Benzylamine antioxidants: relationship between structure, peroxyl radical scavenging, lipid peroxidation inhibition and cytoprotection

1993 ◽  
Vol 36 (9) ◽  
pp. 1262-1271 ◽  
Author(s):  
Melvin J. Yu ◽  
Jefferson R. McCowan ◽  
Lee A. Phebus ◽  
Richard D. Towner ◽  
Peter P. K. Ho ◽  
...  
Food Research ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 288-293
Author(s):  
Riyanto ◽  
Ch. Wariyah

Aloe vera contains a phenolic compound that has bioactive activity. Previous research showed that microencapsulation of aloe vera powder with maltodextrin as an encapsulation agent produced instant aloe vera with high antioxidative activity. The problem was the hygroscopic instant caused rapid moisture and oxygen absorption during storage, therefore decreasing the instant aloe vera antioxidative activity periodically. The aim of this research was to evaluate the antioxidative activity stability of instant aloe vera during storage. The processing of instant aloe vera through a reconstituted aloe vera powder with water with a ratio of 1:120 and then added with 2.5% maltodextrin as the encapsulating agent. The solution was then inserted into a spray dryer with an inlet temperature of 130oC, an outlet temperature of 103oC, and the flow rate of the solution is 350.0 mL/h. The resulted instant aloe vera was divided into 15 packs with a weight of 25 g, and each sample was wrapped with polyethylene plastic film with 0.80 mm thickness and then was stored at 25oC with a relative humidity of 75%. The sample was conducted in triplicate. The moisture content, and antioxidative activity that was based on the ability to capture 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical (RSA) and lipid peroxidation inhibition were analyzed every week until the critical condition was achieved at a moisture level of 12%. The research showed that the radical scavenging activity (RSA) and lipid peroxidation inhibition of instant aloe vera before storage were 16.34±1.22% and 39.33±1.68%, respectively, whereas in the critical condition the RSA was 3.63±0.04% and the lipid peroxidation inhibition was 22.31±0.02%. Based on their antioxidative activity, the appropriate storage time of instant aloe vera was about 12 weeks in polyethylene plastic film of 0.08 mm thickness


2009 ◽  
Vol 4 (9) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Mehmet Öztürk ◽  
Ufuk Kolak ◽  
Mehmet Emin Duru ◽  
Mansur Harmandar

The aerial parts of Micromeria juliana (L.) Bentham ex Reichb. were extracted with light petroleum, acetone and methanol, successively. The antioxidant activity of different concentrations of the extracts was evaluated using different antioxidant tests, namely total antioxidant (lipid peroxidation inhibition activity), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, ferric reducing power, and metal chelating. Total antioxidant activity was determined using the β-carotene-linoleic acid assay. Unexpectedly, the light petroleum extract exhibited strong lipid peroxidation inhibition activity. The extract was fractionated on a silica gel column and the antioxidant activity of the fractions was determined by the β-carotene-linoleic assay at 25 μg/mL concentration. The fractions that exhibited more than 50% inhibition activity were analysed by GC and GC/MS; thus, the structure of fourteen compounds were elucidated. In addition, acetyl- and butyrylcholinesterase inhibitory activities of the extracts were also determined in vitro. The light petroleum and acetone extracts were found to have mild butyrylcholinesterase inhibitory activity.


2010 ◽  
Vol 156-157 ◽  
pp. 1372-1377 ◽  
Author(s):  
Cheng Chu Liu ◽  
Guo Ling Zhao ◽  
Ya Ning Li ◽  
Zhuo Ping Ding ◽  
Qi Gen Liu ◽  
...  

