß-d-xylopyranosyl- (1→2)]-ß-d-glucuronopyranosyl-acid-olean-11,13(18)-diene-3ß,23,28-triol (4). The four compounds were evaluated as antioxidant agents using the three antioxidant bioassay tests.


2008 ◽  
Vol 5 (s2) ◽  
pp. 1123-1132 ◽  
Author(s):  
H. Vijay Kumar ◽  
C. R. Gnanendra ◽  
Nagaraja Naik ◽  
D. Channe Gowda

Dibenz[b,f]azepine and its five derivatives bearing different functional groups were synthesized by known methods. The compounds thus synthesized were evaluated for antioxidant potential through different in vitro models such as (DPPH) free radical scavenging activity,ß-carotene-linoleic acid model system, reducing power assay and phosphomolybdenum method. Under our experimental condition among the synthesized compounds dibenz[b,f]azepine (a) and 10-methoxy-5H-dibenz[b,f]azepine (d) exhibited potent antioxidant activity in concentration dependent manner in all the above four methods. Butylated hydroxyl anisole (BHA) and ascorbic acid (AA) were used as the reference antioxidant compounds. The most active compounds like dibenz[b,f]azepine and its methoxy group substituent have shown more promising antioxidant and radical scavengers compared to the standards like BHA and ascorbic acid. It is conceivable from the studies that the tricyclic amines,i.e. dibenz[b, f]azepine and some of its derivatives are effective in their antioxidant activity properties.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4114
Author(s):  
Maria Fernanda Taviano ◽  
Emilia Cavò ◽  
Vivienne Spadaro ◽  
Francesco Maria Raimondo ◽  
Vincenzo Musolino ◽  
...  

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 activity assays. The results of the antioxidant tests showed that the extracts possess a different antioxidant ability: particularly, the extract of M. fruticulosa subsp. fruticulosa exhibited higher radical scavenging activity than that of subsp. coronopifolia (IC50 = 1.25 ± 0.02 mg/mL and 2.86 ± 0.05 mg/mL), which in turn displayed better chelating properties (IC50 = 1.49 ± 0.01 mg/mL and 0.63 ± 0.01 mg/mL). Lastly, Artemia salina lethality bioassay was performed for toxicity assessment. The results of the bioassay showed lack of toxicity against brine shrimp larvae for both extracts. The data presented indicate the infraspecific taxa of M. fruticulosa as new and safe sources of antioxidant compounds.


2010 ◽  
Vol 5 (7) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Baojun Shi ◽  
Wei Liu ◽  
Shao-peng Wei ◽  
Wen-jun Wu

The essential oil from the roots of Bupleurum longiradiatum, obtained by hydrodistillation was analyzed by gas chromatography/mass spectrometry (GC/MS) and evaluated for antimicrobial activity and antioxidant activity. Fifty-one compounds were identified, representing 99.3% of the total oil. The major constituents were thymol (7.0%), butylidene phthalide (6.8%), 5-indolol (5.6%), heptanal (5.3%), 4-hydroxy-2-methylacetophenone (5.3%), 4,5-diethyl-octane (5.3%), bormeol (5.1%) and hexanoic acid (5.1%). The oil was tested against 4 bacteria at different concentrations using disc diffusion and 96-well dilution methods. The inhibition zones and minimum inhibitory concentration values for bacterial strains were in the range of 7.0–18.0 mm and 250 −500 μg/mL, respectively. The in vitro antioxidant activity was assessed by DPPH radical scavenging and inhibition of lipid peroxidation methods. The oil showed a potent free radical scavenging activity, as evidenced by the low IC50 value for DPPH radical (566.2μg/mL) and inhibition of lipid peroxidation (induced by FeSO4, H2O2 and CCl4) with IC50 values of 275.2 μg/mL, 296.9 μg/mL and 118.7 μg/mL, respectively.


