scholarly journals Secondary Metabolites Profiling of Acinetobacter baumannii Associated with Chili (Capsicum annuum L.) Leaves and Concentration Dependent Antioxidant and Prooxidant Properties

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Tahmina Monowar ◽  
Md. Sayedur Rahman ◽  
Subhash J. Bhore ◽  
Gunasunderi Raju ◽  
Kathiresan V. Sathasivam

Secondary bioactive compounds of endophytes are inevitable biomolecules of therapeutical importance. In the present study, secondary metabolites profiling of an endophytic bacterial strain, Acinetobacter baumannii, were explored using GC-MS study. Presence of antioxidant substances and antioxidant properties in chloroform (CHL), diethyl ether (DEE), and ethyl acetate (EA) crude extracts of the endophytic bacteria were studied. Total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferrous ion chelating assay were evaluated. A total of 74 compounds were identified from the GC-MS analysis of the EA extract representing mostly alkane compounds followed by phenols, carboxylic acids, aromatic heterocyclic compounds, ketones, aromatic esters, aromatic benzenes, and alkenes. Among the two phenolic compounds, namely, phenol, 2,4-bis(1,1-dimethylethyl)- and phenol, 3,5-bis(1,1-dimethylethyl)-, the former was found in abundance (11.56%) while the latter was found in smaller quantity (0.14%). Moreover, the endophytic bacteria was found to possess a number of metal ions including Fe(II) and Cu(II) as 1307.13 ± 2.35 ppb and 42.38 ± 0.352 ppb, respectively. The extracts exhibited concentration dependent antioxidant and prooxidant properties at high and low concentrations, respectively. The presence of phenolic compounds and metal ions was believed to play an important role in the antioxidant and prooxidant potentials of the extracts. Further studies are suggested for exploring the untapped resource of endophytic bacteria for the development of novel therapeutic agents.

2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Elizabeth Sánchez ◽  
Marisa Piovano ◽  
Erika Valdés ◽  
Manuel E. Young ◽  
Cristian A. Acevedo ◽  
...  

Radical scavenging activity (RSA), antioxidant content (TEAC), total phenolic compounds content (TPCC) and volatile profile (VOCs) were measured in 26 honeys obtained from the Valparaíso Region (Chile). Persea americana honey was the most interesting sample according to these evaluated parameters. A Projection to Latent Structures (PLS) based algorithm was used to model the possible relationship between antioxidant activity, total phenolic compounds content and volatile profile. Concerning the volatile profile, only nine volatile compounds, of a total of fifty, showed dependence on antioxidant activity and total phenolic compounds content.


Food Research ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 438-445
Author(s):  
M. Roy ◽  
M.Z.H. Imran ◽  
M. Alam ◽  
M. Rahman

The effects of two processing methods (boiling and roasting) on physicochemical qualities of dark red kidney bean (Phaseolus vulgaris) were investigated. Changes in total polyphenol content (TPC) and antioxidant activity due to processing were also analyzed by using Folin–Ciocaltue method and 1,1 diphenyl-2-picrylhydrazyl (DPPH) assay, respectively. Analysis of physicochemical properties exhibited substantial variations (p<0.05) in the levels of moisture, ash, protein, fat, carbohydrate, gross energy and pH of raw and processed beans. Meanwhile, there was no considerable difference (p<0.05) in the fibre content of fresh and processed beans. Investigation of total phenolic content showed the significant (p<0.05) reduction of phenolic compounds in boiled (5.53±0.74 mg GAE/ g) and roasted (8.15±1.60 mg GAE/g) beans than raw samples (12.55±1.42 mg GAE/g). DPPH radical scavenging activity was also decreased significantly (p<0.05) in boiled and roasted samples with IC50 value of 0.0608±0.0765 mg/mL and 0.0523±0.0026 mg/mL, respectively. In the case of household cooking, keeping boiling water would be advised for the preservation of minerals, vitamins and phenolic compounds. The roasting process may be used to develop high-quality health-promoting dark red kidney bean products.