The polyphenol and flavonoid contents and antioxidation capabilities, including total reducing power, DPPH radical scavenging capability and lipid peroxidation inhibition, of ethanol extracts of water hyacinth (Eichhomia crassipes) were investigated and compared with those extracted from red tide seaweed (Enteromorpha prolifera) and from the most common seaweed (Porphyra haitanensis). Results showed that E. crassipes contained higher amounts of polyphenols [6.68 mg gallic acid equivalents (GAE)/g] in the leaf than in the stem (4.37 mg GAE/g) or in P. haitanensis (4.27 mg GAE/g). The E. crassipes also contained higher contents of flavonoids [1524 and 453 mg rutin equivalents (RE)/g in leaf and stem, respectively] than did E. prolifera (233 mg RE/g). Accordingly, both the leaf and stem of E. crassipes had relatively higher reducing power [118.35 and 47.21 100μg ascorbic acid equivalents (AscAE)/g, respectively] and DPPH radical scavenging capability (74.6% for leaf and 62.7% for stem) when compared with E. prolifera (reducing power of 16.5 and DPPH radical scavenging capability of 42.96%). Statistical analysis showed that the antioxidation capabilities, especially reducing power, of extracts of the three aquatic plants were positively correlated with their total polyphenol contents, but not with the contents of flavonoids. The correlation coefficient (r) of the content of polyphenols and reducing power of those extracts was r=0.9028, that for DPPH scavenging and lipid peroxidation inhibition was r=0.9311 and 0.9099, respectively. These results indicated that phenolic compounds are the main compounds contributing to the antioxidation activities of seaweed extracts. E. crassipes can be a source for extracting natural antioxidants.


2003 ◽  
Vol 9 (5) ◽  
pp. 339-346 ◽  
Author(s):  
Nalin Siriwardhana ◽  
K.-W. Lee ◽  
Y.-J. Jeon ◽  
S.-H. Kim ◽  
J.-W. Haw

Water and organic extracts (diethyl ether, chloroform, ethyl acetate, acetone, ethanol and methanol) obtained from Hizikia fusiformis were screened on reactive oxygen species (ROS) scavenging assays (1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, hydrogen peroxide and hydroxyl radical) and lipid peroxidation (inhibition of linoleic acid oxidation) inhibitory assays. Water, methanol and ethanol extracts showed significant ROS radical scavenging activities. Water extracts showed high scavenging activities on hydrogen peroxide (around 76%) and DPPH radicals (around 75%) while it presented a moderate scavenging activity on hydroxyl radicals (around 54%). Comparatively higher ROS scavenging activities were recorded in hydroxyl radical and DPPH scavenging assays. DPPH radical scavenging activities were well correlated with the polyphenolic content. ROS scavenging and lipid peroxidation inhibition activities indicated that H. fusiformis might be a valuable natural antioxidative source containing both water and fatsoluble antioxidative components.


2019 ◽  
Vol 18 (3-4) ◽  
pp. 140-147
Author(s):  
R. Salam ◽  
R. Rafe

Grewia abutilifolia (Tiliaceae) tree is known for its uses in traditional medicine due to its various degrees of ethno-pharmacological activities. In this study, Grewia abutilifolia was evaluated for its in vitro antioxidant activities; further, flavonoids, flavonols, total phenolic content and proanthocyanidins content were determined to justify its uses against various oxidative stresses.We evaluated antioxidant activity by determining total antioxidant, Fe3+ reducing power, DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radical scavenging, and lipid peroxidation inhibition activity. Aqueous fraction (AQF) contained highest total phenolic content (238.56 mg of gallic acid equivalent/g). Crude methanolic extract (CHE) contained maximum flavonoid (211.54 mg) and flavonols (380.25 mg) content equivalent to quercetin which showed significant reducing activity. Proanthocyanidins content was highest in petroleum ether fraction (PEF), 45.89 mg of catechin equivalent per gram. PEF showed maximum activity in DPPH scavenging assay (IC50 = 3.82 ± 0.055 μg/ml) and in hydroxyl radical scavenging assay (IC50, concentration required to inhibit the process by half, of 6.45 ± 1.297 μg/ml). Lipid peroxidation inhibition activity was also performed in the test chloroform fraction (CLF), which showed the highest inhibition (IC50 = 15.62 ± 1.31 μg/ml). These results suggested its potentiality against various diseases related to oxidative stress.


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