scholarly journals Antioxidant and Fluorescence Properties of Hydrogenolyzised Polymeric Proanthocyanidins Prepared Using SO42−/ZrO2 Solid Superacids Catalyst

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2445 ◽  
Author(s):  
Liwen Ni ◽  
Fanbin Zhao ◽  
Bolun Li ◽  
Tong Wei ◽  
Hang Guan ◽  
...  

Larix bark oligomeric proanthocyanidins (LOPC) were prepared from larix bark polymeric proanthocyanidins (LPPC) by catalytic hydrogenolysis using SO42−/ZrO2 solid superacid as the catalyst. The catalyst to polymeric proanthocyanidins ratio was 0.2:1 (m/m). The LOPC, obtained after hydrogenolysis at 100 °C for 4 h under 3 MPa hydrogen pressure, retained the structural characteristics of proanthocyanidins. The average degree of polymerization was reduced from 9.50% to 4.76% and the depolymerization yield was 53.85%. LOPC has good antioxidant properties and, at the same concentration, the reducing ability of LOPC was much higher than that of LPPC. The IC50 values of LOPC for scavenging DPPH• and ABTS•+ radicals were 0.046 mg/mL and 0.051 mg/mL, respectively. LOPC is biocompatible and has fluorescent properties that are affected by external factors, such as solvent polarity, pH and the presence of different metal ions. These features indicate that LOPC could be developed as a new biological fluorescent marker. The depolymerization of low-value polymeric proanthocyanidins to provide high-value oligomeric proanthocyanidins and the development of new applications for proanthocyanidins represent significant advances.

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 329
Author(s):  
Daniel Chavarria ◽  
Ophelie Da Silva ◽  
Sofia Benfeito ◽  
Sandra Barreiro ◽  
Jorge Garrido ◽  
...  

Neurotransmitter depletion and mitochondrial dysfunction are among the multiple pathological events that lead to neurodegeneration. Following our previous studies related with the development of multitarget mitochondriotropic antioxidants, this study aims to evaluate whether the π-system extension on the chemical scaffolds of AntiOXCIN2 and AntiOXCIN3 affects their bioactivity and safety profiles. After the synthesis of four triphenylphosphonium (TPP+) conjugates (compounds 2–5), we evaluated their antioxidant properties and their effect on neurotransmitter-metabolizing enzymes. All compounds were potent equine butyrylcholinesterase (eqBChE) and moderate electric eel acetylcholinesterase (eeAChE) inhibitors, with catechols 4 and 5 presenting lower IC50 values than AntiOXCIN2 and AntiOXCIN3, respectively. However, differences in the inhibition potency and selectivity of compounds 2–5 towards non-human and human cholinesterases (ChEs) were observed. Co-crystallization studies with compounds 2–5 in complex with human ChEs (hChEs) showed that these compounds exhibit different binging modes to hAChE and hBChE. Unlike AntiOXCINs, compounds 2–5 displayed moderate human monoamine oxidase (hMAO) inhibitory activity. Moreover, compounds 4 and 5 presented higher ORAC-FL indexes and lower oxidation potential values than the corresponding AntiOXCINs. Catechols 4 and 5 exhibited broader safety windows in differentiated neuroblastoma cells than benzodioxole derivatives 2 and 3. Compound 4 is highlighted as a safe mitochondria-targeted antioxidant with dual ChE/MAO inhibitory activity. Overall, this work is a contribution for the development of dual therapeutic agents addressing both mitochondrial oxidative stress and neurotransmitter depletion.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2891 ◽  
Author(s):  
Xiao Chen ◽  
Jia Xiong ◽  
Shenlin Huang ◽  
Xun Li ◽  
Yu Zhang ◽  
...  