2017 ◽  
Vol 12 (11) ◽  
pp. 1934578X1701201 ◽  
Author(s):  
Emmanuel Atsalakis ◽  
Ioanna Chinou ◽  
Maria Makropoulou ◽  
Sofia Karabournioti ◽  
Konstantia Graikou

This study was carried out to evaluate the antioxidant properties of Greek endemic Cistus creticus L. (rock rose) bee pollen and define its phenolic compounds. In the framework of our scientific studies on Greek bee keeping products, we report herein our research on three Greek bee pollen samples from Cistus. Their pollinic spectra were obtained by Louveaux's quantitative microscopical analysis and it showed that one of them had Cistus sp. (Cistaceae) as abundant pollen (together with low percentage of Brassica sp. (Cruciferae). Throughout the chemical analysis of the extracts, several secondary metabolites of flavonoid structure have been identified as major components. Specifically, quercetin-7-rhamnoside (1), quercetin-3-neohesperidoside (2), kaempferol-3-neohesperidoside (3), myricetin-3-neohesperidoside (4), kaempferol-3-glucoside (5) and quercetin-3-glucoside (6) have been isolated and their structures were elucidated on the basis of spectral evidence. Moreover, the total phenolic and flavonoid content was estimated and the free radical scavenging activity was determined by DPPH and ABTS assays. The antimicrobial activity of the extracts was tested against six Gram-positive and -negative bacteria and three pathogenic fungi, and the butanol extract showed a very interesting broad antimicrobial profile (MIC 1.98•10−3 - 2.98•10−3 mg/ml) against all the assayed microorganisms.


2020 ◽  
Vol 32 (12) ◽  
pp. 2985-2990
Author(s):  
Edi Suryanto ◽  
Mercy R.I. Taroreh ◽  
Lydia Irma Momuat

This study aimed to purify and characterize the antioxidant activity of liquid smoke acquired from corncobs. The smoke of crude liquids was generated through pyrolysis and was purified through fractional and simple distillation. The liquid smoke was analyzed using crude fibres, cellulose, hemicellulose, lignin, antioxidant activity and total phenolic compounds. Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the volatile compounds of liquid smoke. Fractional distillation exhibited the higher carbonyl and phenol content than simple distillation, and the overall acid content of fractional distillation was relatively lower. Moreover, the liquid smoke obtained from fractional distillation exhibited the higher total antioxidant and free radical scavenging activity than simple distillation. The GC-MS results showed different derivatives and phenolic compounds as the most dominant components of the liquid smoke of corncobs. The major antioxidant components of fractional distillation include 2-methoxyphenol, phenol, 2,5-dimethylphenol, 2-methylphenol, 2-methoxy-4-methylphenol, 4-ethyl-2-methoxyphenol and 4-ethylphenol, and those of simple distillation include phenol, 2-methylphenol, 2-methoxy- phenol, 2,6-dimethoxyphenol and 3-ethylphenol.


2021 ◽  
Vol 17 ◽  
Author(s):  
Jorgiane da Silva Severino Lima ◽  
Larissa Morais Ribeiro da Silva ◽  
Thatyane Vidal Fonteles ◽  
EvâniaAltina Teixeira de Figueiredo ◽  
Ana Erbênia Pereira Mendes ◽  
...  

Background: This study assessed the effects of solvent proportion, time, and power intensity of ultrasound processing on the extraction,bioaccessibility, antioxidant and antimicrobial activity of phenolic compounds (PC) from acerola (Malpighia glabra DC) coproduct (ACP). Methods: The ultrasound process with water as a solvent in a ratio of 1:2, power intensity of 75 W/cm2 during 10 min was selected as the optimal condition to provide higher extraction of the total phenolic compounds (4126 mg gallic acid.100 g-1 with total antioxidant activity of 98.62 μMTrolox.g-1). Power intensity and solid: solvent proportion were the parameters that increased the total PC quantification. The main phenolic compounds from the ACP tentatively identified by UPLC-ESI-QTOF-MS/MS were rutin, luteolin, and quercetin. Ultrasound extraction also improved antimicrobial activity against Listeria monocytogenes and Staphylococcus aureus(40 mg.L -1). Results: These results indicate that antioxidant and antimicrobial activities in the ACP phenolic extracts are quite potent and implicate the presence of compounds with potent free-radical-scavenging activity. Conclusion: It is possible to extract phenolic compounds from acerola coproducts using sustainable “green” technology, only using water as a solvent and ultrasound processing.


