Ion Reducing Antioxidant Capacity Research Articles

Physicochemical and Phytochemical Properties of Different Extracts of Sumac Plant (Rhus coriaria L.) Grown in Tunceli, Türkiye

In this study, sumac plant (Rhus coriaria L.) naturally grown in Tunceli (Türkiye) was collected from 5 different provinces and investigated for their phytochemical properties. In sumac samples, pH, color, ash amount, total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging capacity, metal chelating capacity, copper (II) ion reducing antioxidant capacity (CUPRAC), reducing power, mineral matter content, organic acids as tartaric acid, malic acid and citric acid, phenolic compounds as gallic acid, vanillic acid, caffeic acid, routine, resveratrol, (-)- epicatechin, and (+)- catechin hydrate contents were determined. The highest TPC was found in the acidified methanol extract (AME) and the DPPH free radical scavenging capacity was found in the acidified acetonitrile extract (AAE). It was determined that all extracts of sumac sample 5 (S5) collected from Pertek district, metal chelating capacity was higher than the other samples but lower than the metal chelating capacity of ethylene diamine tetra acetic acid (EDTA). CUPRAC was detected at the highest concentration of 118.0±3.0 mg caffeic acid equivalent kg-1 (mg CAE kg-1) in the AME, at the lowest 10.2±0.6 mg CAE kg-1 in the AAE for S5 sample. It was found that the reducing powers of all samples were found to be lower than the reducing power of synthetic antioxidants (butylhydroxytoluene (BHT), α tocopherol, and vitamin C), and the samples were rich in mineral substances, the predominant organic acid was malic acid, and phenolic compound was gallic acid.

Effects of Cold and Hot Infusions on Antioxidant Activities of Rosehip Tea Bag

In this study, the antioxidant activity values of infusions at different temperatures of the commercially sold rosehip tea bag. To determine the effect of different infusion temperatures on antioxidant activity, 7 different temperatures (0, 15, 30, 45, 60, 75, 90°C) also including cold infusions temperatures were selected. Infusions of the rosehip tea bags were prepared with packaged drinking water for 5 minutes (recommended time in tea bag packaging) at these temperatures. Antioxidant activity values of the infused extracts were determined by antioxidant activity determination methods: TPC (Total Phenolic Compound), CUPRAC (Cu (II) Ion Reducing Antioxidant Capacity), FRAP (Iron (III) Ion Reducing Antioxidant Power) and ABTS•+ (2.2-azinobis- (3-ethylbenzothiazoline-6-sulphonic acid)) radical scavenging assay. According to the results obtained by the antioxidant determination methods, the highest and lowest activity values for TPC, FRAP and ABTS were measured at 90°C and 0°C, respectively, and a positive correlation was found between temperature and antioxidant activity values. Contrary to the activity values determined in these methods, in the CUPRAC method, the highest and the lowest activity value was measured at 45°C and 90 °C, respectively. As determined in the CUPRAC method, infusions of rosehip tea at low temperatures may provide an advantage in terms of the solubility of some phenolics that can be denatured at high temperatures. In addition, rosehip tea infusions at lower temperatures will contribute to lower energy costs.

Investigation of Antioxidant Activities of Fruit, Leaf, and Branche Extracts of White (Morus alba L.) and Black (Morus nigra L.) Mulberry Species from Diyarbakır

This study aims to determine the antioxidant activities of fruit, leaf, and branche extracts of Morus alba L. and Morus nigra L. species collected from Diyarbakır. Different in vitro methods such as Total Phenol Content (TPC), Total Flavonoid Content (TFC), Copper (II) Ion Reducing Antioxidant Capacity (CUPRAC), 2,2´-diphenyl-1-pikrilhidrazil (DPPH), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging methods were used to evaluate the antioxidant activities of the two Morus species. The highest total phenolic amount belongs to acetone extract (257.5±0.05 μg gallic acid equivalent mg-1) obtained from M. nigra branches, while the highest total flavonoid content was found in acetone extract (185.8±0.15 μg catechin equivalent mg-1) obtained from M. nigra leaves. In the CUPRAC test, the highest activity was observed in methanol extracts from M. alba branches (IC50 values is 35.63±0.22 μg mg-1). The IC50 values of the DPPH radical scavenging activity of the extracts are between 128.1±0.13 and 2494.7±0.30 μg mg-1, the best radical scavenging activity was demonstrated by acetone extract (128.1±0.13 μg mg-1) prepared from the M. alba branche. The highest ABTS radical scavenging activity belongs to the methanol extract (75.5±0.25 μg mg-1) obtained from the M. alba branches. The results prove that both Morus species possess antioxidant properties, not only in leaves and fruits but also in the branches. At the end of the study, it was determined that M. alba and M. nigra have medicinal usage value which can be used as natural antioxidants.

Investigation of the Biological Activities of Different Extracts from Dipsacus laciniatus Aerial Parts

Background: The aerial parts of Dipsacus laciniatus are traditionally used in the treatment of colds as cold tea; decoction prepared from its roots and aerial parts are used for the treatment of diabetes and cancer, respectively. The extraction procedures and solvents are important steps in the processing of bioactive constituents from the plant materials. Objective: The aim of this study was to evaluate in vitro antioxidant, antimicrobial, anticholinesterase and cytotoxic activities for the first time in plant’s different extracts. Methods: The antioxidant activities of extracts were examined using FRAP and CUPRAC methods, including total phenolic and flavonoids contents. In addition, the antimicrobial, anticholinesterase and cytotoxic activities of extracts were investigated using microdilution, Ellman and MTT methods, respectively. Results: In the present study, methanol extract showed stronger iron (III) ion reduction (FRAP) and copper (II) ion reducing antioxidant capacity (CUPRAC) than other extracts and also contained higher total phenolic and flavonoid compounds. It was also found that there was a linear relationship between antioxidant activity and phenolic compounds in this study. It was demonstrated that the chloroform and methanol extracts showed moderate antimicrobial activity against S. epidermidis and C. albicans strains. The chloroform extract had a strong and selective cytotoxic activity for the MCF-7 and HT-29 cell lines, while the methanol extract showed low cytotoxic activity on the same cell lines. In addition, according to the obtained data, chloroform extract showed a toxic effect on normal cell line (NIH/3T3), but other extracts showed no toxic effect. Conclusion: Since methanol extract has no toxic effect on normal cell line and has strong antioxidant, anticholinesterase and antimicrobial activity, it is thought that this extract may be useful as an antioxidant, anticholinesterase and antimicrobial agents in the future.

Heterocyclic β-keto sulfide derivatives of carvacrol: Synthesis and copper (II) ion reducing capacity.

Sixteen β-keto sulfide derivatives of carvacrol (4-19) incorporating phenyl or N, O and S heterocyclic moieties were synthesized in three steps. The relationships between heterocyclic structure and cupric, Cu(II), ion reducing antioxidant capacity (CUPRAC) were examined. Nine of the compounds (8-9 and 13-19) showed better CUPRAC activity than trolox at neutral pH, with trolox equivalent antioxidant capacity (TEAC) coefficients ranging between 1.20 and 1.75. Two derivatives (11-12) showed comparable reducing capacity to trolox, with TEAC values of 0.95 for 11 and 1.02 for 12. Compounds 8-9 and 11-19 were more effective at reducing the Cu(II) ion than ascorbic acid and the parent compound, carvacrol. The most effective antioxidants were those containing an oxadiazole, thiadiazole or triazole moiety. In particular, the methyl thiadiazole derivative (15) had the highest Cu(II) ion reducing capacity, with a TEAC coefficient of 1.73.