The proanthocyanidins from ethanol extracts (80%, v/v) of Acacia mearnsii (A. mearnsii) bark on chemical-based and cellular antioxidant activity assays as well as carbolytic enzyme inhibitory activities were studied. About 77% of oligomeric proanthocyanidins in ethanol extracts of A. mearnsii bark were found by using normal-phase HPLC. In addition, HPLC-ESI-TOF/MS and MALDI-TOF/TOF MS analyses indicated that proanthocyanidins from A. mearnsii bark exhibited with a degree of polymerization ranging from 1 to 11. These results of combined antioxidant activity assays, as well as carbolytic enzyme inhibitory activities of proanthocyanidins from A. mearnsii bark, indicated an encouraging antioxidant capacity for the high polyphenol content and a potential for use as alternative drugs for lowering the glycemic response.


Author(s):  
Kavitha S ◽  
Parthasarathi Perumal

 Objective: The present study was undertaken to assess the α-amylase inhibitory activity and antidiabetic experimental catfish model and antioxidant properties of Piper betle L. ethanolic (PBE) extract.Methods: The phytochemical analysis of PBE extract was performed. The PBE extract was tested for their inhibitory effect on the α-amylase assay, which compared to the control, acarbose. The absorbance was read at 540 nm using a spectrophotometer, and IC50 values were calculated. In this present investigation, diabetes mellitus was induced in catfish, Clarias gariepinus by epaxial musculature injection to glucose and standard drug, Metformin hydrochloride. After 24-h incubation, the treated fishes were dissected, and the blood, liver, tissue samples, and epaxial musculature regions were collected. In addition, the antioxidant properties of PBE were determined by 2,2-diphenyl-l-picrylhydrazyl (DPPH) radical scavenging and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging (ABTS) assays.Results: The phytochemical screening of PBE revealed the presence of alkaloid, flavonoids, tannins, phenol, glycosides, sterols, saponins, and quinines. Furthermore, the values of (μg/ml) 3.038 and 7.672 α-amylase enzyme inhibition were excellent activity when compared to the acarbose. Moreover, elevated the glucose level (mg/dl) was estimated in blood 1.9±0.35, liver 0.5±0.25, tissue 0.2±0.25, and epaxial musculature 0.8±0.2 after 24-h incubation. The antioxidant effect of maximum activity was found in PBE; IC50 values (μg/ml) of DPPH and ABTS were 9.362 and 6.606, respectively.Conclusions: These studies might be responsible for the P. betle L. that was used as the new source of antidiabetic and antioxidant agents. 


2014 ◽  
Vol 10 (2) ◽  
pp. 2305-2316 ◽  
Author(s):  
Manel Ben Ali ◽  
Kais Mnafgui ◽  
Abdelfattah Feki ◽  
Mohamed Damak ◽  
Noureddine Allouche

Diabetes mellitus is a serious health problem worldwide that has adverse and long-lasting consequences for individuals, families, and communities. Hence, this study sought to investigate the inhibitory potential of rosemary extracts on key-enzymes related to diabetes such as α-amylase and pancreatic lipase activities, as well as to assess their antioxidant properties in vitro. The IC50 values of Rosemary essential oil, ethyl acetate and methanolic extracts against α-amylase were 28.36, 34.11 and 30.39 µg/mL respectively, and those against pancreatic lipase were 32.25, 36.64 and 34.07 µg/mL, suggesting strong anti-diabetic and anti-obesity effects of Rosemary. The methanolic extract was found to be the highest in levels of phenolic (282.98 µgGAE/mg extract) and flavonoids (161.05 µg QE /mg extract) contents as well as in the antioxidant activity (IC50 = 15.82 µg/mL) as compared to other extracts ethyl acetate (IC50 = 32.23 µg/mL) and essential oil  (IC50 = 96.12 µg/mL).Antioxidant efficacy of Rosemary extracts has been estimated in the stabilization of sunflower oil (SFO) at three different concentrations, i.e. 200 (SFO-200), 500 (SFO-500) and 1000 ppm (SFO-1000). Results showed the highest efficiency of SFO-1000.The results obtained in this study demonstrated for the first time that Rosemary is a potent source of natural inhibitors of α-amylase and pancreatic lipase with powerful antioxidants proprieties that might be used in the food stabilization and the prevention of diabetes and obesity complications as a complementary pharmacological drug.