2020 ◽  
Vol 21 (3) ◽  
Author(s):  
Magdalena Woźniak ◽  
Lucyna Mrówczyńska ◽  
Anna Sip ◽  
Marta Babicka ◽  
Tomasz Rogoziński ◽  
...  

Introduction. Honey, propolis and pollen belong to bee products that have beneficial biological properties. These products exhibit e.g. antibacterial, antifungal and antioxidant properties. Due to biological activity and natural origin, bee products are used, e.g. in the food industry, cosmetology and pharmacy. Aim. The aim of the study was to compare the antioxidant and antibacterial activity of honey, propolis and pollen from an apiary located in Wielkopolska Province. Material and methods. Honey, propolis and pollen used in this study came from the same apiary located in Wielkopolska Province. The antioxidant potential of bee products was evaluated applying DPPH· free radical scavenging activity assay. The antimicrobial activity of the tested bee products was determined by the point-diffusion method against 13 strains of pathogenic and potentially pathogenic bacteria. In addition, the total content of phenolic compounds in honey, propolis and pollen was determined by the colorimetric method. Results. Propolis exhibited higher antioxidant activity, in comparison to honey and pollen. The antiradical activity of propolis was equal to 80% approx. activity of Trolox, the standard antioxidant. Among tested bee products, propolis was characterized by the highest total phenols content. In addition, honey, propolis and pollen showed antagonistic activity against tested bacterial strains. Conclusions. The obtained results indicate that among the tested bee products of native origin, i.e. honey, propolis and pollen, propolis characterized by the highest antioxidant activity and the total content of phenolic compounds. In addition, all bee products showed bactericidal activity against the tested bacterial strains.


2021 ◽  
Vol 17 ◽  
Author(s):  
Brahim Asseli ◽  
Reguia Mahfoudi ◽  
Amar Djeridane ◽  
Mohamed Yousfi

Background: Research on medicinal plant antioxidants has emerged as a potential therapeutic to prevent free radical generated damage in the human body. Hammada elegans Botsch (popularly known as “Ajram”) is a xerophytic plant widely found in Laghouat region, but there are only a few reports about the biological or chemical properties of these species. Hence, the aim of this study is to investigate the antioxidant and the antihemolytic activities of hexanic, acetonic, methanolic and aqueous extracts of aerial parts of Algerian Hammada elegans Botsch by employing different in vitro assay systems. Methods: The total phenolic content, the flavonoid content and the condensed tannin amount were analyzed using Folin-Ciocalteu, aluminum chloride and vanillin assays, respectively. The in vitro antioxidant capacity of extracts was assessed by CUPRAC, iron chelating, ABTS•+and antihemolytic assays, and was expressed as EC50 values. Results: Among the analyzed extracts, the aqueous extract had the highest phenolic, flavonoid and tannin contents. Also, this extract displayed the highest antioxidant capacities compared to the other extracts and standards. Its EC50 value for ABTS radical-scavenging activity was 0.265 ± 0.003 mg/L. Moreover, this extract showed high iron (II) chelating ability (EC50 = 0.958 ± 0.001 mg/L), and good antioxidant activity in the cupric ion reducing activity (CUPRAC) in a concentration dependent manner (EC50 were 0.709 ± 0.002 mg/L). Additionally, this extract had the best antihemolytic activity against AAPH-induced hemolysis (EC50=0.090 ± 0.004 mg/L). Conclusion: Our study revealed that the aqueous extract of Hammada elegans Botsch, is a potential source of antioxidants which possess a high protective effect of membrane against free radical.


2017 ◽  
Vol 71 (5) ◽  
pp. 361-370
Author(s):  
Slavica Grujic ◽  
Ana Dzamic ◽  
Violeta Mitic ◽  
Vesna Stankov-Jovanovic ◽  
P.D. Marin ◽  
...  