Author(s):  
Usmangani A. Attar ◽  
Savaliram G. Ghane

Objective: The aim of this study was to analyze phytochemicals, antioxidant potential and phenolic profiling of leaf and fruit extracts of Diplocyclos palmatus.Methods: The leaves and fruits were subjected for sequential extraction with hexane, chloroform, methanol and water. All extracts were subjected to biochemical studies such as phenols, tannins, flavonoids, terpenoids and antioxidant assays such as 1,1-diphenyl-1-picryl hydrazyl (DPPH), 2,2’ Azinobis (3-ethyl-benzothiozoline-6-sulfonic acid (ABTS), ferric reducing antioxidant property (FRAP), metal chelating and phospho- molybdenum reduction assay. Further methanolic extract was used for phenolics characterization by reversed phase-high performance liquid chromatography (RP-HPLC).Results: It was observed that methanol fruit extract showed significantly higher phenolics (9.29±0.01 mg tannic acid equivalent (TAE)/g extract), flavonoids (15.02±0.96 mg catechin equivalent (CE)/g extract) and terpenoids (276.73±0.76 mg ursolic acid equivalent (UAE)/g extract). However, chloroform extracts of leaf and fruit exhibited a high amount of tannins (22.07±0.06, 6.99±0.10 mg CE/g extract) respectively. The extracts were subjected to assess their antioxidant potential using various in vitro systems such as DPPH, ABTS, FRAP, metal chelating and phospho- molybdenum reduction. Among the various extracts, methanol fruit extract had highest DPPH radical scavenging activity (26.73±0.14 mg ascorbic acid equivalent (AAE)/g extract), metal chelating activity (0.80±0.01 mg EDTA equivalent (EE)/g extract) and phospho- molybdenum activity (291.24±2.19 mg AAE/g extract). In ABTS radical scavenging assay, aqueous leaf extract (12.11±0.07 mg trolox equivalent (TE)/g extract) showed the best response. The effective ferric reducing antioxidant property (141.54±10.12 mg Fe (II)/g extract) was exhibited by aqueous fruit extract. Overall, methanol and water were found to be the best solvents for the extraction of antioxidant compounds from fruit and leaf. In the RP-HPLC analysis, the major bioactive phenolic compounds such as catechin (CA) and hydroxybenzoic acid (HBA) were recorded in leaf as compared to fruit. In leaf, CA and chlorogenic acid (CLA) were principal compounds in leaf and fruit respectively. However, gallic acid (GA), HBA, CLA and vanillic acid (VA) were widespread in leaf and fruit. Conclusion: On the basis of the results, it was found that D. palmatus may serve as a novel and rich source of natural antioxidants and it can be further explored for pharmaceutical purposes.


2015 ◽  
Vol 10 (3) ◽  
pp. 639 ◽  
Author(s):  
Fatih Göger ◽  
Yavuz Bülent Köse ◽  
Gamze Göger ◽  
Fatih Demirci

<p class="Abstract">The aim of this study was to reveal the phytochemical constituents, antioxidant and antimicrobial activity of <em>Ajuga orientalis</em>. According to the antimicrobial results, the methanol extract of<em> A. orientalis</em> showed a MIC value of 312.5 µg/mL against the tested pathogenic bacterial strains. Anticandidal activity of extract was found as 156.3 µg/mL both against <em>Candida albicans</em> and <em>C. parapsilosis</em> strains. Whereas the extract was more effective against <em>C. tropicalis</em> with the MIC value of 78.1 µg/mL. The<em> in vitro</em> DPPH radical scavenging activity of the extract was determined as IC<sub>50</sub>=0.4 ± 0.02 mg/mL whereas the standard BHT IC<sub>50</sub> was 0.01 ± 0.00 mg/mL. Trolox Equivalent Antioxidant Capacity (TEAC) of extract was determined 1.3 mM TEAC, while BHT, 1.9 mM TEAC.</p><p> </p>


2017 ◽  
Vol 23 (4) ◽  
pp. 349-357 ◽  
Author(s):  
Szabolcs Molnár ◽  
Kata Mikuska ◽  
Katalin Patonay ◽  
Krisztina Sisa ◽  
Hussein G Daood ◽  
...  