Author(s):  
Iserhienrhien Lucky Osafanme ◽  
Okolie Paulinus Ngozi

Aim: This study investigated the phytochemical constituents and in vitro antioxidant properties of methanol and aqueous leaf extracts of Geophila obvallata using standard methods. Materials and Methods: The in vitro antioxidant assays carried out were 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging ability, Nitric oxide (NO•) radical scavenging activity assay, 2, 2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS•+) radical cation scavenging assay, ferric reducing properties and hydroxyl radical scavenging assays. Results: Phytochemical analysis revealed the presence of alkaloids, flavonoids, phenolic compounds, steroids, saponins, terpernoids and cardiac glycosides in both extracts. Relative to the aqueous extract, the methanol extract contained a higher amount of the secondary metabolites. However, both extracts exhibited appreciable and dose-dependent capacities for quenching DPPH, ABTS•+ and NO• free radicals, and potent ferric reducing ability to levels comparable to those of ascorbic acid. The crude methanol extract showed significantly increased (P<0.05) antioxidant activity than the aqueous extract. Conclusion: It was concluded that the extract possesses strong antioxidant properties due to its content of phytochemicals, and provides scientific basis for its ethno medicinal applications.


2021 ◽  
Vol 21 (12) ◽  
pp. 615-625
Author(s):  
Ayse Kose

Seaweeds are one of the ancient food supplements on Earth. Especially Asian countries use seaweeds as the fundamental ingredient in their cuisine. Seaweeds are photosynthetic organisms living in aquatic ecosystems and in the coastal territories. Seaweeds out of farm areas are frequently observed as coastal wastes. However, seaweeds are outstanding sources for bioactive substances and investigation bioactive properties of seaweed RuBisCO has never been done. RuBisCO is the most abundant protein on Earth but a vast amount of RuBisCO goes through waste. In this study, bioactive peptide prediction of frequently consumed seaweed RuBisCO proteins were analyzed in silico to identify possible bioactive peptides as substitute or support for grain, meat, and dairy based bioactive peptides. A huge portion of peptides were di-, tri- peptides with IC50 values less than 300 µM according to the comparison of BIOPEP database. Including gastric digestion, more than half of the peptides showed DDP-IV and ACE inhibitory activity followed by antioxidant properties. Also, novel antiinflammatory and anti-cancer peptides were found through in silico analysis.


2018 ◽  
Vol 3 ◽  
pp. 133-143 ◽  
Author(s):  
Oluwole S. Ijarotimi ◽  
Sunday A. Malomo ◽  
Adeola M. Alashi ◽  
Ifeanyi D. Nwachukwu ◽  
Tayo N. Fagbemi ◽  
...  

The aim of this work was to produce wonderful cola protein hydrolysate fractions with in vitro antioxidant properties coupled with blood pressure-reducing ability when orally administered to spontaneously hypertensive rats (SHRs). Wonderful cola protein isolate (WCI) was hydrolyzed with pancreatin to produce a hydrolysate (WCH), which was subjected to ultrafiltration separation using 1, 3, 5, and 10 kDa molecular weight cut-off membranes to obtain <1, 1–3, 3–5 and 5–10 kDa peptide fractions, respectively. The <1 and 1–3 kDa fractions had higher contents of arginine when compared to the 3–5 and 5–10 kDa peptides. The WCH and <1 kDa peptide fraction had significantly (p < 0.05) better DPPH radical scavenging (55–67%) and metal chelation (83–93%) activities but lower hydroxyl radical scavenging power (10–32%) than the WCI (46, 46 and 63%, respectively). The <1 kDa had significantly (p < 0.05) higher in vitro inhibition (80%) of angiotensin converting enzyme (ACE) activity while the 5–10 kDa was the most active inhibitor (90%) of renin activity. All peptide fractions so produced had better systolic and diastolic blood pressure-lowering effects than WCH and WCI. However, the <1 kDa fraction produced significantly (p < 0.05) stronger systolic (−33 mmHg) and diastolic (−30 mmHg) blood pressure reductions 6 h after oral gavage to SHRs. Thus, wonderful cola proteins contain encrypted bioactive peptides that may be used to formulate antioxidant and antihypertensive products.