Antioxidant and free radical scavenging activity of methanol, ethanol, ethyl acetate and chloroform extracts of aerial parts of Lamium purpureum L. was determined by DPPH, ABTS, FRAP and TRP assays. Contents of flavonoids and phenols were also investigated. The total phenolic content in the extracts, determined using Folin?Ciocalteu assay, ranged between 8.57 to 128.00 mg GAE/g d.e. while concentrations of flavonoids in the extracts varied from 24.20 to 39.80 mg QuE/g d.e. The highest phenolic content was found in methanol extract (128.00 mg GAE/g d.e.). The highest content of total flavonoids was identified in the methanol extract (39.80 mg QuE/g d.e.) and the lowest was in the chloroform (24.30 mg QuE/g d.e.). DPPH scavenging of the extracts was determined and obtained IC50 values ranged from 0.12 to 3.12 mg/mL of solution. The values of ABTS radical scavenging activity ranged from 0.35 to 1.80 mg AA/g. The highest ABTS antiradical activity was registered for methanol extract. The FRAP value was found within the range 0.08 to 1.04 ?mol Fe/mg. The best radical scavenger was methanol (1.04 ?mol Fe/mg). In reducing power assay different extracts of L. purpureum showed increasing of activity with increased concentration, and all extracts possessed substantial dose dependent antioxidant activity. The best reducing capacity was obtained with methanol extract of L. purpureum (0.0132 mg AA/mL). The results in this study confirmed that L. purpureum possesses moderate antioxidant properties.


Botanica ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 76-87
Author(s):  
Aziza Lfitat ◽  
Hind Zejli ◽  
Abdelkamel Bousselham ◽  
Yassine El Atki ◽  
Badiaa Lyoussi ◽  
...  

AbstractWe conducted this study to determine and compare the content of phenolic compounds and flavonoids in the argan and olive leaves as well as their antioxidant capacity in aqueous, methanolic, and ethyl acetate extracted fractions. In vitro antioxidant activity was evaluated in comparison with synthetic antioxidants by assessing DPPH• radical scavenging capacity, ferric reducing antioxidant power, scavenging ability by inhibiting the β-carotene/linoleic acid emulsion oxidation, and by the ABTS radical scavenging activity assay. Total phenolic content in argan samples ranged from 221.69 ± 2.07 to 1.32 ± 0.01 mg GAE/g DW and in olive samples from 144.61 ± 0.82 to 1.21 ± 0.02 mg GAE/g DW. Total flavonoids content in argan samples varied from 267.37 ± 1.12 to 25.48 ± 0.02 mg QE/g DW, while in olives from 96.06 ± 0.78 to 10.63 ± 0.05 mg QE/g DW. In vitro antioxidant studies strongly confirmed the antioxidant potency of argan and olive leaves and their richness in secondary metabolites that are effective in free radicals scavenging and metal chelating capacities, indicating their antioxidant power.


2003 ◽  
Vol 128 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Md. Shahidul Islam ◽  
Makoto Yoshimoto ◽  
Koji Ishiguro ◽  
Shigenori Okuno ◽  
Osamu Yamakawa

The phenolic content and the radical scavenging activity were compared in leaves of sweetpotato (Ipomoea batatas L.) cultivars Shimon-1, Kyushu-119 and Elegant Summer grown under different temperature and shading conditions. Compared to cultivar differences, there was less effect of temperature and shading on the total phenolic content in sweetpotato leaves, however certain polyphenolic components differed widely among the treatments. The positive correlation between the radical scavenging activity and the level of total phenolics (r = 0.62) suggests that phenolic compounds are important antioxidant components of sweetpotato leaves. All the reverse-phase high-performance liquid chromatography (RP-HPLC) profiles of the cultivars tested showed peaks at the same retention times but peak areas of individual phenolic compounds differed with respective temperature and shading treatments. The phenolic compounds identified in the sweetpotato leaf were caffeic acid, chlorogenic acid, 4,5-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, 3,4-di-O-caffeoylquinic acid, and 3,4,5-tri-O-caffeoylquinic acid. Most of the phenolic compounds were highest in leaves from plants grown at 20 °C without shading except 4,5-di-O-caffeoylquinic acid. The results indicate that growing leaves under moderately high temperatures and in full sun enhances the accumulation of phenolic components. These phenolic components have possible value in enhancing human health.


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