The present paper reports about a comparative survey on the chemical composition, antioxidant activity and in vitro antimicrobial activity of selected propolis samples collected in Hungary. The total levels of polyphenolic compounds including flavonoids in ethanolic extracts of propolis were assessed. The major constituents of ethanolic extracts of propolis were analysed by gas chromatography/mass spectrometry analysis. Total phenolic content was determined spectrophotometrically using a Folin–Ciocalteu reagent. Free radical scavenging activities were evaluated by means of 2,2-diphenyl-1-picrylhydrazyl assay. In vitro inhibitory activity was investigated against eight different bacterial strains by agar well diffusion assay. An extensive comparison was carried out regarding general parameters and specific polyphenolic components. The experimental data led to the observation that there is considerable variability in terms of the quality and the biological value of the distinctive propolis samples. These findings confirm the hypothesis of the study; versatile experimental results are required for proper, well-reasoned, balanced and standardised industrial applications. The major flavonoid components were found to be chrysin and pinocembrin; however, versatile minor components were also detected. The total polyphenol content of ethanolic extracts of propolis ranged between 104.6 mg/g and 286.9 mg/g (gallic acid equivalent). The radical scavenging activity of ethanolic extracts of propolis varied between 101.7 mg/g and 286.9 mg/g (ascorbic acid equivalent). As the quality of propolis depends on the season, vegetation and the area of collection, marked differences were found among the different products examined in terms of both composition and general characteristics. The studied samples exhibited significant differences in term of antimicrobial activities.


2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Rahma Yulia ◽  
Dachriyanus Dachriyanus ◽  
Amri Bachtiar

This Study has tested the antioxidant activity of the extracts from Sida subcordata Span. Testing is done with antioxidant activity using DPPH method provides. Testing of antioxidant activity in vitro with spectrophotometric methods based on absorbance measurements radical DPPH (1,1-diphenylpicrylhydrazyl). All the extracts Showed radical scavenging activity. The ethyl acetate and methanol extracts were the most Appropriate as sources of antioxidant compounds as shown by Reviews their inhibition percentage (IP) values. Percentage inhibitor to extract ethyl acetate and methanol extract respectively 76.16% and 79.28% at a concentration of 1 mg / ml to 0.05 mM DPPH. while the results of the testing activities of antioxidant compounds y pure ethyl acetate extract fraction showed a smaller percentage inhibitor that is equal to 30% at the same concentration. Keyword - Sida subcordata Span, Malvaceae, Antioxidant, Alkaloid


2020 ◽  
Vol 10 (1) ◽  
pp. 41-45
Author(s):  
Reem Ghassan Alali ◽  
Mays Rizk Khazem

Germander (Teucrium, Lamiaceae) is a genus commonly used as a medicinal herb in the middle east. The aim of this study was to estimate total polyphenols and antioxidant activity of different extracts from two Syrian Teucrium species (Teucrium polium and Teucrium creticum). Total polyphenols content was measured using Folin-Ciocalteu assay and the antioxidant activity was evaluated in vitro by DPPH assay (free radical scavenging activity against 1, 1 –diphenyl-2-picrylhydrazyl). The total polyphenols content and antioxidant activity of T. creticum extracts were higher than T. polium ones. Phenols contents ranged from 16.388 to 105.672 mg GA E/ g dry weight extract. The extracts showed significant scavenging activity against DPPH, with IC50 values ranging between 0.195 and 0.710 mg/ml. The methanolic extracts show higher antioxidant activity from the two species. A good correlation between DPPH scavenging activities and contents of polyphenols was found. These results show that Syrian Teucrium species, especially T. creticum least Known among all, is a rich source of phenols and natural antioxidant compounds, that can be used as a natural food preservative.


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