2015 ◽  
Vol 51 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Muhammad Yar ◽  
Muhammad Arshad ◽  
Ariba Farooq ◽  
Mazhar Amjad Gilani ◽  
Khurshid Ayub ◽  
...  

Alzheimer's disease (AD) is a fast growing neurodegenerative disorder of the central nervous system and anti-oxidants can be used to help suppress the oxidative stress caused by the free radicals that are responsible for AD. A series of selected synthetic indole derivatives were biologically evaluated to identify potent new antioxidants. Most of the evaluated compounds showed significant to modest antioxidant properties (IC50 value 399.07 140.0±50 µM). Density Functional Theory (DFT) studies were carried out on the compounds and their corresponding free radicals. Differences in the energy of the parent compounds and their corresponding free radicals provided a good justification for the trend found in their IC50 values. In silico, docking of compounds into the proteins acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), which are well known for contributing in AD disease, was also performed to predict anti-AD potential.


2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Hashini Imalsha Abeysuriya ◽  
Vajira P Bulugahapitiya ◽  
Loku Pullukkutige Jayatissa

Sri Lanka is a habitat of diverse fruit varieties; nevertheless 95% of them are underutilized by people due to unawareness of their nutritional values and health aspects, and hence become ‘minor fruits’. This study was aimed on revealing vitamin C, iron and antioxidant contents of 29 varieties of minor fruits (MFs) with the comparison of the same with three best commonly consumable fruits (CFs), namely Carica papaya, Mangifera indica and Psidium guajava. Ascorbic acid (Asc), dehydroascorbic acid (DAsc), vitamin C (TC), phenolic (TP), flavonoid (TF), iron (Fe) contents and antioxidant capacities (AOCs) of fruits were determined using standard methods. The results of mean Asc, DAsc, TC, TP, TF and Fe contents in 100 gm of MFs ranged from 3.1 to 121.5 mg, 1.2 to 70.7 mg, 6.6 to 136.1 mg, 24.9 to 1613.3 mg Gallic acid equivalent, 6.2 to 228.0 mg Quercetin equivalents and 0.2 to 4.9 mg respectively. DPPH and Ferric Reducing Antioxidant Power (FRAP) assays were used for AOCs and variation of IC50 values in a DPPH assay was 1.2 to 245.4 mg/ml whereas FRAP values ranged from 9.6 to 486.7 ?mol FeSO4/gm. Among the studied minor fruits, Melastoma malabathricum (Maha bovitiya/ Malabar melastome) is found as the best respect to all considered parameters. As a conclusion, it can be stated that, the Sri Lankan minor fruits are good alternatives to the common fruits as they are recognized as good source of vitamin C, iron and higher content of antioxidants. As an outcome, Sri Lankan minor fruits can be promoted as alternatives to common fruits and as source of revenue for national economy.


Antioxidants ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 2 ◽  
Author(s):  
Marco Bonesi ◽  
Maria Tenuta ◽  
Monica Loizzo ◽  
Vincenzo Sicari ◽  
Rosa Tundis

The aim of this work is to investigate the in vitro acetylcholinesterase (AChE) and butyrycholinesterase (BChE) inhibitory activities of essential oils obtained by hydrodistillation from the leaves of Prunus armeniaca and P. domestica in relation to their composition, analysed by Gas Chromatography–Flame Ionization Detector (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS) analyses, at different times. Moreover, considering the role of free radicals in the progression of neurodegenerative disorders, the antioxidant properties of essential oils were investigated by using, 2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and β-carotene bleaching tests. The relative antioxidant capacity index (RACI) was used to achieve more comprehensive comparison between analysed antioxidant effects of essential oils. P. armeniaca oils were more active than P. domestica oils against AChE. Against BChE, the most active was the essential oil from P. domestica leaves collected in August with an IC50 value of 95.80 μg/mL. This oil exerted the highest inhibitory activity of lipid peroxidation with IC50 values of 11.15 and 11.39 μg/mL after 30 and 60 min of incubation, respectively. All samples demonstrated a remarkable ABTS radicals scavenging activity, with IC50 values in the range 0.45–0.57 μg/mL in comparison to the positive control, ascorbic acid.


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